Bad Karma

So there I am, busting out the Crank and main bearings teardown to drop my block off at another place today for a second opinion...(First guy said "nothing wrong doesn't need to be bored"-after listening to a few guys here, I convinced myself to take it to another place to confirm").

I find that the Crankshaft Bearings are stamped "Clevite 77"... "010."

I'm going to go out on a limb here and say that maybe my block has been worked before since I don't think that Clevite 77 made crank bearings for FoMoCo and that the Crank may have been turned .010.

Can one of the motor guys chime in here and let me know what the deal is?

This makes a deal to me since/if the crank was turned why was the cylinders not bored? Also, when ordering up parts for my 306 rebuild, what am I looking to buy?

What to do fellas?

Thanks,
Ivan

Hurricanedt77

Whats up man, I just rebuilt my bottom end and I obviously went with new clevite bearings. I went 0.001 because I didnt want my crank turned. I'm totally going ot assume that your engine was torn down once before and the crank was turned. As far as the block being boared out, maybe the person didnt want that done. You gotta think, some 45 year old lady could have blown the motor or something and just wanted a simple rebuild. I'm sure somone whos not a car guy and just wants a regualr car would have any thoughts of going 306..

Bad Karma

So do you think that my Crank was turned .010 since the stamp on the Bearing says ".010?"

That seems like alot to your .001.

What internals do you go with? How about pistons and rings??


Thanks,
-Ivan

Grimace5.0

yup

myshifter

the crank is cut 10-10 no big deal, standard practice, nothing wrong with that

Bad Karma

Should I worry about having to cut it again and go to a different bearing size or would you just buy another set of .010 bearings and let her fly??

Thanks,
Ivan

Grimace5.0

Your machine shop guy can make that call. I'd say as long as it's not scored or F'd up in any way it won't need cut any further.

Bad Karma

At what point would a crank need to be replaced? I mean if he comes back and says that it needs to be replaced, what are the throwaway specs on it? I'm not sure that I want to start a buildup if .010 is already close to that throwaway spec.

Thanks for the info guys,
Ivan

tinman

There are main bearings for as much as .040 undersize in this world. i wouldn't be worried about .010 if it were done right....
I'll go out on the limb here and say that there maybe some H.P. with an undersize crank but thats sort of MHO stuff.........