lost on a head choice

[vega]

I picked up a 86 camaro iroc - intake, engine harness, ecu, injectors, and sensors for 150 bucks.

 

283 block 283 forged crank, 283 forged rods pistons have not been chosen because I have not chosen the heads yet.

I need to run a 194 x 150 valve

the heads need to work with that intake

running the lunati 401A3LUN cam

http://www.lunatipower.com/Product.aspx?id=1966&gid=284

I need to be at no more than a 9:1 compression ratio

 

I know the 305 tpi heads are something like 58cc and the 350 tpi heads are 64cc (but from my understanding the 87-89 aforementioned 350 tpi heads wont work with that intake?). I have no idea what that will give my 283 for compression.

 

help would be great!

 

I need to know what my best choice for heads are so i can pick up pistons.

[rsicard]

What are the goals for this engine? What is the budget for this build? What vehicle is this going into?

[Mike C]

For a little motor, the Dart SR torquer is probably the way to go. Or a set of Corvette L98 aluminum heads if you want an aluminum head.

[vega]

very small budget, but carefully bought parts cheaply. the only 80s vette tune port heads that will work are the ones from 85-86 the intake changed in 87 and is a pita to work with.

 

Basically what cc chamber am I looking for to keep the compression down to 9:1? And of the heads that are of that chamber size what is the best to go with as far as flow goes? If there are heads that can be ported that is an option for me too. I also need to keep it a 194 valve because - again its a 283.

 

As for the car this is going into, that is on the d.l. right now. As soon as it goes in the car (which should be shortly after this is figured out and parts are received) I will make a build thread of the entire car from scratch.

[vega]

some teasers;

 

http://i938.photobucket.com/albums/ad226/faytmorgan/tuneport2.jpg

 

http://i938.photobucket.com/albums/ad226/faytmorgan/tuneport1.jpg

[rsicard]

Vega:

 

As was recommended before the L98 heads would be good if you can find a good used set which is unlikely. Recommend saving your money and going to KMJ on Ebay and purchasing a new set of 190 cc intake aluminum heads complete for $650. The cylinder heads are the key to good and efficient performance. Same with the camshaft. Use good Hyper pistons, zero deck the block, use MLS head gaskets, use cylinder head STUDS!! and you will get optimum sealing. Use good (Loctite) thread sealer on the studs so there are no coolant leaks. Use ARP thread lube on the washers and nuts on the studs. Do it right the FIRST TIME. You should be able to reuse or sell the cylinder heads if needed. Use Loctite 598 sealer on the other gaskets as it seals well and removes easily. Use a good NEW oil pump from Melling and new ARP oil pump drive shaft. Good oil pressure/flow and good coolant flow are very important. Hard to emphasize this enough. Use good quality oil pan gasket, NOT CORK and adequate 598 sealer on the gasket and pan. Don't need 598 on engine block to pan gasket surfaces.

[jt1]

Wallace Racing has a calculator to help you determine your compression ratio. Use it to determine your piston cc after you make a head choice. You will have to make an assumption on your deck height.

 

http://www.wallaceracing.com/cr_test2.php

 

Mike C's choice of the L98 head is a good one, and will save some weight. The 305 tpi heads would be ok, but you're better off to spend your money on an aluminum head and up the comp ratio.

 

Not many shelf piston choices for a 283. You might have to go custom.

 

jt

[Pyro]

The cam you want is too big for a 283 and a tpi system.

 

check out compcam's website. They have tpi cams.

 

with flat tops a +0.030" 283 will make around 8.4 cr with a 64c head. 8.8:1 cr if you zero deck the block.

 

If you run a cam much bigger than stock, then the ecu will need a re-tuned.

 

check out this cam. compcam 252AH-12, 206/212 at 0.050" 112 lsa. makes power to 5000 in a 350 so add about 500 rpms for a 283.

 

world product SR heads would be OK. get the smallest port possible, since you are only using a 283 and the tpi system is a low rpm, high torque setup.

 

you would be better off using a 350 block.

Edited July 19, 2011 by Pyro

[vega]

I will be tuning the ecu with a moates ostrich.

[vega]

http://support.moates.net/2009/05/07/gm-86-95-obd1-guide-read-me/#comments

 

<- the tuning software I am using.

 

How is it that you say the TPI system is low rpm? because the intake? I am having it port matched/extruded, edelbrock runners, etc.

 

Looks like the l98 heads (which btw there are a lot of choices... no wonder why gm is bankrupt) are the best choice from a ton of reading and advice from a lot of people.

[Pyro]

hard to get a tpi to make power in the higher rpms (ported or not). yes, because of the intake.

 

L98 heads don't flow well. But either does the tpi intake so it should be a good match.

[Mike C]

The L98 aluminum heads didn't get the revised intake pattern the iron bolts head did if I recall correctly. They weren't the greatest flowing head as mentioned, but they are more than adequate for the TPI with stock runners. Some bowl work on the heads along with a port matching of the intake and exhaust should work pretty well. If your TPI is from a 305, get 350 throttle body and injectors. I think the Comp 260 cam would be a fair choice. (210 @ .050). My buddies '74 'vette convertible has a TPI 305 in it he swapped in back in '88. It has a Summit flat tappet cam, headers, and an Edelbrock intake base. Still has the iron heads. With 3.07 gears and the TH700 in ran 13.97 in Houston. That's at 3600# plus driver...