Tore down my car's original engine today. Its been sitting in various barns since about 1930 while another engine has been in the car since I've had it.
I found things to be in pretty good shape but found what seems to me to be excessive front/rear movement of the crankshaft. Sorry, no feeler gages (gotta get a set) but assume I am correct. Does the 3rd main CAP handle all of the thrust load on its own or does it share that load with the babbitt in the block?
I found about .002 in the mains as they sit and they all still had at least one shim (number 1 had 2 shims). So I am wondering if I just need to replace only the caps or have it repoured.
Steve
Originally only the rear main cap had a babbitt thrust surface. Some engine rebuilders added thrust surface to the block too. If properly done the crankshaft end play would have been .004 when new. As it wears (remember the clutch spring) the magneto gap increases with obvious results depending upon how much wear there is.
I'll leave the main clearance question to others.
Ron the Coilman
Steve, the 3rd main handles all the thrust load and there is no thrust surface on the block. If everything else is in good shape, you can just fit a rebabbited 3rd main cap. I just did this on an engine for a local guy. We put in a new mag, recharged the magnets, honed the cylinders and installed new rings. The valves were replaced at some time prior so left them alone.
Thank you gentlemen. I will get a couple of folks to look at the mains in the block. Perhaps I can avoid the expense of a re pour.
Steve
Crankshaft end play can be repaired with this procedure. Crankshaft Endplay Repair
Ron the Coilman
Thanks Ron.
Sounds to me like I just need to send in my caps for newly poured caps. I have that in my budget already. Unless of course the new caps one gets from the vendors or some of the rebuilders don't carry enough bulk to ensure resolution of this issue.
Steve