Identifying VIN engine

Identifaction of VIN, case numbers and cylinder heads
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ozpan
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Identifying VIN engine

#1

Post by ozpan »

Can anyone tell me what this weird mating is, and what the numbers denote

Hello, I'm new here but have already got a lot of information from the forum. But I need some help identifying my engine: my bike's registered as a '55, but has an aftermarket left side alternator case, numbered 55FLH4008, with the belly number 173-2686. There are no makers' marks or logos, just an 'H' behind the rear cylinder. The right side case is numbered 155-1166. Can anyone tell me what this weird mating is, and what the numbers denote? Any ideas who the manufacturer of the left hand case could be? Thanks!



fourthgear
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Re: Identifying engine

#2

Post by fourthgear »

ozpan
I am no expert in this , but it looks like it is a renumbered 1973 left case and a 1955 right case . Not absolutely sure and am surprised that others here that do, some what of which they speak haven't answered this . I could be wrong ,but I do know they didn't make alt. cases in 55. Could be after market . Are your numbers in a number boss on the left case? Because I think in 73 stock HD's did not have a boss on them like Panheads do. I think it changed in 70 with the cone type Shovels.

caschnd1
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Re: Identifying engine

#3

Post by caschnd1 »

The belly number tells what year the case was machined. 173-xxxx indicates this was a 74" case (the first digit) machined in 1973 (the second and third digits). The xxxx portion is just a sequential number that would have matched the other half of the case. Perhaps the left side case on your motor was damaged and replaced with this repair case. This case would have come with a blank number boss and the repair shop (or Harley-Davidson?) would have restamped the new case with your old 55FLxxxx number.

Well... that's one way it could have gone down. No way to know for sure.

-Craig

ozpan
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Re: Identifying engine

#4

Post by ozpan »

Thanks Craig: so that 173 number means it's definitely an HD case? Would they have made pan alternator repair cases in '73? Presumably a generator case can't be machined for an alternator?

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Re: Identifying engine

#5

Post by mbskeam »

well you never know what went on in the back room of some places.

but if some cop wants to really look at the numbers, Top and Bottom you WILL have problems. as you try to explain why it says 55 on the side and 73 on the bottom.

what does the title say?

mbskeam

ozpan
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Re: Identifying engine

#6

Post by ozpan »

It's registered as a '55. Still can't see that HD would have been making alternator Pan cases though.

rigidpanman
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Re: Identifying engine

#7

Post by rigidpanman »

harley may have still been making gen cases for reasons like that.

caschnd1
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Re: Identifying engine

#8

Post by caschnd1 »

Ok...I'm going to have to dig up my "What Fits What" book now. I thought that you could used an alternator (shovel) left side case with a generator right side case. This may be what you have. They may of had to swap to a shovel motor shaft on the wheels and maybe do some other modes as well. But I'm pretty sure you can make it work.

Regarding the motor number and the belly number not matching. It's not uncommon for these numbers to mismatch in terms of the years. Harley would machine a bunch of cases, say in 1950 and then they may not use all of them until well into the 1951 model run. So the motor number is 51FLxxxx and the belly number is 150-yyyy. The belly numbers and motor numbers do not have to match. Now in your situation you have a belly number that is 18 years apart from your motor number. But there is no way to get around that when you have to replace a case half. Whoever repaired it way back when would of had a tough time finding a case with a 1955 belly number.

-Craig

ozpan
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Re: Identifying engine

#9

Post by ozpan »

Ah! That's what I was wondering. It seems the most likely scenario that it would be a shovel case (would it have been a very early alternator case in '73, can't remember when the generator shovels phased out). It needs a new inner primary so at least I know what to look for now, thanks guys! No wonder the bike was cheap!

fourthgear
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Re: Identifying engine

#10

Post by fourthgear »

hplhp
1970 was the first year of alternator cases and also the first year of the cone type cam case. How are the numbers put on? The alt. cases were not on a number boss on the left case.

ozpan
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Re: Identifying engine

#11

Post by ozpan »

fourthgear, no boss, numbers are stamped into the flat metal between the cylinders.

fourthgear
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Re: Identifying engine

#12

Post by fourthgear »

ozpan
Sorry about wrong name calling . I didn't think there was enough room on the flats between cyl. , but you do have a left shovel case . I would keep all paper work with you when ever you ride . In some states they get real pricky about that kinda stuff and Datona Bike week is one of them.There was a story here about a bad experience with numbers at DBW . Have you had it checked out at your local highway patrol? Although that might not be a good idea and may hurt you,But I would have to know, one way or another.

ozpan
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Re: Identifying engine

#13

Post by ozpan »

I'm actually in Australia, and it's very unlikely anyone (especially cops) would know to check the belly numbers. The case number will be checked against my registration documents once a year for the annual inspection, but that's about it. So I'm not too worried ... thanks to all replied for clearing up that mystery!

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