Difference between 'V' and 'M' hemi bearings

Hi guys.

Clevite stock both 'M' and 'V' rated CB-1512 rod bearings. We ran a forged crank with 'V' rod bearings for many years with no issues at all.

This year we moved to a billet crank and ran 'V' bearings to find even after one run the bearings would come out of the motor very rough and pitted. After asking some of the TAD/TAFC racers over here they all seem to run the 'M' bearings on their cranks.

Do billet cranks prefer the 'M' bearings instead of the 'V' bearings? And also what are the differences between the two?

Any information would be appreciated.

Thanks a lot
Joe

 

bearings

M 's are a little softer. If you are just learning run the M so you need to check often.

 

we found Ms on the rods are a pain in the ass, It takes so little to squash them Ms on the crank work fine for us,
we check all our bearings every pass and find Vs give a better indication of whats going on in the cylinders, Ms just squash because they can, or at the slightest little provocation, which is all the time in our car

but i bet you will get a different answer from every one who answers this one
good luck