The Stovebolt Site Forums The Shop Area Engine Shop Engine assembly

I am ready to reassemble my engine. This engine did not run when i bought it but did turn over. Compression was 148 to 151 on each cyclinder. Had two bent push rods and one broken spring. I replaced all push rods, spring and retainers. Lapped the valves and cleaned. I checked all the bearings and everything was around .002 to .0025 on a plastigauge. Bearings all look good so I do not plan on replacing them. I am not trying to be tight on cost, just see no reason to replace good bearings. Am I nuts for doing this? If I do change bearings, parts house askes if it is a early or late "55". Casting is 3836233, a "54" to "55" with powerglide. Would that be considered early?

Early 55 mains had dowel locating pins on the upper and lower bearings, late 55 had dowels on the lower and tangs on the uppers.

Mine would be early, now to decide if I should change them.

If they are in good shape, why change them out? Sounds like you are just doing a good refresh and not a true rebuild and using good used parts is part of a freshening up. Its lasted this long and I doubt you are going to run it to death, so why not use them.

Joe

You are in there and have an opportunity to tighten some clearances. Bearings are cheap. I would also break the glaze on the cylinders and put in new rings.

If it were me and that engine had shims in the main bearings, I would try and bring the clearances down to minimum, somewhere around .0015". I would also install a new rear main seal. Getting the clearances down and installing a new seal will give you many happy miles with no leaks.

Changing the upper bearing halves will be a challenge- - - -involving dropping the crankshaft down a long way to allow the bearings to roll out past the dowel pins and the new ones back in. You'll probably end up pulling the transmission and possibly removing the timing cover, or at least the harmonic balancer to allow the crank to drop far enough. Be careful to keep the timing gears from getting out of position.
Jerry

I have the engine out of the truck and completly tore down. I have replaced the rear main seal. There are shims on the caps, I will recheck the clearance and adjust with the shims. So far, I see no reason to spend another $150 or more for bearings that look like new.
Thanks

You're the wrench.

I wouldn't be spending money on bearings that are still good. Oh by the way, a new timing gear should give added reliability. The fiber ones seem to wear out eventually.

Or fail catastrophically, as in sheer the teeth. Ask me how I know...

i,d send the head to machine shop and have it done right myself....... your head will make or break your engine.
jmo
bob