The Ford Barn

1939mars · 09-09-2025, 04:47 PM

Hello, I am looking for someone in the Los Angeles area that can (and will) do the insert main conversion on a 21 stud engine. I’ve tried 2 places. One hasn’t gotten back to me and the other isn’t interested in the job. Any leads would be appreciated. Thanks, Scott

Willit Stop · 09-09-2025, 05:04 PM

Have you tried H and H Flatheads?

1939mars · 09-09-2025, 11:26 PM

Yes

38 coupe · 09-14-2025, 07:33 PM

I am not familiar with any inter main conversion for the Babbitt main flathead V8 blocks.
The 36 LB motor is a water pump in head engine produced by Ford in partial production for the 1936 model year that introduced insert mains to the Ford flathead V8. The same intert mains and crankshaft were used through 1938 in the 21 stud motors with water pumps mounted on the front of the block. The late 21 stud blocks can be used in earlier applications by adding block off plates for the top opening for the water pumps in the block.

Ggmac · 09-15-2025, 06:27 PM

I have never heard of a conversion. Main caps are different . Main studs go all the way through the block . All of this is from memory so take it with a grain of salt . I do have 2 very good late 36 blocks with insert bearings. Dont need them anymore .

1939mars · 09-17-2025, 03:46 PM

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Ggmac,
I sent you a direct message
-Scott

BlueNotes · 12-31-2025, 08:51 AM

I have some NOS 18-6333 front and intermediate main bearings that also are listed in the Green Bible. It appears that they were used as retrofit to replace the babbit bearings in the 1932-35 blocks. Can anyone confirm this, or am I completely wrong here? See attached pics (68-6333 is for the 1936LB onwards).

glennpm · 12-31-2025, 09:13 AM

Quote:

Originally Posted by BlueNotes

I have some NOS 18-6333 front and intermediate main bearings that also are listed in the Green Bible. It appears that they were used as retrofit to replace the babbit bearings in the 1932-35 blocks. Can anyone confirm this, or am I completely wrong here? See attached pics (68-6333 is for the 1936LB onwards).

glennpm · 12-31-2025, 09:13 AM

Quote:

Originally Posted by BlueNotes

I have some NOS 18-6333 front and intermediate main bearings that also are listed in the Green Bible. It appears that they were used as retrofit to replace the babbit bearings in the 1932-35 blocks. Can anyone confirm this, or am I completely wrong here? See attached pics (68-6333 is for the 1936LB onwards).

Kurt in NJ · 12-31-2025, 11:13 AM

those thick inserts were to be able to use the early crankshaft in a later insert bearing block

prewar · 01-03-2026, 06:45 PM

Sent you a PM

09-09-2025, 04:47 PM	#1
1939mars Senior Member Join Date: Jun 2011 Location: Altadena, CA Posts: 160	21 stud insert main conversion in LA area? Hello, I am looking for someone in the Los Angeles area that can (and will) do the insert main conversion on a 21 stud engine. I’ve tried 2 places. One hasn’t gotten back to me and the other isn’t interested in the job. Any leads would be appreciated. Thanks, Scott

09-09-2025, 05:04 PM	#2
Willit Stop Senior Member Join Date: Feb 2013 Location: Eureka Calif. Posts: 1,007	Re: 21 stud insert main conversion in LA area? Have you tried H and H Flatheads?

09-09-2025, 11:26 PM	#3
1939mars Senior Member Join Date: Jun 2011 Location: Altadena, CA Posts: 160	Re: 21 stud insert main conversion in LA area? Yes

09-14-2025, 07:33 PM	#4
38 coupe Senior Member Join Date: May 2010 Location: South Texas Posts: 2,135	Re: 21 stud insert main conversion in LA area? I am not familiar with any inter main conversion for the Babbitt main flathead V8 blocks. The 36 LB motor is a water pump in head engine produced by Ford in partial production for the 1936 model year that introduced insert mains to the Ford flathead V8. The same intert mains and crankshaft were used through 1938 in the 21 stud motors with water pumps mounted on the front of the block. The late 21 stud blocks can be used in earlier applications by adding block off plates for the top opening for the water pumps in the block.

09-15-2025, 06:27 PM	#5
Ggmac Senior Member Join Date: Jul 2016 Location: Lake worth Florida Posts: 1,466	Re: 21 stud insert main conversion in LA area? I have never heard of a conversion. Main caps are different . Main studs go all the way through the block . All of this is from memory so take it with a grain of salt . I do have 2 very good late 36 blocks with insert bearings. Dont need them anymore .

09-17-2025, 03:46 PM	#6
1939mars Senior Member Join Date: Jun 2011 Location: Altadena, CA Posts: 160	Re: 21 stud insert main conversion in LA area? Sponsored Links (Register now to hide all advertisements) Ggmac, I sent you a direct message -Scott

12-31-2025, 11:13 AM	#10
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,673	Re: 21 stud insert main conversion in LA area? those thick inserts were to be able to use the early crankshaft in a later insert bearing block

01-03-2026, 06:45 PM	#11
prewar Member Join Date: May 2010 Location: LA,CA Posts: 90	Re: 21 stud insert main conversion in LA area? Sent you a PM