53 Panhead Cylinders

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Sieber60 +
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53 Panhead Cylinders


Post by Sieber60 + »

I'm new to the site, Eric has been helping me ID a frame and swingarm and turned me on to this site. Very cool info. So I would like to ID the cylinders that on a 53' FL motor I bought recently. This is what I see.
Front Cylinder
M 14-9

Rear Cylinder
D 5-0 I think

Appreciate this help!

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Re: 53 Panhead Cylinders


Post by RUBONE »

The letter is the month, the first set of digits the day of the month, and the last digit is the year. They repeat so you could be looking at a '49 and a '50, or a '59 and '60. Then you need to see what other features there are. Prior to '53 there was no drain hole in the side of the cylinder (although some have been owner drilled). So a bit more info will help.

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Re: 53 Panhead Cylinders


Post by Speeding Big Twin »

John, welcome to the forum. In cast-iron cylinder date codes the letter I was skipped due to confusion with the number 1 and therefore M indicates December. In the beginning H-D Pan cylinders had no date codes. It is unclear exactly what month they began but the earliest I’ve seen appears to be from Jan 1950. (It was a rear cylinder.) Check for a drain hole in the bore as Robbie mentioned. For the front cylinder there is something about the top fin that may help determine 59 or 49 so could you please post a photo of the entire top of the cylinder.

D 5-0 indicates casting on April 5 of 1950 or 1960. Again check for a drain hole in the bore. Also in this instance a picture of the date code may help because the date code plates were not always the same size.

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