3.4 heads

[Marks95GAGT]

Can 3.4 heads bolt on to a 3.1 block? Also if so, what is the differences in the heads and what do I need to do to make it work? Mark:???:

[HondaCivicsSuck]

no the heads will not work..... why dont you just port the ones on there

[Marks95GAGT]

Porting is fine. I was don't what the differences are in the heads. If the 3.4's have slightly larger valves, then I wouldn't have to consider enlarging them any. I wasn't sure, but you know it never hurts to ask.

Porting is an option that I have considered, but sometimes you can find better parts from other engines, like the intakes for 3.4's. I just thought that if the intake and exhaust ports match up, then the heads might be a direct bolt. I will have to look into it further. Thanks.

[CDR Speed]

Hey guys, i don't know about your cars, but i have put more than a few 3400 SFI top ends (intake, heads, exhaust manifolds, and throttle body) on standard issue 3100 SFI motors with very little in the way of problems, but those were ALL beretta's and a corsica. You guys DO have the 60° motors in those buggers, right ? (Cuz the 3400 heads are about 50,000,000,000,000x better than the 3100 heads) If so, then get the intake, heads, and exhaust manifolds and they will pop right in, no wiring change, no computer change, and not a big enough hp jump to warrant bigger injectors and a recalibrated MAF or a heavily retuned ECU, so long as you have an MAF computer system. On the speed density cars, since they monitor manifold vacuum (very dumb, but they can't all be perfect), swapping in these heads, intake, and throttle body would do nothing more than increase airflow, and since this type of computer system doesnt monitor air flow, then you would need the computer retuned for more agressive fuel and timing maps in order to realize any substantial gains. If you guys live near milwaukee, WI, let me know if you're interested in this swap and i would be glad to quote you a very reasonable price to do the hole thing. I know some shops that have done AMAZING port and polish jobs, some better than my own work, but have gotten very meager gains, if any, due to the computers not being able to accomodate all this newfound airflow with more fuel and timing. Just tryin to give you guys the same edumacation i have. Thanks for the soap box, Dave. Attached is a picture of a DSM head i sent out not too far back.

[MJE95GAGT]

Hey Dave, its Mattao27. Glad to see you found the board :thumbup2: Im sure your help will be greatly appreciated

[CDR Speed]

Hey Mattao, thanks for the warm welcome and i hope i can help everyone on here in some way or another. Thanks, Dave

[Jason Lesbirel]

I was having a hard time with the statement that they wouldn't fit, mainly because the block is essentially unchanged from the 3100 - indeed, the 3400 is simply bored out slightly over the 3100 engine. And the 3400 heads supposedly had improved ports, although the 2000+ 3100s also received head mods and improved Intake Manifolds.

[Marks95GAGT]

I thought they would, but wasn't sure. I thought maybe they were like the Ford 302 and 351 clevland engines. The clevland heads are kick butt on the 302 block, but you have to make changes for the cooling system.

One thing though. I thought a 3.4 was a stroked 3.1. Not a difference in bore, just a difference in stroke. GM sells on it's performance web site a stroker kit for the 3.1. They say it is the 3.4 crank. Just wondering.

I am glad to hear that there are no real problems with the swap. I plan to have an aftermarket computer for some day. There are some pretty good systems out there that you can connect to and modify the programming in with a laptop. Thanks for the information. I already started my search for the new block that I hope to have in the next week.....

Oh goodie, I am going to be F A S T ER!!!!

Mark