Ls1-ls6 pistons in a 3900's

[trash boat]

So I put one in and found out...compression height is beautiful, probably gonna need to be fly cut but a word to the wise (because I made this mistake) ls1-ls6 are only floating wrist pins 04-05. So I'm gonna continue the rest of my measuring with this piston but I will need to order the 04-05 pistons, who know our 3900's had floating pins? Clearly not me

[trash boat]

Picture at tdc

[Guest]

Yep floating pins

I put ls1 Pistons in my 3900. Dont use factory ones. Compression ratio is gonna be stupid high.

Mine have a 21.8cc dish. Comp checks in around 10.5:1 I think. Ill have to look the numbers up.

Also the rods need mqchine work for my setup. Stock bushing on the small end is like .943 and the ls1 piston is .945

[Guest]

Oh yea my Pistons were off the shelf je forged

[trash boat]

Shooting for 11.5...still need to be fly cut

[trash boat]

Yep floating pins

I put ls1 Pistons in my 3900. Dont use factory ones. Compression ratio is gonna be stupid high.

Mine have a 21.8cc dish. Comp checks in around 10.5:1 I think. Ill have to look the numbers up.

Also the rods need mqchine work for my setup. Stock bushing on the small end is like .943 and the ls1 piston is .945

Did some math, I'm getting 13.4-1...lol. 1800lbs car, good gear and 94 at the pump. I think I might just go with a water/meth kit and run the little sweet heart. What do you think? 400 HP with my custom grind? Gotta have a little fun sometimes

[Guest]

[trash boat]

[sharkey]

imo it depends on what your doing with the car. if its gonna spend much time on the street its gonna be a pain to have that much compression with pump gas and water/meth. e85 is a good option if you can get it.

with enough air flow and cam i dont think 400hp would be too far out of the question. i havent really looked at the 3.5 and 3.9 intake manifolds but im sure that would be your limiting factor. im going to be building a 2.8/3400 hybrid using flat tops, im looking at around 14:1 and my goal is 350+ hp, however im going to be building an itb intake that will use very little of the factory lower intake manifold. ill be running race gas though.

[trash boat]

imo it depends on what your doing with the car. if its gonna spend much time on the street its gonna be a pain to have that much compression with pump gas and water/meth. e85 is a good option if you can get it.

with enough air flow and cam i dont think 400hp would be too far out of the question. i havent really looked at the 3.5 and 3.9 intake manifolds but im sure that would be your limiting factor. im going to be building a 2.8/3400 hybrid using flat tops, im looking at around 14:1 and my goal is 350+ hp, however im going to be building an itb intake that will use very little of the factory lower intake manifold. ill be running race gas though.

The vvt3500 intake is a nice piece, I got one...I'm not overly worried about making "400". I've always been interested in making a high compression motor run on the pump. There's a ton of tricks and what
better motor to play with, then one I can cheaply replace when it melts down. Zx6r has 13.3-1, people say 10.5 because there's so many things that can lead to detonation.