Maney cases

I have a set of Steve Maney cases and they SEEM to run hotter than stock cases. My guess is that they are thicker and hold heat longer...am I correct? also the primary case SEEMS to run hotter than usual. I am guessing that the motor cases are transferring an unusual amount of heat to the primary cases so they too are running hotter. The bike is running like a champ with no apparent problems.

Heat transfer theory dictates that a thicker material will necessarily have a greater temperature differential from one side to the other, as compared to similar, but thinner material, when both materials are conducting the same quantity of heat.

In your case, comparing Maney cases to stock (no pun intended), theory says the interior temperature will be higher with the thicker case. The outside temperature should be little different.

IMO, I doubt one could tell any difference "by feel", particularly since Maney cases are thicker only at areas of high stress. If you are certain your Maney cased engine is running hotter, I would investigate other factors such as mixture and timing. Did compression ratio increase pre-post Maney? What about barrel paint and color? A thick powder coat on barrels could increase temp, as would silver paint vs black.

Slick

Jim Comstock did some testing on the temperature of cylinder barrels with different coatings, black, silver, powder coated etc. His general impression was that it didn't make a great deal of difference to the cylinder temp.

gripper said:

Jim Comstock did some testing on the temperature of cylinder barrels with different coatings, black, silver, powder coated etc. His general impression was that it didn't make a great deal of difference to the cylinder temp.

Click to expand...

The key word in my post above is <thick>. It makes a difference principally because it smoothes out the surface texture and reduces convective heat transfer. I doubt Jim would ever apply powder to barrels, much less in a thick manner (which may be unavoidable ... which is probably why he would not do it). As far as colors, I am familiar with Jim's post, and I do not think his testing protocol was sensitive to radiation heat transfer, which would detect a difference due to color. I discussed this point in Jim's thread.

The main point of my post was to discount the Maney cases as the source of the perceived temperature increase that the OP reports.

Slick

The timing is correct, the compression is a little higher using the JS rods and pistons. The carburetion is the stock Amal concentrics. It starts in one kick sometimes not even that much. It runs very well. But it appears to be giving off quite a bit of heat. I have not measured it yet but will do so today after a 5 mile run. Will post later. By the way, I am at sea level.

A Commando can handle tremendous heat. As long as your ignition timing is set, you are not pinging the hell out of the engine and your plug chops are looking decent I would not worry about it.

My hunch is you have bumped the compression up a bit which usually yields more heat.