Piston rings on an Allis C

[atlarge54]

I have an Allis C engine that's been torn down and on the shelf for about a decade. I don't really need it and it seems people don't really seem too interested in parts but DO seem interested in assembled engines.

Today I looked at the block and the bores look pretty decent maybe a couple thousandths ridge. I haven't really cleaned up and measured the pistons but they don't look too bad. So I remove the top ring from one of the pistons and put it in the bore just below the ridge------HOLY CRAP end gap of .125". Is this a common pattern of wear for old iron?

I was kind of thinking about putting together a short block to sell. Gasket set, cam bearings, rings---nothing fancy. I'm pretty certain from past experience I can polish and shim the old crank and rod bearings and have a nice snug bottom end. I did one a decade ago that was many many times worse than this one.

 

[Janicholson]

Find a Buyer first, then build it with new rods/mains for insurance, and the owner's bragging rites. If I were keeping it and the parts were rare, I might shim bearings. but the surface coating is probably worn some. .006 pre inch of bore on the ring gap. .003 taper, maybe .004 would work with a ridge ream and hone. Jim

 

[rustred]

yes but try that with a new ring . them old rings are worn also. try that used ring at the bottom of the bore where there is no sleeve wear
and u will see how bad the ring is worn. the spec is 3-4 thou. for every inch of bore.

 

[Dennis K (WA)]

Manual says ring end gap - .007-.017
Dennis
Personally I think low end of spec is a bit tight.

This post was edited by Dennis K (WA) on 01/18/2023 at 07:50 pm.