I have been considering putting on some nos aluminum heads from an 87 on my 84 cfi motor. Other than valve covers what else needs to be changed? Would like to retain the cfi system because it runs good. I realize there would be a weight savings but what else? My heads need to be done over and the oppertunity came up on the al. heads. 1.6 rockers? cam change? headers?
TIA
Bob

 

 

http://www.crossfire.homeip.net/

That will help you out.

 

The 113 aluminum heads will raise your compression too high. The best winter crossfire mod is porting the intake. You can do it yourself. Once the intake is ported, a good exhaust and 1.6 rockers, parallel plumb the throttle bodies, tune the computer, and you'll be surprised at how much the motor wakes up. CFI-EFI has a very nice crossfire that didn't have too many mods. I'm sure he'll post here.

As for your heads, why do they need to be redone? Bad valve seals? Burned valve? I've got stock '84 heads on my 383 and they aren't that bad. A little bowl-hog work and larger exhaust valves and they flow decently well for your purposes. Couple that with the few mods listed above and in a winter you can have your car running way better than ever before.

Definitely check out the crossfire board.

 

Other than the valve covers, you will have to give up your EGR valve function and figure out how to deal with the very high compression ratio you will end up with, somewhere between 11.0:1 and 11.5:1. You will be going from a 76 cc combustion chamber to a 58 cc chamber. You can do the math. I have, but I forgot the exact number. You may be able to enshroud the valves enough to bring the compression ratio down, some.

JLeatherman is 100% correct about porting the intake manifold. Is is the one single biggest, and one of the cheapest, things you can do to improve your performance on a daily basis. The only other single contenders are N2O, not always there and moderately expensive, and supercharging, always there along with the payment book.

I can't imagine any advantage to parallel plumbing. Computer tweaking could provide some gain. My car has a stock long block. It has the stock computer and chip. It does have a fairly free flowing exhaust, but no headers (recommended), and a 2600 RPM stall converter. It has never had a head off. It has 165,000 miles and burns a quart of oil every 250 - 300 miles. It runs in the high 13s, with no more in modifications. Maybe some day I'll get serious and go for the 12s.

RACE ON!!!

 

CFI,
Parallel plumbing goes along with replacing the injectors/porting/retuning the ECM. The second TB in the system runs a different injector than the first one to receive fuel. Supposedly by running the same injector in both and parallel plumbing the fuel delivery (with an external AFPR) you gain much better fuel distribution. Never got around to doing it myself, but I believe it's not too hard.

BTW, Blackbear, I've got an '84 manifold and top plate from my car for sale for $75. If you want to buy it you can port it while you continue to drive yours. That's how most people do it, so the car isn't down too long.

 

Thanks for the advice. I knew the compression would be higher, but I didn't stop to think by how much. I will have the heads redone (bad guides) and port the intake.
Bob
Long live the 84

 

And supposedly by running different sized injectors in both and serial plumbing the fuel delivery (with the stock AFPR) you get very good fuel distribution. Why reinvent the wheel and change everything, just to get back to where you started from? That sounds, to me, like a case of change, only for the sake of change, a case of severe "tinkeritis". A great solution to a nonexistent problem.

RACE ON!!!

 

CFI,
Parallel plumbing typically isn't done on a stocker. It's done when you need higher pressure injectors and you can't get a higher pressure pair where one is different. Neither here, nor there. he won't be going that far.

Bob, not sure how emissions are where you live, but while the heads are off I'd put on headers and do a nice free-flowing exhaust. It complements a ported intake nicely. 1.6 RRs are also very nice with a ported manifold.