The Stovebolt Site Forums The Shop Area Engine Shop 235 basic inspection

Had a first time experience with plastigage checking out the clearances on this 58 235. All of the connecting rods measured from 0.0015-0.003 with most at 0.002. Started with the third main and it checked out at 0.003. For the second main bearing, I had to switch to the red plastigage as it measured out 0.005...bummer. Can I get away with replacing that one bearing with one that is 0.002 oversize?

If your crank journal is worn perfectly round, without scoring, and you replace the old bearing with a 0.002 undersize (not oversize), you will end up with 0.003 oil clearance. I believe that is at the outer limit of tolerance.
I haven't ever seen a 0.003 undersize bearing. They are usually 0.010, 0.020, 0.030 and are used for reground crank shafts.
I hope, for your sake, that I am mistaken.
HRL is likely standing on the sidelines for someone like myself to step in it with both feet, so that he can swoop in to the rescue, ridicule me in public for my ignorance, (which I welcome BTW. No lessons are better learned than those which involve pain or embarrassment.)
Carl

Thanks Carl. I have seen bearings that were 0.001 and 0.002 oversize, and I presume they were manufactured to do exactly what I am trying to accomplish. I don't have the tools to accurately measure taper other than the plastigage. When I gauged the journal, there was little difference in the measurement from one side to the other, and scoring could barely be felt with my fingernail.

Just playing in the grease and oil.

Paul

I find it hard to believe that one main journal is worn that much, and different from the rest. Also, I wouldn't put a rod back together with .003". That would be right at the limit.

I hear you Paul. I always try to do what I can to get every mile out of my old engines. I recently forked over $2,300 to have a 235 thoroughly rebuilt. I would rather not have to do that again if I can help it. Do some research on checking for out-of-round. I think you will find it to be not too difficult, and you can add that task to your bragging list.
Carl

i would not suggest it nowadays.. but in the 60's during my used car lot days it was a common practice to file a rod cap some to clear up a rod knock.. but that was just a quick fix which was a toss up on how long it would last

Long enough for the check to clear so you can buy some new huge bell bottom wildly colored corduroy pants, a shirt with a giant collar, and a tacky sport suit jacket with the fake leather elbow pads. How big was your hair?
Carl