45 Flathead Belly Numbers

[Chris Haynes]

i have nos wla cases that have no vin# but they have belly # from 1945 belly # match left and right. why would a worker but his stamp on a unfinished motor?

The belly number are line bore numbers. When the two case halves are matched they are stamped to prevent mixup.

[Rubone]

Brian,
It came out of an old dealership that ran from '35 to '65 and then was independent until the '80s. When I got it 30 years ago it still had the part number tag on it. Looks just like Flat Happy's case. The guy had a stack of them. Along with tons of other parts. I got several pair of NOS big flathead cases, 45 cases, and knuckle cases from him as well. I don't doubt it could be a factory second of some sort. Perhaps the mating case was bad and was found out after it was stamped but before the vin. Who knows? I have never tried to mate it to anything. All I am saying is that it is another type of original case out there that does not fit the norm.
Robbie

[bmh]

I have an NOS '53 casting number Pan left case with no VIN and the belly number factory removed, looks like it is belt sanded off.
Robbie

How do you know who sanded it off and when? Just cause the serial boss is blank doesn't mean it wasn't stolen. Could also be a quality control reject, race size could be outta spec or a center distance missed by a few thousandths.

[Rubone]

I have an NOS '53 casting number Pan left case with no VIN and the belly number factory removed, looks like it is belt sanded off.
Robbie

[rwm]

i have nos wla cases that have no vin# but they have belly # from 1945 belly # match left and right. why would a worker but his stamp on a unfinished motor?

[flat-happy]

After a soak in the bath and a period of contemplation I feel the belly numbers were put on first and the engine numbers later.
My reasoning is thus, I have a nos set of 1930 VL cases that have belly numbers but no year, model code or numbers stamped on them. 30 679?
I presume these cases were sent to a dealer as part of the update that happened due to the problems that beset the early VLs and were never used.
Now before everybody jumps in and says the VL situation was an exception I also have a set of 1937 UL cases that have belly numbers, 37 284? and nothing else as well as the crankcase set used in the rebuild of my 1944 WLC. 44 1016?
To this day I haven't stamped the pad on the WLC and the authorities here were quite happy to use the belly numbers as the engine/vin numbers.
When I thought about it I'm pretty sure thats what was told to me by guys at the factory, the crankcase set was allocated a job sheet number, line setting number, line bore number, call it what you will and this followed it through the system.
I don't remember asking anybody as to at what stage the engine/vin numbers were put on. I do know that my time at the factory was way too short and it was only Trev Deeleys influence that got me where I did get to go.
Trev was a fantastic man and friend God Rest His Soul.

hi tommo---that is just the way it should be. as mentioned before the factory seldom built bikes on speculation and usually only built when ordered by dealers. after all the bikes were built the remaining cases were sometimes machined as a pair and sometimes sent out individually to dealers as replacement parts sans the vin number. the system was only used when complete engines were built. i have a nos left knuckle case that has not been mated yet and has no belly number or vin number

[Paps]

No matter what machine I manufactured [ industrial manufacturing ] which called for a serial number, Each employee who machined on it, had to place his mark upon it. Every entry upon it was put in sink with the first, thus creating a manufacturers code. This code provided the company will a fall guy, just in case something was machined incorrectly. The vin number was put on last. The vin identified each individual machine for both ownership identification and machinining specs. Knowing what the machining specs oringinally were, helped with producing needed replacement parts, further on down through time and use. Paps

[Ohio-Rider]

he said that every engine builder had an employee number. he also said that except for the war production years harley never had more than 125 employees building engines. the number side cases were stamped with a vin number first then when the case was matched to a right side case the employee added his badge number to the vin number and that was how the belly numbers were chosen.

This would help explain why some belly numbers are five digits long and others are four digits long. Depending upon the builders assigned number. Assuming that the builders numbers where assigned to them sequentially by seniority, then we could also assume that engines with a four digit number where assembled by the more experienced builders. This topic just keeps getting more interesting by the day.

Thanks to the AMCA for providing this place for a discussion like this to take place and to all you knowledgeable guys who share what you have learned over the years. And better yet is the fact that we have gone 5 pages without a pissing contest. -Steve

[Tommo]

After a soak in the bath and a period of contemplation I feel the belly numbers were put on first and the engine numbers later.
My reasoning is thus, I have a nos set of 1930 VL cases that have belly numbers but no year, model code or numbers stamped on them. 30 679?
I presume these cases were sent to a dealer as part of the update that happened due to the problems that beset the early VLs and were never used.
Now before everybody jumps in and says the VL situation was an exception I also have a set of 1937 UL cases that have belly numbers, 37 284? and nothing else as well as the crankcase set used in the rebuild of my 1944 WLC. 44 1016?
To this day I haven't stamped the pad on the WLC and the authorities here were quite happy to use the belly numbers as the engine/vin numbers.
When I thought about it I'm pretty sure thats what was told to me by guys at the factory, the crankcase set was allocated a job sheet number, line setting number, line bore number, call it what you will and this followed it through the system.
I don't remember asking anybody as to at what stage the engine/vin numbers were put on. I do know that my time at the factory was way too short and it was only Trev Deeleys influence that got me where I did get to go.
Trev was a fantastic man and friend God Rest His Soul.

[flat-happy]

tommo i'm not sure if the sequence was always or ever like that. i am mostly a knucklehead era guy and i don't know squat about the earlier stuff. i wish i did. the guy i talked to started about 1940 to about 1966

[Tommo]

I've just looked at some of my spare engines, all of which have matching belly numbers, and will quote them here but will omit the last numeral of the engine numbers in the name of security. This shouldn't effect things too much.
First will be the belly number followed by the engine number.
I9 181 19A 811?
D0 256 20T 277?
E8 694 23F 604?
25 3233 25JE 460?
25 6708 25JE 537?
25 15681 25JE 1487?
26 2345 26J 146?
27 6849 27JE 101??
28 3601 28J 463?

Do any of these fit your pattern? They are all factory numbers.

[flat-happy]

that isn't what he meant----he meant do the numbers on record match his cases not each other. everyone knows they don't match each other. i'd like to see them for this reason and i've talked this over with bruce palmer. i knew and old guy years ago who was an engine builder at the factory during wwII. he said that every engine builder had an employee number. he also said that except for the war production years harley never had more than 125 employees building engines. the number side cases were stamped with a vin number first then when the case was matched to a right side case the employee added his badge number to the vin number and that was how the belly numbers were chosen. he also said the it was a secret code the factory had and if the belly number was not within 125 of the vin the case was usually a restamp by a dealer or whoever. in all the years i have tried to apply that formula to cases i knew for a fact had never been apart-----usually a lot of grease grime and oil and still standard bore with no marks on the screw heads etc-----i've only found 2 engines that didn't make sense. after telling bruce that he said he had never heard that before so we went into his house and his computer where he has stored photos of every set of cases he has ever come into contact with with their vin numbers and corresponding belly numbers and for the most part the war years didn't fit the formula. there were several sets that did though. nearly all the photos he had were nice clean glass beaded cases. it was a very impressive collection of photos. the guy i knew also told me that some employees would subtract their number instead of adding it just to screw with the company and who doesn't do that once in a while. i have never had anyone else tell me how the belly numbers were arrived at and believe me over the years i have asked some very important people who should have known. 25-35 years ago the factory was much more helpful than they are now----hell i guess everyone was. anyone have any information on how the belly numbers were chosen?

[Tommo]

I go with Chris on that one as I have never seen an engine number that goes anywhere near matching a belly number

[Chris Haynes]

I have never seen a case where the line bore number matched the serial number.

[bmh]

If you can't understand by reading the previous posts I will never be able to explain it to you.

Please try, as I said it is a question that requires a simple yes or no answer. Either yes the case half numbers and the VIN are a match or no they are not. No one outside the Company ever need see the list. If you can't provide both of these numbers then there should be no question that the parts you are holding are not legit. Sorry guys but not every bike can be a survivor. While I have no doubt that you and Tommo have seen this info I also absolutely know neither dealers nor State police have access to get that simple yes or no answer, let alone little old me. If it's a money thing, I'd pay a fee. I'm sure lots of other enthusiasts would too. I doubt the GM historical division researches your vehicle and sends out all that info for free. I don't get the problem, though I have a suspicion that perhaps the factory's record keeping wasn't what it should've been. From what I hear their restoration dept. sure isn't.