74 cylinders

[exeric]

A friend of mine is building a late 74" knuckle motor and is looking for cylinders. I asked him about reproduction cylinders and if someone was making a good copy that looked right and had the right material composition. I hear that you can get a good Indian cylinder from India. How about for knuckleheads?

[Chris Haynes]

There are several companies making repop Knuck cylinders. V-Twin carries three or four different brands and S&S has the FHP cylinders.

[Lonnie]

I have the "Replica" V-Twin cylinders on my '42 which have the markings and passed AMCA judging - no problems at about 1800 miles. I bought them as the pre-fitted set with pistons and clearances were good. I have been told by a reputable engine builder that he has seen sets with the clearances out of whack and has had to bore them .010" over. So if you go that route double-check them.

[exeric]

Thanks Lonnie, I'll pass that information on to my friend.

[Chris Haynes]

I have the "Replica" V-Twin cylinders on my '42 which have the markings and passed AMCA judging

That is great, until you run into the judge who checks date code castings.

[dommi7]

That is great, until you run into the judge who checks date code castings.

So what should the cast codes look like?
Do all originals have the M over C inside the triangle? Or is that only for the early 4 fin cylinders?

[Chris Haynes]

So what should the cast codes look like?
Do all originals have the M over C inside the triangle? Or is that only for the early 4 fin cylinders?

That is the trademark for Motor Casting Company who did the casting.
Here is an example of date codes. The letter is the month. A=Jan, B=Feb, ETC. Note that the letter i was not used so it wouldn't be confused with a number 1.
The first number is the day, seperated from the second number by a hyphen. The second number is the year.
This jug was cast on September 1, 1938.

[dommi7]

Great info Chris - thanks.
So the 5 fin cylinders don't have the Motor casting company logo? At least the 4 I have do not. And the month code is 'around the corner' on the adjacent face.
Can you confirm this is correct?
(see the panhead thread for another question)

[Chris Haynes]

Great info Chris - thanks.
So the 5 fin cylinders don't have the Motor casting company logo? At least the 4 I have do not. And the month code is 'around the corner' on the adjacent face.
Can you confirm this is correct?
(see the panhead thread for another question)

Correct on both counts. The MCC logo came and went several times.