MTFCA Forum

I have my 1926 TuDor engine out for a generally inspection. It has about 20K miles on it since the last major rebuild. Here are a couple pictures of the pistons. They are 1 to 4 left to right. You can see that the wear pattern is generally down the center of the pistons. #1 is well cenetered, but #2,3,4 on the split side show wear more on the left of center side. Then on the non split side, only #3 show off center wear. Could this wear be the result of slightly bent rods?

Next the piston pins show some slight sticking as the rod end moves back and forth. I was considering removing the pins and polishing them so that they move freely.

Then one last question. How would I know whether or not to replace the piston rings. They do not look bad, are free in the slots. The last compression check I made on the engine earlier this year showed even 55# per cylinder.
Thanks Mike

Now that you have removed the pistons I believe you really have no option but to replace the rings as there is no chance of you getting them back EXACTLY as they were. As such they will leak compression and oil past.
Yes I think polishing the wrist pins at this time is a good idea

Les. since my engine has 20K miles on it since the pistons and rings were new, I had a pretty good idea I should replace the rings. But..... you mentioned that since the pistons are out, the rings should be replaced, because the rings would not be exactly in the same place. I was under the impression that the rings move and the only requirement is to make sure the ring gaps are not lined up.
Also, a friend is bringing over a bore gauge. We will measure the bore. Then as far as the rings go, should I just purchase 0.030" over to match the pistons? I seem to recall reading that there are other oversizes to pick from. For example 1 or 2 thou over the oversize. When would you use those? What are all the items to consider when changing rings? Thanks Mike

Mike,
i think it is smart to measure the piston clearance, the pistons looks a little bit tight in the bore.
if you replace the rings always re hone the bores to make sure you got a good seal with the new rings.
Succes Anthony

Based on the pictures, #2 and #3 rods are bent- look at the wear pattern on the skirts.

I agree with Dan