Board index Flathead Power- General Announcements and Various Subjects Motorcycle Trivia Identify the cylinder contest

Identify the cylinder contest

Test your knowledge or someone else's with trivia questions about your favorite subject. Let's be realistic with the questions so everyone has a chance at answering them.

Moderators: Curt!, Pa

Post Sun Jan 28, 2007 6:59 pm

Posts: 607
Location: Menomonie, Wisconsin, USA
Here is a link to a cylinder. I would like to hear from our experts on what vintage they think it is and whatever else that they may know. Hopefully the answer will surprise a few people.

Follow the link and look under Knuckle cylinder.

http://new.photos.yahoo.com/hd36ohv Thanks Jerry

Post Sun Jan 28, 2007 8:23 pm

Posts: 640
Location: Wisconsin, USA
Looks like a rear cylinder from a 36 knuck. What am I missing?

Post Sun Jan 28, 2007 8:29 pm

Posts: 2687
Location: Los Angeles, CA
It appears to be a 4 fin 1936-1939 61" OHV cylinder.

Post Sun Jan 28, 2007 10:34 pm

Posts: 607
Location: Menomonie, Wisconsin, USA
I am going to let this go for a few days and see what happens. Kyle, you know the answer if you just think about because you and I have talked about it.

Jerry

Post Mon Jan 29, 2007 8:48 am

Posts: 2687
Location: Los Angeles, CA
Perhaps if we had more than one dark photo we could make out what it is. It does carry the part number of a 1936-1939 61" OHV cylinder.

Post Thu Feb 01, 2007 8:04 pm

Posts: 607
Location: Menomonie, Wisconsin, USA
Chris I apologize for my poor photos but I am a tractor/motorcycle mechanic and not a photographer.

OK - more about the cylinder. If you are an astute knucklehead kinda guy and see this photo you will come to the same conclusion that Chris came to - 4 fins = 36 to 39. If you even more knowledgeable you will recognize this as a 1936/37 cylinder by the raised casting numbers. Somewhere around the 1937/38 split they changed the casting numbers to recessed - I have never been able to determine when.

Now - would anybody believe that this cylinder was actually made much later than that - 1944 to be exact - June of 1944. If you do not believe me go back to original post and follow the link now and see the second shot of this cylinder with its' 6-4 casting date. This is the original rear cylinder on my 1944 E knucklehead. My 1943 E has the same rear cylinder only with a 10-2 casting date. Ronnie Cox's 44 E has the same situation.

Here is the only explanation that I can come up with. All 3 of these bikes have a late 39 casting date on the front cylinder so I surmise that they must have had a bunch of fronts in warehouse and made a rear to match but somehow used the earliest casting mold that they had.

I would love to hear anything anybody has to say about this.

Jerry

Post Tue Feb 06, 2007 11:29 am

Posts: 950
Location: Paris ::: France

Jerry,
Nice info thanks for sharing.

About the recessed / raised casting numbers on cylinders, I have seen an untouched 38 EL export bike in the 3000 serial number range that still had the raised numbers. Hope this helps.
Eric
Eric @ B.O.S
www.beautyofspeed.com
A state of the art power quest

Post Tue Feb 06, 2007 12:54 pm

Posts: 640
Location: Wisconsin, USA
I took a look at a pair of cylinders I have for my 38, with raised part #'s and the casting dates are 12-31 and 10-7. Did they use a week-day system?

Post Wed Feb 07, 2007 11:11 am

Posts: 2687
Location: Los Angeles, CA
I have looked at a few dozen Knuck cylinders in the past few days. It appears the later 5 fin cylinders have a full date code on them. A raised letter fot the month and the tag with the day and year on it. All of the 4 fin cylinders I found had a code system I haven't figured out yet. Things like 41 9. Anybody have a clue to this earlier date code system?


Return to Motorcycle Trivia