The Ford Barn

Lawrie · 07-16-2016, 09:20 PM

I,m assembling a C69a engine,I ordered the main bearings for 1939-1948, the rear bearings won't fit into the block ,they are too narrow on the id of the rear main thrusts,(D dimension) the overall width is right(C dimension) where they fit into the crankshaft,also they only have a narrow locating tag,where as in the block it is a wide style.
looking at my stuff it looks like the bearings I got are for an 8Ba.
I think I need the 81a-6331 style.
Am I right
Lawrie

Ronnie · 07-16-2016, 10:12 PM

Turn the bearing over is there a part # on it?

R

Lawrie · 07-16-2016, 10:14 PM

yes King MB3351S1-020

Brian · 07-16-2016, 10:55 PM

You are right; 81A prefix.

GOSFAST · 07-17-2016, 06:17 AM

Quote:

Originally Posted by Lawrie

I,m assembling a C69a engine,I ordered the main bearings for 1939-1948, the rear bearings won't fit into the block ,they are too narrow on the id of the rear main thrusts,(D dimension) the overall width is right(C dimension) where they fit into the crankshaft,also they only have a narrow locating tag,where as in the block it is a wide style.
looking at my stuff it looks like the bearings I got are for an 8Ba.
I think I need the 81a-6331 style.
Am I right
Lawrie

Hi Lawrie, if there's anyone in your area with a decent lathe you will be able to use that set. Not all that difficult for a good machinist?

You need to remove .015"/.016" from the backsides of the thrust surfaces on both shells. We've done a number of these over the years when the early sets weren't available/out-of-stock.

Thanks, Gary in N.Y.

P.S. Lawrie, on a side note here, this shot may help with another question you asked. These are nice pieces (stainless) considering the cost, just put another large number on the shelf.

Walt Dupont--Me. · 07-17-2016, 06:33 AM

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Hey lawrie, I'm not familiar C69A but I'm sure you need rear bearing from the what we call 59AB the center and front bear are the came. accually 39-53 have the same center and front bearting, Walt

Ronnie · 07-17-2016, 07:06 AM

What Walt said^^^

R

Juergen · 07-18-2016, 08:54 AM

I had the same problem and fordbarners came to my rescue. Sealed power sells the 39-48 mains under their number 533M which has a generic number MS 108M while their bearings for a 49-53 are numbered 646M which has a generic number MS 352A. The selling vendor claimed the MS 352a would fit all years. Also barner "barnfind08" had the 39-48 rear main that I needed and would sell me only the rear main.

rotorwrench · 07-19-2016, 12:11 PM

The Canadian Windsor plant started in with the insert rod bearings a good bit before the 8BA (C8BA) came out. This does make for some interesting combinations since the Canadian C69A has a bit of both eras for bearings.

Mart · 07-19-2016, 12:55 PM

FWIW the French motors use 59A type main bearings, not 8BA as I first thought. That was an expensive mistake.

Mart.

07-16-2016, 09:20 PM	#1
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,728	main bearing drama I,m assembling a C69a engine,I ordered the main bearings for 1939-1948, the rear bearings won't fit into the block ,they are too narrow on the id of the rear main thrusts,(D dimension) the overall width is right(C dimension) where they fit into the crankshaft,also they only have a narrow locating tag,where as in the block it is a wide style. looking at my stuff it looks like the bearings I got are for an 8Ba. I think I need the 81a-6331 style. Am I right Lawrie

07-16-2016, 10:12 PM	#2
Ronnie Senior Member Join Date: May 2010 Location: Canada Where it snows Posts: 2,059	Re: main bearing drama Turn the bearing over is there a part # on it? R

07-16-2016, 10:14 PM	#3
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,728	Re: main bearing drama yes King MB3351S1-020

07-16-2016, 10:55 PM	#4
Brian Senior Member Join Date: May 2010 Location: Masterton, New Zealand Posts: 4,097	Re: main bearing drama You are right; 81A prefix. __________________ Unfortunately, two half wits don't make a whole wit!

07-17-2016, 06:33 AM	#6
Walt Dupont--Me. Senior Member Join Date: May 2010 Location: Gardiner Me. Posts: 4,200	Re: main bearing drama Sponsored Links (Register now to hide all advertisements) Hey lawrie, I'm not familiar C69A but I'm sure you need rear bearing from the what we call 59AB the center and front bear are the came. accually 39-53 have the same center and front bearting, Walt

07-17-2016, 07:06 AM	#7
Ronnie Senior Member Join Date: May 2010 Location: Canada Where it snows Posts: 2,059	Re: main bearing drama What Walt said^^^ R

07-18-2016, 08:54 AM	#8
Juergen Senior Member Join Date: May 2010 Posts: 536	Re: main bearing drama I had the same problem and fordbarners came to my rescue. Sealed power sells the 39-48 mains under their number 533M which has a generic number MS 108M while their bearings for a 49-53 are numbered 646M which has a generic number MS 352A. The selling vendor claimed the MS 352a would fit all years. Also barner "barnfind08" had the 39-48 rear main that I needed and would sell me only the rear main.

07-19-2016, 12:11 PM	#9
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 18,006	Re: main bearing drama The Canadian Windsor plant started in with the insert rod bearings a good bit before the 8BA (C8BA) came out. This does make for some interesting combinations since the Canadian C69A has a bit of both eras for bearings.

07-19-2016, 12:55 PM	#10
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 9,239	Re: main bearing drama FWIW the French motors use 59A type main bearings, not 8BA as I first thought. That was an expensive mistake. Mart.