The Ford Barn

FRANK PKNY · 02-28-2023, 08:23 PM

Are the full floating bearings for the rods the same from 39 trough 48?

Brian · 02-28-2023, 09:55 PM

No...the 221 and 239 engines, whilst running floaters, have different sized crankpin journals and correspondingly, different con rod dia's. The 221 series run a 1.999" dia journal, the 239 runs a 2.139" dia.
The main bearing dias of both series are the same dia, so, conceivably, one could fit either crank into either sized block

Ken/Alabama · 02-28-2023, 11:58 PM

Ford bearings will have a prefix of 81A for the smaller journal. The larger journal Ford bearings will have a prefix of 99A. Federal Mogul is 9800 for the small journal and 9805 for the larger journal.

Ol' Ron · 03-01-2023, 09:52 AM

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I've used Floaters for years, early stroker and race engines. Often wondered why the Ford engineers went to the 2.139 size and not 2.140 or 2.130. Didn't make much sense.
Chevy went from 1.998 to 2.100, that doesn't make much sense either. Can't believe the .050" would add that much strength to the crank???
At least we can get 1/8 more stroke from the Ford crak.
Gramps

02-28-2023, 08:23 PM	#1
FRANK PKNY Senior Member Join Date: May 2010 Location: POUGHKEEPSIE NY 12601 Posts: 1,016	rod bearings Are the full floating bearings for the rods the same from 39 trough 48? __________________ [email protected]

02-28-2023, 09:55 PM	#2
Brian Senior Member Join Date: May 2010 Location: Masterton, New Zealand Posts: 3,835	Re: rod bearings No...the 221 and 239 engines, whilst running floaters, have different sized crankpin journals and correspondingly, different con rod dia's. The 221 series run a 1.999" dia journal, the 239 runs a 2.139" dia. The main bearing dias of both series are the same dia, so, conceivably, one could fit either crank into either sized block __________________ Unfortunately, two half wits don't make a whole wit!

02-28-2023, 11:58 PM	#3
Ken/Alabama Senior Member Join Date: May 2010 Location: Alabama Posts: 3,261	Re: rod bearings Ford bearings will have a prefix of 81A for the smaller journal. The larger journal Ford bearings will have a prefix of 99A. Federal Mogul is 9800 for the small journal and 9805 for the larger journal.

03-01-2023, 09:52 AM	#4
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,861	Re: rod bearings Sponsored Links (Register now to hide all advertisements) I've used Floaters for years, early stroker and race engines. Often wondered why the Ford engineers went to the 2.139 size and not 2.140 or 2.130. Didn't make much sense. Chevy went from 1.998 to 2.100, that doesn't make much sense either. Can't believe the .050" would add that much strength to the crank??? At least we can get 1/8 more stroke from the Ford crak. Gramps