Harley EL four fin cylinder?

[T. Cotten]

Ric!

"Torque plates" are machining fixtures that distort the cylinder as if installed.
The amount of distortion of a standard bore cylinder is negligeable, as they were designed to be.

By the time the cylinder is .060" oversized, however, the distortion is significant, and it increases dramatically beyond that overbore, to the point where the piston skirts will rub the cylinder.
Stressing the cylinder for machining becomes critical.

The benefit of stress-plating lesser bores is that warm and cozy feeling of achieveing the ideal, whether critical or not. A round cylinder will have the best ring seal, which we presume should extend its life.

....Cotten

[ricmoran]

Tom,

Thanks for more info.

What I am scratching my head is to understand how a torque plate could be used on the old cylinder design VS the new cylinder design where the holes would not line up VS the new design where the holes would line up.

Is there an offset assembley to accommodate this or how is the machine set up to handle that on something like a .060" over bore? Is there a sweet spot, where plates should be used, say starting at .040" for best results, or is it just at the max of .060"?

Is it possible to cut the skirts back or to taper them as well to aid in better efficent fit?

By the way, the peek seal system work you did for me is working well, I may be sending you another manifold sometime in the near ffitmentsor fitment as it never hurts to have a reserve!

One thing that is really strange is I am getting a black soot build up on the front cylinder and a perfect burn on the rear. I had a manifold to carb leak issue as previous I found the rear plug burning quite lean.

Thought well the heads are fine as when tested previous there were no leaks at the inserts, it has the peek seals so I figured it has to be the carb perhaps coming loose at the manifold.

There was a stripped hole in the carb body on the rear cylinder side, lower screw. And that is squared away for now. I took the manifold off, and found the somehting that was rather strange, there is a lot of corrosion build up inside the manifold. I have never seen this before.

I know I live in a humid chloride and sulfuric dioxide rich atmosphere form the volcano, as rainfall here is about 4.5 pH, but to have that happen was an eye opener. I cleaned it up and reinstalled the manifold but this does not take rocket science to realize that air flow = surface erosion, then when ethanol fuel that seems to have H2O in it along with the corrosion rich atmoshpere tells me it is just a matter of time before the manifold pin holes.

Crazy stuff for sure.

[Rubone]

The torque plates as Cotten mentioned are merely BOLTED to the flanges just as a head and a crankcase would be thereby creating distortion to the bore when tightened to proper torque values. No offsets, no magic, just plain old physics blended with common sense. The theory being that when bolted on the actual cases and heads the distortion would be repeated and the finished bore would once again become round!
Robbie

[T. Cotten]

I could quickly upload a pic of torqueplates,
if only this wasn't such an over-engineered website.

....Cotten

[ricmoran]

Tom, No need worry about it. I can see all one would have to do is use a 1/2" metal plate with the holes drilled and the diameter of the top/bottom spigot to fit into the plates and you'd be good to go.

Thanks Robbie and Tom & Robbie for the info.......it is time to go RIDING!!!! Yea! Blue skies, and the trades are blowing at 20 - 25 to keep things cool!

[Chris Haynes]

My JDH had F Panhead pistons in it.