Knucklehead "belly" numbers

[tbickle22]

I,m trying to find the "belly" numbers on a 1944 Knuckle. The vin is on the top of the cases between the cylinders and is 44FL1350. The thing is I have always heard there is another set of numbers stamped into the bottom of each half of the crankcase that can help you find out if the cases match each other or are a mish-mash of different years. can anyone help me on this? Thanks ahead.
JD

[Scooter]

The belly numbers are located on the bottom of both halves of the engine cases.  It consists of three digits, followed by a dash, followed by four digits.
For a knuck, the first digit will be "1", the next two are the year (possibly one year earlier than the 44 you already know because they are stamped before assembled and might sit on a rack for a while).  The remaining four digits are just a sequence and will NOT match the number by the timing hole.
The belly numbers on each half should be the same.

[Speeding Big Twin]

Scooter, JD also posted on the general board and received some responses there.

The first portion of the belly numbers on a 1944 Knucklehead won’t consist of three digits and the same thing applies to all other Knucklehead years. Knuckleheads only have two characters in the first portion of their belly numbers. They do not have the first (or extra) digit you mentioned. The extra character coding system wasn't introduced until 1948.

And no offense meant but could you please advise where you got your info about belly numbers. Was it from a book? Website?     Eric     

[Scooter]

I stand corrected.  My source is an old (late '70s) article from EasyRider's magazine.

[Speeding Big Twin]

Thanks for the reply, Scooter. I have an article here from what I think was a Jammer's Handbook from around 1980 and it may be similar to the article you have from Easyriders. Mine covers four full pages and has the following title: Straight Facts about Harley’s ID Numbering and Coding Systems. But some of its info is incorrect, including some of the belly number info.

I was in a serial number discussion on the Hydra-Glide forum in August-September and another member posted some info which was from a document dated July 1981. It rightly gave 1948 as the start year for the extra belly number character, although some of its other belly number info was incorrect in a similar fashion to my Jammer article.

The same 1981 document helped explain why 1962 is often incorrectly mentioned as the start year for the even/odd code used for H-D serial numbers. My Jammer article incorrectly gives 1962 as the start year for the even/odd code and your article may also say 1962. I’ve recently been studying a mate’s Clymerâ,,¢ Panhead service manual (ISBN: 0-89287-565-8) and it gives the same incorrect start year: 1962. But in fact, evidence indicates the even/odd code used for H-D serial numbers began with the 1960 models.

I won’t be surprised if all the info stems from the one source, being transferred over time to magazines, books, service manuals, websites etc with the result being that some of it has remained incorrect for around thirty years.     Eric