Ring gap problems...

[fish10782]

Running a wiseco 72 mm piston and the rings that come with it are averaging a gap of 20 thousands... I got my piston to bore set at .0025 and may be a little loose for what I'm doing SO what are you setting yours at and who are you getting your rings from? got three sets and all have huge gaps

[C-LEIGH RACING]

.025,,, is that 25000th or your saying 2 1/2 piston to cylinder clearance.

0.00250 to 0.00300 is what the 72mm should be set up at.
That normally should give around a 5 to 8oooth ring end gap
If the bore is that big, 0.025, you may have to much piston to cylinder clearance & that piston wont last long till it bust.
Neil

[fish10782]

Why are the rings from factory not even close to what I need??? bought the piston and spare rings from esr...

[C-LEIGH RACING]

It probably would be best, to get that cylinder bore measured proper, just to be sure to have the proper piston the cylinder bore clearance.

Rings that come with a piston kit, are set so that they will have the proper end gap not to bind up once the engine is at operating temps.
If they have to wide of an end gap, then either the bore of the cylinder is to large or by some chance the wrong ring set was put into the piston kit.
In all my years though & as many piston kits as I have touched, never once did I have the wrong ring set for the piston, but, it could happen.
Neil

[Langbolt]

What was the Part# for the Rings ?

The Part# usually is the BORE size in inches

So for a 72mm piston the bore is 2.834"

So the Ring set is Part#2834

:devil:

[fish10782]

I sent the piston with the jug to get re Nik. had some problems with the place I was using. there nik was poor. OR it doesn't like they cryo process which fallows it. so the piston is set at the right gap. I had the decimal in the wrong spot Neil. the rings that came with the piston measured out at .022 I had esr send two more sets for that piston. one set is the same and the other is at .018 I through them in there. The nik on my cylinder looks a little chaffed right on the sides of the exhaust port. the exhaust port is huge on the psi jug so a tight rings are crucial. Im thinking eithere somthing got sucked in or the ring is not doing it's job. Next time i'll get the piston set tighter yet and order a set of rings for the 72.25mm piston and giver a go. 8.4hrs on this build nik starts to wear rough. somthing went wrong.. last time 13.4 and the nik pealed. I been using powerseal to do my coating. u s chrome made more power but theirs was the one that peeled on me. I loook for the part numbers on the bags. thanks guys I'll post the numbers yet today.

[fish10782]

They sent me ring part # 2835CD says on then 72 mm rings

[C-LEIGH RACING]

Originally posted by fish10782
They sent me ring part # 2835CD says on then 72 mm rings

With those rings, the cylinders finished bore should measure 2.8350
Neil