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Discussion Starter #1
Ok so i have a 377 2 bolt . It has fully ported 292 heads and flat top pistons, triple springs , rev kit, 600 lift 300 duration lunati roller, harland sharp rockers, ported Victor jr. and 1 3/4" headers. When it ran it wouldn't pull power past 6700 Rpm's. Dyno'd 505 hp and 425 ftlbs. My first thought was modern Aluminum heads would wake it up a little! It ran on pump premium due to the big cam overlap which was a plus. What suggestions does everyone have to help it rev higher and make more power while staying streetable? Im not lloking to spend a small fortune but will spend what i need to!:yes: Oh and this is not for my son's Nova but for my AC Cobra. So the weight is 2450 lbs and is manual shift!
 

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is your 377 a 400 block with a 350 stroke or a stock 350 bore with a 400 crank? I don't know how old the engine is but check the valve spring seat pressures, higher revving engines need some good springs and pressures. Also the 292's, as good as they are may be killing it on a 400 block, how big are the valves? what do they flow? I had a set on my 400 with a 630 roller and it pulled to 7,000 no problem but only mustered a 122mph trap speed.


I'd go with a better set of heads and a super victor or a bowtie intake or a newer holley strip dominator. Maybe even step up the cam.
 

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Discussion Starter #3
400 block! 2.02 valves
 

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Did it pull higher RPM's before or are you looking for more now?

Inadequate valve springs and pushrod flex will cause high RPM instability which will effectively limit what it will want to turn. A solid roller expected to turn over 7500 should have around 220-250 pounds on the seat and close to 600 pounds of ACTUAL open pressure. Pushrods should be at LEAST .080" wall 3/8" diameter, one piece moly. Mine are .120" wall 3/8" Smith Brothers pieces. Believe it or not, they're not much more expensive than the typical .080" wall 5/16" stuff that's so popular out there.:rolleyes:

The older heads my be choking it a bit but it would still turn the RPMs. Just not make as much power up there.

If you're REALLY wanting to twist it up there and make a TON more power, look at the new Pro-Filer fully CNC'd 230's and some of the new Voodoo solid rollers.:yes:
Like this:
# Advertised Duration (Int/Exh): 285/293
# Duration @ .050 (Int/Exh): 255/263
# Gross Valve Lift (Int/Exh): .600/.600 w/1.5 or .640/.640 w/1.6 rockers
# LSA/ICL: 110/106
# Valve Lash (Int/Exh): 016/016

You can get quite a bit more aggressive with the roller but lifter and valve spring life will suffer especially if you like to drive the car.:yes: The Voodoo's typically run a pretty tight lash setting and your rev kit should help as well.:yes:

Look at your compression carefully. 11.5:1 should be fine in that kind of combination as long as the quench is good and the tune is right on.
It's gonna take some pretty small chambers to get it that high with flat tops!!:yes:
 

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Discussion Starter #5
Did it pull higher RPM's before or are you looking for more now?

Inadequate valve springs and pushrod flex will cause high RPM instability which will effectively limit what it will want to turn. A solid roller expected to turn over 7500 should have around 220-250 pounds on the seat and close to 600 pounds of ACTUAL open pressure. Pushrods should be at LEAST .080" wall 3/8" diameter, one piece moly. Mine are .120" wall 3/8" Smith Brothers pieces. Believe it or not, they're not much more expensive than the typical .080" wall 5/16" stuff that's so popular out there.:rolleyes:

The older heads my be choking it a bit but it would still turn the RPMs. Just not make as much power up there.

If you're REALLY wanting to twist it up there and make a TON more power, look at the new Pro-Filer fully CNC'd 230's and some of the new Voodoo solid rollers.:yes:
Like this:
# Advertised Duration (Int/Exh): 285/293
# Duration @ .050 (Int/Exh): 255/263
# Gross Valve Lift (Int/Exh): .600/.600 w/1.5 or .640/.640 w/1.6 rockers
# LSA/ICL: 110/106
# Valve Lash (Int/Exh): 016/016

You can get quite a bit more aggressive with the roller but lifter and valve spring life will suffer especially if you like to drive the car.:yes: The Voodoo's typically run a pretty tight lash setting and your rev kit should help as well.:yes:

Look at your compression carefully. 11.5:1 should be fine in that kind of combination as long as the quench is good and the tune is right on.
It's gonna take some pretty small chambers to get it that high with flat tops!!:yes:
I cant remember the seat pressure but i know it was up there!!! The builder made a comment about it. The engine would rev further but wouldnt make power above 6700! It ran great and at 2450 lbs and short wheel base the lack of torque was great for driveability, since the rear wanted to pass the front all the time:eek: even once at 85 on the frwy:eek::eek:. With a convertible and not wanting to cage it it is street driven only! So the driveability and pump gas are issues i want to keep.
 

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Discussion Starter #7

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Heads are killing it. Intake is marginal. What size carb are you running?


I went from 2.02 double humps fully ported and blended to mildly ported brodix track 1 heads on my 13.5:1 383 stroker and picked up half a second in my 3600 pound camaro. My car was also falling flat around 5500 rpm even with the new heads. Ended up the 750 double pumper was not flowing nearly enough for my engine. Swapped on a 1050 dominator and she revved to 7200+ and pulls hard the entire way!

Now a 377 is a big bore short stroke high revving engine and it needs the correct heads, intake, carb and cam to support it. They all need to match and work together. I have always wanted to build a 377. I ended up building the 383 because I could not for the life of me find a 400 block. I would still rather have a 377 over my 383.
 

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Discussion Starter #9
Edelbrock states up to 8000 rpm for the Vctor jr. And it was ported also! 750dp . Dont get me wrong it runs pretty good ,the only time i got to run it (no cage or even roll bar) it pulled a 1.53 60ft with drag radials and pump gas. I just expected it to rev higher than it did. I figuered the heads were the week link. This when the springs were brand new!!
 

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Discussion Starter #12 (Edited)
thats a good point. Why rev it if its making good power at 6500? Do you like to hear a small block sing? lol...
A good 377 should rev better than a 406! If all of my parts allow for more power at higher rpm's but one of them is restricting it, while its apart i should change it to get more out of it right? if i can get another 20-40 hp at 7500rpm's then i'm game!! If you wanted 550 hp at 7500 rpm's and had what im starting with, what would you change??????
 

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You can look at any number of killer CNC'd small block heads these days. Pro-Filer, Canfield, Dart, Brodix and TrickFlow just to name a few.

A Super Victor, Dart, Brodix, Bowtie or MoTown single plane intake would probably shine over what you've got. Remember the RPM range of a LOT of the parts out there is based on estimations of a 350. So the larger engines will diminish the top side.:yes:

As for the cam.....Look real hard at Lunati's new solid flat tappet VooDoo cams. Since you're driving on the street it would be nice to not have to worry about a roller lifter going away.:yes: And I can probably get more "Area under the curve" than what you have with your low lift roller now!!
Something like this with 1.6 rockers would certainly work.
http://www.lunatipower.com/Product.aspx?id=1883&gid=269

or if you wanted to stay with the roller something like this.
http://www.lunatipower.com/Product.aspx?id=1915&gid=271
or
http://www.lunatipower.com/Product.aspx?id=1942&gid=275

The tighter the lash you run, the longer your lifters will last.:yes:

Or better yet....Give Ol' Harold Brookshire a call and see what he has to say about what you need.:yes: 662-562-4933
 

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good 377 should rev better than a 406!
Nonsense,
It's all in the combo as to how it revs. A 377 with a 65lb. crank, big heavy pistons and rods, and lousy heads isn't going to rev like a longer stroke engine with a 37lb. crank, 340g. pistons, 500g. rods and killer heads.
And just because the manifold claims to be good to 8000, doesn't mean you'll come even close to hitting that rpm.
Your head and cam package might be an 8000 rpm combo in a 283 or 302.
 

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Nonsense,
It's all in the combo as to how it revs. A 377 with a 65lb. crank, big heavy pistons and rods, and lousy heads isn't going to rev like a longer stroke engine with a 37lb. crank, 340g. pistons, 500g. rods and killer heads.
And just because the manifold claims to be good to 8000, doesn't mean you'll come even close to hitting that rpm.
Your head and cam package might be an 8000 rpm combo in a 283 or 302.
Yeah I wasn't gonna go there because of the flame fest the 283 thread turned into.:devil:
I'll agree completely with you on this one!! I've seen just as many 572's and 632's turning 8500+ as I have little motors.:yes:
Simply put, if it's built to turn it properly it'll sing..:yes: No matter the stroke!!:rolleyes:

Man them big motors sound pretty up there!!!

Everyone should go to an ORSCA event at least once and listen to the music of the 700 and even 800 inch motors in the Outlaw cars twisting up!!! Nothing sounds quite like a Kasse 800 cid, 14.5:1 monster with 4 kits.:no:
 

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Discussion Starter #16
Nonsense,
It's all in the combo as to how it revs. A 377 with a 65lb. crank, big heavy pistons and rods, and lousy heads isn't going to rev like a longer stroke engine with a 37lb. crank, 340g. pistons, 500g. rods and killer heads.
And just because the manifold claims to be good to 8000, doesn't mean you'll come even close to hitting that rpm.
Your head and cam package might be an 8000 rpm combo in a 283 or 302.
Assuming equally built!!!! For my application (light car , short wheel base, 5 speed , street driven) torque is not necessarily what i want. I want faster reving , higher reving, horse power. I put it to the floor at 85 in 3rd on the frwy once and it grabbed traction in the carpool lane at 120 from the number 4 lane!:eek: Im not trying to argue about cubic inches! This is what i have and how can i improve it? The engine was originally built in 94 by Boyd racing in Harrisbug, MS at 456 hp and 419 tq , then refreshed in 2000 here in Cal and bored 30 over manlle pistons and different cam to 505 hp and 425 tq. Appears stock crank and rods, arp bolts! lunati roller (from 94) 591/597, not sure what my Harland Sharp rockers are 1.5 or 1.6 (how can i tell), rev kit , screw in studs , guide plates ( hopefully they used a good pushrod), triple springs ( cant find the info on them), 292 heads full ported ( dont have any flow numbers on them) matched to ported Victor jr , 750 dp ,1 3/4 headers with 3 1/2 exhaust. 2.73 gears jag rear with nash 5-speed 3.28-1 first and 1-1 5th
 

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victor jr

when the victor jr's came out ,, they were recommended for 331 ci and down, the victor was rated for the bigger motors. There used to be the victor 4+4 that ya don't see much anymore. I called Edelbrock once and asked them the difference between the victor manifolds. Can't remember everything he said , but i do remember he told me the victor jr was designed for class racers that had to use the double hump heads in super stock and econo altered.

victor 4+4
http://cgi.ebay.com/ebaymotors/Used-Edelbrock-Victor-4-4-SBC-Chevy-Intake-2976_W0QQcmdZViewItemQQcategoryZ36474QQihZ002QQitemZ120416769561QQrdZ1QQsspagenameZWDVW

victor e kinda cheap
http://cgi.ebay.com/ebaymotors/Edelbrock-Victor-E-Intake-Manifold_W0QQcmdZViewItemQQcategoryZ107063QQihZ015QQitemZ250419999576QQrdZ1QQsspagenameZWDVW

I've saw 355's pull hard as hell to 8000 with big hydraulic cams , double hump heads , crappy intakes from 30 years ago and 750 vs carbs . A 377 should wind IMO. This might even be an ignition problem.
 

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A good 377 should rev better than a 406! If all of my parts allow for more power at higher rpm's but one of them is restricting it, while its apart i should change it to get more out of it right? if i can get another 20-40 hp at 7500rpm's then i'm game!! If you wanted 550 hp at 7500 rpm's and had what im starting with, what would you change??????
well IMO for me to have a 377 make power as much as a 406 yes you need to rev it higher. I would sell off the intake heads and cam. I'd hit up camgrinder he has a 377 as well and he knows his stuff. I'd go with some 220 cc heads and a super victor or the strip dominator and have them ported to match the heads. I'd also run a 4 hole tapered spacer too. There are significant gains to be made in the intake itself. Definitely get good valve springs like pacaloy or Kmotion. Titanium retainers and if you can get some shaft rockers. If not you can use regular roller rockers, 1.65 on the intake, 1.5 exhaust with 7/16" studs and a stud girdle. Good pushrods, 1 7/8" headers, 850 or 950 carb.
Then have john grind you a nice solid roller cam and tell him you want to zing it and make power at 7800!!!!
 

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Discussion Starter #20
Thanks for all your help!:yes:
 
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