Help, main & rod bearings 81A or 1BA
 

Hi Fordbarners

Need some guidance on this. I have 59L block '46-48 Ford truck, using a '49-51' Merc. 4" crank, and 8BA rods, do I use 81A mains or 1BA/8CM mains, or are they all they same for a later Merc crank in an earlier block.
Thank you, Russ

Re: Help, main & rod bearings 81A or 1BA
 

If your useing the 59 block you must use the main bearings that goes with the block, ( 59 mains) the merc crank will fill fit fine. Use the 8BA style rod bearings. Walt

Re: Help, main & rod bearings 81A or 1BA
 

Thanks Walt.

Re: Help, main & rod bearings 81A or 1BA
 

Just a "tip" here, if you have trouble locating the early mains, especially when certain undersizes are required, you can use the later main set in the earlier application by simply machining .015" off the backside of the thrust flanges.

This is the only difference between the 2 sets!

The dimension between the flanges on the early set is 2.065" and the later set is 2.095". Easily machineable with a decent lathe and a small fixture.

(Add) July 08, 2011, just realized the above dimensions are "reversed" in this post, should read: dimension between the early flanges is 2.095" and the later is 2.065", the machining is still correct, .015" off the late brgs! Sorry!

Thanks, Gary in N.Y.

P.S. I know of numerous sets done this way and out there running with not a single issue!

Re: Help, main & rod bearings 81A or 1BA
 

Hi Gofast

Thanks for the tip on the 8BA mains. .015 off the thrust flange is duck soup in my lathe.

regards