Hey Guys,

I've been working on putting together the bottom end on this 350 I'm building...a while ago, I reringed the pistons and cleaned a whole bunch of things up.

I started putting in the main bearings, and all of them line up fine with exception of the rear main bearing. I don't like the way it lines up with the oil passage. I'd say around 1/6th of it is covered by the bearing. The book I have says that bearing is a really tight fit... I'm not sure wheter I need to go gorilla style on it and shove it down towards the cam (the engine is flipped on a stand) or what. I've been thinking about this for a while, so if anyone who has built a bottom end before has a suggestion I'd love to hear it. I'm going to try to fix this problem and put the crankshaft in tomorrow.

Thanks,
Will

 

Another thought that occured to me was to take the bearing to a machine shop and have the oil hole enlarged...

 

FE Fords (390, 428) can be much worse than 1/6. Try 1/2 covered. When I build an FE, I use a carbide bit to put in a small chamfer on the block in the direction of the opening in the bearing so oil flow is unobstructed.

But in all the sbc's I've done, I can't remember having had the problem of misaligned oil holes. Does the tang on the bearing seat correctly in the block? I don't understand what you mean when you ask if you should shove it toward the cam. Could you clarify?

Definitely do not gorilla. The bearing can be a tight snap fit, but it shouldn't require a huge amount of force to seat it.

My method: first I take a fine tooth file and lightly chamfer the sharp edge of the block where the bearing end goes opposite the side with the tang. Then I clean the bearings with carb cleaner and place the end with the tang in the block. Then I push the opposite end a little to slightly compress the bearing and slide it down. This is why you chamfer that edge, so it doesn't shave metal off that might end up under bearing. Same idea for popping them in the cap.

I install them dry, then after all clearances check good, I pop off the crank and put a light coat of moly lube on the bearing surfaces for startup protection.

 

Don't you just love Moly lube An engine builders best friend