Knuckle Heads on Panhead Bottom End

[PanKnuck]

I have a 1950 Pan Bottom End That had a Shovel Head Top End.I sold the Shovel Heads and Cylinders and would like to install a Knuckle Top End.Are there any modifications i would need to do to install these heads & cylinders on a Pan Bottom end?I would be happy to provide more info as far as numbers or photos or more info if needed.This engine will be for a Bobber Project that i will be working on this winter.
Thanks

[T. Cotten]

PK!

Your greatest challenge will to be to find a way to drain the heads without boogering classic hardware.

Gravity alone won't cut it.

I have a dormant similar project.
My choice is to grease-zirque some early rocker shafts, and not oil at all!

....Cotten

[indianut]

Cotten, I really don't think Boogering Classic Hardware should be a concern of yours when figuring out your oil return dilemma!

[Rooster]

Interestingly, I have a set of '41 Knuck cases with a panhead upper end grafted on. In this situation, there are two issues to deal with. A panhead cam must be used so the valve train geometry functions properly, of course, and because of this, the rear intake tappet roller (innermost lobe) does not ride fully on the cam lobe, it is partially off the lobe. Therefore, condition of the needle bearings must be checked more frequently.
Second issue is oil feed; the panhead cylinders must be drilled and tapped into the internal oil passageway, and an external line with a 'T' in it fabricated to feed from the fitting in the timing cover, much the way a knucklhead is fed.
I've ran this motorcycle for 35 years with no problems.

I mention this because you will need to run a knucklhead cam, and I wonder how the tappet rollers will align. I am certainly not a 'motor guy', perhaps an expert motor builder will have better details.

[T. Cotten]

Cotten, I really don't think Boogering Classic Hardware should be a concern of yours when figuring out your oil return dilemma!

Indianut!

Drawing vacuum on Knuckle heads would require boogering the Pan cases (except '65).
I cannot endorse that, even though I've done many worse things myself.

Merry Christmas everyone,

....Cotten

[koanes]

When S&S was developing their Sidewinder Kits for the knucklehead they returned the oil thru the timing plug hole with a fitting they made. They initialy installed a one way valve in the return as well but decided it hurt more than helped the flow at higher RPM. They ran the motor very hard in the dyno and it returned oil from the tins without a problem. Interestingly, they made the most power with a set of small port heads that Sid pulled out of his stash to try.

[Jerry Wieland]

Kyle That interesting - where did they return the oil to - the timing hole only without a check valve?

My experience has always been that a small port 61 will out run a big port 61 but have always wondered how the small ports would do on a bigger engine.

We talked about that picture of one of the very earliest "Tramp" bikes that S&S built that stated that it was a 80 inch 1947. It was a single carburatored bike with 1939 vintage heads on it. I someday would like to build a 74 inch knuckle with small port heads just to see.

Jerry

[T. Cotten]

Hey Kyle!

I saw that S&S machine in a magazine.
Always wondered how the bike drained when just tooling around the countryside, instead of full-tilt dyno torture...

And why the MOCO went to such byzantine extremes to pull a vacuum?

Know anyone who tried it and got the same results?

When I was a test-tube juggler, we called such data irreproduceable.

...Cotten

[Rubone]

Hey Rooster,
How about some close up shots of the engine in your Pan/Knuckle hybrid. If it truly has knuckle cases there are several things I am curious about. And I am sure others are as well.
Robbie

[dommi7]

Rooster, I'm curious too.

Hey Rooster,
How about some close up shots of the engine in your Pan/Knuckle hybrid. If it truly has knuckle cases there are several things I am curious about. And I am sure others are as well.
Robbie

[Rooster]

Hey Rooster,
How about some close up shots of the engine in your Pan/Knuckle hybrid. If it truly has knuckle cases there are several things I am curious about. And I am sure others are as well.
Robbie

Robbie, what exactly are you curious about and what would you like closeup photos of? Wanna start with how the oil is supplied to the top end? The panhead cylinders were tapped into the oil passageway, and a custom-made oil line with a 'T' in it feeds from the kucklehead timing cover. Here's a photo of that.