Aging an engine by crankcase numbers.

Identification of case numbers and cylinder heads
old man emu
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Re: Aging an engine by crankcase numbers.

#16

Post by old man emu »

It would be interesting to see a list of engine numbers and the date code associated with that engine number to see if there was indeed any sort of sequence in the assembly of engines.

I suppose one would have to study how the production of bikes was ramped up from the numbers made in 1941 (both WL and WLA) and the numbers produced in subsequent years. I imaging that a lot of effort in 1942 went into producing all the various components to assemble a bike, then in 1943 production rates rapidly increased to a plateau level where they remained until late 1944, early 1945 when demand started to fall due to the end of the war being in sight.

OME
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Re: Aging an engine by crankcase numbers.

#17

Post by RUBONE »

By 1941 full military production was underway and 45 production was virtually all going to the Army, along with BT SV models. Note this is dated 6 months before the attack at Pearl Harbor, and 8 months before civilian production is ceased.
1941 document.jpg
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1941 document 2.jpg
1941 document 2.jpg (131.91 KiB) Viewed 3980 times
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Re: Aging an engine by crankcase numbers.

#18

Post by Pascal »

old man emu wrote:It would be interesting to see a list of engine numbers and the date code associated with that engine number to see if there was indeed any sort of sequence in the assembly of engines.

I suppose one would have to study how the production of bikes was ramped up from the numbers made in 1941 (both WL and WLA) and the numbers produced in subsequent years. I imaging that a lot of effort in 1942 went into producing all the various components to assemble a bike, then in 1943 production rates rapidly increased to a plateau level where they remained until late 1944, early 1945 when demand started to fall due to the end of the war being in sight.

OME
For the WLA models only, there's a list on the Yahoo sites.
You have to log in to be able to see the list though..
Some do and some don't have the castingcode listed, but it will give an overall look into things.

@Robbie: what a nice piece of history that letter is.
It gives a grand look in how hectic things became as war-production went booming..
Thanks!
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Re: Aging an engine by crankcase numbers.

#19

Post by Andygears »

Yep, Robbie that hails to a different age... When each and every customer was important. Sadly I'm afraid those days have become history, to read about but not experience.
Thanks

Andygears
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Re: Aging an engine by crankcase numbers.

#20

Post by Speeding Big Twin »

I made a list of some DCs, BNs and SNs for Flathead 45 left cases cast in May 39 thru October 45. It looked fine when I typed it but it doesn't come out that way in the preview so I'll try another approach tomorrow.
Eric
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Re: Aging an engine by crankcase numbers.

#21

Post by Speeding Big Twin »

In this post and the next is the list I made. Some BNs and SNs are unknown however and several SNs are non-factory (N-F) but maybe this will help give some idea how things went. As we'd expect, not every case was used in the order it was produced.
Eric
1939-40.jpg
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1941.jpg
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1942 Feb-May.jpg
1942 Feb-May.jpg (72.81 KiB) Viewed 4144 times
1942 June-Dec.jpg
1942 June-Dec.jpg (112.07 KiB) Viewed 4144 times
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Re: Aging an engine by crankcase numbers.

#22

Post by Speeding Big Twin »

1943.jpg
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1944.jpg
1944.jpg (99.72 KiB) Viewed 4143 times
1945 Jan-April.jpg
1945 Jan-April.jpg (103.08 KiB) Viewed 4143 times
1945 May-Oct.jpg
1945 May-Oct.jpg (82.8 KiB) Viewed 4143 times
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Re: Aging an engine by crankcase numbers.

#23

Post by Bigincher »

That's quite an impressive accumulation of numbers, Eric. As I was looking through them, I became curious- What started you down this particular path of research in the first place, if I may ask? I know it's more than VINs and B/Ns you study, it's pretty much all markings on Harleys over a wide range of years.
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Re: Aging an engine by crankcase numbers.

#24

Post by Speeding Big Twin »

Thanks Tom. I have photos of several others too for 39–45 but they didn’t show some details clearly enough to use in a list. Originally for this study I was working on 38–52 but then decided to start with May 39 because that is the earliest I have with 1940 BNs. And I ended with 1945 because there was no need at this stage to go beyond that.

I began DC research in earnest after a photo of L 6 on a BT trans case appeared on the old HTT. The owner, who is also a member here, said it meant Dec 46 and he was right. But a certain person disagreed and said it was Nov 46 because the letter I was skipped. Palmer’s 37–64 FE had nothing about the omission and I had not heard of it before so I asked questions. That certain person replied with an alleged update on DCs but he only confused things further. Anyway, I couldn’t believe the book and I didn’t get anywhere on the forum so I began researching DCs, casting numbers and other forms of ID for transmissions, crankcases, cylinders, heads etc.

Research into VINs really began after a Knuckle was discussed on the old HTT. It was alleged to be 36 but had a 40s long-rib case and an altered number boss. I didn’t know much about H-D stamps going back that far so I began studying the different types and what years/models they applied to. Later on I began researching BNs and other crankcase markings. And frames, BT round swingarms etc.
Eric
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Re: Aging an engine by crankcase numbers.

#25

Post by Pascal »

Nice list Eric...impressive.

I don't know who that person was stating that dropped 'I' from Date Codes, but that was not done before 1948...
It's a shame much of old information is lost in time due to fires, negligence or simply throwing papers away without giving it much thought..
Although much is made digital over the last years, not all is (or ever will)...so we're flying blind sometimes...no paper-trail to follow.
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Re: Aging an engine by crankcase numbers.

#26

Post by Speeding Big Twin »

Thank you. I agree the letter I was not dropped before 1948. But if it was skipped for 48 and/or 49 then what parts did that omission apply to? Exactly what happened with that letter and the letter M? For me the situation remains unresolved at this stage as far as aluminium parts are concerned.

In his 37–64 SE (2014) Palmer said from 1948 and on the letter I was dropped from cast-aluminium DCs. However, via email in 2012 I had told him I had photos of I8 on 1948 BT trans lids, I 9 on 1949 BT trans cases, I8 on a Pan left case and I 9 on a Pan R-H case. Palmer replied, saying he had I8 on a 49F although he didn’t say what the part was. Crankcase? Trans case? He didn’t say.

Below is a photo of M9 on a 45ci left case but it doesn’t necessarily mean the letter I was skipped for DCs on these cases in 1949.
M9 on Flathead left case.jpg
M9 on Flathead left case.jpg (189.17 KiB) Viewed 4073 times
Do you have any info about the letters I and M for 1948–49 DCs on cast-aluminium parts, 45ci and/or BTs?
Eric
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Re: Aging an engine by crankcase numbers.

#27

Post by Pascal »

No sorry Eric; my info comes from the same books you read and mention.
Haven't seen examples that contradict these claims.
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Re: Aging an engine by crankcase numbers.

#28

Post by 1950Panhead »

I had told him I had photos of I8 on 1948 BT trans lids, I 9 on 1949 BT trans cases, I8 on a Pan left case and I 9 on a Pan R-H case.
Have you seen an M8 or M9 on any of these parts?
Below is a photo of M9 on a 45ci left case but it doesn’t necessarily mean the letter I was skipped for DCs on these cases in 1949.
Have you seen an I9 on a 45 left case?
old man emu
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Re: Aging an engine by crankcase numbers.

#29

Post by old man emu »

Would it be a useful if we posted the casting date code and corresponding crankcase numbers and engine numbers so some documentation could be created for researchers?

OME
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Re: Aging an engine by crankcase numbers.

#30

Post by Speeding Big Twin »

Liberator, thanks for your reply. I have several examples of DCs that contradict Palmer and I posted some on CAI in the thread about errors in his 37-64 SE. In 2012 I even sent him photos of a certain BT trans case with features indicating it had not been cast in 1939 but in later-1949. It has date code I 9.
I 9 on BT trans case.jpg
I 9 on BT trans case.jpg (70.41 KiB) Viewed 4034 times
I also have several examples of I8 on BT trans lids cast not in 1938 but in 1948 as per the one below.
Eric
I8 on BT trans lid (1948 casting).jpg
I8 on BT trans lid (1948 casting).jpg (123.13 KiB) Viewed 4034 times
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