piston rings question

[Brubaker]

Unmarked with regards to the bore. Is the part number(M1025) significant? Could it translate to .125? Thank you in-advance for the help.

 

[Ron/IA]

Brubaker - I am just guessing here, but my interpretation is .025" over.

However, take a ring and close it to the gap it should be, and then measure the diameter. That figure should tell you what the cylinder bore diameter would be.

Others may have a better way of doing that.

 

[Brubaker]

Thanks Ron. I guess I thought the bores were in even increments. Much to learn(taking it one part-at-a-time).

 

[gilitos]

See if you can put one of the compression rings in your bore and measure the end gap with a feeler gauge. If they're right for your bore, you should have about 0.004" x bore, or about 0.015" end gap.

 

[Brubaker]

This is NOT a 'what is it worth', but more of a 'is there value?' question. When I get to my engine, I have someone lined up for the rebuild job. So, I have a set of rings that need to find a better home. When the engines are professionally rebuilt, are there specific piston rings that most folks buy(new)? More directly, do older rings have value(manufacturer unknown)?

 

[Jim Brierley]

.025" oversize would be an odd number. Pistons generally come in +.020, .030, .040, .060, .080 and .125". Granted you will occasionally see other sizes but not commonly. I would think M 1025 is a part number???