Why can't HD do this or the aftermarket.

[metaliser]

Saw them build a Evinrude engine and they put roller or timken style bearings on the wrist pin and also on the cranks, I couldn't believe it, I was just talking about this the other day to a freind, if only we could do this, now I know that the crank rides on bearings but these were the rods also, anyone else seen this. 

[autoworker]

Seen needle bearings on connecting rods many times.......on two cycle engines.

[harleyjt]

Mercury outboards were the same way - may still be.
jt

[Ultrashovel]

I don't see any advantage to a needle bearing on a small end of a connecting rod. The plain bushngs have worked well for 100 years or more.

It's probably a manufacturing decision for some companies. They can produce wrist pins to a certain diameter and using a needle bearing, there is no fitting needed. 

I would like to see Harley-Davidson go to a plain bearing crank like a car in their touring bikes. That would provide real oil pressure and permit a completely forged one-piece crankshaft. Voila! No more runout problem, longer life, better oil pressure and so on. They will undoubtedly do that when they change to a liquid cooled V-Twin. I think they did that with the V-Rod.

The only thing is, they would need to retain the 45 degree design to maintain most of the sound that people like. That would keep some of the old-timers as customers anyway.

[PC_Hater]

Where there is enough oil you don't need needle roller bearings on the gudgeon pin (wrist pin).
Two strokes don't have enough oil so needle rollers either caged or uncaged must be used.
The bush is probably lighter than any set of needle rollers.
It is a 'needs-must' thing.

Do you think the reduced friction from the needle rollers would help my 45 go faster? When you can't increase power easily you have to resort to reducing the losses!

[PoorUB]

Saw them build a Evinrude engine and they put roller or timken style bearings on the wrist pin and also on the cranks, I couldn't believe it, I was just talking about this the other day to a freind, if only we could do this, now I know that the crank rides on bearings but these were the rods also, anyone else seen this. 

Typical 2-cycle engine. I do not think needle and roller bearings are better, more moving parts, more chance of failure. I would like to see HD get away from the rollor bearings and go plain bearing on everything. Much better design, supports more load. I think they did with the V-Rod, all plain bearing IIRC. The auto manufacturers has done with plain bearings forever and engines can run as long or longer than we need to.

[Phu Cat]

It's probably a manufacturing decision for some companies.

Yeah, somebody's BIL owns a needle bearing plant.  So one guy scratches his back and he scratches...........you know how it goes.

PC

[cheetah]

Two cycle engined use oil in the gasoline for lubrication.
This does not provide proper lubrication for a babit bearing as used in the auto industry.
That is the reason for needle bearings used in  two  cycles.
C

[Shadowdog]

. . .

I would like to see Harley-Davidson go to a plain bearing crank like a car in their touring bikes. That would provide real oil pressure and permit a completely forged one-piece crankshaft. . .

Howdy Folks,

I would bet they would use a cast iron crank like the Royal Enfield Interceptor did.

Best to all,

Shadowdog

[metaliser]

I forgot they were 2 cycle, heck those vtech engines are very good and alot more efficiant than they used to be but I see the point now. 

[mark61]

   Here is that main journal , bearings  and crank wheels for a TC.

[attachment removed after 60 days by system]

[Glenn W]

Saw them build a Evinrude engine and they put roller or timken style bearings on the wrist pin and also on the cranks, I couldn't believe it, I was just talking about this the other day to a freind, if only we could do this, now I know that the crank rides on bearings but these were the rods also, anyone else seen this. 

You go through the Sturtevant, WI plant? I used to work there.
Anyway, those engines are designed to run at higher HP, RPMs, and wide open throttle for hours on end, and lube is at a premium with the direct injection vs the H-D oil pump.

[PC_Hater]

. . .

I would like to see Harley-Davidson go to a plain bearing crank like a car in their touring bikes. That would provide real oil pressure and permit a completely forged one-piece crankshaft. . .

Howdy Folks,

I would bet they would use a cast iron crank like the Royal Enfield Interceptor did.

Best to all,

Shadowdog

The Enfield Interceptor used a dynamically balanced nodular iron crankshaft.
For those who have never heard of it nodular iron is a very high quality cast iron. It is a major leap beyond old-style cast iron cranks. I might even feel inclined to defend HD using a modern cast crank assembly for a low revving under powered V twin. We'll ignore the outrageously wide run-out specification. Different issue.

[Ultrashovel]

. . .

I would like to see Harley-Davidson go to a plain bearing crank like a car in their touring bikes. That would provide real oil pressure and permit a completely forged one-piece crankshaft. . .

Howdy Folks,

I would bet they would use a cast iron crank like the Royal Enfield Interceptor did.

Best to all,

Shadowdog

The Enfield Interceptor used a dynamically balanced nodular iron crankshaft.
For those who have never heard of it nodular iron is a very high quality cast iron. It is a major leap beyond old-style cast iron cranks. I might even feel inclined to defend HD using a modern cast crank assembly for a low revving under powered V twin. We'll ignore the outrageously wide run-out specification. Different issue.

There's nothing wrong with a high quality cast iron unit. For years and years, Harley-Davidson used what is called "Meehanite" castings for their flywheels. It's a patented process that produces very fine-grained, strong and corrosion-resistant parts. I wouldn't be a bit surprised if that is the process that they are still using.

The only cast iron Harley flywheels I've ever seen give out were being used on drag strips. For anything else, there's nothing wrong with cast iron at all, in my opinion of course.


http://en.wikipedia.org/wiki/Meehanite