Hope you can help

[James Rogers]

James, with the snap ring still in place, how do you explain all that damage on that end of the piston?
Did a broken end of the other snap ring travel through the hollow wrist pin and get jammed in that end?

Ya know Tom, I really don't know. I was puzzled by that very thing when I took the engine apart and the keepers were still in their holes.The one in the first picture was just like that and showed wear on the part that stuck out. The one in the second picture was worn like it had been sliding up and down the cylinder wall but had tension and was still in the groove. I don't think the pin ever touched the cylinder wall just the clips. I also had an engine come in that had inserts on the mains using MG or some bearings like that and the rods had inserts in the caps with babbitt in the rods, talk about shadetree. If you work on these long enough you will see some crazy stuff.

 

[George Miller]

I've shorted the plugs at different speeds. Both have a good rpm drop. The noise seems to get louder when warm. I did think I noticed the noise getting a little erattic today when I got up around 40 but can't be sure. I've also dosed the gas with liberal amounts of MMO. #1 cylinder did have some scoring when I put it together but didn't go all the way up and I honed it down pretty well.

Could be a slight bend or twist in the rod. Which could cause the small end of the rod to be hitting the piston, from moving side to side. Did you check your rod piston ***'y on a rod checker.

 

[Tom Wesenberg]

I wonder if the damage wasn't done during installation of the new pistons and rings when an oil ring slipped out of the ring compressor before it entered the top of the cylinder?

 

[Peter J]

No George I did not. Funny thing was when we test ran it for about a minute, I wasn't making any noise. I still need to do a compression check which seems to be the only logical step. I don't know if a busted ring would show a drop though.

 

[Peter J]

Thanks Guys,
I remembered that the definition of crazy is doing the same thing over and over and expecting different results. I'm just going to pull the head and look. I would have to do it anyway (wife is thrilled). I'll pass on my findings.
Thanks,
Pete