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Any sbc 400 spacer bearings issues?

Posted: Mon Jan 06, 2020 12:36 pm
by DCal
I'm in a situation where the thicker bearings (400 blk and 350/350 crank) won't get me to the proper main clearances. The thick bearings can be coated .0005 per shell but its still not where I wanted to be and I haven't warmed up to coated main bearings anyway. If I use bearing spacers I can use regular 350 bearings which offer much more versatility. Years ago I built a 377 engine and I saw no issues but sold the car and never got to inspect it. I can force them to grind me another crank but I don't have the time--I don't even buy green bananas anymore! Has anyone had problems with spacers? This will be hi-perf street around 550 hp Thanks

Re: Any sbc 400 spacer bearings issues?

Posted: Mon Jan 06, 2020 12:47 pm
by novafornow
i ran them years ago and did not have any problems. No recent experience though.

Re: Any sbc 400 spacer bearings issues?

Posted: Mon Jan 06, 2020 5:54 pm
by DCal
DCal wrote: Mon Jan 06, 2020 12:36 pm I'm in a situation where the thicker bearings (400 blk and 350/350 crank) won't get me to the proper main clearances. The thick bearings can be coated .0005 per shell but its still not where I wanted to be and I haven't warmed up to coated main bearings anyway. If I use bearing spacers I can use regular 350 bearings which offer much more versatility. Years ago I built a 377 engine and I saw no issues but sold the car and never got to inspect it. I can force them to grind me another crank but I don't have the time--I don't even buy green bananas anymore! Has anyone had problems with spacers? This will be hi-perf street around 550 hp Thanks

Thanks for the reply. Apparently there is no problem with the spacers due to the amount of replies.

Re: Any sbc 400 spacer bearings issues?

Posted: Mon Jan 06, 2020 7:33 pm
by swampbuggy
DCal: I can remember a guy who ran a S.B.C. in 1/4 mile asphalt oval racing back in the 1970's. Late Model class, 1964/5 chevelle, the engine was a 400 block with a 302 (3" crank) and it had main bearing spacers. 322 C.I. screaming son of a gun, won a lot of races, must of had Carrillo rods in it LOL. But no issues with the main bearings and or spacers. With good machining you should be fine. Mark H.

Re: Any sbc 400 spacer bearings issues?

Posted: Mon Jan 06, 2020 7:37 pm
by prairiehotrodder
i ran them in a 377 for 4 years of torture in a street / strip 65 chevy truck. Finally the block cracked but the spacers never failed.

Re: Any sbc 400 spacer bearings issues?

Posted: Mon Jan 06, 2020 9:04 pm
by houser45
What size are the main housing bores? More than likely they are too large and the block needs align honed

Re: Any sbc 400 spacer bearings issues?

Posted: Mon Jan 06, 2020 9:57 pm
by DCal
houser45 wrote: Mon Jan 06, 2020 9:04 pm What size are the main housing bores? More than likely they are too large and the block needs align honed
I don't have them here but they were in tolerance and so was the line bore, the crank is undersize on the mains but fine on the rods. The block work is being done by a Nascar engine builder friend of mine so I'm confident we'll get it right without coating the bearings.

Re: Any sbc 400 spacer bearings issues?

Posted: Mon Jan 06, 2020 10:07 pm
by GARY C
prairiehotrodder wrote: Mon Jan 06, 2020 7:37 pm i ran them in a 377 for 4 years of torture in a street / strip 65 chevy truck. Finally the block cracked but the spacers never failed.
Same hear on a .040 over 13.1 nitrous engine, I think we had 6 years on it before we broke the front main web out of the block, the only thing usable from the short block was the cam, pistons and the spacers and they got reused.

Re: Any sbc 400 spacer bearings issues?

Posted: Tue Jan 07, 2020 6:33 am
by leahymtsps
Morning Dave,
I've installed at least a dozen sets in circle track engines years ago and don't
remember any of them having any issues with the spacers. OTOH can't say the same
about the life of the blocks.

Tom

Re: Any sbc 400 spacer bearings issues?

Posted: Tue Jan 07, 2020 7:03 am
by gmrocket
DCal wrote: Mon Jan 06, 2020 12:36 pm I'm in a situation where the thicker bearings (400 blk and 350/350 crank) won't get me to the proper main clearances. The thick bearings can be coated .0005 per shell but its still not where I wanted to be and I haven't warmed up to coated main bearings anyway. If I use bearing spacers I can use regular 350 bearings which offer much more versatility. Years ago I built a 377 engine and I saw no issues but sold the car and never got to inspect it. I can force them to grind me another crank but I don't have the time--I don't even buy green bananas anymore! Has anyone had problems with spacers? This will be hi-perf street around 550 hp Thanks
Coatings vary quite a bit...Calico is what you mentioned, others can add 3 times that if you want.