My #2 main bearing did spin but doesn't look like it's real bad. Can it be align honed or are they always trashed when this happens?

John

John,
This is one that you are probably going to have somebody look at in person to give you a good answer. More than likely it will be repairable, but its hard to tell without looking and measuring it. Take it to your machine shop, they will let you know.
Main thing is to find out why it happened.
Hope this helps,

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

In my 30+yrs of building engines, I've maybe seen half dozen blocks with a spun main bearing(s). ALLLLLLLLLLLLLLLLLLLL of them were repairable with either line honing or boring/honing. As BillK says, it is impossible to tell without seeing it in person, but I would be willing to bet that it can be fixed.

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Tom Parsons

cool! Thanks guy's, it's a motor I picked up for a future project, so I don't know the history but man all the rod bearings and one main. The main did not look that bad to me.

The only big block I've seen with a spun main that wasn't trashed looked like it had been run quite a while on the bad main. It didn't chew the block up as it only spun far enough to misalign the oil hole, but it got gawdawful hot. The cap and saddle were blackened from heat and burned oil. The machinist and I almost missed a crack that ran back-to-front thru this saddle, straight thru the oil hole. It was very small, but big enough for me to trash the block. The cap rattled in the registers, so it was pretty far out of round, too. Hope yours is repairable.

HOT ROD magazine did an article about saving a spun block a few months ago. This was a race block with big $$$ worth of machine shop time in it, so the owner wanted to save it at all costs. Check their website for the article. The shop actually "sleeved" and pinned a new cast iron insert into the saddle. Neat idea and machine work.

If it didn't spin too badly, and the saddles didn't get "work/heat hardened" too deeply, the block should be salvagable by line bore/honing.

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"Atomic Batteries to Power...Turbines to Speed"

(The Minnesota John D)

'64 El Camino
383 - TH-350 - 12bolt - 4wh pwr discs
Bedded down for the Winter.