performance 262, 267, 283, 302, 305, 307: Combined threads

[novaboy009]

Well, I had my '78 out today because it was 58 degrees and the salt had finally been mostly washed away. I was coming home from work when I noticed smoke coming out of the hood scoop and smoke coming out of the exhaust, along with a lovely burnt coolant kind of smell. I looked at my temp guage and it went from 210 to 230-240 in about 4 seconds flat. I pulled it off the road and popped the hood. All the smoke looked like it was coming out of the power steering pump but it was obviously coolant. It wasn't blowing everywhere, just a little drip. Coolant seemed low, but there was still some left inside of the overflow bottle. I haven't popped the radiator cap yet because it hasn't cooled down (AAA came and got me towed home in about 20 minutes, A+ for them!).

So, I'm going with:

A) Waterpump
B) Cracked Block
C) Cracked Head
D) Freeze Plug Blown (?)
or
D) Head Gasket

Based on it's unique smoking location. Any guesses?

Kev

[patman]

Were any unusual stresses put on the engine just beforehand? :)

[jason snyder]

I am lost, you have smoke coming out the exhaust,and the exterior of the block.IT sounds like a cracked block to get hot that fast,but what explains the underhood steam.

ITS TIME FOR THE 350!!!

[novaboy009]

There was no unusual stress put on the engine, just part throttle cruising. The motor has been beat very hard the last two or three years its been in the car.

Kev (If it's anything worse than a waterpump that motor is going out to pasture)

[NIGHTSHADE]

If ya got it coming out the front and rear, my guess would be a head gasket.

Time for a big block!:D

[Joe]

Maybe with Steam around the P/S Pump,could be the Weep Hole in the Water Pump?That wouldnt Explain the Exhaust but One thing at a Time.
Joe

[the FLYER]

it's not one a them new avatar type a things is it ??? i mean THAT one looked FUN !!!


best thing ta do is ta BABY it Kev, BABY it !!!!











leadfoot :rolleyes: :eek: :eek: :eek: :D :D :D

[patman]

You sure you don't have a leak in the radiator or a hose? That sort of leak can travel to lots of places in the engine compartment.

[novaboy009]

Survey says.....

A BLOWN WATER PUMP GASKET!!!

That's an odd one. I apparently didn't silicone it very well when I changed the cam about a year and a half ago. It was spraying right out of the space between the block and the pump surface. The smoke coming out of the exhaust was actually coolant going against the hot pipes. $1.69 worth of gaskets and an hour worth of my time and it's up and running just fine now.

Kev (Can't kill that stupid little motor! :):):))

[the FLYER]

Survey says.....

Can't kill that stupid little motor! :):):)



a suggestion ??? something i've discovered that works ????


in park, rev up by hand to 4500rpm's... slowly drop 1/4-20 nuts down carb... one at a time. for faster results drop multiple nuts at a higher rate of speed... just FEED THE MONSTER !!! :eek: :eek: :eek:


it'll kill the Beast ;)






Johnny (first hand experience) ;) :) :)

[jinxproof77]

I have a 283 I pulled out of my 63 and am replacing with new 350. I did have a question about something weird on the 283. What is the tube coming out the back of the engine? Is it some kind of breather? It also just kind of rests in the hole that is in the block, doesn't seem very stable.


http://home.comcast.net/~caustic/block1.jpg

[KenDog]

I think they called that a road vent tube, should have a bolt to hold it in place. It just vented tthe crankcase.

[wskaiser]

This is what preceded the PCV valve on modern engines. The vacuum was created over the bottom of the tube when the vehicle was moving and that helped to evacuate the fumes from the engine. They ususally smoked some when the engine was running.

[NovaResource]

http://www.novaresource.com/carstuff/earlyblocks.jpg

[chevynuts88]

It also relieved crakcase pressure.Without it or a breather of some kind the oil would come up your dip stick tube.

[jinxproof77]

Thanks for the info everyone. It seems funky but I guess it worked. Doesn't matter cause I'm tossin the engine anyways. Bigger and better.

[Gloryhound]

I would hold onto that 283. They are good little engines. My fathers 63 Impala SS convertable has one. No it doesn't whip you back in your seat, but he does get decent fuel mileage for a power glide full size car. (15-16 mpg) His is #'s matching origional car so we really don't want to do much to it. Once my Nova is done the extra space I use for working area will be taken up by this convertable.:D

[WILMASBOYL78]

If I lived closer you could throw it away in the back of my truck!!! Love the 283 motor..my first ride was a 64 Malibu sport coupe with 283/glide...p/s...p/b...bench seat..wish I had it now. Paid $250.00 for it in 1973!!!!!


wilma(showing his age):D

[jinxproof77]

Well, once I am ready to get rid of it I will let everyone know.

[njciscool]

hey

I just pulled the heads off of the "350" I was going to use as a dirt-track motor, and got a nice surprise... I don't have a 350, or a 305, but a 307.

I see that a 307 stroke is 3.25. so, if I put this crank in a 350 block, I have a 327, right? would the rods work as long as I got 327 pistons? I assume the 307 is large journal too?

I think a 327 might be better for dirt tracking because of higher rpm potential, right?

either way, I've got a 350 crank I could have turned or something if I need to.

thanks.

[NovaResource]

hey

I just pulled the heads off of the "350" I was going to use as a dirt-track motor, and got a nice surprise... I don't have a 350, or a 305, but a 307.

I see that a 307 stroke is 3.25. so, if I put this crank in a 350 block, I have a 327, right? would the rods work as long as I got 327 pistons? I assume the 307 is large journal too?

I think a 327 might be better for dirt tracking because of higher rpm potential, right?

either way, I've got a 350 crank I could have turned or something if I need to.

thanks.


Yes, a 307 crank in a 350 block will give 327-ci.

[Paul Wright]

A 307 crank has different counter throw balance because 307 pistons are smaller and lighter than 350 pistons. You may be close and better off if you use light weight pistons. However, a 307 is no match for a 350. 43 cubic inches is too much of a handicap.

[njciscool]

thanks. I've got a couple of 350 cranks I could have turned I guess.

so, uh.... anyone want a 307 shortblock :D

[Mike Goble]

How about a 400 crank in a 307 block?

[Nova_Guy]

How about a 400 crank in a 307 block? You will have to bore the main bearing bores out a bit. Or have the crank turned down.

[njciscool]

I'll pass on the 400 crank in the 307, but how about a 307 (0r 327) crank in a 400 block? that would be a high-reving motor, no?:p

[Mike Goble]

I realize that there are fitting issues, just curious about the rules allowing the displacement or configuration.

I've read an acronym for RPM - ruins peoples motors...

[njciscool]

the rules say no stroking or destroking, but honestly, the tech guys aren't going to check. I know of two 383's running out on that track, and though they've got more power, they always loose the races because they can't drive and they have too much cam.

however, a 350 would be best since I'd be closer to my peak torque when exiting the corner, where I need it the most.



thanks for the insight guys.

[KenDog]

If the track is real sticky, I would build the biggest smallbock possible, the more power you have the better. But, if it gets real dry slick before the main event, you can get away with a smaller less horsepower motor, like a 327.

KenDog

[njciscool]

this track is a clay track, so it is REALLY sticky. the promoters are very good at keeping the track just right. honestly, this track is stickier than asphault I think! I had a 350 crank of mine checked out today, and its all good. so thats what I'll be running


thanks

[super_davecars]

I have ran a 307 crank in a 350 block to build a large journal 327 It worked fine with no probems ran smooth.I would do it again. I ran it in a 4 speed camaro wiht a comp 268 cam and 3.08 posi it turned 14.75 the one time I had it at the track.

[sYc_12B]

if it a real tacky track then you want toque. a 327 will scream at the end of the straights but you will be playing catch up because the small stroke on a 327 wont give you torque off the corner that a lagar cubed motor will.

that said biuld the largest small block you can afford.

also pay attention to how the car handles, all the motor in the world isn't worth a darn if you can't get through the turns.

remember the sooner you can get back on the gas the faster you will be down the straights.

good luck!

and let see some pic's....I love good old fashion dirt track racing.

http://community.webshots.com/album/70552942HBxmOW


Will

[fixing-gpas ride]

ive got a 1973 4 door nova that was g-pas with a 307 in it. he has since passed and would like to build up the car to be "g-pas lil sleeper". my question is should i rebuild the 307 and punch it out or find a differant motor and rebuild that one. we would like to have it look like g-pas sunday driver until you stand on it and blow the doors off the guy laughin at ya. thx
jeffrey

[KenDog]

If power is what you are looking for, the 307 wont be a good investment. Cubic inches is what you want, and a 400 or 350 looks just like a 307. 350's are cheap to build, but the more cubes the better. The 307 can be built to make more power, but it cost the same as a bigger motor.

KenDog

[fixing-gpas ride]

thx for the info kendog. what about building up a 327?

[Paul Wright]

Read my tag line.

[YFH8SIT]

Dont lead the guy on telling him it cost the same.

I had to fork out $25 to have steam holes drilled in my 406 that he wouldn't need in his 307:D .

Other than that, the parts cost me basically the same 350 or 406. However, I am quite sure there are deals to be found on 350 parts because they are so plentiful.

[KenDog]

A 327 would be better than the 307. It has a bigger bore, 4" as compared to the 307's 3.875". They both use a 3.25" stroke crank. There is no magic sizes really, just bigger is better. I think the bigger bore,4.00'' is a better choice, a 4.125" 400 block would be even better. Most cylinder heads with big valves need a 4" or bigger bore to get the best flow.;)

KenDog

[the FLYER]

Hey Jeff, as i said in my PM reply to you... depending on the cost of the different engine core to be rebuilt... being it's yer first hotrod, as i believe you said, i'd possibly rebuild the 307 and take the extra money you would have spent on the core... and invest that money elsewhere in yer project... you can rebuild the 307 and get "punch" out of it, maybe not as much as a 350, 400 or whatever else... but yer gonna find, no matter what ya got or how fast ya are... there's guys that'll be faster... and guys that are slower...

personally, i'd utilize the 307, get some learning experience with this project in preparation for yer next one... save as much as ya can by using what you already have... there's guys here who've shown they can be respectable with a 307...


also, i welcome ya to the Site... i'm glad ya jumped in... lotsa great guys here ta help ya... and remember... opinions are like "XXXXXXXX" we all have one :rolleyes: ... so weigh out all the good advice ya get and keep what ya need and remember the rest fer later...

my 2 pennies :D



Johnny :D :D :D

[JBimmolate]

My camaro has a puped up 305 in it and it hauls @ss. I had it bored .030 over and had some 350 heads milled down so I could have the bigger valves and keep my compression up. I went with an RV cam since I still had to smog it and a rpm intake w/edelbrock carb & headers. I have a th350 and 3.08 gears w/28" tall tires in the rear and it will roast them with little efort and still cruises great on the freeway. Great little motor and didn't cost all that much to do. Plus w/the rebuild kits you can get on ebay w/everything you need being so cheap. I would think you could do it for way less than what I spent 10 years ago. Cost me $750 to have the engine built by a local machine shop. SBC's ar so easy to assemble I would just have them do the machine work and balance the assembly then assemble it your self if want.

Miles:D

[fixing-gpas ride]

i thank all you guys for all your input on this question.like flyer has said its my very first build and i need all the advice i can get. flyer and nightshade have been very patiant with my questions and i thank all of you for your 2 cents worth.:) if you guys have any other helpful ideas on building g-pas ride i would appreciate it.
thx jeffrey

[2doorpost]

I've seen 307s really rock Back in the day. I think they are a respectable motor.

[novaboy009]

My little 307 has run down a couple of them 4" bore motors in its time;)

Send me a PM and I'll give you the low down on the mini mouse motors...

Kev (It's no PW 350, but it's really hard to kill!)

[Pauls72]

I had a 307, I rebuilt it and built it up. Not a bad little engine, had a long life with decient power. It was now burning and leaking oil after another 120k miles. So time came to do something again. Adios to the old 307 and I'm replacing it with a bored and stroked 350 (388).


There is an old saying and it's very true: "There is no substitute for Cubic Inches". More cubic inches means more torque and more power.
A small block Chevy is by far the cheapest engine to do anything too.
350 is by far the most common of all the small block Chevys, with the largest number of after-market performance parts and the lowest cost. It's the rule of supply and demand, lots of parts drives the price down. Price a rebuild kit for a 307 and 350, the 350 is cheaper. Price pistons for a 307 and 350, 350 is cheaper. So dollar for dollar a Chevy 350 is the cheapest thing to build.
Can you build a high performance 307, sure but it will cost you a small fortune and drive like crap on the street.
If you buy a used 350 and take the rest of the money you were going to invest 307 and invest it in the 350, you will have more torque and hp.


For my 2¢, go find a good rebuildible core of a 350 for $100-$200 and spend your money and time on it. This will give you the best bang for your buck. The 307 isn't a bad engine, but you would be much better off investing you money in something bigger and only investing it once. :D

If you want to keep it all orginial then rebuild the 307.

If you have a quite a few bucks to spare stuff a 502 in it. It will make a great sleeper.

[BBaker]

ive got a 1973 4 door nova that was g-pas with a 307 in it. he has since passed and would like to build up the car to be "g-pas lil sleeper". my question is should i rebuild the 307 and punch it out or find a differant motor and rebuild that one. we would like to have it look like g-pas sunday driver until you stand on it and blow the doors off the guy laughin at ya. thx
jeffrey

An option would be to spend your money for things that you could put on a 350 at a later date. Headers, intake, different carb, and maybe a cam are all relatively low cost, and they could be transfered over to a stronger motor in the sleeper at a later date.

[fixing-gpas ride]

i really want to thank u guys for all ur input.like flyer told me ask and ye shall recieve answers:D my dad has brought up the notion of stuffin a 327 under the hood.he can get the engine for free. even runs:eek: but i still would like all your suggestions they are all very helpfull thx guys.....jeffrey

[the FLYER]

i'd grab the 327 and bag it. keep it under my work bench for a future project... build and learn from the 307 and get yerself a HotRod later on and stuff the 327 in that...


you can never have too many engines....

[fixing-gpas ride]

yea i guess i never thought of that one :D thats why im on here asking the true nova builders thx

[NIGHTSHADE]

Hey Guys, Jeff just left my place a few minuites ago. He came down to look at some parts from my 74 cut up car.

I'll tellya this much, he's no snot nosed kid, not in the least. A pretty cool guy at that too!:D

From talking to him, I can say this much. The Nova's definitely not his first car maybe the first chevy. That would be why all the questions. But he's not so new to the world of muscle. The user name is a little misleading.

So Jeff go for the 327 that you mentioned today and build it to the hilt. And maybe when your Lil' Sleeper's all done we can meet in Sauk and go eat some rice!!!:D :cool:

[the FLYER]

didja hook him up Jonesy ??? ;) :D :D :D


Hey Jeff !!! ya know Jonesy's gotta stash of cars hiding that he's got written down... ya aughta have him show ya a few possibilities ;)

[NIGHTSHADE]

didja hook him up Jonesy ??? ;) :D :D :D

I will be doing just that come Saturday!;)


Hey Jeff !!! ya know Jonesy's gotta stash of cars hiding that he's got written down... ya aughta have him show ya a few possibilities ;)

Not a chance!!! That treasure map will have to be pried from this pirates cold dead grip!!!:D :D :D

[fixing-gpas ride]

hey jonesy thx for the words on my behalf. i guess the name does make me sound like a snot nose kid, but the name is the truth. ya when granpas lil sleeper gets done we'll got kick some rice outa the real snot nose punks:D :D
like i said b4 u guys have gave alot of good info. keep it up.see ya saturday with the truck for parts.:D :D :D

[Pro-touring72]

Before you toss the 307 read this article. The block can be a good starting point for a realy nice mill. http://popularhotrodding.com/enginemasters/articles/chevrolet/smallblock/0207phrbeckem/

[Jinks]

it's all about the parts you put on the engine.. if you are using stock parts ( intake, heads, carb, cam ) the engine wont ever have much potential... but if you are getting all aftermarket, or stock performance parts, it should work just fine. Anything you get for the 307 ( other than the bottom end ) will work on almost any other sbc ( like they said if you to a 400 you ahve to get steam holes drilled out, which isnt abig deal ).

If you are going aftermarket, you could go with something simple such as some performer heads, or a vortec head setup. You can probably pick some up used for cheaper than the desirable old SBC castings, with better results. You can get a performer or equivalent intake for a reasonable price. You could also find a 600-650 holley or equivalent for fairly cheap. A hydraulic cam and lifters is only going to cost you a couple hundred, so you can see you could build a fairly decent motor out of the 327 or the 307. I think you'd be better off taking the free 327 obviously.. like someone else said, you can always build one engine up while the other is in the car..

most important of all.. have fun with it :D There are lots of people on here who could help you with combo's (should basically be the same for both engines )when you get to that point!

good luck :)

[Jinks]

heh heh, pro-touring, that isnt your average 307 engine build up nor is it the most practical build up. cool article none the less :D

[fixing-gpas ride]

well guys after weighin in on all ur input and talking to a few very reputable engine builders in my area, we decided to build up the 307 for my nova project.i found a very reputable builder with awesome references. were lookin at gettin 1.5 to 1.7 hp per cube after the build for a nice price.when i hit my build stage further along ill get a camera and start postin pics. thx for all the info guys. im sure ill be askin more:D jeffrey

[taz3]

Trick I used to do when I was first getting into playing with cars,go out and find the cheapest running big block i could put a cam,intake,carb,& headers on it andplay with the suspension to get the car to hook up and beat alot of guys who thought the more power the better.If it don't hook up it's no good any way.Like previous there will always be faster and slower than yours.Try to beat guys on a budget that's fun cause if you loose who cares you didn't spend a ton of $ you still get to laugh.My 1 cent.Oh ya welcome to the sight.

[Pauls72]

To get 1.5 to 1.7 hp per cube out of a 307 is possible. But I don't think it's a realistic expectation. Several things you should consider first:
At what rpm will you make this 460-522hp?
Will it be drivable on the street? More specifically will there be any low end power at all.
Will it run on pump gas?
With this massive power output, how long will it last?
How much more will you have to invest in your drive train to support this kind of power?

The other year in the Engine Masters Challenge John Beck got 556 hp @ 6500rpm out of a 307 block. Take a look at a few of the facts: It's bored and stroked to 366cid, it took him 83 dyno pulls to get to this point and it would take $16,000 to duplicate the engine. He is only making 1.54hp per cubic inch.

http://www.popularhotrodding.com/tech/0207phr_beckaimsb/

http://www.popularhotrodding.com/enginemasters/0303PHR_Enginemaster/

heh heh, pro-touring, that isnt your average 307 engine build up nor is it the most practical build up. cool article none the less :D

Read Jinks comments, then look at what you are saying you are going to do. A realistic goal for a reliable street engine is more like 1-1.25hp per cubic inch.

I'm not saying don't build the 307, just set yourself realistic expectations.

[Paul Wright]

well guys after weighin in on all ur input and talking to a few very reputable engine builders in my area, we decided to build up the 307 for my nova project.i found a very reputable builder with awesome references. were lookin at gettin 1.5 to 1.7 hp per cube after the build for a nice price.when i hit my build stage further along ill get a camera and start postin pics. thx for all the info guys. im sure ill be askin more:D jeffrey

IMO, He's yankin your chain. 500HP (assuming .030" over 311 cubes) is unrealistic especially for a "nice price". What is your definition of a nice price? While you could get that kind of power from a 383 or 406, it would cost big bucks to get it from a 307. I would have him put the power goal (minimum WHP estimate) in writing and plan on taking the car to a chassis dyno.
With any deal, "If it sounds too good to be true it probably is."

Ask him specifically what parts/specs are going to be used.

[taz3]

Check April issue of Super Chevy they have 307 build up pretty good info.

[fixing-gpas ride]

boy i feel stupid :( :( my fingers got a lil carried away while typin. after rereadin his info its supposed to be 1.115 to 1.117 max per cube. sry for the confusion. i jus gotta slow down while typing.
after readin the posts i thought that seemed a lil overborard myself so i rechecked the info. sry guys have one on me :beer:

[Kens 67]

I have a original 283 with 57,000 miles on it. This is a 195 horse 9.5 compression motor with a 2 barrel carb. I have been thinking about putting on my set of 462 casting 194 heads and a 67 four barrel intake on it until I can properly rebuild a 327. Will this make the performance worse or should I put the original heads back on until I can afford to finish the other motor? Any opinions would be appreciated.

[Dan_Lebherz]

At best you will be going from 58cc combustion chambers to 64 cc, and maybe much larger chambers. This will reduce you compression ratio and turn the 283 into a real pig. Been there, Done that. Those powerpak heads are really not that bad for a 283, if they are in good shape. The factory had a couple of combinations using old technology that produced one HP per ci. I'd go with an aluminum intake with a 600 cfm carb, small tube headers, something like a Comp XE 262 cam. maybe even smaller on the cam. It should run very nicely. If you really want to change the heads there are some Edelbrocks made for the 305 that should work.

[66marinabluess]

I've used 305 heads with the 1.94 / 1.5 valves with the 58cc combustion chamber on the 283 engine & they work great. There is also a 1.82/1.5 valve 58 cc head that works good as well. Early-mid 80's 305 with the 4 bbl carb engines used these heads.

[64PRONOVA]

Your 283 will be a "pooch" with 64 cc heads. If your 283 has the 896 casting heads on it, keep 'em. They flow better than the 305 heads and have more potential. A lot of 305 guys have embraced the old 896 Power Pack heads. I would remove the heads and do some inexpensive rework to them and bolt-on a nice dual-plane 4-bbl intake. Dan has the right idea with the cam. You'll notice a difference.

[Paul Wright]

Camquest had the XE262 as 12th choice;
279.7Hp @ 5,000
328.8 lb/ft @ 3,500

In the Extreme Energy line it preferred the XE256H for your 9.5 283 with stock heads and a dual plane intake with a 600 carb..

273 Hp @ 5,000
331 lb/ft @ 3,000

[stock z/28]

Hi,

Interesting thread. I agree the 283 needs a pretty small chamber head.

Just out of curiosity, what is better about the 896 head, than the 305?

Why are they using those on 305s? I use a lot of the 305 heads, but I have a lot of the 896s and 520s still around. I was always under the impression that the 520s flowed better than the 896s.

Just curious
Thanks
Jeff

[the FLYER]

it's been years and years, my number's prolly off a bit... i had a 283 i slapped on a set of 997 (?) heads (57 Vett w/FI or 2x4's) and it screamed... had an old TRW perf parts cam in it ;)

[loneagle]

A fellow I know has the 64cc Edelbrock RPM heads on a 283. I've always heard you couldn't run these due to the small bore size. The engine was built by a top engine builder in my area.

[stock z/28]

Hi,


I don't think its so much a matter of valve size as it is compression ratio. The 64cc heads would probably be kinda marginal if it still has a flat top piston.

Sometimes volume of the heads can become a bit of an issue. I have cced a lot of the 283 heads and don't ever remember finding one that was actually the listed "spec". It usually takes about a .060" angle mill to get them in spec..

Years ago I used to build quite a few .060" over 283s with large valve (2.02-1.60), but these had large dome pistons.

I think the original 1.94 valve first appeared in a 283 in 61. I don't remember for sure but I think a few were built with aluminum heads, but later were recalled and replaced with iron heads.

On the nova 283 stick cars (65-67) I have put 327 cranks and 307 flat top pistons with a double hump head (usually a 1.94). This is about 317 inches and makes a pretty nice street engine.

On the Edelbrocks, I guess you would have know all the details and even then, if the customer is happy I guess all is well.


Sorry to ramble
Jeff

[novaboy009]

A 283 block with a 327 crank is a 307:)

Scrappy little motor, that one is.

Kev :D

[stock z/28]

Hi,

Your are right Kev.. I forgot to add that I usually take these .060" over.
I have taken a few .125" over with out any problems (knock on wood). As a matter of fact the motor in my 67 now is a ChevII 283 block bored to 4.000" with a set of std bore L79 style pistons. I really beat this bad back in the early eighties.

Good Luck

Jeff

[stupesnova]

I'v got a 283 in my 66 that has the 305 heads, punched 40 over with a single plane intake and a 350 horse 327 cam in it, and it suprised the hell out of my buddies 350 chevelle.:D :D :D :eek:

[Kens 67]

Thanks for the input everyone. I feel a lot more confident about making my next few decisions. I'II be going with the stock heads a mild cam, and 4 barrel intake and carb. I had taken off the timing cover today to see if it had the original nylon timing gears. Well it did but all three bolts on the cam gear were so loose I could take them off with my fingers. Now is that not good timing or what.

[babydeuce]

I have a 283 30 over with vortec 64CC heads, and the XE256 cam. It runs great on the top end, but is a dog down low, even with a stall converter. If you want to run the XE256, you want the 58CC heads. Mine idles like crap, and does not kick in until about 3k, after that it moves rather well. I am actually going to step down to a XE252.

Jack

[BTHOMAS67Wagon]

You guys have me thinking...

Okay, I have a 76 305, a 66 283, a set of 305 heads (76cc) and 3 sets of 3884520 (powerpack) heads (60cc).

I was toying with the idea of building the 305 and cutting my teeth with a turbo or putting a 331 stroker kit in the 305...

Now, I am toying with the idea of the 305 with the 60cc heads ?!

Hmmmm...
;)

-Brent Thomas
Ohio

[Scooter]

Does anyone know a good site for performance 283 info? I might be getting a 283 and building it up a little. So far I am thinking this:

- Vortec heads from Scoggin Dickey
-Bore it out to 4" bore (should be a 301 or 302 then I think..)
-Use stock rods and crank
-RPM air gap intake (woudl this be a bit to extreme for the small 283?)
-some kind of smallbody hei or msd e-curve dist.
-performance cam of some type, kinda clueless on what specs to get
-500 or 600 cfm holley (would a double pumper be better or vacuum secondaries?)
- 4 speed manual tranny
- I have open 3.08s in the rear but I could change them.
- for lifters I am undecided between solid or hydro, I've heard this engine should wind up pretty good so wouldn't solid be better? Then again this will be a daily driver so adjusting all time would be somewhat of a pain, but if solid is really that much better then I am willing I suppose..
- either a C20 front sump or a Ebay rear sump oil pan
- Full length headers of sometype
- self aligning full roller rockers (probably scorpion brand)
- flat top pistons (hyper or forged?)
- Hopefully have pump gas friendly 9.5 or 10 to 1 compression
- about 26" rear tires
- get rotating assembly balanced
- dual 2.5" exhaust

What kind of rpm would an engine like this be able to handle safely? Think it would be a good runner? I know I should just get a 350 or something but a good deal is available with the 283 and from what I've heard, everyone that has built up these smaller engines has loved them, i guess becuase of the quick revving. It will be a daily driver with manual brakes, no a/c, manual tranny, and will go into my 64 4 door. I tried searching steve's for some 283 info but "283" is too short and the search thing won't take it, and thats basicly the only term to use to find 283 info. Thanks for any comments or suggestions.

-Aaron

[Paul Wright]

Yawn.
Yeah, I couldn't find too many but this is a fairly common frequently occuring question. I should probably find all the small V-8 engine hop up threads and merge them into one. Just browse the collection of threads. If you find any let me know.
Here's one I found:
Original 283 (http://www.stevesnovasite.com/forums/showthread.php?t=44963) to get you started.

Here's the answer to your question in a nutshell. You're wasting your time and money building a small displacement engine that will make less power than a stock 350. The 350 weighs the same, easy to find and costs less to modify.
Why bore out a 283 to 4" when you can buy a 4" bore block for less money? Why use a 3" stroke when a 3.25" stroke will beat it hands down. In the sixties the 301 was dropped like a hot potato when the 327 came out.

Trust me on this. I learned all about 283's, 301's, 307's and even 305's when I was much younger and that was all I had. The legend of the "high winding giant killer" is a myth pure and simple. You ever wonder why you see tons of 383 kits for sale and not any 283/301 kits? Ever wonder why 283's are so cheap to buy or even free?

[Dawg]

Paul brings up some good points....

Since you want a 4.00 bore/3.00 stroke combo why not find a small journal 327 or 350 and install the 283 crank? You'd get the 302 bore you were after without having to spend the extra cash to bore all the cylinders over....and then even if you wanted to you'd still be bigger than 302 cubes. (306 if I'm not mistaken)

If you can't find a small journal 327 or 350 I'm pretty sure a 302 crank from a '68/'69 Z/28 in a large journal 327 or 350 would work too....dunno what them 302 cranks are going for these days.

Hopefully that "good deal 283" is free.....I have a friend that was given a 283 for free....he's offered it to me for free....I was going to build it too and put it in an S-10 (may still do it) but I'd do a budget build on it (replace rings., bearings) but reuse most of the parts....it's foolish to put any real $$ into a 283 unless it's original to the car and you want more power while keeping it numbers matching.....

[novaboy009]

Get a 350. Seriously. After I sent a rod through the side of my 283 (which was pretty slow even with all the above mentioned mods) and a 307 that I couldn't whip into the 13's if my life depended on it, I'm working with a little more potent 350. Trust me, there is a HUGE difference with displacement.

Kev

[SuperNova69]

Yeah I gotta say, my old 283 looked and sounded nice and got good mileage (I believe it was 17-ish city mpg), but it was horribly slow. Of course it had low compression (I think one or two cylinders had 90 psi :eek:), an unknown Comp cam, and a few other things thrown at it, but I'll never forget the day I raced an early 90's Integra and lost. :eek: :eek: :eek:

The only reason I'd recommend building the 283 is, like someone already mentioned, putting it in an S10. Or a 280Z/300ZX. My friend has a 300ZX and he's gonna take my 283, rebuild it, and stuff it in there. Should be pretty sweet. :)

Matt

[ovrdrive]

I have a 64 327 small journal block and my original 283 crank that I am going to make that 302 combo work. By the time I get done with it, it will be pushing 307 CID and that will freak some of those kids out when all they see is tail lights. Or tell them that it is a 302 CID and watch the expression on their face when I tell them that GM had a motor of that size. Now, all I need to find is a donor car to put it in. Something like a Cavalier, Sunbird, or a Citation. But the modifications needed will cost me a miniature forutne. So, it's off to find a lightweight RWD car that is looking for a "heartbeat".

Dan

[Dawg]

Now, all I need to find is a donor car to put it in. Something like a Cavalier, Sunbird, or a Citation. But the modifications needed will cost me a miniature forutne. So, it's off to find a lightweight RWD car that is looking for a "heartbeat".

If I may suggest, a Vega/Astre, a Chevette/T-1000, a Monza or an early S-10....if you go the S-10 route get a stripped down 4 cylinder model....they usually weigh 2500 w/o driver; the 283 will add another 200 lbs.

If it doesn't have to be GM I hear the old AMC Gremlins and the Ford Pintos are great too...just make sure you run a fuel cell in the Pinto incase you get rear ended.

And yes you are right, a Cavi, Citation or Sunbird would need alot of mods to make it work due to being FWD....with the exception if your Sunbird happens to be a '76-'80 model which is pretty much a facelifted Monza.

Other facelifted Monzas = '75-'80 Buick Skyhawk and Olds Starfire.

[Gloryhound]

If your looking for a light rear wheel car that is a bit more modern you could always look into a Mazda Miata. I think they already make a kit to drop a V8 in called a Monster Miata kit.

Back to the origional question:

As far as even using the 283 for a numbers car, unless you plan to show it as a numbers car most people are pulling them and sticking them in the corner so they can return the car to numbers matching and sticking a 350 or 383 in. I'm even starting to see people do this with 327's. I think you will see the end of 283's and 327's (BBC 396's and 402's should be included in this list.) in non concourse origional number restorations within another 5 to 10 years. How many Hot Rod tri fives do you see driving around with a 348 boat anchor?

[Ironman]

Although I am never against someone trying something different, I'd say find a junkyard 350 to start with. As a side note, I have seen a 283 push a steel body chassis car to a 5.90 ET in the 1/8 mile. It sounded like it had a power range from 8-10000 rpm. Good luck with whatever you decide.

['72 nova]

My '72 has its stock 307, rated at 130 hp, i (obviously) want some more. this weekend im switching from the stock 2 barrel carb and intake to an edelbrock 600 cfm performer carb and intake. but i was wondering if there are any other ways to gain horsepower. if you could point me towards certain products, that would be amazing. or would i be better off just dumping the 307 and getting a 350? im fairly new to this whole deal. and kind of on a money crunch, since im still in school.

Thanks guys!

[72Orange]

I think we should combine the last three thousand four hundred and seventy five "how do I hop up my 307" threads and sticky them.

To answer your question seriously though, do a quick search using "307" and I'm sure you will get a TON of answers.

[1quik69]

If you can swing the money, I would get a 350. The 350 responds a lot better to modifications. The 307 has small bore/stroke, heads etc.

[Real McCoy]

Why invest money in a 307 when it would cost no more to buy parts for a 350 which will give you lots more bang for the buck. 350s are pretty easy to find around here and I would think about anywhere. Just a much better motor for power. JMO, RM

[tpinovaII]

My '72 has its stock 307, rated at 130 hp, i (obviously) want some more. this weekend im switching from the stock 2 barrel carb and intake to an edelbrock 600 cfm performer carb and intake. but i was wondering if there are any other ways to gain horsepower. if you could point me towards certain products, that would be amazing. or would i be better off just dumping the 307 and getting a 350? im fairly new to this whole deal. and kind of on a money crunch, since im still in school.

Thanks guys!


The short and most honest answer is the 350 does everything better than a 307. (There is no replacement for displacement.) At rebuild time, it cost the same to build a 307 or 350. I would make it a goal for the future.

In the meantime, let's look at your best bang for the buck. The 307 had low compression. A set of small chamber, (small valve) 305 heads would be a good low buck way to bump up the compression and make more power. (You don't want to try to run big valves with the 307's small bore.) Add a mild camshaft and you will be well pleased with the results. And remember, that Edelbrock 600 cfm Performer carb and intake could bolt right to a large displacement small-block later on.

[batman09]

dump the 307.....its a boat anchor:eek:Pick up a nice little 350 long block for $1200.bm

[the FLYER]

being yer on a budget and ya have ta maybe nickle and dime it, which we've all done at one time or the other... the intake & carb sound good... the heads also. maybe a set of headers and a good set of pipes would be next on yer list (or put th headers higher than the heads and get those first ;) whichever way ta suit yer pocket book... a short-block/long block 350 "would" be a better long term choice... but if yer only able ta piece the 307 for now... there's still hope for ya, don't worry we can still help ;)

best of luck to ya :D

[novaboy009]

My little 307 embarrassed a few cars back in the day....

Kev:cool: (but my 350 does it better now:))

[novaken]

I also remember when my AMC Hornet with 258 6cyl embarrassed a lot of people. Late 70's early 80s was a terrible time for high powered engines.

[2doorpost]

Toughest/hardest hooking Nova I ever saw at the track in the early 70s was a 66 Nova SS campained on a shoestring budget running a 307, thru a Muncie,12 bolt posi- into a set of 5:13 gears.

The 307 was cammed out to the max....heads were off a hi po motor. Sorta setup like a poor man's 302. Topped out with a refrigerator white Earl Sheib paint job.

I do agree that there's no replacement for displacement, but, don't discount the hi-revving 307 when its set up right.

[veno]

One thing no one has talked about is the 307 block construction. GM made the 307 from poor grade of iron. The walls are soft as compaired to any 350/327 which have more nickle. 307 have very low to no nickle content so the cylinder bores dont last. (this is straight from the chevy power manual before anybody jumps me) While the bore /stroke show favor is some recent enigne build ups the block is just not suitable. Save your cash and build a 383. Everybody here said If you going to build a motor grab a 350 block, sure just dont build a 350. Your going to buy every thing else new, why settle for 3.48 stroke when 3.75 cost the same. right now 383 is the second cheapest motor to build after the 350. go 383/385/388:D

Right now http://www.eaglerod.com/specials.html has all the blem stuff on incrediable savings. I am running a eable blem crank. and it was 109 plus shiping. for a standered main -.010 rod.

Right now there is 2 383 cranks for the new 1 piece blocks: part#Z03523750 with external balance for 199. 1 with internal balance with 5.7 rod : part#Z0352375057i. These cranks are all Standared mains/rods. just cosmetic blems.

If you dont favor the cast steel cranks then this is available: 4130 Chevy 350 crank, 3.750" stroke, cosmetic blemish part:Z53503750 for 400.00

Good luck.

[Scooter]

To answer your question seriously though, do a quick search using "307" and I'm sure you will get a TON of answers.



"The following words are either very common, too long, or too short and were not included in your search : 307"

I ran in to the same problem when trying to find 283 info.

[69NovaSS]

"The following words are either very common, too long, or too short and were not included in your search : 307"

I ran in to the same problem when trying to find 283 info.

you normally need to use words with 4 or more characters in them so that the search function will work. BUT sometimes the words are too commen..."like", "with" as example of words that the search feature might consider too common.

[stock z/28]

Hi,


Veno, Im certainly not "jumping"on you but could you please provide me a little more detailed info on where and what specific power manual you found the "nickel" content article.


I have seen and heard no many different thoughts on this (nickel content on various blocks) and I am always curious.

I have never found an easy way to tell with out testing them.
I know the main webbing in 307s (well just about everything except 69 up 4in and larger bore blocks) is very weak, compared to the fully machined blocks.

I have bored several of these to 4in and used std bore 350 pistons and cranks, a few are still running. Not very sensible in this day and age.

Just to stir things up a bit. I think a 307 is about as comparable to a 327 (and possibly a 350) as to what a 383 is to a 400. Both just small bore, versions of the larger. So go ahead and blast me.

To really sound stupid (I know thats not hard for me to do) I am just ( as in today) finishing a basically stock (while we are on the subject of small cube small blocks) 305 for my daughters 92 Camaro. Its just for her (and me) to learn how to bracket race (shes 15). It will be interesting to see how fast it goes. I really dont care as long as its consistent. Im going to put a stock 400 turbo in it with with a Holley 500 2 barrel. I really hate automatics in a "race car" myself, but shes just learning. I have a real healthy 355 in the car now with a 288 super T10, that we cruised a bit with this summer and it seems pretty quick, but the rear axle the stock 7.5 10 bolt I put a 4.10 and a posi in, and Im not sure it would tolerate a lot of power. I will eventually put a 12 bolt in it with DN 5 speed, but I really cant afford the housing now.

[Paul Wright]

I merged all the small displacement posts I could find into one. If anyone has any information, links and combinations that work for small bore engines this is the place to put them. When we get done it will go into the FAQ section.

I'll start with an old one with newer heads:

283
Performer manifold
Holley 600 vacuum seconday
S/R torquer 305 (1.94 intake 58cc chambers) heads
11:1 pistons domed
L-79 cam
Headers
3.55 or 3.73 gears & higher stall converter.
Should run in the 14's in a Nova and have a "lumpy idle"

With some porting to 225 CFM
CamQuest picks XE256H
329 Hp @ 6,000
355 lb/ft @ 3,500

[stock z/28]

Hello.

I guess I'm a little confused.

Are you building this engine, Paul?


Jeff

(no, just giving some tips for the small engine~ Paul)

[69NovaSS]

To really sound stupid (I know thats not hard for me to do) I am just ( as in today) finishing a basically stock (while we are on the subject of small cube small blocks) 305 for my daughters 92 Camaro. Its just for her (and me) to learn how to bracket race (shes 15). It will be interesting to see how fast it goes. I really dont care as long as its consistent. Im going to put a stock 400 turbo in it with with a Holley 500 2 barrel. I really hate automatics in a "race car" myself, but shes just learning. I have a real healthy 355 in the car now with a 288 super T10, that we cruised a bit with this summer and it seems pretty quick, but the rear axle the stock 7.5 10 bolt I put a 4.10 and a posi in, and Im not sure it would tolerate a lot of power. I will eventually put a 12 bolt in it with DN 5 speed, but I really cant afford the housing now.

Hey Jeff, is this the motor you had mentioned, sometime back, that you might wanna run E85 in?

Also speaking of the nickle content of blocks I have heard many times over the years that the olds 455 blocks have a pretty high nickle content in them have you ever heard that?

You know Jeff I'm sorta begining to think that all this stuff about this block or that block being high nickle is really just an Urban legend..:)

[Dan_Lebherz]

With all of this discussion about small displacement v8s I have to tell about an older gent who races a '55 chevy at the local track. It has a bored out 283 making all of 287 inches. He runs a manual trans. He built the car for nostalgia drag racing. He is as consistent as anyone out there. Pops a small wheelie on every launch, runs 11.90-12.1s on every pass. Really cool to watch him launch and bang through the gears at 8,000 RPM. Not a street driver by any means though. I believe he runs a 6 something rear gear and one of those Jerich or whatever transmissions.

[stock z/28]

Hi Duane,

I might try it in here but I dont think this will have enough compression to really work well with the E85. This is just kinda a last min deal.


I really dont know much about the olds hardness specs, but Im sure someone does. I have several hardness testers, If you have an Idea as to what one should be, I have a couple blocks around here.

Jeff

[69NovaSS]

Hi Duane,

I might try it in here but I dont think this will have enough compression to really work well with the E85. This is just kinda a last min deal.


Ya no need to run the e85 if you dont have the squeeze as it wont do ya any good. The gov in this state appears to be doing a push for e85 to make it more avialable. If he does that I think I will for sure give it a try in the Nova. right now the nearest place to get it is about 100 miles from here....give or take 10 miles...thats just a bit too far to have to go for my liking...



I really dont know much about the olds hardness specs, but Im sure someone does. I have several hardness testers, If you have an Idea as to what one should be, I have a couple blocks around here.



I have no idea what the hardness should be. Do you think a person could use a handheld rockwell tester to test various blocks and compare them?

[stock z/28]

Hi Duane.

Thats exactly what I do on the hardness testing. I have several Wilson brand testers that are bench mounted testers. One willson is a superficial tester that will measure case hardening or surface hardening kinda like nitriding or Tufftriding.
The other is standard style tester that I use on valve seats and lifters among others.

The portable ones are A wilson and an Ames brand. The ames one is very small and handy.

To me these are much more accurate for comparisons than actually determining a true value. I just cant justify the cost of having these testers calibrated to the degree that most industry can. So the comparison method is what I generally go for.

The one that I use on valve seats and some fasteners is fairy accurate by most standards and I generally trust my figures with another tester or spec that may be provided.

I know next to nothing about metallurgy ( I know enough to know that I really know about 0) but it really interests me. I think if I ever had the opportunity to go back to school thats the field (automotive anyway that I would like to study) but I think Im to old to consider it. So I just read what I can.


Jeff

[veno]

Hi,


Veno, Im certainly not "jumping"on you but could you please provide me a little more detailed info on where and what specific power manual you found the "nickel" content article.

It was and is the old Chevy power manual from the mid seventies that was sold By chevrolet in the parts department. It is the Gm how to for and from GM on the SBC and BBC including the cosworth I4. From GM racing program of the era. It listed all the block contents(metalurgy) and the Gm way to build a race wining combo based on the interworkings of chevrolet racing program Using strickly Gm parts.

It has been out of print for some time with at least 4 updated printings that I am aware of, However; a verson is still @ your local chevy dealer parts department. If you want the older verson printed from the 70s then I would look to ebay.

[onecarnut]

I know this has migrated off the original thread, but wanted to comment.

You can remove that vent tube and stop up the hole --IF you vent the valve covers.

Otherwise, oil will find a way out of the engine.

Experience is a good teacher. My (former) 63 SS convert, 327 powered, looked like I was fogging for misquitoes before I vented the valve covers.

[chevynuts88]

In 1970 I embarassed every big block in town camaros ,hemi satellites with my "283" .060 over,align bored and built to run J/stock at the races[best time 12.97 @ 107].It had 2 wcfb carbs 270hp solid lifter cam and 327 250 hp heads. With 4.88,s it more than"cut it". It made me alot of money on the street. At he drags best I could do was second because two of Jenkins prepared cars were there! I,m just a nobody self taught nowhere near the capabilities of jenkins.

[Carl Stevenson]

I keep hearing a 283 block with the casting number 721 will bore to 4 inch. Has anyone actually done this? I will likely get it sonic tested to see anyway,but I am real curious about this.

Carl

[bowtie0069]

It was pretty common back the day to make a 301(later to be called a 302)
Must not be too big a deal.

[Paul Wright]

They called that an 1/8" over 283.

You might want to price out how much sonic checking and boring/honing 8 holes .125" That's the equivalent of overboring 4 times @ .030"

I'm almost willing to bet it's more than just buying a 4" bore 350 block or if you want to use your small journal crank, an early 327 block.

[Carl Stevenson]

The reason I am looking to do this is I want to use a Nova block. "Semi" restoration, and thought it would be neat to have a sort of correct block. I am changing my car over to a stick from a Powerglide. I also have a 283 Nova block that is not a 721 casting, so I may just go with a 283 and use that one. Somehow though, 327 is a lot more appealing. Lately I have really been missing my 327 4 speed 66 SS I sold about 18 years ago. Somehow, 283 4 speed is not quite same appeal to me...

I also have a 327 non-Nova small journal engine. However, I just mailed my clutch Z bar conversion bracket to Johnny Rotten a few weeks ago, so that is not an option!!!

[kalle]

I have friend that have one of those 283 made 302 in his nova 63. What an engine! It revs like a Japanese motorcycle, and almost sounds like on to. The car is almost like driving a Mitsubishi evo or something like that!

Kalle

[stock z/28]

hi,

I have bored several of the Nova style blocks to 4in over the years, and a few are still in service. I have one myself. I don't think I have ever had one crack a cyl wall (knock on wood).

I'm not sure on casting numbers. I usually sonic test the walls. I'm not sure a 327 cranks counterweights will clear in a pre 1965-64 block.

I prefer the 67 block because the main webbing is quite a bit stronger, you can usually spot it because the front of the block where the oil fill (usually completely round on earlier blocks) is located, is the later style, about half a circle.


As far as cost goes, I charge about $200 to $250 to bore .125" and hone with plates. I would check your local shops for price.

Good Luck
Jeff

[kk67ss]

I wanted to do the same on my 67 Nova 219 block. It was also a 283 block. My builder would not bore it unless it was sonic tested. We had the test done and the block did have some core shift. My builder explained that if bored to 4'', I would have paper thin walls on a few cylinders.
I too wanted to keep the cars original block. So we took the block out .030, added a 327 crank, had some special Wisco 10.5:1 pistons installed. Topped it off with a pair of Brodix Race-Rite heads, special built with 1.94/1.50 valves(could not use 2.02 valves on less than 4'' bore). Air-Gap and Edelbrock carb.
My little 311''(as it came out) motor Dyno'd at 352.9@5700 HP and 349.6@5200 TQ. I am sure just as much or more power than any factory built L-79!!!
For all I spent on the Original 283, I could have bought 2 ZZ4 motors or built one torque monster 383. But, I fiqured the "Original Thing" was the way to go along with a sweet running 311" motor..

[stock z/28]

Hi,

I agree, that generally makes a nice motor.

I have built several. I generally go to .060" over. There used to be off the shelf forged "307" pistons available for this, but Im not sure if they still are.

Im not sure about the L79 comparison, but Im sure it runs good.

The L79 was a (just my opinion) was a killer combination in its day.
Good Luck
Jeff

[novaboy009]

That's a pretty nasty 307!!!

I don't think mine put out those kind of numbers running 14 flat....

Kev

[69NovaSS]

That's a pretty nasty 307!!!

I don't think mine put out those kind of numbers running 14 flat....

Kev

Well the ol' Moroso Power-Speed Calculator says if your doing 14 seconds flat in the quarter and your cars weighs 3600lbs (just a quess what a 4th gen weighs) you have 220HP

Now I have never been sure if these things estimate Brake HP or RWHP

[stock z/28]

Are you talking about front wheel HP Duane?

[69NovaSS]

Are you talking about front wheel HP Duane?

no I ment Flywheel HP...maybe I need to rephrase it

[69NovaSS]

Are you talking about front wheel HP Duane?

I changed it to Brake HP...that is a much better term:)

[supernovanator]

Well the ol' Moroso Power-Speed Calculator says if your doing 14 seconds flat in the quarter and your cars weighs 3600lbs (just a quess what a 4th gen weighs) you have 220HP

Now I have never been sure if these things estimate Brake HP or RWHP

it should be 3300, no? I had mine insured at 3300lbs, then i went to look at my grandma's '99 cavalier and it weighs 3700! where did that weight come from?!?!

[69NovaSS]

it should be 3300, no? I had mine insured at 3300lbs, then i went to look at my grandma's '99 cavalier and it weighs 3700! where did that weight come from?!?!

I could be easily wrong on this but my understanding is that each generation of Nova got a little heavier and from what I have read on here most 3rd gens are ballparkish around 3400lbs...give or take a bit depending on options...SO for Kevins 4th gen I just guessed at 3600lbs..but if it weighs less then my quess it will of course take less HP to get to a 14 second quarter if it weighs more then my guess it will of course take more HP to get to a 14 second quarter

[novaboy009]

You sure that's not wheel horsepower? Seems to be a tad low for 14 flat. The 1970 307's are rated at 200 hp and I don't think they go about 17.2's or so if I recall lol. I know the early motors are overrated, but that's a pretty big jump!

Kev

[Carl Stevenson]

Stock Z/28

What is the minimum thickness you would recommend, either before or after boring? I plan to get the sonic done, so it's easy enough to calculate from there.

[stock z/28]

Hi,

Well it kinda varies. If its a real high load or something that you want to "really" be dependable and maybe trouble free, I like to see about .100 to .125" at the finished diameter.

I have ran them with less, but I wasn't crazy about it.

The part of the cyl you measure is (again just my opinions here) very important. The thrust sides are where you need the strength. The area where the cyls kind come together may be the thinnest. I have seen 010 350 blocks .030. over that had less than .060-.090 in this area. Thats why I like the Siamese cyl walls. The general hardness and density of the casting is important as well.

I cant post pics but I have a 350 block that I milled the deck off so you can see the way its cast and the thickness. Its kinda scary.

Sorry to ramble, but .100-125. I guess.

Jeff
Good

[69NovaSS]

You sure that's not wheel horsepower? Seems to be a tad low for 14 flat. The 1970 307's are rated at 200 hp and I don't think they go about 17.2's or so if I recall lol. I know the early motors are overrated, but that's a pretty big jump!

Kev

Like I said I have no idea if that is supposed to be flywheel or rear wheel HP.

If its RWHP then you would have had about 275 HP at the flywheel (275 - 20% = 220).....now remember the assumptions that the Moroso Power-Speed calculator makes are based on a perfect world with no traction issues etc....

[Paul Wright]

based on 3500 lbs and 14 flat, I got 251.4 hp.
I don't know if that's flywheel or rear wheel.
I think I remember it's increasingly understates HP over 100 mph because it doesn't take into account air resistance.

[69NovaSS]

based on 3500 lbs and 14 flat, I got 251.4 hp.
I don't know if that's flywheel or rear wheel.
I think I remember it's increasingly understates HP over 100 mph because it doesn't take into account air resistance.

What gave you that???

The Moroso calculator i have says that 3500lbs with a 14 second ET = 214HP....I'm not saying this calculator is right.....I'm just wondering what your using....it would sorta be funny if we were using the same thing just different years or something like that...

[Paul Wright]

My HP48 with the following formulas:

ET= (lbs/hp)^.333 x 5.825 (assumes perfect traction)

HP= (mph/234)^3 x lbs

MPH is a better reference of HP but as I said it doesn't take into account air resistance. It's less accurate the farther north of 100 mph you get.
between the two you can get a rough estimate.


With Kev's previous best MPH of 99 mph I get 265 HP
Taking the average of both:
(251 + 265)/2 = 258 Hp (estimated power at the flywheel)

We both might be right if mine is flywheel and yours is wheel HP.

258 -220 = 38
(38/258)x100= 14.7% driveline loss.

[Carl Stevenson]

Thanks Jeff, that gives me a good idea. The guy who will do the sonic does some race engine work, but a second opinion is always good.

[Hawkeye]

I was wondering if anyone has recently built a 302 Chevy? One using a large journal block and crank. I'm tring to weigh between this and a 406. I already have a 350 long block the needs to be rebuilt. I know the two engines are on two different scales. I think it might be fun to have an engine that should rev quickley. Any comments welcomed. Thanks Hawkeye.

[bowtie0069]

I think it might be fun to have an engine that should rev quickley. Any comments welcomed.

Mo bigga, Mo betta--you should hear my 414 at 8000 rpm!

[ovrdrive]

OMG!!!

just by saying 302 Chevy, U have set off the alarm!!! :eek:


Just kidding. I am pretty sure that in order for you to build a 302 large journal block you will need a large journal 283 or original 302 crank. 1969 was the last year of the famous 302 and finding a crank is going to be expensive. There will be many on this forum who will tell you to go big. But, that is your decision. I am doing a small journal 302 as a fun build and doing some extensive research on what cam, comp ratio, trannmission, and a donor car to put this motor in. The lighter the car, the faster it is... If you want to do some background on this, use the "search" option on this forum and do a search on 302 and small journal motors.

And, by the way, WELCOME TO THE FORUM!!

Dan

[novamike]

I say "go for it" lets build it with about 8.5-1 compression with a mid size roller with about 114 degree lobe separation and put a 2 stage nitrous of a total of about 400 hp.
Mike:beer:

[Bscman]

I contemplated the same thing for quite a while before I came across a good deal on a fresh 400 block...
Now I'm going to build a 377...
Same basic idea, just more cubes!

[Dan_Lebherz]

Take a look at some of the original Chevy configurations while you're at it.

9.5 compression, duntov solid cam and 2 WCFBs - 283 HP as I recall it.

I would think to make your small engine run right, you'll not get away with 8.5 compression because you'll need a hot cam and that won't be compatible with the low compression.

[novamike]

Take a look at some of the original Chevy configurations while you're at it.

9.5 compression, duntov solid cam and 2 WCFBs - 283 HP as I recall it.

I would think to make your small engine run right, you'll not get away with 8.5 compression because you'll need a hot cam and that won't be compatible with the low compression.

The nitrous will make up for the low static compression.
Mike

[bowtie0069]

The nitrous will make up for the low static compression

Why not run about 14-1 compression AND nitrous? My 14.5-1 motor LOVES nitrous! Might as well make it run N/A or squeezin'

BTW, I have nothing against little engines(I love the sound of Z/28 302's) It's just that it costs the same to build a 400+ as it does a 283/302/327.......
Torque is what moves ya, and with the right stuff a 434" will buzz like a 302!
I have a friend with a 440" sbc that pulls a 4300lb car in the 9's, and it screams over 7500 rpm.

[veno]

while the 302 is a high winding Screamer and will make the same HP as the 406
(different parts) the 302 will be harder on parts because of the RPM. valve springs will be changed more often because of the higher cam lift you will have to run, and again the rpm or engine cycles the springs will see. piston speed and cycles are vastly increased, as well as bearing cycles or rotation lenth the bearing sees for a given distance. over all if your running Super comp then consider a 260 to 280 inch motor with a 4+ inch bore and tiny stroke. while I like hearing 9000+ ( WOW, man did you here that?) the 406 will cost less and give better service in the long run.

After thought, the 302 will be peakie? in it's power band and have a very narrow TQ curve. you will need a close ratio 5Spd to keep it in its power band. The 406 will be like a frieght train from low speed to high it will be tougin along @ 600 rmp.

[Mike Goble]

while the 302 is a high winding Screamer and will make the same HP as the 406

What kind of handicap are you putting on the 406? It seems to me that the laws of physics are somehow suspended when the number 302 is entered into the equations.

[veno]

It seems to me that the laws of physics are somehow suspended when the number 302 is entered into the equations.

Now thats Funny.

you have to reread what I said: "while the 302 is a high winding Screamer and will make the same HP as the 406 (different parts)" The key is different Parts. the RPM of the two engines differ greatly there for require different parts. Its easer to make big HP with a big motor than it is with a smaller motor but you can make the same hp the TQ will differ greatly. Lets face it that he 302 will zing to 12000+ with the correct parts and proper assembly and make scads of HP, Now the 406 will zing to..... 8000? with a stock block and make the same HP (no ntirous) however the TQ will be very different.

[David_D.]

Comparing the 302 to the 406 is comparing apples to oranges. This is going to be totally about preference.

What is the intended use of the engine?

[veno]

yes apples to oranges. very good.

build the 406. The lengendary 302 was just that, lengendary GM rated it @ 209 hp and NHRA said 480hp? So on the street it was a mouse that roared in 67-69 it suprized many a unsuspecting or unknowing driver in the other lane. it had its time in the sun, the sun has set on that combo,(not cost effective).

[stock z/28]

Hi Guys

I just could not resist it anly longer.

The 302 is probably my favorite small block, probaly the coolest parts out of the factory.

But there is no way it will compete against a 406.

Years ago when cheap "big" heads were not around a small motors ability to make "more power per cube" was somewhat of an advantage, but now using "budget" parts, Im not sure you couldnt get as many RPMs and HP per cube out of the 406, and a massively wider torque curve.

I have customers you run 434s to over 8000, and these arnt "real" expensive motors. When they first started doing this I tried to be in a different county, but"knock on wood" so far so good.

But I really like the little motor anyway. Just a lot of memories I guess.

If you just want to do it to be different go for it. I still build quite a few, Probably 3 for this year. All were restotaion with the exception of one Im working on now for an early nova but It may become a 327 instead (thats what I recomended to him).

Cranks for a LG are kinda hard to find. A good steel 283 crank will work in SJ block, but you have to use 11/32 rods or buy aftermarket pieces and most SJ stuff is more money than large on the "budget" rods.

It sure makes a 350 look good

Jeff

This work is property of DR. Phil and may not be read and/or understood without the express written premision (just like everything else) of Oprah

[Never Satisfied]

The lengendary 302 was just that, lengendary GM rated it @ 209 hp and NHRA said 480hp?

I believe that the rating was 290 not 209.

[veno]

I just wanted to stir the pot. :D

them thair 4 hunderd motors aint werf a hill o beens, they crack, over heat, and,, and ,,, and,,, my dyslixeia is showing for real I believe that the rating was 290 not 209.

[Hawkeye]

Thanks for all the replies. The engine I end up building will be going into a 67 chevy II Sedan. It will mainly be street driven. I was looking at crank manufactures the other day. The cranks them selves don't seem to be all that more expensive. I have yet to look at pistons, which is probably be my down fall in price. I just thought I could maybe build a 302 with the block I already have. I know the bigger the better is a geed rule to follow when building an engine, but everyone seems to have a 383 or some kind of stroker motor. I'm just mulling over possible combo's. I was wanting some seat of the pants experience of a 302 in a first or second gen nova. Hawkeye

[wskaiser]

I say build what you want, its your motor and your money. If someone wants to give you their hot 383 or 406 or big inch whatever, take it, but if you want a 302, build it. I personally like the 302. I am not into racing, just enjoy a good running motor.

[64PRONOVA]

A 302 won't hold a candle to a 406. The 406 has tons more torque and more HP too. With a 377 all you'll be seeing are the tail lights of the guy with the equally-prepped 406 too.

[69NovaSS]

A 302 won't hold a candle to a 406. The 406 has tons more torque and more HP too. With a 377 all you'll be seeing are the tail lights of the guy with the equally-prepped 406 too.


To me that right there is the key. IMHO no matter what you do or how much you spend on a 302 IF you do the same and spend just as much on a 406 the 302 will lose. I dont see how its couldnt. BUT what do I know...I've never had either motor:p :)

[David_D.]

I say build what you want to build. It seems to me that it's not about bragging rights or ego with you. If it were, we wouldn't be having this discussion. I also think you have enough common sense to know that the 406 would outperform the 302, however since your not getting into a pi$$ing match, the 302 will be just fine in your car.

Again, build what you want!!!

[wskaiser]

To me that right there is the key. IMHO no matter what you do or how much you spend on a 302 IF you do the same and spend just as much on a 406 the 302 will lose. I dont see how its couldnt. BUT what do I know...I've never had either motor:p :)

No argument there, the big motor will outperform the 302 all the time but if he wants a 302 why not build it. There are guys with 6 cylinders that spend a lot of money on them and they will not run with a 406 either but if that is what they want, that is what they have. To each his own, not everyone has to have mega cubes to enjoy a motor.

[64PRONOVA]

I remember when I was a teenager in the '70s. My first car at age 16 was a '70 Chevelle SS396 4-speed and my best friend had a '69 z/28 with a 302. Both cars were bone-stock and only a few years old. The Camaro seemed really fast and was definitely a screamer. The truth was told at the dragstrip though when we lined-up several times and the Chevelle smoked the Camaro by about a second every run.

The 302 is a cool engine but the only reason I would ever want one would be if I were restoring a z/28. An equally-prepped 350 will even smoke one. The 302 was a 'freak' engine. The only reason GM even made them was to get the '67-'69 z/28s into road racing where the cubic inch limit prohibited the 350. That's why it was short-lived and was only ever put in the '67-'69 z/28.

The 302 then made a comeback in the late '70s, early '80s in dirt track sprint car racing. The cubic inch limit at the time was 311 CI. This narrowed the Chevy engine selection to the 283 or the 302. Racers gobbled-up all of the GM 302 parts and that is a big reason why you can't find any of them anymore. They would turn 10,000 RPM down the straights. All sprint cars run alcohol with mechanical fuel injection and magnetos.

In the early '80s, the cubic inch limit was raised from 311 to 378 CI. That's when you started seeing the 377s come into vogue. The 302s were no longer competitive and didn't stand a chance against the 377s.

Then a few years after that, the cubic inch limit was raised to 410 CI. Everyone switched to the 406 and the 377 was no longer competitive. Today just about everyone runs a 400+ inch sbc in big-time sprint car racing.

302s are nice little engines but are more of a nostalgia piece than anything else. My advice is to go with as many cubes as possible. You won't be sorry. The 302 is pretty "gutless" at the low end and doesn't really get motivated until around 4,000 RPM.

[Hawkeye]

My original plan was to build a 406 fuel injected motor. While I'm still going with the EFI induction. I know a 406 will pull like a Frieght Train, but what I had "put together" might be a little over kill. Most likely I will still go with the 406. I just like to ponder "What If". Hawkeye

[69NovaSS]

I just like to ponder "What If". Hawkeye

Me too....I love to think about and talk about potential combos....talking about the pros and cons etc.....:cool: :)

[Nova_Guy]

I'm going to build a 302 for my Nova if I swap to a SBC. I'm going to bore mine to 4.185 and stroke the crank to 4.00; the bigger bore will help it breathe better and the longer stroke will help it produce more torque down low. With good parts it should still rev to 7000rpm.

[ovrdrive]

Nova-Guy,

if possible, could you explain that set-up you are talking about? Is it safe to bore out a block that much??

Dan

[Nova_Guy]

Is it safe to bore out a block that much??It is if you start with a 400 block! :D That was kind of a joke. I used to know someone that would always tell people he was running a 427. Sometimes it was bored .125 and stroked a .250. But it was always a 427; same thing with his SBC. They were all 327 or 283's. Just mildly bored and sroked to around 412.

[walkerjay]

My first motor was a 283 bored .125. It ended up at 301 and was really a screamer. 7k no problem on the tach. It really roared. Did run a bit hot though.

[ovrdrive]

Nova-Guy... Ahhh, I get jokes!!! Now I see what you are talking about.


Dan

[sproosemoose]

this question comes up about every 6 months without fail. it'll make 450hp at 9000 rpm and peak torque will be about 200...

[Dawg]

The 302 then made a comeback in the late '70s, early '80s in dirt track sprint car racing. The cubic inch limit at the time was 311 CI. This narrowed the Chevy engine selection to the 283 or the 302. Racers gobbled-up all of the GM 302 parts and that is a big reason why you can't find any of them anymore. They would turn 10,000 RPM down the straights. All sprint cars run alcohol with mechanical fuel injection and magnetos.

In the early '80s, the cubic inch limit was raised from 311 to 378 CI. That's when you started seeing the 377s come into vogue. The 302s were no longer competitive and didn't stand a chance against the 377s.

Then a few years after that, the cubic inch limit was raised to 410 CI. Everyone switched to the 406 and the 377 was no longer competitive. Today just about everyone runs a 400+ inch sbc in big-time sprint car racing.

302s are nice little engines but are more of a nostalgia piece than anything else. My advice is to go with as many cubes as possible. You won't be sorry. The 302 is pretty "gutless" at the low end and doesn't really get motivated until around 4,000 RPM.

Good reading......amazing at what you can learn....I guess some still think 302's 377's and double hump heads are the best things to come along since sliced bread.

[dreshersun]

Good reading......amazing at what you can learn....I guess some still think 302's 377's and double hump heads are the best things to come along since sliced bread.

I can second 64pronovas last sentence ,the 66 i have came with a 68 Z-28 302 thing felt like you were driving a rotory motor. that motor is now collecting dust on a stand.

[onecarnut]

I think most of the post tell you that you are looking at two different "animals."

The 302 does not come alive until it gets up high in the revs and the 406 makes lots of low end torque.

I favor the 406 because it will be more useful and less expensive to build.
On the negative side, they are hard to keep cool.

[novaboy009]

I can second 64pronovas last sentence ,the 66 i have came with a 68 Z-28 302 thing felt like you were driving a rotory motor. that motor is now collecting dust on a stand.

Is that a bad thing?

Kev (Rotor-head:))

[deuceman]

I second the factory HP. rating of the DZ302---290Hp. The race motors ran 8500 rpm all day long, to build one of those, take a second out on your house!

[75novacaine]

i just wanted to add a comment about 400's running hot.

yesterday i broke in the cam of my 400. i did this in a garage with only the garage door open. even while the engine was buzzin at 2500-3000 rpm in an enclosed space for 20 minutes, the temp never went above 170. i believe the myth of 400s running hot came from guys trying to use 2 row STOCK copper brass rads on them AND not running steam holes, which leads to myth two. 400's crack heads easy.
when i took it for a ride, the temp was rock solid at 160. the temp outside was about 50-55

my cooling system is as follows:
160 thermostat
2 row summit universal aluminum rad
i run the factory fan shroud, which works terrific
hi volume summit aluminum water pump
16" mechanical flexalite fan
6 steam holes in EACH head
i also use ceramic coated headers which helps reduce underhood temps

it has so much low end torque, it would be unsafe to drive for somebody who wasnt used to high h.p. engines. and it does use alot alot alot more gas than the 200 hp 350ci engine it replaced. that should be a consideration.

[bowtie0069]

My nearly stock(but .060 overbored)350 is harder to cool than my half filled 400 block, and I've never run steam holes in any 400 that I've owned. My last 400(no hard-blok)ran under 190 even on 100+ days.

[1977Chad350]

Im getting back to work on the nova. Well I sold my 350 4 bolt main block awhile back. But I still have the old 200,000 mile 305 and still runs. Im wanting to build a stroked out 305 for around 1,000. My plain was to get a 400 crank, 350 pink rods, flat top pistons, and 194 heads. feel free to add your .02 cents.

-Chad

[Ed's68]

If it were me I would keep a eye out for a 350. As I was looking for that I would get some things to up grade the 305 that could still be used later on for the 350.

[stock z/28]

Hi,

Unless you are looking for milage I would find a 350 block myself.

I have several 305s with the 400 stroke but I generally use the 5.565 rod, but im jut looking for milage in a pretty light vehicle. THey are great for that, but I wouldnt waste the money for one for performance application.

One more thing, the 1.94 heads usually have a lot larger chamber than most 305 heads, and be carefull on the intake valve interfering with the cyl wall.

[bluehat]

I run a 307 myself, been rebuilt once needs a decent set of heads but I like having the same size engine that came in the rig. :o :)
When I can't make it go any faster with the 307 for a reasonable price I will get a 350. :rolleyes: :)
The way my budget goes I don't think I'll ever have the 350, but I bet I can get the 307 to get under 13 seconds. ;) :D

[Bscman]

Having built a few 305's (one being a stroker) I would also recommend you keep your eyes out for a 350. The 305 is an okay engine for daily driving/economy/and okay power...but it won't be able to match a well built 350, especially if you look at price per HP.

For $1,200 will get you a good 350 long block, and save you the time and mess from building the 305...you'll also have a warrantee!

If I had it to do all over again, I would've bought a GM 350 long block and scrapped the whole idea of stroking the 305. I would've saved money and made more power. It was a smooth running motor, and got ~14mpg in the old long box chevy it was in, but not worth the hassle IMO.

[LarryMc]

If I could just find a 327 & build it back as a 350 hp & be happy shouldn't cost that much to build & shouldn't have any trouble running hot & be able to run on pump gas
larry

[Nova77X]

If your on a budget dont bother with stroking a 305 or buying a 350, go with what ya got. Otherwise look for a 400 block.
If ya kind find a decent pair of vette al 58cc heads, those are good on a 305, also a mild cam, headers and a hi rise dual plane intake will make a big difference.

[tpinovaII]

I have been wrenching on cars for 27 years (that I can recall). I have driven and worked on countless cars & trucks with 305's. Many of these had aftermarket heads, camshafts, intakes, carbs, & etc. I have even driven the stroked versions. I have never been behind the wheel of a 305 powered vehicle that did not make me long for a larger engine.
I ran a 305 TPI engine for five years. It ran great in stock form. I never clocked the sixty foot times, but they were pretty quick. The 1/4 and top end weren't that impressive but throttle response was silky smooth. When we added a larger camshaft and bigger runners, the sixty foot times and good manners were gone. I always wished I had left it alone and saved my money. The day I dropped in a stock 350, I saw a dramatic change. The AC no longer lugged the engine down and there was more torque everywhere in the power band.
The fact is, 305's do not take well to performance upgrades. They are a pain to tune and the return on your investment is very small. The oldest rule of hot rodding is to build the largest engine you can afford and drop it in the lightest car you can find. If you can find a small block 400 at a price you can afford, grab it up quick. If not, Chevrolet built a lot of 350's. I, personally, wouldn't invest ten cents in a 305.

[76NovaSS]

Pay the local junk yard a visit and your local machine shop. Machine shops tend to sell the engines of dead beats who dont pay their bills. 350's are a dime a dozen.

[footjoy]

My son and I bought a 70 Nova 307 /350 we don't have enough money to build a 350 right now so what heads would zip up 307. It was rebuilt before we got it runs, but we want to get more power out of it. It has a cam big enough where it needs a little stall.

Thanks (be nice)

Greg

[bowtie0069]

For the money, it's hard to beat plain old Vortec Chevy heads--If going with aftermarket stuff, you can't use a very big valve size because of your small bore. Before you buy, verify that the valves will clear. The bores can be notched, but just be aware of what you're buying. On that small an engine you'll want to keep the port volume low too--170-180cc should be more than enough. Stay away from 210-220's

[Bscman]

Any idea what the cam specs are?

+1 on vortecs...but be aware the guides may need machining with a high lift cam. Also, vortecs require a special intake.

If you're looking for something else aftermarket, I'd look at Pro-Topline Torkers. I believe they have 167cc intake runnners, and advertise 30hp improvement over stock.

For a smaller displacement motor seeing mostly street use, keep the intake runners small 170cc or so. Too large of a runner and you'll lose velocity, which means you'll lose performance. Also, pay specially attention to chamber size, as going too large will drastically reduce compression in your 307 and too large will limit you to high-octane fuels.

[footjoy]

The info is great the cam is small rv as far as I can tell

Greg

[Nova77X]

I have a 307 in my 77 and it has Comp268 cam, headers, Eddy 600 carb, intake and heads from 350. Idles good with lope, not much torque but runs strong on the highway. 307s wake up nice with a few mods. My advice buy some 64cc 1.94 heads, Vortecs are nice but that conversion isnt cheap, maybe for now look at old school 492/041/186 heads or 305 heads reworked with bigger valves.

[bluehat]

Hey there's nothing wrong with that 307 in my book. :)
I have a 307 in my 73 hatchback I put rings and bearings in it and a Napa RV cam that seems to lope and run nice, edelbrock dual plane intake, and a Holley 650 double pumper with manual secondaries, the down side is the 993 heads the 76cc chamber is too much for the ci's. I would like to have a set of 305 heads either the 601's or 416's and when I find the right deal and have a $ in my pocket I'll get em. :cool: :D
Before I get the heads though I'm going to have to have something better than the 273 peg leg giving me a push. :eek:
Hey it's your car do what makes you happy. :cool:
Me I like to run iron parts and am sort of old school on how things should be on my car. I will get my "Sweet li'l Greenie" under 13 without any big mods or aluminum. That'll make me happy!!! :D :D

[71SS454]

A 307 can be built to be pretty stout. Mine pulls to 7000+ rpm's and has great mid range. On my old combo I ran Vortec heads, but you need to have them decked .030-.040" to get compression where you need it to be. Compression with 64cc heads is too low. Stock 307 pistons are around .030" below the deck. With the heads shaved .040", this gives you around 58cc combustion chambers. With a .015" thich shim style head gasket on a stock short block, and with 58cc combustion chambers this will give you a 9.75-9.8 compression ratio, which is perfect for this engine. The only problem with Vortec heads is the need for a special intake and center bolt valve covers. They also use special gaskets and need self aligning rocker arms. The best deal I've seen on Vortecs are from Scroggin Dickie. They sell the heads in a complete kit that comes with everything you need (head, head bolts, rocker arms, intake, gaskets) for around $800 I beleive. If you're looking for a cheaper used head that will give you a little more performance over the stock heads, look for a set of 58cc heads from a 305H.O. These engines can be found in Monte Carlo SS's, Trans Am's from 84-92. Grab all the necessary parts with them (valve covers, rockers, etc.). These will improve your lower end torque, but if you can swing it, go the Vortecs. When you want to upgrade your bottom end and cam, these heads will still be what you'll want and if you decide to build a 350 in the future, you can us these heads with a dished piston on that engine as well, so for a budget kind of guy they will be your best investment. As for valve size, you can run 2.02/1.60's without much problem, but for your street engine, you don't need them. Run a set of 1.94's and you'll have more than enough for what you need. Also don't go any bigger than a 600cfm carb. If you keep your rev's around 5000-5500, a 500 cfm carb will work good while maintaining good throttle response. Also, all you need for headers is a 1 5/8 tube, so the $80 header sets from places like Summit and Black jack, etc. work perfect for this smaller engine. Also if you go the Vortec route, an Edelbrock Performer intake will work better then the Performer RPM, you don't need the large runners of the RPM. As for a stall convertor, list your cam specs (duration at .050", cam lift, and LSA (lobe seperation angle)) or your cams manufacturer and part number so we can look it up. A TCI Saturday Night Special will probably be enough for you, but with the lower torque of your engine due to size a TCI 11" break-a-way convertor will probably work very well for you. It will stall a little lower than it's rated 2500rpm behind a 307. Good luck.:cool:

[72Ventura]

I toyed with the idea of boring mine .030 and putting a 350 crank in it. It would make it run out at 333 CI (I'd call it a 335 'cuz it sounds cooler).

Bought a $400 '70 Camaro 350 instead ... Of course, I'm already $400 in and haven't even touched the motor ... I could have re-rung the 307, put in a mild cam, and bought an intake for that ...

RC

[Mike Feudo]

Get a set of 305 HO heads they should be about the best you can use for a mild motor. Keep the cam on the mild side and use a small carb or Q-jet.

[footjoy]

Ipresently have a 500cfm edelbrock and performer intake it came with, heads I have a set of 624 heads from old project 76cc with new stainless 194s can those 305 be opened up for the 194s?

Thanks for the info the article link on the 305 was great 300 hp is all I would want out of a 350 let alone a 305 or 7.

Greg

[footjoy]

The 624s are sitting there oxidizing I thought I would pull guts out which are new and put them in 305 heads. If I find some.
thanks
Greg

[gtoponcho]

I have a '69 Nova that came with the #'s matching 307 block. I have read some past posts on 307 performance building and it seems that the overall opinion is to leave it alone. What is the difference between a '69 302 / 327 / 350 / 010 block and the '69 307 020 block? Can I put a 350 crank and pistons into a 307 block bored to 4" and have a 350?

[bowtie0069]

I don't think a 307 block will go to 4"

[MarkV]

Get you a 400 block, bore and stroke it to a 427 or something crazy like that, and tell everyone it's a 307, or 283 no one will know the difference, don't waste your money on the 307.

[stock z/28]

Hello,

I have bored the 307s .125" (4in.) and made 302-327-350 cube engines. I have not done one in quite while (maybe 15 years-not much demand). A few are still running around. Im not sure what an approximate Wall thickness might be, but a few were drag raced quite a bit.

The 020 307 block doe not have nearly as good of main webbing as an 010 350 style block, but the block is still pretty solid.

As others have said, unless you just want to be a bit "different", its better to start with a better suited block for more cubic inches.

Jeff

[gtoponcho]

Bowtie; Why not? Cooling passages? Oil delivery? Anyone know?

MarkV: Don't misunderstand, my first reaction is to bag the 307 and store it but I wanted to do some research here first. I have not heard of anyone building a 350 out of a 307 and I want to understand why. Mathematically, it should work.:geek: I do have a few other options, I have a '72 Ventura that has a complete BBC set up and my original intention was to put this in my Nova. I also have a 350 SB that needs a crank and I was planning to put the 307 crank in that block along with 327 pistons and bulding a large journal 327 to put back into the Ventura. While doing some research on this, I found that there isn't a lot of difference in the '69 SB block castings (or at least I could not find anything). I was checking to see if anyone has built a 350 out of a 307 so that I could keep the original block with the car without giving up performance.

[gtoponcho]

Thanks Jeff,
I was convinced that it was possible. I am still curious as to why I don't see more of this type of build up. Is it really that far fetched? I feel that if more people knew that they could keep the numbers matching block in the car and get the same performance as building a later 350 they would pay a little more for the machining IMO.

[Paul Wright]

Bowtie; Why not? Cooling passages? Oil delivery? Anyone know?

I have not heard of anyone building a 350 out of a 307 and I want to understand why. Mathematically, it should work.:geek:
The reason you don't hear of people doing it is because it's a waste of time, money AND you might ruin the 307. The 307 is essentially a large journal 283 block with a 327 stroke. Going a whopping .125" over bore is a lot and all you get is a thin wall 4" bore block.
A real 4" bore block is really easy to find. In fact a complete, running 350 is even easier.

Besides what good is "matching numbers" 307 if it's not a 307 anymore? It's not a valuable engine option so your motivation is pointless to keep the block stock but butchered up. Sounds like it would lose value as a collector item and not be as good as the real thing.

Either keep it stock and hope some day it's worth something or pull it out and set it aside and install a crate 350 and be done. Stamp the same numbers in it if you want.

[stock z/28]

Hello Guys,

Well for one thing its pretty expensive to pay for the machine work. It generally cost quite a bit more to bore that far.

In my opinion you would be better off to start with a 4 in style block, they are still pretty cheap. With proper machine work you could end up with a much better product for about the same amount of money, maybe less.

Your 307 crank is generally the same as a cast large journal 327, just balanced for a lighter bobweight.

On a side not I still have 2 of the 307 blocks that I built into 302s back in the early 80s. I used them i