Reply To: Need Help with an Oilhead ring replacement

[Roger A PivonkaKeymaster]

Hi Guy,

When I retired I took an 18 month course with Ohio Technical College (PSI division) to become a certified Motorcycle Tech…So I can tell you some basics:

1. Ring replacement is a sign of heavy wear on a motor…so what else?
2. Typically, we’d check the bottom end; Crank bearings/clearances, etc to wear limits
3. Bore diameter check within limits; diameter and concentricity; top to bottom differences.  Does cylinder need boring; resleeving?
4. If the bore is good, the cylinder must be HONED with a stone before adding rings
5. Sime Routine for Pistons; diameter and wear limits; sing slot wear and limits…
6. New rings; check end gap and installed clearances
7. Typically, I’d want to inspect valves; grind and lap as needed; Oil seals; spring function
8. New gaskets all round.

Having said all that, some people will short cut and take their chances.  I’m sure I can dig out my School books and find more exact procedures.  I have not done a motor rebuild.

Regards,

Glenn Lonsberry

506 Danbury Lane, Avon Lake, OH 44012

Phone 440 933-2657 Cell 440 787-4082

Glenn,

Thanks a lot for the prompt reply.  Your right of course, needing new rings is a heavy wear situation as reflected in the age, miles, etc.  I also appreciate the additional points of emphasis and the various implications… including some of the cost considerations that are pretty clear reading between the lines of doing all that you point out.

Yet, I am in a situation where, while not operating in a broken down on the side of the road senario, I still find myself between a rock and a hard place without all the “species specific knowledge” that I’d like to have to sort out next steps.

In example, you are right to point out (#4) cylinder preparation for fitting new rings.  I just have questions such as if that is at all changed by the Nikasil coating in some bmw motors?  If this is one of those motors? How this may change what strategies I use to do the job?

I am not in a position to do a full engine rebuild and since it is still running I am hoping to explore what is necessary, optimal and what I can get away with given some limitations.

Thank you.  I really appreciate you assistance.  Guy