Harley Davidson Forums - Looking for info or years on these knucklehead cylinder parts

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Looking for info or years on these knucklehead cylinder parts

Welcome Rachel.

I hope you continue to enjoy your ride here with us on the HDFORUM.

Only as a suggestion, create a signature line similar to my one line on my bike information.

The year, model, and all the letters Harley assigned to the bike. It will appear at the bottom of your post.

Doing this will be helpful if you ask a question, or to someone asking a question. All Harleys aren't the same with many changes and variations over the years.

You can also add a favorite picture to the signature line.

If you like, you can also add a favorite picture for an Avatar you see at the top left of all your post as a postal stamp.

@imoo6170

The @ to the USER IMOO6170 is flaging (poking) a Community team member.

Being the Welcome Area this area is not the best area for questions.

Probably this area would be better.

☆Here… https://www.hdforums.com/forum/knuckle-head-63/

If the Community team imoo6170 moves this thread, make another new post here in the Welcome Area to say hello.

Or you can just make another new post yourself but title it slightly different.

Welcome from Spartan Country, Michigan!
I tell a lot of new comers to the forum to get: Factory Service manual and the Parts manual. Take to an office supply store and have them put a spiral binder in place of the glued binder. That will let the manuals lay flat on your bench. Get a three ring binder and record all your maintenance, repairs, accessories, etc. This will be a great reminder of what was done when. And great material to pass along to the new owner should you sell and upgrade. Also know how large your fuel tank is, a rough idea of your range per tank, and record your fuel usage. I have an app called Simply Auto that I record all my fuel used. I use the odometer and use the fuel gage as reference only. I reset the odometer to zero on fill ups, and I know I can safely get 200 miles on a tank on around town riding, and upwards of 230+ on trips.

@rk2095561 I have moved this post from the Welcome section - you will get a better response in this section thatn in the Welcome section. Suggest that you create a new post in the Welcome section and introduce yourself

OP you need member @Speeding Big Twin he`s the guru on numbers
Disregard post # 3
Get your "google on"
61" std bore was 3 5/16ths
74" 3 7/16ths
https://cimg2.ibsrv.net/gimg/www.hdf...75d3cbaf7b.jpg

Just so you know the early cylinder were prone to crack as you over bore them

Rachel, welcome to the forum.
On one cylinder the date code looks like 7-28? If so it indicates casting on July 28. And this cylinder may have been cast in 1936 so it may be a 61ci cylinder.
The triangular logo represents Motor Castings Company in Milwaukee.
Is this the cylinder with 1-35? It’s a casting number for front cylinders.

On the other cylinder the letter D indicates April and one number looks like 25? If so the cylinder was cast on April 25. But what is the other number? Is it 8? If so I think it indicates casting in 1938 so it may be a 61ci cylinder.
Again the triangular logo represents Motor Castings Company in Milwaukee.
Is this the cylinder with 1-352? It’s a casting number for rear cylinders.
Eric

eighteight, thanks for the kind words.
Re the info below that you posted, I know where the trans case date code info that I highlighted is from but where is the rest of the info from? Is it from the same person? Can you post a link to it please.
Eric

https://i.imgur.com/4dcOcxk.jpg

Sorry , it was a random pop-up labeled "Copilot"
The "this site" doesn`t respond and I lack the savvy to follow it backwards
https://cimg8.ibsrv.net/gimg/www.hdf...56629de170.jpg
.

Thanks. That text says when it comes to Knuckle cylinders the ‘casting numbers’ can reveal interesting details. But then it dives into DCs so what casting numbers was it referring to?

It also says the letter corresponds to the month (eg, A = Jan, B = Feb and so on). That gives the impression that the letter I would have been used (to indicate Sept) but in Knuckle cylinder DCs the letter I is something I have never seen and it appears to have been skipped.

It says the first number after the hyphen represents the day. But the text had already mentioned that typically a letter was part of the DC so when a letter is present the first number after the hyphen won’t represent the day but will instead represent the year.

It says for instance a Knuckle cylinder cast on Sept 1, 1938 would have a DC like 00-00. But again the text had already mentioned that typically a letter was part of the DC so why doesn’t it say what letter was used for Sept? And because it doesn’t say, people may think Sept was represented by the letter I. But it wasn’t and that letter appears to have been skipped as I mentioned above. And why does the text indicate four characters on the DC plate when in that particular instance only two would be needed?

As an example of a cast-iron DC for Sept 1, 1938, here’s a Knuckle front cylinder. The DC plate has 1-8 and the letter is J.
Eric

https://i.imgur.com/q68ZmcN.jpg