VL front cylinder

[Buster]

I have been searching for sometime for a rebuildable front cylinder for my 1932 VL. Why are front cylinders so hard to find, I thought it was rear cylinders that were most worn out. Also, I have talked to several members that have had valve seats replaced on VLs, but they cannot remember who did it. I know this is a much discussed subject, but does anyone know of someone good that replaces flathead valve seats. Has anyone here had valve seats,successfully replaced on a flathead.

[exeric]

I've always heard it is the front cylinder on a V-twin that gets hotter than the rear; and that is because the front fender blocks air flow.

[T. Cotten]

Golly Eric,

You have opened the door for armchair engineers to argue endlessly!
Some figure that the un-even degrees of timing draws more cooling fuel to the rear; Some figure the vertical throttleshaft starves the front.
My favorite is "driving force", the same theory that causes hot water pipes to freeze in winter before cold pipes, as the front cylinder actually gets more airflow.

My perspective is that a well-constructed motor will burn evenly on both cylinders.
If not, the manifold is the first suspect.

And Buster!

The problem with seat inserts for Flattys is the higher running temperature.
Modern "hardened" tool steel seats must be installed at an enormous, sometimes destructive press-fit to stay put. Elevated temps cause them to shrink.

Back in the day, replacement seats for cast iron cylinders were cast iron.
Good luck finding them today,

....Cotten

[MMasa]

I like the idea that the rear cylinder gets more oil sling from the flywheels and that the front gets less.
Mark

[Jerry Wieland]

I am prone to believe that whatever cylinder is serviced by the forked rod is more apt to be junk. (Sorry about the thread hijack)

[Steve Slocombe]

With the flywheels turning clockwise when viewed from the right, I also believe like Mark that the rear cylinder gets more oil splashed into it and so runs less hot than the front. Anytime you run out of oil it is the front cylinder that nips up. The closed baffles on the VL front crankcases can then be seen as an effort to suck oil mist preferentially into the front cylinder.

I used to have seat inserts put in and used stainless valves for the modern gasoline, but stopped doing it and went back to nitrided valves and no inserts without apparent ill effects. Maybe restored VLs don't get the mileage they used to.

I sold all my VL cylinders last year, except for the 1936 ones, to a guy in VA. There were some usable early ones in there so maybe he'll chip in to this thread. Front VL cylinders should be harder to find and more expensive than rears, but so far I've not seen this. The swap meets used to be littered with VL cylinders and heads, many holding down tarps in the wind, but it's a sign of the times that much of this old stuff is getting hard to find.

[T. Cotten]

Folks,

Wouldn't the flywheels have to be spinning prettly slowly for a difference in splash between the cylinders?

I'm aware of how Indian attempted to increase oil to the front, so I constructed a plexiglas box over a flywheel sitting in a shallow pan of oil on my lathe, and observed the "windage" of where oil sprayed.

A difference of "front and back" only existed upon start up. Thereafter, a spray in two lines off of the sides of the wheel were constant and even, visible on the top of the box in the attachment.

Presuming the sump is adequately evacuated, any constant supply of oil would come from the rods, and raises two variables for the female rod. Its position, front or rear, and whether it is open or closed. It has been suggested that the closed H-D rod, moved to the rear is cupped to throw oil forward. As if it isn't blasted into mist?

All of these scenarios would only seem to apply to extremely low RPM.

I still think the front shows more heat signatures because more heat passes through it.

....Cotten

[johnnyfire]

I have several.I'll check tomorrow to see what I have and if I can spare one.

johnny

[Rubone]

A rotating flywheel in oil tells little of actual conditions. Without timed pressure pulses and heat of actual conditions your experiment it is merely an interesting example of cling and shear.

[T. Cotten]

A rotating flywheel in oil tells little of actual conditions. Without timed pressure pulses and heat of actual conditions your experiment it is merely an interesting example of cling and shear.

Its more direct, empirical observation than anyone else has offered.

....Cotten

[T. Cotten]

Here's another real-life experiment, Folks!

Its relevant to the "fender blocking the wind" theory, and any and all of you can try it.
Place a lit candle on a table about arm's length away from you, as see how hard you have to blow to put it out.
Then place a bottle right in front of it and compare.

....Cotten