Cylinders for an early-50 model Panhead

[Speeding Big Twin]

I’m still trying to find out when date codes first appeared on H-D Panhead cylinders. Two weeks ago I started threads on this forum and the Panhead and Flathead forum. Both threads have received more than 90 views but no answers yet which is why I’m starting this new thread.

When AMCA judges examine an early-50 model Panhead do they check the cylinders for date codes in the belief that codes from certain months should be present?
And if so, what is that belief based on? And what months should these codes be from?

Also what happens if no date codes are found but the cylinders appear to be H-D? How would judges determine if the cylinders are correct or not for an early-50 model Pan?
Eric

[Chris Haynes]

Cylinders are wear items that get replaced during the life of a motorcycle.

[Speeding Big Twin]

Cylinders are wear items that get replaced during the life of a motorcycle.

Some cylinders may get replaced during the life of a motorcycle. But I imagine some antique motorcycles still have their original cylinders.

Here are my questions again:
1. When AMCA judges examine an early-50 model Panhead do they check the cylinders for date codes in the belief that codes from certain months should be present?
2. And if so, what is that belief based on? And what months should these codes be from?
3. Also what happens if no date codes are found but the cylinders appear to be H-D? How would judges determine if the cylinders are correct or not for an early-50 model Pan?
Eric

[duffeycycles]

They only take a few minutes per bike.I have seen many unnoticed incorrect parts on high point restorations.Club politics have also altered judging.

[BNSONS]

H-D Factory replacement cyl. don't have date codes.

[Chris Haynes]

According to AMCA Judging Replacement or Reproduction parts are allowed on restored machines as long as it is the best available. Unrestored machines must be original parts with the exception of wear items. These being parts replaced during the normal life of a motorcycle. Tires, chains, ignition, lighting, upholstery, and any other parts replaced when they are worn out. Cylinders wear out.
I have never seen a date code on '48-'50 as where the were was machined away for base nut clearance.

[Chris Haynes]

H-D Factory replacement cyl. don't have date codes.

I have several NOS cylinders with date codes. Do you think that Motor Casting Company knew whether their castings were going to be used as replacements or not?

[Speeding Big Twin]

I have never seen a date code on '48-'50 as where the were was machined away for base nut clearance.

I too haven’t seen DCs on 1948–49 model Pan cylinders. But I’ve never seen evidence that they were machined away for base nut clearance. I know some DCs were partly machined away in that area on Knuckle cylinders because some of the DC plate is still visible as proof of what happened. But on Pan cylinders I’ve never seen evidence that their DCs were machined away in that area. Do you have evidence of this happening with 48–49 model Pan cylinders?

And you also think DCs for 50 were machined away for base nut clearance? What makes you think their DCs were in that area in the first place?
I’ve never seen evidence of DCs for 50 being machined away. Instead I’ve seen DCs on Pan cylinders for 50 and here’s one of the earliest examples I have. Judging partly by the size of the plate the DC appears to indicate casting on January 24, 1950 (as opposed to 1960).
Eric

[BNSONS]

I have several NOS cylinders with date codes. Do you think that Motor Casting Company knew whether their castings were going to be used as replacements or not?

I also had NOS cylinders with date codes, the key word is replacement (Factory replacement parts). Just like NOS replacement rear fenders with two sets of taillight mounting holes. The Factory didn’t obsolete parts for knuckles and pans for at least 10+ years after the model production run. In that time, if a Dealer needed a cylinder for a certain model, and it’s 1969, but the customer needs a rear cyl. for his old 51 pan, The Dealer calls up the Factory. Now, do you believe the Factory has a man running up and down the cylinder isles looking for a date coded 51 cylinder? He goes to the replacement parts and gets a pan cylinder. Either front or rear, 61” or 74”. The production run has long been over, there is no need for date codes anymore, it’s dimensional fitting and specs.

[Speeding Big Twin]

I have never seen a date code on '48-'50 as where the were was machined away for base nut clearance.

I still see no evidence that DCs on Pan cylinders were machined away for base nut clearance. What makes you think it happened with Pan cylinders for any of those three years?
Eric

[Speeding Big Twin]

As I mentioned above, I know some DCs were partly machined away on Knuckle cylinders because some of the DC plate is still visible as proof of what happened. Here is an example.








Bruce Palmer is aware of this too and he provided a photo on page 270 of his 37–64 SE. Apparently for Knuckle cylinders the DC plate was only in this position for those produced from about mid-40 thru about mid-42?

But did any Panhead cylinders have DCs in that area? And if so, were they removed for base nut clearance?
Eric