As for compression: if hes using the PRC 6.0 heads(72cc) then its going to end up around 9.75:1 with .040 thick gaskets and -15cc pistons.

-Lurius

 

blown3qtr ,, thats good set up,, about the cylinder heads i'm going to use Stage 3 CNC ported cylinder heads 72cc Chamber.

Thank you for your support





TurboBerserker ,,, i want to make around 650-750rwhp ,, but for know i don't know how much power the 408 will make before adding FI?


Thank you very much

 

Lurius ,,, you are right , and thats good for adding FI

Thank you for your support

 

Running a 408 that is set up for NA will make much more baseline power than a 408 that is set up for high boost -- 11:1 compression for NA and 8.7:1 for high boost.

To make 750 rwhp, I'd run a 9:1 forged 408 with a turbo, FMIC and meth capable of 15 psi.

 

Mine are TSP PRC stage 3 6.0L heads casting #317. I had my engine builder check the flow and combustion chambers. the chambers turned out to be 69cc. He says the 317 castings he's seen lately have been about 70cc out of the box. That is smaller than what is advertised w/ the 317 castings. Maybe someone around here has more input on that. Mine were a used casting and they look like they have been decked, but TSP did not include any of that info w/ the heads. I was originally shooting for about a 9.5:1 compression ratio to run moderate boost. Now I'm not sure what I'm gonna do. I think I'll build it and see how much boost it can take w/ in reason.

 

blown3qtr ,,, with 9.5:1 compression ratio you can go with up to 15-20psi , i have seen some people in my counrty using Toyota Land Crusier 4.5L 24valve I-6 engine stroker and Nissan Patrol with 4.8L V6 stroker kit with Y2K Turbo + 800 MOTEC and they runs easy 15-20psi and some people runs 2,4 bar of boost making 650-750rwhp. The compression close to yours or higher in a smaller engines.

 

What are they doing for detonation control? Are they using meth or alcohol injection. They can't have the engines spinning that hard and be using it as a daily driver set up with that much boost?! I know the engines can take it but that seems outside of practical use limitations.

 

yurs78 ,,,, i'm not sure which injection they are using. You are right its too much boost in small engines. also its not for a daily driver, but i gave this example because the 408 stroker with 9.5:1 compression ratio can reach this power without problem.

 

You'd better look at how many head bolts per cylinder they have as well...


That's alot of cylinder pressure........

 

It is not too high boost at all for 408ci. First you have to think about size of turbo. because you'll get more boost on cold days, good 2-4psi cold day, less psi on Hot day.

if you looking to achieve 750WHP, most likely you'll need gt76.
You can go high as around 20psi if you have crisp tune.