Main Bearing Issue

GRX · 04-13-2003, 07:10 PM

I've rebuilt a few motors in my time ranging from VWs to Datsuns to of course Chevys, but have never had a problem with main bearing fit. I am trying to install Clevite 77 main bearings and they seem to pop out about .0025". They fit good in my old 2 bolt main L98 block. Can anyone offer insight? Is this permissable? Should I remove the excess bearing material?? ...or just install as-is??? :confused:

[Modified by GRX, 3:14 PM 4/13/2003]

danno85 · 04-13-2003, 09:44 PM

That's not a problem, and it's not unusual. The parting line between the
block and main cap may be slightly off center. There's no requirement
that the point at which the cap and block (or cap and rod) meet be exactly
at the center. That why the bearing shell tabs or locks are both on the
same "side". The part of the beariing that sticks out on the other
side will wind up in the cap (or block). You don't want to gring that off or
you won't wind up with the correct bearing crush. Just make sure your oil
clearance is right and put it together.

Dan

GRX · 04-13-2003, 10:46 PM

Thanks Danno85, I've never run into this type of thing. Has this happened to you?? :)

danno85 · 04-13-2003, 11:12 PM

Quote:

Thanks Danno85, I've never run into this type of thing. Has this happened to you?? :)

Yes. In a past career I spent 10 years working in automotive machine shops
and rebuilding engines.

Good luck and have fun with it,
Dan :cheers:

427Hotrod · 04-14-2003, 08:04 PM

As mentioned...you WANT it to be like that. Without it you won't have the proper bearing crush and the bearing will spin. That is what holds the bearing in place.

Has the block been line bored or honed? That is about the only time it could get messed up.

JIM

GRX · 04-14-2003, 08:45 PM

Well, its brand new...and the machine shop just bored it to 4.000 and honed it.

SWCDuke · 04-14-2003, 10:15 PM

It's called "bearing crush". The shells are slightly oversized so that when you tighten the main and rod caps the shell is "crushed" slightly to lock it to the bore. Somewhere I've seen specs for bearing crush and they are about the same as bearing clearance so the amount you measured is probably okay.

Duke