Cylinder I.D.

[Chris Haynes]

So how did they change that letter???? different set of mothers for every month? I seriously doubt it, that makes no sense from a production stanpoint.

Brian,
I don't know how or why they did it. It the Knucklehead years you see those letters. Sometimes next to the plate and other times just around the corner from it.

[panz4ever]

bmh, could you clarify what you stated here please..."Date codes don't even appear until very late 50 models...." as in late 1950? or as in late 50s models?

And you offer that the code is week (Julian calendar) and year. Therefore there should be week codes from 32-52. Perhaps you or someone here can post a pic establishing this.

[Chris Haynes]

Here are a few cylinder flanges with the Month letter not on the same plate as the day and year numerals. Some are right side up and some upside down. On some the letter is around the corner from the numerals.

[harleytoprock]

BMH, It doesn't make sense to me either. From a production standpoint , you would think they would have a glue on symbol to specify the year and would stay on all year. Then the screw on tag would be changed daily that would specify month and day. Or even a screw on tag that include month,day, year. Why would they want to change a glue on symbol monthly?

[panz4ever]

harleytoprcok...well there are no tags on cylinders that indicate m/d/y; there is a cast letter (its intended purpose in question) and a cast 2-number (its designation is also in question). So are you suggesting that the letter represents the year? (starting when?) and the numbers represents the month and day?

One reason why that is probably flawed analysis... there is no 31 st month and there are only 30 days in September.

[Chris Haynes]

harleytoprcok...well there are no tags on cylinders that indicate m/d/y; there is a cast letter (its intended purpose in question) and a cast 2-number (its designation is also in question). So are you suggesting that the letter represents the year? (starting when?) and the numbers represents the month and day?

One reason why that is probably flawed analysis... there is no 31 st month and there are only 30 days in September.

That looks like an August 31 1949 to me.

[panz4ever]

That looks like an August 31 1949 to me.

Chris agree with you. Just trying to point out the failed logic in his post that the 'screw tag' would translate to 'month/day'

[Chris Haynes]

Chris agree with you. Just trying to point out the failed logic in his post that the 'screw tag' would translate to 'month/day'

As I was agreeing with you.

[harleytoprock]

I'm not pretending to have the final answer. I'm just exploring different possiblities which I have to admit are running out. Your right, there are only 30 days in September. Although it wouldn't be the first time a foundry worker made a date error. At one point, I figured the letters represented the pattern ID as I'm sure they weren't casting one cylinder at a time and they probably were using a whole bunch of patterns. The whole purpose of dating castings weren't so people could tell if they had the right castings for their restoration 50 years later. Quality control and knowing when the failure occured by which pattern was the main concern. Have we seen all 12 monthly letters and none more? Again, why the glue on monthly letter? Why wasn't the whole date (month, day year) incorporated on the screw on tag like the auto world does?

[Chris Haynes]

Again, why the glue on monthly letter? Why wasn't the whole date (month, day year) incorporated on the screw on tag like the auto world does?

That is a question for Motor Castings Company. In later years they did go to a screw on plate with month-day-year on it.