It actually looks a lot like a "Buellized" VROD Revolution motor to me.

 

While you are technically correct, oil is not a coolant in the V-Twin or any other motor. It is the source of heat just as the combustion process is another source of heat. In all the bearings (camshaft, rod pinion and main, and shaft), oil is "pumped" into a decreasing wedge using hydrodynamic forces to establish a very small (.0005"-.0015") film thickness where extreme pressures are realized. It is this film thickness that prevents metal to metal contact between the moving parts and their stationary housings. This causes a significant temperature rise in the oil. Having a larger oil supply will not diminish this rise, just make it easier to cool the oil before it re-enters the same repeating process.

While some of the heat is carried away in the oil, it can be easily cooled enough as to make it a mute point in the design process. Most of the heat created in this process remains in the metal parts since their coefficient of thermal conductivity is very low. If temps in the metallic parts increase too much, the design tolerances in the bearings are decreased due to thermal expansion which results in even smaller oil film thicknesses..higher pressures...higher temperature rises.

Fluid dynamics is a very involved science and almost everything you do will affect something else in the system. You cannot keep raising the HP and torque outputs of the engine past a certain point without either making some radical changes to the system or dramatically increasing the price.

 

I think it is time the MOCO provided options, why not allow you to choose what motor you want at the time of order or purchase, have different derivatives available, I personally do very little town riding so the air-cooled engine suits my needs but a friend of mine commutes to work every day and says he often switches off his bike at traffic lights because his temperature goes so high, give the public the options and see what direction it goes,

 

I pretty much agree with paragraphs 2 and 3 swestbrook, but I must disagree with the description regarding compression of the oil being much of a heat source. Even if a significant heat increase could take place (think about it, fluid dynamics comes to mind but more importantly, physics), it would be a negligible issue at the system level. I'm convinced that the major issue, combustion, and carrying heat away from the heads/cylinders is much more critical.

ETA: Of course I'm also obviously biased...

 

The temperature rise through this wedge will most likely run around 30 degrees F which doesn't sound like much. However, when you consider the actual volume of oil constantly flowing through this area there is a significant build up of heat in the bearing and shaft itself. In higher load systems we often had to go to bearing materials such as chromium copper or Ampcolloy to maintain decent bearing temperatures since they have a much higher coefficient of thermal conductivity. Even higher system we had to abandon "sleeve" bearings and go to advanced design such as tilting pad design and direct lubed systems.

Its true that the oil will also receive some transient temperature gains from the combustion process but the air flow through the fins are the primary method of cooling this area of the motor.

I used 30 deg. F as an estimate temperature rise because that was the basic target temperature rise we designed for when creating rotating and reciprocal machinery such as turbine, turbo-chargers, compressors, pumps, etc. The actual is specific to any given system of course. One of the product design groups I managed for 20 years was for bearings and getting the heat out of them was one of the primary concerns, even in systems that had no other heat source such as combustion.

 

I'm mainly basing my opinion upon some practical experience too but at the system level and cannot/should not dispute the facts you're explaining at the more detailed level. However (and sorry this will be a little long)...

Years ago (many years , but I'm pretty sure it's still valid) I was drag racing a Norton Commando and my sponsor, a small dealership for Nortons and Yamahas, was able to obtain some expert help from Don Vesco (BTW - he helped a LOT of us semi-pros in San Diego). We were interested in seeing if cooling the oil would decrease temperatures enough to matter.

Don already had a dyno, even way back then. We base-lined with the stock oil system - temp sensors on the heads, cylinders, and oil reservoir. Then we added just the cooler, a typical finned radiator. Temperature drops averaged about 4 or 5 percent IIRC, mostly attributable to the heads though and I'm pretty sure about that. HP/TQ went up just slightly - hard to even measure reliably.

Then 1 qt. additional oil capacity was tried improving temps to about 10% better than stock but still not enough to improve HP/TQ enough to brag about, improved but not dramatically. I honestly can't remember for sure but I seem to remember that several runs showed about 1-2 HP more, that was all. For racing it was enough to be worthwhile but that's not my main point.

Throughout the experiment, engine temperatures did go down so I'm basing my stance on that experience.

ETA: I'm an old engineer too thanks to GI Bill (electronics and physics, progressed to systems, and then mgmt. - space industry) so as a geek type, I certainly bow to your obvious expertise in this region but still think I have a valid point.

 

+1. I did get a free sticker once.

 

Here in Commiefornia (also know as Mexifornia, homofornia, People's Republic of Chinafornia...) the EPA, Sierra Club, Friend's of the Bay, CARB, etc have more power than the government itself. This is the most corrupt state and white people rank 3rd behind trees and illegals...if the government passes something that the aforementioned don't agree with, they get it put on the ballot for a public vote...why even elect politicians? You folks in the normal 48 can blame this one for all the messed up laws, restrictions and so on...

By the way, does anyone's air cooled bike really run that hot? I run mine all over this state and others and in temps up to 114, which is the hottest I have ridden in and my bike ran OK. It gets a lil iffy at temps over 100 but ****, I don';t like riding in temps that hot anyway and as long as you keep the bike moving, it's fine. I think if they go to water cooled, I will stick with my 07 and go back to building customs for new bikes. Frame 1500$, Motor & Tranny $10,000, rest of the stuff needed to build a bike $5000. Telling Harley to stick their water cooled bike up their *** - priceless.

 

I got one and filled it out. I just kept checking air cooled, air cooled, air cooled. But, it's obvious they're fishing for reaction to liquid cooled. And I agree with IzzoQuazzo that if they don't pony up a prize pretty soon like they used to do, (ball cap, drink holder thingy, pin, etc) I'm gonna quit taking my time to fill them out. Are you listening HD Advisory people?

 

Well with water cooled engines just look at the additional inventory HD could sell you, water pumps, water hoses, thermostates, radiators, special water coolent etc. all the above in Chrome, flat black, shiney black, natural aluminum etc.

And if a Champion spark plug at HD cost $5 more than the same plug at any auto outlet, just imagine the price on a made in China water hose and it is the only thing that will fit.

My wife and I doubled up on an air cooled Honda 750 Four and rode all over the US of A. And now we ride 80 Evo and 88 Twin Cam.