gtcali

I'm switching over parts from an old block to my new block with JE pistons.

If I have JE pistons, should there be a .5 to .75 mm (guesstimate) between the piston and the cylinder walls? I know they expand, but that much? Does anybody have a large (high res) birdseye view of aftermarket pistons in a block that I can look at? The stock pistons in the stock block don't really have a gap at all.

TurboInteg95

Well, its not really supposed to be a guesstimate. There should be about a .004-.005 of an inch piston to cylinder wall clearance.

dustin

That is 1cm up from the bottom of the piston skirts though. The top of the pistons do have more clearance, and you should be able to rattle them around somewhat in the cylinder.

Dustin

gtcali

Everything is put together. The guesstimate is me eyeballing the block with the JE in, and comparing it to the block witht he stock pistons.

A friend had the bottom end sent out to be bored .020, and he put the bottom end together for me. When I started swapping parts over from another block I noticed a big difference in the gaps between the stock and the JEs. I just want to make sure the block didn't get bored out too much.

from Dustin's post I guess it sounds about right?

tegman2

I was kinda wondering about this too. I got some JE 84mm 10:1 flat tops from gsr lude and when I measure them with calipers theyre only like 83mm. I was thinking that they were 83mm to compensate for their expansion after they get hot. Is this right?

Thanks,
Aron

tegman2

^^^