Confused by Engine VIN
#1
Confused by Engine VIN
I recently picked up a custom chopper and was told the engine is from a 1971 Sportster XLCH. It's definitely an Iron Head with right side drive and shift, but the serial number on the block doesn't make sense. It is 6A10419H1. Everything I read online says the format shown on my engine started in 1970 and that the "6A" is a SS-350 Sprint, although the H1 seems to match the 1971 year I was told the engine was. I just don't see how the "6" could be anything but a "6" (see picture). Any ideas?
#2
#5
You're correct, the prefix "6A" doesn't makes sense on a 1971 motor.
There are some other minor tells on a unaltered OEM 1971 motor..... a few more pics:
- "H1" suggests 1971 for sure
- Combined with the sequence number "10419" suggests an early 1971 motor.
- "6A" suggests it has been altered from original.
There are some other minor tells on a unaltered OEM 1971 motor..... a few more pics:
- left side case
- mounting bolts for the oil pump
- cyl head bolts
Last edited by The Doctor71; 09-01-2024 at 09:31 AM.
#6
More pics….
You're correct, the prefix "6A" doesn't makes sense on a 1971 motor.
There are some other minor tells on a unaltered OEM 1971 motor..... a few more pics:
- "H1" suggests 1971 for sure
- Combined with the sequence number "10419" suggests an early 1971 motor.
- "6A" suggests it has been altered from original.
There are some other minor tells on a unaltered OEM 1971 motor..... a few more pics:
- left side case
- mounting bolts for the oil pump
- cyl head bolts
#7
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#8
The pics reveal:
To find & interpret the numbers, this reference should help (scroll down to belly numbers):
https://sportsterpedia.com/doku.php/...:ih:engmech01b
Fingers crossed the belly numbers haven't been ground off or altered.
- left side case is from a 1000cc motor. That rules out a '71 900cc (actually 883cc) motor.
- cyl head bolts suggest the cyl heads are from a 1000cc motor. Further confirmation we're not looking at a '71 900 cc motor.
- right side case is of unknown origin at this time.
To find & interpret the numbers, this reference should help (scroll down to belly numbers):
https://sportsterpedia.com/doku.php/...:ih:engmech01b
Fingers crossed the belly numbers haven't been ground off or altered.
Last edited by The Doctor71; 09-02-2024 at 07:40 AM.
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pgreer (09-02-2024)
#9
1971 Harley-Davidson XLH Sportster | HowStuffWorks
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rockersteve (09-02-2024)
#10
ahhhh...... I guess you're thinking "primary chain case cover" and "cam cover" ? I am NOT. I'm focused on the the engine castings..... left & right side
So I guess I should have been much more explicit and said:
So I guess I should have been much more explicit and said:
- left side ENGINE casting is from a 1000cc motor. That PRETTY MUCH rules out a '71 900cc (actually 883cc) motor.
- cyl head bolts suggest the cyl heads are from a 1000cc motor. Further confirmation we're not looking at a '71 900 cc motor.
- right side ENGINE casting is of unknown origin at this time
The following 2 users liked this post by The Doctor71:
AJSHOVEL (09-02-2024),
sleighcrane (09-04-2024)