3.4 Iron Head Performance

[Mad Max]

I bought a '91 S10 with a nuked 2.8.
The local U Pull had a good '95 Camaro 3.4 - which I bought for $176 complete. I installed it in the S10 with these mods:
I replaced the injection with an Edelbrock intake, a Mallory dual point dizzy, a really big cam (I have to look at the specs, but it sounds like a pro stock rig with open headers I think the lift is in the high .492(?) and duration is .292 advertised), I advanced the cam 4* (true roller chain), a set of headers running through a 3 inch exhaust and cat, a set of crane 1.5 rocker rollers, ( a rocker stud broke(!) I am guessing from the cam having big lift) and a 390 CFM Holley 4 barrel. It has a 5 speed, and a 4.10 posi rear end. I still have to dial it in, it ran a best of 16.3 with NO traction in first and part of second. I have to look at the 60 ft times to see how bad it was. Reaction times were around .2 or less. I was hoping to see 14s, and even with a good off line hook, I don't think it's going to happen. It was REALLY hot at the track the day I ran, maybe cooler weather will help out alot.
This thing pulls REALLY hard about 3,000 RPM on, I'm pretty sure I get spring float after 5K cause the springs are stockers. I guess I still have some tuning to do, maybe a set of heavier valve springs and an electronically controlled iginition system, rejet the carb, dial in the iginition timing curve. I suppose I should gasket match port the heads and maybe some light bowl work.
Anybody ever set one of these up like this? I know most of the posts I've seen are with injection and the alloy heads and stuff.
Maybe I'll spray the bi*ch hard and see what it does. I wanted to run all engine into the 13s, but I don't think it's gonna happen.

[geoffinbc]

LOL sounds like you spent more time spending money then you did doing your homeowork.

Your right the springs need to go with ANY aftermarket cam. Stock ones are very weak. Valve float is very detrimental so don't let it happen. It sounds like your setup is intended to be very aggressive so porting PROPERLY and increasing airflow will help a lot. Stock compression is very low for the type of cam you are describing so when you take the engine apart it would be wise to stuff in some new pistons to get the compression into the 12's. If your going to make the engine spin it would be very wise to also go over the crank and rods and make sure they are perfect. Throwing is some ARP rod bolts and main studs will be a big help too.

Back in the days of midget racing guys were routinely squeezing 220 to 250 hp out of the old 2.8L's. But don't kid yourself they did that with a lot of experience and trial and error plus a whole mess of dyno time.

[Mad Max]

I knew the springs were weak, I was planning on changing them at some point in time. All of the mods I did were when the engine went in the truck, it was on an engine stand getting painted and ready for the install. I didn't want to go for a complete tear down. All of the parts were way discounted.
I bought all of the parts on Ebay very cheaply - Cam + lifters = $95, intake = $100, distributor = $75 etc. I had everything ready to bolt together before the engine went in. I did spend some $$ on the suspension and driveline knowing that I wasn't going to change any thing again.
I have a 3.8 Grand National Buick engine on an engine stand that is going in this S10. It has 10 to 1 pistons, cutom rods, Fluidampr, balanced, custom ported heads, intake, 455 CFM Holley, MSD ignition, coated headers, big cam similar to the 3.4, 4* advance on the cam, performance valve springs, retainers and keepers. I am not running the turbo, I want to see if this will go into the 12s all engine. It is also set up for a 5 speed. I also have a complete spray set up adjustable to 250 HP.
When I pull the 3.4 out, I will go through it and do everything - balance, ARP, rods, pistons, head port work, springs, etc. I will probably end up installing it in an Isuzu Gemini coupe (Buick Opel in this country) that I have sitting in my barn.

[geoffinbc]

Uh oh a Buick man. LOL

Well if your still interested in finishing the 3.4L then at bare minimum just fix up the springs and if you feel like it gasket match the heads. But that will require removing the heads and valves.

When its all said and done and using stock heads I think the 3.4L will lay down better numbers than the 3.8L plus its lighter. But you never know.

[Mad Max]

I'm going to go the rest of the way. I typed a large resonse and the FU**ing thing kicked me off and lost it

[Mad Max]

DAMN IT. I hate computers sometimes.
I'm going to finish the 3.4. Money isn't really a big issue, I just didn't want to blow the whole engine apart and spend the time at that point.
I built the Buick because I bought it at a good price, and the parts were at a good price too. I have a feeling it will go pretty well.
I am going to finish the 3.4 with pistons, balancing, and detail to the reciprocating parts - including ARP and hopefully some nice pistons. I don't know of anyone who makes compression pistons for a 3.4 with iron heads. I want to run a primitive carb / distributor setup for ease of installation because I'm not at home. I just don't think that there is alot of streetable fast power out of one of these units - like a 12 second street engine. I like these engines, they are small and have plenty of possibilities.
Anyway, I'll post more pics and time slips as they come up.
BTW, I have done my homework and do know a little of what it takes to make stuff go. I'm just not necessarily running in the right chronological order for everything to fall into place... I will make it all happen it with the right time warp factor. Yo.
I still have spray...
BTW, I DO have a complete supercharger set up for an Edelbrock lower manifold unit. I'll post pics if anyone is interested. Its a custom built unit set up for a Holley square bore carb. Pretty trick.
I hope I die before I get old.

[geoffinbc]

Well GM did make 12:1 pistons for the 2.8L but I don't think you can get them anymore. Flat top DOHC pistons will bump up compression some but they are not forged. Custom forged may be the way you need to go.

[Pretty Boy]

i wish i could of used mine. I sold the block be4 getting to put it together. but still have all the pieces just need the short blcok and than i think it would be alot of fun.






yep P&P heads with new locks and springs and the 272H crane cam with new lifters never even got to put it together if i could find a cheap 3.4 short block again i would build it with prob a set of 10-13:1.1 prob go carb cause they say its easy to work with