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| Team Apathy |
Great info, thank you! I was wondering about compression. I knew that compression would go down some but kind of figured that is somewhat offset by the extra fuel/air mixture that can get in there due to the better flowing head. Is that not how it works? I don’t know much about all this. I wondered about the intake manifold and if it is up to the task. I planned on looking into that more later. I briefly googled the GM part number but didn’t find much in the way of specs at all. I’ll have to dig more. I’m not against a bigger cam. Do you have any specific suggestions? Maybe the COMP 08-423-8 or 08-432-8? I really like the way the car sounds now but I’m open to a change. However the big loping cam sound isn’t necessarily my thing. I have zero idea what the converter spec is. Frankly, I wasn’t even aware of it until this thread. I had the transmission rebuilt by a local shop probably 12-13 years ago after 2nd started slipping. I seem to remember having them install some sort of shift kit but I don’t remember anything else. I’ll look into the suspension brand you mentioned. I’m not going for any specific look, I just want it to handle better and get better traction. | |||
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| Member |
I'm not the Chevy expert but I know my way around a Small Block Ford pretty well. My former employer marketed a 347 CID short deck that was rated at 450 HP and typically made 475-ish on dyno. That's a real dyno and not a happy dyno. It was 10.0:1 so it would run on pump premium. The cam was .555"/.565" I/E, 224/230 @ .050" lift and 112 lobe separation angle. The intake was an Edelbrock Victor Jr. single plane and the carb was similar in size to what you have. Your heads are down about 30 CFM on both sides compared to what we used and your compression is lower so maybe you'd be in the 425 range? Of course, that assumes the intake isn't a cork and the headers/exhaust are also up to the task. I'd look at a COMP 08-423-8 or one step further would be a COMP 08-432-8. Either one, make sure it is ground on a billet steel core and nothing else. Either one will sound good and still give you decent idle quality. The need for a gear and convertor change would become real apparent with these changes. The COMP book even says so. Replace the distributor gear with the appropriate steel gear at the same time as the cam change. DO NOT use brass or polymer. Getting the gear installed correctly can be a challenge. Best to have a competent machine shop do it on a Bridgeport and don't attempt it at home with a Black & Decker. | |||
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Go Vols! |
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| Member |
Yes, more lift. But the other specs are close. | |||
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| That rug really tied the room together.  |
Your engine comes with very good heads. The 200cc Dart heads will kill your low end torque. With your highway gears in that thing, and large heads, with a larger cam, I’d expect it to stumble and actually lose power off the line compared to what you have now. You want a torque cam in that engine with your current gears. Your friends used camshaft is right on the money in specs, but honestly it’s not worth the effort as what you have now is decent and not that different. I ran that exact cam (the used one) in a 327 El Camino and it sounded nice and ran well. If you want more power you need different gears and a higher stall converter. Used heads can be a gamble. New heads are not that expensive when you factor in rebuilding them and replacing springs. A 230/236 cam sounds freaking awesome but it will kill your low end torque, which you desperately need. I don’t know much about that GM intake but I know for certain that an Edelbrock performer RPM air gap intake is good for a lot of power and might give 10-20 hp bump just changing that. Does your engine have roller lifters and roller rockers? You’ll probably have to factor in the lifters that you currently have before upgrading. I sure wouldn’t swap roller lifters out for a flat tappet cam design. Best bang for the buck? 3.73/4.11 gears and a new 4L60 or 700R4 overdrive transmission. ______________________________________________________ Often times a very small man can cast a very large shadow | |||
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| Thank you Very little  |
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Only the strong survive |
Unless you go to a track, there is no place that you can let it hang out. I like a manual better and changed the transmission in my 78 Corvette to a Doug Nash 5-speed. Then I changed the rear-end from a 3.36 to a 2.73. I used an Edelbrock dual plane manifold and a Holley 650 with a MSD-6 ignition. I also indexed the plugs for better gas mileage and got 26 MPG on the highway. The cam was an older Corvette cam and had been retarded so I fixed that. 41 | |||
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| Member |
This, with your current engine setup is where you should stay. The Dart heads dropping compression to 9:1 and the other cam (which has less exhaust lift than what you have) would make your car more of a dog than what it is and it would utterly stumble off the line and a good portion after with your current gearing and exhaust and you'd be losing HP. You don't need to make more power and can't from the car setup you have until you focus on what the engine is bolted to. Rearend, you don't need to go to a 4 link to hook. I used to be the master of street racing back in the day (built/ran a FFW/Fast Ford Street Renegade class car, place 3rd). You need 3.73 gears (3.55 at worst) with a good posi-traction unit, good upper and lower control arms and that's about it in the rear end and GOOD tires. THIS is necessary to even see half the potential of what you already have. If you have an automatic, you need a higher stall converter to match the cam you have or are hoping for, and a shift kit. Then you need to focus on the exhaust, good headers and a good flowing dual 2.5" exhaust. With the right car setup, you should be in the low 12's in the 1/4 mile with that engine. You're somewhere in the high 13's/ low 14's right now. | |||
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| Team Apathy |
Very interesting. So you think changing the heads and cam will not produce more power, largely due to the drop in compression? I would think that the compression drop is largely offset by the great volume of air/fuel mixture that is able to get into the chamber with the better flowing head/bigger cam. GM DID market the fastburn heads and a “hot cam” kit for the ZZ4. I suppose the chamber on those heads might have been the same size as stock? Next set of tires will be a summer performance. Any suggestions? Exhaust should be good to go. It’s got headers and a nice Flowmaster system all the way back. Very interested in the rear suspension. Traction is a big problem for sure. Do you have links on the control arms? Perhaps the leaf springs are tired as well? | |||
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| Member |
)Rearend, you don't need to go to a 4 link to hook. I used to be the master of street racing back in the day (built/ran a FFW/Fast Ford Street Renegade class car, place 3rd). You need 3.73 gears (3.55 at worst) with a good posi-traction unit, good upper and lower control arms and that's about it in the rear end and GOOD tires. THIS is necessary to even see half the potential of what you already have.( Absolutely correct that a 4-link is overkill and unnecessary. Upper and lower control arms would be kind of pointless not to mention hard to find as that era Nova has a leaf spring rear suspension. Leaf springs don't use control arms. Search Detroit Speed or Calvert Racing for upgrade parts that will fit and work as intended. | |||
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Member |
A 4 link might be overkill but if you're running 350+HP you'll want to control that back-end or you 'll have such bad wheel-hop! You'll want to add traction control bars if you're sticking with the leaf-spring set up. Hedley Lamarr: Wait, wait, wait. I'm unarmed. Bart: Alright, we'll settle this like men, with our fists. Hedley Lamarr: Sorry, I just remembered . . . I am armed. | |||
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| Member |
Going from 10:1 compression to 9:1 compression naturally aspirated, would lose 10-20% horsepower (all else being equal). How many miles a year do you plan on driving it? Drag radials would provide the utmost in traction. Michelins hook pretty darn well on the street. Given your setup, the ZZ4 is a pretty well thought out motor out of the box. I'd put 3.73 gears first and get the car to hook. That's your very first and most necessary step to make the car fast. Then if that's not enough, throw a 100 hp nitrous kit on it, cheapest bang for the buck (just make sure to retard the timing enough and use 93 octane fuel or better). I don't know much about suspension components for your year Nova, but had a friend that had one, that was all motor (SBC) and ran 10.80's back in the day and on the street with 26"x10" slicks, would hook so well it would lift the front tires 3-4' off of the ground, and he didn't have a 4 link rear end. Contact Tyree at Tytech performance in Tennessee, he's been building very fast Nova race cars since the dawn of eternity, including his own, and will tell you what you should do with it suspension-wise and you can run the engine (head/cam) scenario past him also. He's a very good friend of a friend of mine and built his red 93' trans am and fields it that runs 8's in the 1/4. | |||
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Member |
Thumper...Please take this as intended. A friend and I used to run a drag car here locally. For the most part, I wrenched it and he drove (and broke  ) it. My suggestion to you is to find yourself a good, experienced, performance engine builder in your area, and work on building an ongoing relationship with them. I found a guy here in Central Florida who built motors for 30 years, and I can't tell you how much I learned from him. Our interactions also saved me a lot of headaches, hassles, and broken parts. Input on the web is entertaining to participate in, but nothing tops working one on one with someone who does this for a living.----------------------------- Guns are awesome because they shoot solid lead freedom. Every man should have several guns. And several dogs, because a man with a cat is a woman. Kurt Schlichter | |||
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| His diet consists of black coffee, and sarcasm.  |
How do you put that on a leaf spring car? | |||
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| Team Apathy |
Taken as intended. I know that I don’t know much. This thread has been great and given me lots of points to jump off of and do some reading. It started because the coworker offered the heads at a significant discount and if it was/is a wise deal I didn’t want to miss out. It seems there isn’t a clear consensus on the wisdom behind those heads so more research is called for.
The kits I’ve seen require removing all the old components and the new system completely takes its place.This message has been edited. Last edited by: thumperfbc, | |||
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| Team Apathy |
Would this be a good first step? Pretty affordable. https://www.summitracing.com/p...chevrolet/model/nova Edit: I also called a rear end shop. They quoted just under $1000 to switch out the 2.73 to 3.73, parts and labor. An additional $600 to go with a posi carrier. Does that seem about right or high?This message has been edited. Last edited by: thumperfbc, | |||
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| That rug really tied the room together. |
That price seems high to me, but Ive been out of the game for a while so it might be going rate. You used to be able to get a complete top notch aftermarket rear end with whatever gears you wanted and posi for less than that. ______________________________________________________ Often times a very small man can cast a very large shadow | |||
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| Member |
That sounds very high to me. Although I too have been out of the game a while. It used to be 2 hours (3 at worst labor) to change rear end gears. Gears run $200-300 usually...…. a posi carrier also $400 or less, going from memory. | |||
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| His diet consists of black coffee, and sarcasm. |
You don't say.  But I'll rephrase the question. The axle may already have mounting brackets for the control arms and the lower seats for coil springs, but if not, they could be U-bolted on. How do you put the brackets for the front of the control arms on the car body? This is a unit body (separate subframe/cradle for the engine and front suspension), not a full frame. Wouldn't the brackets have to be welded to the sheet metal along with some kind of reinforcement? Where do the upper ends of the coil springs fit? I'd like to see a link to this kit, as this really has me curious. | |||
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