Author Topic: How much piston clearance to run on a ESR 330? (Read 2728 times)

flynbyu · « **on:** January 15, 2016, 05:40:17 PM »

Hey Guys,

What kind if piston clearance would you all suggest on a 76.5mm Wiesco piston in a newer ESR PV 330 cylinder. I am planning on having the cylinder nikasil plated since I will be on my last bore of the cylinder. I have heard anything from .0025 (seems too tight to me) and.00525 and that seems too loose.

I would appreciated any and all input.

broken1 · « **Reply #1 on:** January 15, 2016, 06:34:20 PM »

Just found this old thread. Hopefully it's what your looking for:
http://trx250r.org/threads/3774-piston-cylinder-clearance

flynbyu · « **Reply #2 on:** January 15, 2016, 07:51:54 PM »

That thread helps. I guess I was just putting a feeler our there as to what has worked for others. I guess I am thinking.004

hickwheeler · « **Reply #3 on:** January 15, 2016, 08:19:15 PM »

Shouldn't a 330 go to a 77.5 bore

flynbyu · « **Reply #4 on:** January 15, 2016, 08:38:22 PM »

If your cases are bored yes a 330 goes to 77.5. If they are not and you are running a direct bolt on 76.5 bore is as big as you can go I am told.

hickwheeler · « **Reply #5 on:** January 15, 2016, 08:44:40 PM »

Oh ok. Ya mine have cases bored. I keep forgetting that there is a bolt on 330.