Engine number help and block stampings

[MsRose]

Please could I get some advice/info?

I have a 1957 MM and am currently going through the process of getting an age related plate through MMOC.

I have had to take lots of pics and I have a couple of questions, one relating to its ID, but the other is just something I’d like to know for myself.

1). The engine number (small plate) is missing. You can see where it used to be attached, but on the left front of the block is a four digit number, stamped in. Someone mentioned it may be due to a rebuild of the engine. Could this be the case?

2). On the flat face, next to the pistons there are numbers inside a diamond shape. Only very low figures, like 1 and 2. Is it usual to see these? What do they indicate?

I’m not sure how to get pics on here.

[philthehill]

The block number is more than likely the reconditioning companies I.D./job number.
If you apply for a Heritage certificate it will tell you the original engine number which you can reapply to your block.

The numbers inside the diamonds are related to the bore/piston size gradings and are quite common on ex factory engines. Not all bores will have been bored to the same exact size and graded pistons were used to match those exact bores.

[MsRose]

Thank you. I do now have the heritage certificate which shows the engine number.

[geoberni]

Adding photos...

I’m not sure how to get pics on here.

You Drag & Drop into the Box where you type, or you use the Attachment Tab and click on [Add Files].

Be aware that the site doesn't like files that are more than about 2MB, so if your phone defaults are taking HD 5MB (or more) images, you need to change the settings... (Who needs such high quality photos when all they do is look at them on a phone screen... )
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[MsRose]

Thank you geoberni. I'd like to post my build on the board so knowing how to add the photos will be a great help.

[svenedin]

Exactly as Phil says. On later engines like mine (1969) the numbers are no longer inside a diamond but the same principle applies. They are from the production line so that the correct size pistons were fitted to match the bores. In my case, the numbers are all the same.

Stephen

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[MsRose]

Brilliant, thank you