There is a number located on the front right side (starboard side), just below the compression release. The number is 8758. That is it no prefixes.

I suppose this is a replacement engine.

I have been removing some paint looking for yellow. The bike was originally destined for the auto association. From the pictures it looks like they used yellow paint on the tank. So far no yellow on the tank. The engine only has one thin coat of shiny green paint. Other parts have several layers of greens.

email (option): cbhaws@verizon.net

Same here Charlie, my number is 8202. 🤔

John

email (option): john.kater@chello.nl

email (option): cbhaws@verizon.net

The prefix is on the left of the engine. Close to the breather.

John

email (option): john.kater@chello.nl

I have a bottom end - painted in green which I think is a REME rebuild

This has engine no 8210

Br
Jo,b

email (option): jonnyob1@googlemail.com

What make or type are we talking about??? this is a WD bike forum, so it could be anything??

Cheers,

Lex

email (option): welbike@welb**e.net

Bsa’s of course Lex

😬

email (option): jonnyob1@googlemail.com

email (option): cbhaws@verizon.net

Lex is right you should make it clear the machine you are talking about.

I'm also confused about which side of the engine you are "all" talking about, it doesn't sound like you are all on the same page?

And how about some pictures please.

Rob

email (option): robmiller11(a)yahoo.co.uk

How i look at it if its a M20 then it could be a date stamp 8 July 1958 I have seen these date stamps on post war crankcases. i have a set of old cases with this type of stamping and its under the tappet cover under the exhaust valve. As said earlier in this thread the engine number should be on the otherside near the breather, but i have seen unstamped cases that must have been new replacement cases that have never been stamped up when put into service.

I also have a strange engine nr, W 7382. Near the breather.
There is still some green paint on the cases, between the engine plates.

['How I look at it if its a M20 then it could be a date stamp 8 July 1958 I have seen these date stamps on post war crankcases..']

Crank cases were date stamped after the war, usually just above the timing cover but sometimes inside the timing cover on the face of the crank case wall adjacent to the idler gear spindle...A 1958 engine would be different to a WD engine in that there would be no breather on the primary drive side, as by that date it was fitted into the timing cover...

However, crank case halves can be 'mixed' without any difficulty on M and B Series engines of this period so a check of the crank case half numbers might be in order to determine whether they are an original pairing...Date stamp fonts were about 1/8" high and show a full date...'7 6 54' for example..If the font size is bigger than 1/8" and they are original WD crank cases then a WD marking is probably what it is....

It seems that might be the case here as the other numbers don't make a 1950s date...As Rob notes 'a picture speaks a thousand words' in these cases and makes an explanation a lot simpler....Ian

email (option): ian@wright52.plus.com

Hi rob

I have sent photos of my m20 bottom end to you - maybe you can post them

Br
Jo’b

email (option): jonnyob1@googlemail.com

Johns pictures

email (option): robmiller11(a)yahoo.co.uk

I think you are going to have to try better a resolution, I'm struggling to read this.

Rob

email (option): robmiller11(a)yahoo.co.uk

Here is Charlie's picture.

Rob

email (option): robmiller11(a)yahoo.co.uk