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Author Topic:   spun mains?
Dirt Forum Racer

Total posts: 88
posted September 18, 2001 08:29 PM
What would cause a 350 chevy to spin main bearings?This is a street motor(short block) I might be able to pick up cheap.But I am wondering about this as a reoccouring prob.I just wonder about ill assembly?Or oil passages?Your thoughts?Thank you

Dirt Maniac

Total posts: 101
posted September 18, 2001 08:58 PM UIN: 40696038
i would say lack of oil! then it wears the bearing down and spins

Dirt Full Roller

Total posts: 54
posted September 18, 2001 09:30 PM
More than likely this problem can be fixed. It can be assy. or a lot of things, needless to say the crank will have to be checked for straightness and cracks and the block will need to be checked also it may need to be align honed but spinning the main bearings is not permanent and can be fixed with some close inspection

Dirt Roller

Total posts: 23
posted September 19, 2001 06:44 PM
If it was a fresh motor, the bearings might not have had enough clearance, or the caps could have been over torqued.

Dirt Full Roller

Total posts: 32
posted September 27, 2001 11:56 PM
if i were you i would take the block to the machine shop sounds liek it needs line honed or bored probably bored if it keeps spinning mains

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