Best Cyl. head for 3.2 hybrid??

[rvbilly]

Hi to all again, I would like to know in your opinions what would be the best head to use on this build,I don`t know if my engine has the Iron or Aluminum heads either,, my block is out of a 1988 S10> 2.8, want to use the Camaro 3.1 Crankshaft and 3.1 40 over pistons, I am going to get my cam reground locally with 206 intake, 212 exhaust@ .050, .440 lift on both, 109 lobe separation, 108 intake centerline, I want the compresion up at as close to 10 to 1 as possable ( may have to shave heads ) , 4.3l TBI and open the intake up to accept that TBI,so which heads would flow best on this block without porting work? and from which year and which vehicle, thanks Bill.. Are the roller rockers a direct bolt in,. what ratio would be best ,1:52 or 1:60 with this cam, I won`t be reving much past 5500 so are they even worth it performance wise?? My truck will also have the HEDMAN longtube headers.. Bill

[ezrollin]

Your heads are iron and have the larger valves[than earlier iron heads]. The 3100/3400 alum. heads will work and flow better but require the 3100/3400 intake and ingition system . You can pocketport your iron heads,it isn't that difficult,just takes time. Don't shave the heads,use the thinnest head gaskets you can find, 10:1 is to high for iron heads. Here's a couple of s10 sites you might want to try: s series.org and s10forum.com

[rvbilly]

3.2 Hybrid

Hi thanks for the reply, from what I`ve found out I have to use the 3.1 Iron head pistons, so 2.8 block + 3.1-12cc dish pistons, + 3100 Aluminum head-26.4-28cc chamber yields a 11.36 to 1 compression ratio,,,way to high on pump gas!If I were to use that setup with the Iron heads that would only give me 8.6 to 1 compression ratio thus I would have to shave the heads at least .045 thou to give me a 9.55to 1 ratio, that would be do-able on pump gas but you say not to shave them -why? When shaving heads the intake surface of the head must also be machined in order for the intake manifold to sit properly on the shaved heads,what am I missing, is there some secret I`m missing? I searched but couldn`t find a thinner head gasket than .040 compressed thickness. Thanks Bill..

[fivepointhustla]

You can run an 11.3 motor on pump gas and 10.1 is not too high for iron heads. Don't shave the heads because you run the risk of it not sealing properly. use the aluminum heads and port them if you choose. Use the intake and the ignition system unless you can or will have the intake modified to accept the distributor.

[rvbilly]

3.2 hybrid

Hi again, If I were to use the aluminum heads, what year and from what vehicle should I search for at my local JYard? The CR calculator figures 11.37 to 1 , are ya sure that will be okay on 92 pump gas ? I am getting my cam reground with - 206 intake @ .050 212 exhaust @ .050 .440 intake .440 exhaust 109 lobe separation and 107 intake centerline, I was going to bore out my intake to accept the 4.3 TBI but am now thinking that it may run really rich on the 3.2, any sugeastions, what if I was to get the pre 85 2 barrel intake off a 2.8 and customize it to accept the Holley or Edelbrock 390 cfm 4 barrel? Do ya think that would work? thanks for all your help Bill..

[fivepointhustla]

What is your method of fuel delivery FI, TBI or carb? If you look in the 60V6 family tree link it has all the info you need on what years the aluminum heads were offered. i have searched on yahoo and all say it is possible to run 11.3 on 92-93 octane, I would run 93 to be safe. The only thing about your cam is that the powerband will be peaky. If you use the aluminum heads you will have to use the intake that it has because it is different than the iron heads. Now with the intake manifold if your s10 has a distributor than the aluminum intake will need to be modified. I won't say that you can run it at 11.3 but I am going to try it this summer and everything I have read says it is cool.

[wheeler]

i'm interested in this mod too and would like to know how easily the aluminium intake can be modified.

[torq455]

a peaky cam yes. i'd go with a 112 LSA. very worth it to use the 1.6 roller tips, more power throughout the power band and won't affect your mileage any. you will need a custom chip or your engine will run dangerously lean at WOT. Bigger TB won't make the engine run rich rather the opposite. these older engines don't have the means to compensate for more air. see the 60degreev6 store for fun parts and talk to SappySE107--it's his store.