New JE Piston Clearence

[1972_911T]

Ive just purchased a set of new JE pistons for my engine rebuild and there seems to be a big clearence between the piston and cylinder so much so that the piston can actually be wobbeled side to side and you can see light through the gap. I know JE are renowned for having big clearences and piston slap when cold but should it be so excessive?



The original mahles I removed were very tight.

Steve

[cnavarro]

Unless you work with pistons and cylinders all day, it's hard to gauge clearance by feel. JE's can be cammed differently than Mahle pistons. You need to measure .500" up from the bottom of the skirt of the JE then measure your bore to come up with the actual piston to cylinder clearance. When you ordered the JE's, did you supply an actual bore size for your cylinders from which they sized the pistons?

[1972_911T]

Hi Charles

The cylinders were sent away to me measured and re-honed, the pistons were supplied by the same place at the same time not sure if they matched them though I will check with them.

Regards Steve

[mb911]

they do wobble a bit. but With rings not so much and once warmed up the forging "grows" to size and works perfectly. For a note My JE's don't slap in my QSC cylinders with .0025 clearence. and runs very strong