rbahr

Hi All,

I am interested in knowing the wear limits and clearance numbers for piston to cylinder wall, for 3.6l & 3.8l, cup and street. Been looking in the documentation and have been unable to find these numbers.

Thanks

Ray

powdrhound

Not sure if it helps Ray, but I looked at a set of Mahle Motorsport pistons and liners that we are using on my engine rebuild and it shows a difference of 0.08mm between the piston O.D and liner I.D. These are not OEM but Mahle makes the OEM stuff so the clearance is likely similar.

rbahr

Thanks!

Does Porsche publish these numbers?

powdrhound

I'm not aware, but both the Mahle Motorport 3.8 and 4.0 pistons and liners I have on hand have the same 0.08mm piston/liner OD/ID difference.

rbahr

Thanks John,

What I heard today was that new Porsche has a clearance of .03mm, and 'no longer good' is .08mm