Aging an engine by crankcase numbers.

[old man emu]

Previously I came up with a build date for my bike based on the 42WLAXXXXX engine number. I am wondering if it is possible to age the engine using the crankcase numbers. From the engine number, I figured that the build date was late January 1943.

The crankcase numbers (both sides the same) are 43-11409. Would this correspond to a late 42/early 43 engine, or did they just make the crankcases and put them on a shelf until the engine builders grabbed a pair to assemble an engine? Would the number, 11409, indicate a machining date later than January 43?

OME

[1950Panhead]

or did they just make the crankcases and put them on a shelf until the engine builders grabbed a pair to assemble an engine? Would the number, 11409, indicate a machining date later than January 43?

The belly numbers were stamped when the cases were machined as a set.
I have seen 43-24074 so they were making at least 2000 per month so 11409 would be mid/late February.
Legend numbers are higher yet, observed cases reflect reality.

[old man emu]

What month of the year are you using for the start of the production year?

OME

[VPH-D]

What are the casting date codes on the engine?
VPH-D

[old man emu]

What are the casting date codes on the engine?
VPH-D

Where are they located?

[1950Panhead]

What month of the year are you using for the start of the production year?

Belly numbers started in September.

Where are they located?

Inside case.

[Speeding Big Twin]

'Where are they located?'

For your Flathead the casting date code on the left case is outside. For example, shown below is date code F 2 indicating casting in June 1942. (This case has belly number 43-131++.) Also present is casting number 112-392:

June 1942 date code F 2.jpg (90.99 KiB) Viewed 4590 times

The date code on your R-H case may have been inside the gearcase compartment near the front but even if it was I wouldn’t expect it to be there now. It often went missing when the hole for the generator was machined. Sometimes you’ll just see an edge of the date code plate but the rest of the plate is gone. Let us know what DC you find on your left case and I’ll see how it and your belly number compare with other examples I have.

And just out of curiosity, what DC is on the trans case? And is it under the oil filler spout?
Eric

[Pascal]

In 1943 there was no more civilian production, but both the WLA and WLC were made.
According to all the VIN numbers made in the '43-production run' (about 1/4 of WLA 16001 to 39229 and all 39230 to 50829, and about 1/3~1/2 of WLC 1000 to 9134, and who knows the actual number of Blanks..) it's pretty difficult to pinpoint the DoM of your motorcase...
I need more info, but it's most probable a type III WLA.

[old man emu]

My engine has the same tag (F2). My engine number is 42WLA328**. The crankcase number is 43-11409.

I wonder if the F2 is not a date code, but an identifier indicating the foundry which cast the crankcase halves. How many casting factories were in action for H-D in '42/'43?

OME

[Pascal]

'F2' is a casting date code, meaning June ( the 6th month of the year, thus the 6th letter in the aphabet) 1942 ( the '2' in F2).
After the castingproces, the cases were mated by lapping them whilst bolted together and stamping them with identical matching casenumbers.
As mentioned before, both Johan and BP explaine this too, a caseset was used to produce a complete motor.
Although war-production was running at full steam, and cases were used as they came off the lathe, it is posible to have a motor from say December 1942 (already '1943' production) with 1942-productionyear casenumbers mentioning it was mated in say July 1942...

[old man emu]

Has anyone seen a similar tag that was not "F2" ?

OME

[Pascal]

Sure: my '41 has



..which makes it cast in March (C) 1941 (1), and my '45 has a ' J 4 ' tag (cast in October 1944)..

[old man emu]

What is the correlation between your engine number and the G1 casting date? Is your engine number between 1000 and 7000?

OME

[Pascal]

No...there is NO correlation...cases were NOT grabbed from the case-kart/-holder in sequence to create a complete engine.
FYI: the above mentioned motor has an 8~thou VIN, the tag reads 'C 1' not 'G 1' (which would've made it cast in August '41)...

Here's my '45 tag: as mentioned, it reads 'J 4' (Oct '44), and has a 66~thou VIN..

[Speeding Big Twin]

My engine has the same tag (F2). My engine number is 42WLA328**. The crankcase number is 43-11409.

I wonder if the F2 is not a date code, but an identifier indicating the foundry which cast the crankcase halves. How many casting factories were in action for H-D in '42/'43?

OME

I do not know how many casting factories were in action for H-D in 42-43 or at any other period. But F 2 is a date code indicating casting in June 1942 as I mentioned earlier.

‘Has anyone seen a similar tag that was not "F2"?’

Yes, plenty, and from several years. But staying with 1942 for the moment, here are three for example (February, March and December):

February 1942 date code B 2.jpg (91.77 KiB) Viewed 4482 times

March 1942 date code C 2.jpg (165.58 KiB) Viewed 4482 times

December 1942 date code L 2.jpg (82.38 KiB) Viewed 4482 times

On the B 2 case I do not know why someone stamped F but it does not represent February. Sometimes other letters are also found stamped in this area and my best guess is they were done by inspectors.

Earlier in the thread I said DCs on 45ci R-H cases often went missing when the hole for the generator was machined and that sometimes you’ll just see an edge of the DC plate. This appears to be what happened with the R-H case below:

Date code missing.jpg (121.5 KiB) Viewed 4482 times

Also earlier in the thread I mentioned I’d see how your left DC and your BN compared with other examples I have. I’m still compiling that list. Stay tuned.
Eric