Diamond Block Questions

[Model A Fan]

I have decided to exit the Model A hobby for the foreseeable future and will be parting with many of my extra pieces and whatnot. I have a diamond block engine that is numbered *A4870927* which brings the year of manufacture in right between 1938 and 1939.

What I'm hoping to find is more information about what their "deal" is. Given Model As were produced up until 1931, it is unusual for an engine to be produced so late. I understand that they may have been extra engines or that they were produced for non-auto uses. Does anyone have more information?

Also, what would be the value on one in good shape and in running condition? Mine has been painted a metallic blue, but is still operational. I don't think it would need a rebuild, but maybe just new gaskets. Thanks for the help.

I have included a link to the pics, they are the very last two photos on the album here:

https://www.jalopyjournal.com/forum/...or-sale.27941/

[TK in LA]

A Fan, Here is a link that should help.
http://www.fordgarage.com/pages/diamondblock.htm
The later castings are desirable for the guys wanting to hop up a banger as the castings had better material and structure. The number on the block is probably not the number for the block itself but was transferred from the previous motor that was removed?
Hope this helps. I know others will chime in.
Good Luck

[springerpete]

If you look on the lower block, carb side just behind the timing gear case you should see a raised letter and two numbers. My diamond block reads C 5 7 which means March 5th, 1937. These blocks had some modern improvements in them. I am sure others will be able to tell you more

[Chris Haynes]

My Diamond block has X240.

[Synchro909]

Originally Posted by springerpete

If you look on the lower block, carb side just behind the timing gear case you should see a raised letter and two numbers. My diamond block reads C 5 7 which means March 5th, 1937. These blocks had some modern improvements in them. I am sure others will be able to tell you more

My diamond A block has 1296 there. Anybody know what that means? I can't read the engine number on it but most likely it is of Canadian origin.

[Chris Haynes]

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It is my understanding that diamond block had no stamped number on the number boss.

[Chuck Sea/Tac]

That number is not a diamond number.

[Chippy Minton]

Aren’t you talking about a Model B block anyway? They would all have been produced after 1931. I would guess that many B blocks have had engine numbers stamped on them as required as, as stated, they did not come stamped.

[juke joint johnny]

On Vince's site that would equate to December 9 1936 1296

[jim1932]

Originally Posted by Synchro909

My diamond A block has 1296 there. Anybody know what that means? I can't read the engine number on it but most likely it is of Canadian origin.

That is probably I296. Or September 29 1936

[Synchro909]

Originally Posted by jim1932

That is probably I296. Or September 29 1936

Thanks, Jim and JJJ.
Consistent with comment above about these blocks not having numbers stamped on them, I can see that there is no star at either end of the number that is or rather, was there. I think it is probably a number put there some time since 1936 by who knows who and who knows why.

[TinCup]

A "B" cam is one of the best parts of the these blocks but mostly that they were run in industrial motors such as combines and irrigation pumps which mean they ran at low rpm's and no lateral crank movement due to no clutch action most of the time. That way the original crank journals are usually in good shape. If the flywheel housing is still attached you will find another date stamp there.

[Chris Haynes]

Originally Posted by Chippy Minton

Aren’t you talking about a Model B block anyway? They would all have been produced after 1931. I would guess that many B blocks have had engine numbers stamped on them as required as, as stated, they did not come stamped.

Model B had numbers on the bell housing, not the block. Model A Diamond blocks were available through the late '30's. Diamond blocks were not numbered.

[Chris Haynes]

...

[Model A Fan]

I am just as baffled by it as well, but I don't have a good photo currently. I will try to get a photo of the serial number before the new owner takes it away. It has stars on both ends of the number and based on one of the websites with the info, it is from between 1938 and 1939. I don't understand why someone would mark it with that number (coinciding to that time period) if it wasn't in fact made during between those years.

Hopefully a picture will provide some clues. I'll check on the block for a date code as well.

Thanks for the interesting discussion. I like that sort of thing.

[JRShaw]

Gentlemen - These discussions have peaked my curiosity about my own (rebuilt) diamond block engine earmarked for my roadster project. The letters are L226 preceded and followed by a slotted round head screw. Am I correct in assuming this lettering would indicate October 22nd of 1936?? Is it known that these diamond blocks came with a "B" cam?? Thank You in Advance.

[Dollar Bill]

Originally Posted by JRShaw

The letters are L226 preceded and followed by a slotted round head screw. Am I correct in assuming this lettering would indicate October 22nd of 1936?? Is it known that these diamond blocks came with a "B" cam?? Thank You in Advance.

Isn't "L" the 12th letter meaning it would have been cast in December?

From my notes: Beginning in August 1932, complete Model A service block engines were all fitted at the Rouge with Model B camshafts and push rods (tappets), according to the Engine Production Foreman's records. This feature carried forward into diamond block production.

[Mike V. Florida]

Originally Posted by JRShaw

Gentlemen - These discussions have peaked my curiosity about my own (rebuilt) diamond block engine earmarked for my roadster project. The letters are L226 preceded and followed by a slotted round head screw. Am I correct in assuming this lettering would indicate October 22nd of 1936?? Is it known that these diamond blocks came with a "B" cam?? Thank You in Advance.

Here is some great information;

http://www.fordgarage.com/pages/diamondblock.htm

[Chris Haynes]

Vince told me he has never seen a number like the X240 without the screw that is on my block.

[Synchro909]

After reading JRShaw's post (#16), I went back to my diamond A block and had a closer look. The number I gave in post #5 was incorrect. In better light, I can see it is J296 (not 1296) and just like JR's, it is preceded and followed by the shape of a screw head.
Following the reasoning expressed here, I figure that motor would have been cast on October 29th, 1936. Is that correct?
The block came to me as part of a deceased estate along with a couple of other disassembled motors, one being a B. The camshaft from the B block is easy to identify by the fuel pump lobe but how do I tell the B cam that was in the diamond A block from the ordinary A cams I also got?