Ok, I've been reading all about H-D's new cams and cam bearings for the 2007 models. The problem I have is, I don't understand how a "plain" bearing, which is (as I understand) nothing more than the end of the cam running in a plain hole in the cam support plate with nothing but oil keeping it from making contact, will be more reliable than the actual roller bearings as used before. In my feeble brain, it seems that with the mechanical loads on a cam, the end of the cam would push down, hard, in the hole in the cam support plate and that the oil film would be squished out. I just don't see how a film of oil could keep the cam from contacting the cam support plate sooner or later. I hope I'm explaining this well enough so everyone can understand my point. I just don't see how this can be more reliable. Can someone in the know explain this to me? I have seen kits offered to convert older TC88's to this new, "more reliable" system. I have a 2002 Softail with 31,000 miles on it and I'm sure I'll be looking at a cam chain tensioner replacement very soon. I have been researching the gear driven set ups, and now this plain bearing roller chain set up as comes in the 2007's. The roller chain set up looks to be an easier swap for the average mechanic, but for the life of me, I don't see how the cam runing in a plain hole in the cam support plate can be better than a true bearing. Thanks and sorry in advance for my ignorance.

 

I am not sure what Harley has done, but I would think it is more like a standard crankshaft bearing.

A crankshaft bearing in a V8/ V6/ 4cyl is nothing more than a piece of thin soft metal that allows a thin amount of oil to float the crankshaft so that it touches nothing but oil, I would think that Harley has come up with something like it. Besides, a roller bearing has more contact which = more heat, heat come from resistance, resistance = robbed power.

 

Did you see the new cam support plate in SE catalog? I am concerned this is a clue that there is a problem with the native bearing idea in the twin cam engines.

 

I too was wondering your same question but after I thought about it for a while the camshafts on cars, trucks, tractors, they all have camshaft bushings, I would think if it would work for a tractor using 90 percent of its horspower 90 percent of the time it would work fine for a motorcycle too, plus you dont have to worry about pressing in bearings or bearings grenading going through your motor.