248 Crankshaft Bearing - Nominal Diam.!!!


New Member
Hello, my name is Dietmar, I come from Germany and drive a 1940 Special Coupe with a 248 engine!
I have a question about crankshaft bearings, is it correct that the dimensions of the crankshaft bearings on the 248 have changed since 1950?
My engine is being overhauled and I need the crankshaft bearing dimensions from the 1940 engine!
Can you help me?
Stay healthy and greetings from Germany!
Here is the data on the connecting rod bearings and crankshaft journal dimensions from the 1940 and 1950 shop manuals. An exact dimension for the crankshaft journal is not given for 1940. The clearance figure for the two manuals is very close. So the 1.998-1.999 inch dimension from 1950 should work for the '40 engine. 1950 was the last year for the 248.

The 1940 engine had cast bearings in the connecting rods. The bearing clearance could be adjusted by removing shims. In early 1949 the design was changed to use removable insert bearings. If your engine has ever been rebuilt since the '50s, it could have the insert bearings. This design change did not affect the crankshaft, but could explain the slight clearance differences.

If you need similar info on the crankshaft main bearings we can dig that up also.


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Active Member
Dietmar, the crankshaft bearings in the 263 CI engine, which debuted in 1950 ,are different. One needs to be certain which engine is involved . Many have been changed.