250Hp 3400

[3.1cutlass]

Would this be possible N/A? I am not very familiar with the 3400 but i am thinking up a new project and want to use the 3400. What kinds of modifications do the 3400 respond to best for me to achieve that number?

[silvergtjrad]

Sure, its possible. A ported 3500 top end, along with a cam, and raised compression will get you close, if not all the way there. Headers and all of the bolt on goodies will probably be necessary as well. Gimme about 6 weeks and I can let you know

[ForcedFirebird]

I'm hoping for 250whp and that's a 3.4 with a 3500 top end and 11.5:1 compression.


I recently sold a 3500 block to a Midget racer who got 340hp out of a 3400.

[3.1cutlass]

Just from doing some reading around the site with 3500 top end and 3.4DOHC pistons i would be looking at around 12:4:1 compression?

[SappySE107]

That was with a .040 overbore. You would have close to that though with other bore sizes on a 3400. Camaro pistons would be in the 11.5:1 range.

[3.1cutlass]

Ok cool thanks.

[rsisbetter]

iron head 3.4 pistons, in a 3400, w/3500 top end will yield 11.5:1 cr?

[Alxsmt]

my goal is 250whp, not sure if im gonna make it but i hope i get close

i think 250 is a magic number lol

[sprucegagt]

That was with a .040 overbore. You would have close to that though with other bore sizes on a 3400. Camaro pistons would be in the 11.5:1 range.

I keep wondering if the cylinder pressures from this setup would be too high for pump gas. Has anybody measured there static compression with this setup?

[SappySE107]

Its been ran on pump gas so I know it isn't too much. Just need to tune

[johnnymossville]

3400 with 3.4 iron head pistons, p&p 3500 heads and LIM/UIM, 65mm TB, 210/215 dur-531/531 lift WOT-TECH cam and I'm looking for 250 whp running on 93 octane Shell gasoline. Although I can get 100 octane Turbo Blue if it is needed to get bigger numbers. The new Cadillac v6 is running 11.3:1 on 89 octane accorging to Road and Track mag.

[mfuller]

The new Cadillac v6 is running 11.3:1 on 89 octane accorging to Road and Track mag.

Bear in mind that you are referring to the DI (direct-injection) motor, which injects the fuel at much higer pressues directly into the combustion chamber (instead of the intake port).
Direct injection is one of the key things that allows higher static compression on less octane.

[ForcedFirebird]

11.5:1 is not that high for AL heads. A freind of mine has an El Camino with a 327 TPI/DFI running 10.5:1 on 87 octane, and has been since 1990.

[mfuller]

11.5:1 is not that high for AL heads. A freind of mine has an El Camino with a 327 TPI/DFI running 10.5:1 on 87 octane, and has been since 1990.

It must be tuned well. Impressive.

[geoffinbc]

Not necessarily. Cam choice has an enormously huge impact on cylinder pressure. The more overlap you have the less cylinder pressure you will build.