Cylinder date code?

[Robert Luland]

Is there a date code to the casting numbers on the sides of Panhead engine cylinders? I looked it up in Palmer's bible and he talks about the three differant types and years but makes no refrance to the casting numbers, Bob

[Chris Haynes]

Is there a date code to the casting numbers on the sides of Panhead engine cylinders? I looked it up in Palmer's bible and he talks about the three differant types and years but makes no refrance to the casting numbers, Bob

Yes there are date codes on cylinders.
There is a letter. This is the month. A=January, B=Feb, ETC. The letter i was skipped so and not to be confused with a 1.
Then come the numbers seperated by a hyphen. Like 00-00. The first number is the day and the second is the year. See this Knuck cylinder cast on September 1, 1938.

Note that pre 1938 codes were different.

[Robert Luland]

So Chris does this dateing code follow though the fifthies and sixties. Bob

[dommi7]

One other question, Chris - Did 1948 also include a casting part number on the base flange in addition or in place of the date code?

[Robert Luland]

Ralph, My 48 cylinders have the casting numbers. Rear has the large E and2-7 on the tag. The front has 9-7 onthe label. Theres a round circle were the letter would be but I guess there was a screw up when they casted it. Hope this helps, Bob

[HD48FL]

One other question, Chris - Did 1948 also include a casting part number on the base flange in addition or in place of the date code?

I've heard different opinions on '48 cylinders. I have a set, that I believe are '48, one has no markings and the the other, I believe the rear, has a stamped number. I've been told by others that this is how they were in '48. Don't know, but if anyone has what they think are accurate '48 cylinders then post pics for all to see.

[Robert Luland]

The cylinders I mentioned eailer were Panhead made in 47. How much more proof ya need but i could be wrong. Bob

[bmh]

there was an early set of cylinders that did not have date codes, they were marked 120-48 on the front cyl only I think. these cyls are different in the oil return area, the block aronnd the return appears heavier and the fins appear smaller. These were used in 48 and perhaps some of 49. here are some pics of one.

[HD48FL]

there was an early set of cylinders that did not have date codes, they were marked 120-48 on the front cyl only I think. these cyls are different in the oil return area, the block aronnd the return appears heavier and the fins appear smaller. These were used in 48 and perhaps some of 49. here are some pics of one.

That's the stamping that I referred to in my last post. I have a set and they look the same.

[Chris Haynes]

That's the stamping that I referred to in my last post. I have a set and they look the same.

Calling a cast in part number a stamping can lead to confusion.
I have looked at the 1948 factory photos and the cylinder casting numbers are on the flat surfaces of the cylinder base that face each other and are not visible.

[HD48FL]

Calling a cast in part number a stamping can lead to confusion.
I have looked at the 1948 factory photos and the cylinder casting numbers are on the flat surfaces of the cylinder base that face each other and are not visible.

Do you have pictures? I said "stampings" because that pic bmh posted shows 120-48. To me that number looks like it was stamped in?

Anyway, if you have pics, post 'em. Are you saying that the pic that bmh posted isn't accurate for '48 cylinders?

[Chris Haynes]

Do you have pictures? I said "stampings" because that pic bmh posted shows 120-48. To me that number looks like it was stamped in?

Anyway, if you have pics, post 'em. Are you saying that the pic that bmh posted isn't accurate for '48 cylinders?

No, I was just saying that by you use of stamping for a casting number is confusing. It doesn't matter it the casting number is raised or depressed it is still a casting number.

[HD48FL]

No, I was just saying that by you use of stamping for a casting number is confusing. It doesn't matter it the casting number is raised or depressed it is still a casting number.

I see what you're saying!

[bmh]

Chris, while I agree these are casting numbers, they are not the typical H-D type deal. these numbers are stamped in and I have seen them only on front cylinders, the rears are unmarked which in itself is curious. At first I thought the marks had to be cast in but after examining more than a dozen or so sets in the past couple months it became appearant they are "stamped" into the part as the spacing and alignment of the numbers is not all that consistant. The later style has the typical raised tags except the code has an extra digit added. for example the front cyl on a mid 51 that I have pics of has the code 24-0 in a large oval tag. from the ones I've seen it appears the first number is a dummy so I think this code is april 1950, any one know if that is correct? I would be very interested in knowing what the earliest date code anyone has seen on a set of pan cylinders.

[Chris Haynes]

Chris, while I agree these are casting numbers, they are not the typical H-D type deal. these numbers are stamped in and I have seen them only on front cylinders, the rears are unmarked which in itself is curious. At first I thought the marks had to be cast in but after examining more than a dozen or so sets in the past couple months it became appearant they are "stamped" into the part as the spacing and alignment of the numbers is not all that consistant. The later style has the typical raised tags except the code has an extra digit added. for example the front cyl on a mid 51 that I have pics of has the code 24-0 in a large oval tag. from the ones I've seen it appears the first number is a dummy so I think this code is april 1950, any one know if that is correct? I would be very interested in knowing what the earliest date code anyone has seen on a set of pan cylinders.

I would love to see a pnoto of your jugs with factory stamped part numbers on them.