The Ford Barn

russcc · 03-21-2015, 09:44 AM

Got the 8BA rods back from the machine shop, and they are saying they measure anywhere from .6.935 to 6.945 center line to centerline from the big end to the small end. In the shortest one, that is .065 less than the stock Ford dimension of 7.000.

Checking them myself, using a 6" vernier dial caliper I get anywhere from 6.990 on the shortest to 6.998 on the longest.

Anyone seen 8BA rods .065 short of the factory spec of 7.000 ?

Any ideas on they discrepancy in measurements between the shops and mine ?

The shop operation is 1st class, with an Italian boring and decking machine that was purchased from Petty Enterprises right after they started sending all their NASCAR engines out to be built. This is the only machine I have seen locally that bores directly off the centerline of the crank versus the usual off the deck. The owner is a perfectionist, as he should be, so I must be missing something in the translation of numbers.

I worked as a machinist 50 years ago, and still have a Bridgeport & lathe so I am not actually a rookie.

Thanks Fordbarners.

03-21-2015, 09:44 AM	#1
russcc Senior Member Join Date: May 2010 Posts: 2,871	8BA rod help Got the 8BA rods back from the machine shop, and they are saying they measure anywhere from .6.935 to 6.945 center line to centerline from the big end to the small end. In the shortest one, that is .065 less than the stock Ford dimension of 7.000. Checking them myself, using a 6" vernier dial caliper I get anywhere from 6.990 on the shortest to 6.998 on the longest. Anyone seen 8BA rods .065 short of the factory spec of 7.000 ? Any ideas on they discrepancy in measurements between the shops and mine ? The shop operation is 1st class, with an Italian boring and decking machine that was purchased from Petty Enterprises right after they started sending all their NASCAR engines out to be built. This is the only machine I have seen locally that bores directly off the centerline of the crank versus the usual off the deck. The owner is a perfectionist, as he should be, so I must be missing something in the translation of numbers. I worked as a machinist 50 years ago, and still have a Bridgeport & lathe so I am not actually a rookie. Thanks Fordbarners.