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Here's my problem, 396 BB in my 71 Nova, previous owner said he built the motor with: roughly 10-1 compression (not verified),Summit cam with 238/248 lift at .50 - 296/306 advertised duration,.540/.540 lift (not verified),closed chamber 68 3917215 heads (verified),Edelbrock c-396 intake- from like the late 60s (verified),headers,4.10 gears (installed by me 3.23s originally),turbo 350 with a 12" converter which he claims was about 2700 stall (feels more like 2000),Mighty Demon 750 ( Installed by me)which I believe to have tuned correctly (have a/f meter installed),Initial timing set to 18 degrees with 38 total in by 3000 rpms (Holley Pro Strip Ahn setup programmed curve),no vac adv.(Installed by me and verified)

This thing may run high 14's if Im lucky!I believe it should perform better than this.Am I right in assuming it needs at least 3500 stall; is this my problem it such a slug?

I like to pop the hood and see a big block under there, but I am seriously thinking of swapping to a 350 that I have sitting in the garage that has the Summit 420 HP, Trick Flow package on it! I would like to go to at least 454, but in these tough economic times, I have to make do with what I have.

Should I ditch the 396 and install the 350, or can we save my 396?
 

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Do a compression test to see how much pressure the cylinders are building. With 10:1 compression, it should have pretty good pressure.
 

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I'm going to try that, I tried to hook up the compression tester that I have and the threaded end isn't long enough to reach into the hole to get to the threads on those heads. I will have to get a new one when I get off of nights.I hate to tear this motor apart,but I may have to, just to find out what I am working with.What kind of cranking pressure do you think I should be looking for with 10-1?
 

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I think the convertor is a bit too large. You need an 11" minimum. A nice 10" would be better. Torque convertors are the governor of the combo. If it's not right, it won't perform. I had a 57 with a 396 in it with oval ports and a small solid cam. It went high thirteens back in 1977. It weighed 3700lbs without me in it. Keep the BB, you will get it right. Dave
 

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Here's my problem, 396 BB in my 71 Nova, previous owner said he built the motor with: roughly 10-1 compression (not verified),Summit cam with 238/248 lift at .50 - 296/306 advertised duration,.540/.540 lift (not verified),closed chamber 68 3917215 heads (verified),Edelbrock c-396 intake- from like the late 60s (verified),headers,4.10 gears (installed by me 3.23s originally),turbo 350 with a 12" converter which he claims was about 2700 stall (feels more like 2000),Mighty Demon 750 ( Installed by me)which I believe to have tuned correctly (have a/f meter installed),Initial timing set to 18 degrees with 38 total in by 3000 rpms (Holley Pro Strip Ahn setup programmed curve),no vac adv.(Installed by me and verified)

This thing may run high 14's if Im lucky!I believe it should perform better than this.Am I right in assuming it needs at least 3500 stall; is this my problem it such a slug?

I like to pop the hood and see a big block under there, but I am seriously thinking of swapping to a 350 that I have sitting in the garage that has the Summit 420 HP, Trick Flow package on it! I would like to go to at least 454, but in these tough economic times, I have to make do with what I have.

Should I ditch the 396 and install the 350, or can we save my 396?
Does the engine run strong or does it feel like it's laying over on itself? How's the idle, what's it idle at and is there any surging?
Does it pull hard from the line, then seem to drop off on the top end?
Or, does it leave the line like a dog, then pick up on the top end?
Do a vacuum check at idle then again at 3000 rpm, post the readings? While you at it, check to see if the vacuum is steady at idle.

Last but not least, are you sure you've got the carb set up properly?

Good Luck!
Jim Smith
 

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Discussion Starter #7
The engine seems to sound strong. The idle is set to 1100 rpms in park which goes down to around 650 in drive. Its just a dog off the line, but seems to run stronger at the top end. I have done a lot of carb tuning by driving and using the Autometer A/F ratio meter in the car. I will have to wait to get the vacuum reading because I have yanked the engine, to change a leaking pan gasket.
 

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Discussion Starter #8
Besides needing more stall,could the intake be choking it down with that cam and is that cam worth keeping?
 

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lazy ol' cam on a 114 LSA

i never was a person that worried much about idle quality and power brakes . The cam you have is ground on a 114 LSA , typical street/ strip old type stuff , trying to give you performance on both senarios and failing miserably.

I've saw some wicked 396's so i'd keep it myself. Yo've got a pretty deep gear for just street/strip stuff , sooo ,, i think you should look more toward the strip/street senario but the cam and converter are whats holding it back IMO.

I really think the cam is the biggest anchor right now. The intake is old skool for sure ( wonder if it would like a 1 inch open spacer ?? ) , i really think its the cam myself. Its on a 114 LSA , prolly to provide good vacume for power brakes , nice mild idle quality , but lack luster performance.

You really have to decide what your willing to sacrifice to gain more performance with a street car. The faster you make it , the more involved things get driving it on the road. Myself, i think its what makes this hobby more fun. Changing the engine , then learning and understanding how it effected the performance and how now it takes more input from the driver. But also getting to experience the increased pressure from the headrest to the back of your head makes the effort worth while.

Are you open to the idea of a solid lift cam ?? A 396 IMO needs to wind up maybe a lil more and a solid cam would help here. A big block already has screw in studs , you could get a set of comp cams roller tip rockers, roller rockers or a set of stock rockers for the high lift cams and your in a pretty decent situation for a solid lifter cam. Matching a set of valve springs will be the biggest obstacle. The gear you picked has solid lifter wrote all over it IMO. The benefits of solid lifters out weigh adjusting the valves on occasion for me.

I've looked around some cam companies for something that might do good. I think you need something on a tighter LSA to hit harder than most of them list in their online catalogs. I'd call Lunati, Cam Motion or whatever you prefer and talk to a tech. Talk to CamGrinder on here , he's pretty nice to talk to.

http://www.drcamshafts.com/

This one might be worth looking at ,, ask them if they could grind it on a 108 LSA maybe. I think the smaller big block might benefit from that.

http://www.lunatipower.com/Product.aspx?id=2137&gid=284

these used to do pretty good on 396's

http://cgi.ebay.com/ebaymotors/Nice-BBC-Chevy-Oval-Port-Edelbrock-Torker-2-O-Intake_W0QQcmdZViewItemQQcategoryZ36474QQihZ002QQitemZ120412752647QQrdZ1QQsspagenameZWDVW

then maybe one of these
http://cgi.ebay.com/ebaymotors/GM-TH350-TH400-9-5-4000-STALL-TORQUE-CONVERTER-350-400_W0QQcmdZViewItemQQ_trkparmsZQ7c301Q3a0Q7c293Q3a1Q7c294Q3a30QQ_trksidZp4634Q2ec0Q2em14Q2el1262QQhashZitem5ad0e3e76aQQitemZ390051653482QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories
 

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I had a 396 in my Camaro and it was a 10.5:1 motor with a solid lift cam and 456's with a 3500 stall converter and it was high 11's- low 12's corked up on old school street tires(Caldwell's)this was 30 years ago.

IMO your converter is your biggest problem by far. Sure you could change the cam and get a more updated grind, but you should be doing much better with what you have. And if you did change the cam and did not change the converter, you would still have a slug and for the $$$ you spent you would be very unhappy.

If the engine is out, get a $300 special from Redneck transmissions. There are better, but for the money these are great converters. I have one and so far so good(I just put it in). I have read nothing but great reviews and I have done plenty of searching, sure there are the people that think they are junk. But those people are expecting and exceeding the level of the Redneck 9.5" converter.
 

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Discussion Starter #11
I have been thinking about going to a solid lift cam, I had one in a 350 and I would check the lash about once a week at first,then every couple of weeks and never really had a problem with losing adjustment. I have a 1" spacer installed and I have roller rockers. I have a 3500 stall TCI sitting on the shelf.I use the Nova as a weekend cruiser, but I would like to go to the dragstrip every now and then; I have a trailer. My biggest worry was that the 396 might not be worth the effort. Mid to high 12's is what I would like to shoot for.
 

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Discussion Starter #13
Lunati Cam

Solid, rough idle. Excellent street/bracket racing cam with very strong mid-range and top end torque and horsepower. Needs 3000-3500 RPM stall converter, headers, 10:1 compression ratio or better and 4.10 gearing.

Advertised Duration (Int/Exh): 285/295
Duration @ .050 (Int/Exh): 252/261
Gross Valve Lift (Int/Exh): .595/.595
LSA/ICL: 110/104
Valve Lash (Int/Exh): .025/.025
RPM Range: 3000-7200
Includes: Cam Only

Part Number: 402A5LUN


I hadn't seen this cam, I had been checking out the VooDoo line. I may give this a shot.
 

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One more question, I have a tunnel ram setup for sbc, Its got two 600 Edelbrocks. I could purchase a Weiand tunnel ram for the 396. It would be cheap because I already have the carbs,linkage, and filters. Would this be a waste of energy? I have a 750 Mighty Demon on the 396, should I stay with it?
 

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Mid to low 12's with a 396 shouldn't be a problem at all. Now if you want to run a tunnel ram and a huge cam, that's fine, but your heads will then be the limiting factor. With their small valves they're just not flowing enough air for that real high rpm range. The ovals really need the 2.19/1.88 valves installed and a bowl blend. This will make a great street/strip head for anything under around 6800rpm or so. I think right now I'd try that other converter you have first before changin anything in your engine.The cam listed here with the 252/261 @ .050 is a huge cam for a 396. Remember that the rated rpm range is based of a 454, so it will be higher in your smaller engine. If it were my engine, and I had about $1500 to spend on it here's what I'd do. I'd get the headwork done with the larger valves and a GOOD 3 angle valve job by a competent shop. Next I'd run a solid flat tappet cam in the 240's @ .050 intake range. I like the Voodoo 60241. It a 241/249 @ .050 with a .590/.610 lift and a 110 lsa. Then run a Performer RPM air gap with your 750 and it should get you into the 12's. If not, add a 150shot of giggle gas and let her eat. It may break into the 11's then with a good chassis set up. Oh, and by the way, all this is with a 3500-4000 converter. Just my opinion.
 

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A few years ago, my nova had a 396 a LOT like this one, VERY CLOSE, I ran a flat hood, 4.56 gear , 9in slick, 10in converter, .550, .550 hyd cam, it ran a best of 12.02
 

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sounds like you need more low torque, change the cam, with those heads assuming they are 2.06/172 valves you need to focus on torque, looks like your combo is off and your gears are a bit deep, 3.73 would be better but 4.10 will work if you get a cam thats 216-220 @ 050 dur. and .500ish lift, 110lsa with a performer intake, set timming to 16 degrees and a 750 Q-jet or AVS, you need it to pull until 5000 rpm, use 28" tall tire. I have a mild 454 with 78' stock heads and 8.2 cr, a 216/.515 cam with 110lsa, performer, q-jet with th400 with a rv convertor and 4.10's and can jump 10 cars on most people until it runs out of steam @4900, it moves like that even with 6 people in my nova, it burned tires in all 3 gears with that setup and its a heavy 74' hatch. My previous built 70' LT-1 engine couldnt keep up with my mild 454 even with a 3000 stall, sometimes less is more if your on a buget. Keep the BBC and keep it simple!
 

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hmm

One more question, I have a tunnel ram setup for sbc, Its got two 600 Edelbrocks. I could purchase a Weiand tunnel ram for the 396. It would be cheap because I already have the carbs,linkage, and filters. Would this be a waste of energy? I have a 750 Mighty Demon on the 396, should I stay with it?

If it wuz me , i think i'd look at a single plane intake , and the 870 street avenger Holley

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY-0-81870&N=700+115&autoview=sku

its got annular boosters , vacume secondaries so get the spring kit
 

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tighter LSA

Mid to low 12's with a 396 shouldn't be a problem at all. Now if you want to run a tunnel ram and a huge cam, that's fine, but your heads will then be the limiting factor. With their small valves they're just not flowing enough air for that real high rpm range. The ovals really need the 2.19/1.88 valves installed and a bowl blend. This will make a great street/strip head for anything under around 6800rpm or so. I think right now I'd try that other converter you have first before changin anything in your engine.The cam listed here with the 252/261 @ .050 is a huge cam for a 396. Remember that the rated rpm range is based of a 454, so it will be higher in your smaller engine. If it were my engine, and I had about $1500 to spend on it here's what I'd do. I'd get the headwork done with the larger valves and a GOOD 3 angle valve job by a competent shop. Next I'd run a solid flat tappet cam in the 240's @ .050 intake range. I like the Voodoo 60241. It a 241/249 @ .050 with a .590/.610 lift and a 110 lsa. Then run a Performer RPM air gap with your 750 and it should get you into the 12's. If not, add a 150shot of giggle gas and let her eat. It may break into the 11's then with a good chassis set up. Oh, and by the way, all this is with a 3500-4000 converter. Just my opinion.
This is why i was thinking he might call them and ask them about this cam ground on a 108 instead of 110. On a 108 is should tighten up the range of the cam some , ,, i've saw some 396's go 7500 on stock internals and never did have a problem ,, JMO
 
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