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"....bearings were assembled too tight (maybe undersize?)"
Would that be a factor some 60,000-ish miles later?
Not unless it had partially seized more than once.
"One one side the wrist pin retaining clip looked like it had been hammered outward a little bit. The circlip was slightly bowed outward. The other side was absolutely unremarkable, as were the other pistons."
Sounds like a side bend in the rod. You could clamp it down on a surface
plate and run an indicator up and down on a wrist pin or maybe just hold
a square up beside it and see if the edge is parallel or at a slight angle
to the pin.
"How is that measured - from the top of the wrist pin hole to the top of the piston? I measured one of mine last night and got 1.35 inches (+- - I can't recall precisely now). I assume if they are close I could get the block decked to match."
The normal machine shop way would be to measure to the top of the wrist pin
with a depth mike and then add the radius of the wrist pin to get the hole
center position. However not all pistons have the hole straight in the middle,
which adds a little confusion. That is the principal reason why the "front" of the piston is marked. Back in 1967 the best deal I could get on B16 pistons
was about $16 each but I found some Rambler pistons for the same bore at 4.70.
They were about 0.070" higher. I milled it off the top of the pistons where
they would have impacted the flat surface of the head. Lasted about 40K miles with good performance and one day with 2 kids in the car going around loop 410
in San Antonio the car filled with smoke. Opened the windows and there was still lots of smoke. Limped home and found that #2 had about a 1/4" hole
melted in one piston and one or two cracks in all the rest. BTW the Rambler
pistons were already about an ounce lighter than the Volvo pistons. So I
learned that milling the top of a piston is not a good deal. If it is a LITTLE
lower, decking the block would be OK. That pretty much constrains you to those
pistons from now on, though. (Most people don't build up an engine planning for
the next buildup, though.)
--
George Downs, Bartlesville, Oklahoma, Central US
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