pilot bearing question

[James O.]

the worn pilot bearing on my 283 appears to be bronze and has an o.d. of 1.132". i think all small block pilot bearings call for an o.d. of 1.093" so i think my only alternative is to make a new one. i can buy "ultra wear resistant bronze" impregnated with 30W oil that meets SAE 841 standards (whatever that means). will that material hold up or is there a better material to use? ideas?

[Joe L.]

Re: pilot bearing question

James-----

I think the material you describe will be fine, maybe even better than original. Make sure you make it with a tapered approach to the ID like the original bushing. Otherwise, you'll have a lot more trouble trying to get the transmission pilot shaft engaged when you install the transmission.

The thing I cannot understand is where these crankshafts with larger OD orifices for the pilot bushing come from. Chevrolet has used the 1.093 OD bushings since 1939 and right through the end of, at least, C4 production.

[Joe L.]

Re: pilot bearing question

James-----

I think the material you describe will be fine, maybe even better than original. Make sure you make it with a tapered approach to the ID like the original bushing. Otherwise, you'll have a lot more trouble trying to get the transmission pilot shaft engaged when you install the transmission.

The thing I cannot understand is where these crankshafts with larger OD orifices for the pilot bushing come from. Chevrolet has used the 1.093 OD bushings since 1939 and right through the end of, at least, C4 production.

[Clem Z.]

Re: pilot bearing question

any other GM engine use this size bore in the crank if so maybe there was a time when chevy used a different torque convertor.

[Clem Z.]

Re: pilot bearing question

any other GM engine use this size bore in the crank if so maybe there was a time when chevy used a different torque convertor.

[Joe L.]

Re: pilot bearing question

clem------

I think that late 50's Chevrolet with Turboglide used a different torque converter which, possibly, required this size crank bore. However, I didn't think that Turboglides were ever used with 283's. Maybe they were, though. Turboglides were never used in PRODUCTION Corvettes; that I know for sure.

[Joe L.]

Re: pilot bearing question

clem------

I think that late 50's Chevrolet with Turboglide used a different torque converter which, possibly, required this size crank bore. However, I didn't think that Turboglides were ever used with 283's. Maybe they were, though. Turboglides were never used in PRODUCTION Corvettes; that I know for sure.

[Clem Z.]

Re: pilot bearing question

TG were in 57 chevys as a friend had a new 57 vert with TG and it was a 283

[Clem Z.]

Re: pilot bearing question

TG were in 57 chevys as a friend had a new 57 vert with TG and it was a 283

[John M.]

Re: pilot bearing question

Joe,
I have a 427 crank in my 67 (replacement engine) that has a 1.074" pilot bore, which caused me untold grief before I realized it. Imagine trying to press the stock 1.093 bushing in there. I remachined one to fit and also made a spare. The guy who built the short block was no help re the bore size; "I dunno"

[John M.]

Re: pilot bearing question

Joe,
I have a 427 crank in my 67 (replacement engine) that has a 1.074" pilot bore, which caused me untold grief before I realized it. Imagine trying to press the stock 1.093 bushing in there. I remachined one to fit and also made a spare. The guy who built the short block was no help re the bore size; "I dunno"

[James O.]

Re: pilot bearing question

that turboglide theory is interesting but i thought all 283 pilot bearings for all years were .593 I.D. by 1.093" O.D. regardless of transmission. is that true? otherwise the only thing that would explain it would be a machining error at the factory.

[James O.]

Re: pilot bearing question

that turboglide theory is interesting but i thought all 283 pilot bearings for all years were .593 I.D. by 1.093" O.D. regardless of transmission. is that true? otherwise the only thing that would explain it would be a machining error at the factory.

[Clem Z.]

Re: pilot bearing question

there had to be a pilot bushing and a torque convertor to fit the larger size crank bore somewhere in the GM parts book. if it was machined wrong the bushing or the convertor would not fit correctly.

[Clem Z.]

Re: pilot bearing question

there had to be a pilot bushing and a torque convertor to fit the larger size crank bore somewhere in the GM parts book. if it was machined wrong the bushing or the convertor would not fit correctly.