Can you use the 3.8 crank in a 3.5 with the standard 3.5 pistons? Is there any gain from doing this if it does work?

Can you use the 3.8 crank in a 3.5 with the standard 3.5 pistons? Is there any gain from doing this if it does work?

Pretty sure the 3.8 has a longer stroke... I don't think it work.

Pretty sure the 3.8 has a longer stroke... I don't think it work.
I think that's the whole point - use the longer stroke to increase engine capacity.

You'd probably need shorter rods (e.g. from the 6g75) to go with the longer stroke, otherwise the pistons might hit the heads and, if not, you'd end up with a 12.1:1 compression ratio (if I've done the calcs correctly)... As for the benefits, barely a 5% increase in engine capacity (3668cc vs 3497cc), which is about how much more power/torque you could expect - not counting whatever effect a change in compression ratio resulting from the overall changes might do. If the combustion chamber capacity remains the same, the compression ratio would go up 5% too, from 9.0:1 to 9.44:1, which might be worth another 2% more power/torque.

3.8 uses the same rods as the 3.5, I believe the pistons would need to be custom...

Either custom pistons or shorter rods should do.

you could always compensate with head gasket to get compression ratio into acceptable factor. (to a degree ofcourse)

But using a thicker head gasket changes the valve timing too - plus you'd need one that's 2mm+thicker than stock, just to compensate for the increased stroke.

All I'm hearing is dollar signs for questionable gain. What's your theory? Stroked 3.5 + what?

Don't get me wrong, I'm behind you all the way, mods like this interest me. If my budget wasn't so tight is be doing crazy staff to.