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[HILLSIDECYCLE.COM]

The sprocket shaft/pinion shaft bearing bores may not be on the same C/L.....?
Scott

[Doc 1]

I'd also check the machining on the face of the oil pump body.....if it's off a few thou it will continue to eat cam plates.
Doc

[FLTR2008TRIKE]

I remember reading on another forum about these similar witness marks on the cam plate under the oil pump housing were caused by the suction side of the pump and the wave washer allows some slight oscillation within the pump housing.   

[bikerboy53]

The sprocket shaft/pinion shaft bearing bores may not be on the same C/L.....?
Scott

Darkhorse did the crankshaft work that included a Timken bearing conversion. I think part of their Timken conversion service includes correcting any misalignment between the sprocket shaft and pinion shaft bearing bores?

I'd also check the machining on the face of the oil pump body.....if it's off a few thou it will continue to eat cam plates.
Doc

Thanks Doc. It's on the fourth new cam plate now, and this time it had to have a new oil pump too. We plan to put about 500 miles on it and go in for another look at things. I'm hoping it was a crooked oil pump body, but depending on what we find, we'll decide where to go from there...

I remember reading on another forum about these similar witness marks on the cam plate under the oil pump housing were caused by the suction side of the pump and the wave washer allows some slight oscillation within the pump housing.   

I don't know if maybe some kind of pressure imbalance inside the pump could cause the rotors to eat the plate, but it seems like more bikes would be experiencing a similar problem if it was something like that? Unless it is a bad oil pump body causing all the problems...?

Thanks again to everyone for all the ideas!

[johnsachs]

Not saying you don't have a problem, but I'm in the middle of another build, and looked at the cam plate when I was installing the new cams. Seems to be worn in the same area as yours. Pulled another 2 out of the parts pile (were upgraded from early to hydraulic), and they look the same as well. Maybe the anodizing makes it look worse. 
If your pinion bushing is worn in 1 area, that may show an alignment problem.
John

[HD Street Performance]

Maybe the anodizing makes it look worse
 
The stock plates do the same. There is a difference between anodizing missing and a deep groove. I suspect you have the former but can't tell entirely by the photo.
The washer keeps pressure on the gears to maintain a seal and pressure therefore if you have a pressure issue and the gears and gear housing show no unusual wear the bypass valve should be checked. That should put the motor is good shape as far as the oil system is concerned assuming the oil gauge is accurate. Not always the case.

[sadunbar]

Not saying you don't have a problem, but I'm in the middle of another build, and looked at the cam plate when I was installing the new cams. Seems to be worn in the same area as yours. Pulled another 2 out of the parts pile (were upgraded from early to hydraulic), and they look the same as well. Maybe the anodizing makes it look worse.  
If your pinion bushing is worn in 1 area, that may show an alignment problem.
John

From the picture, it looks like you have a fair amount of wear in the camplate pinion bushing.  If true, given you only have .0018 crank runout, I agree you may have a camplate alignment issue (or the wear could be the result of a case machining error...)

[porthole]

It's on the fourth new cam plate now, and this time it had to have a new oil pump too. We plan to put about 500 miles on it and go in for another look at things. I'm hoping it was a crooked oil pump body, but depending on what we find, we'll decide where to go from there...
I don't know if maybe some kind of pressure imbalance inside the pump could cause the rotors to eat the plate, but it seems like more bikes would be experiencing a similar problem if it was something like that? Unless it is a bad oil pump body causing all the problems...?

Maybe the anodizing makes it look worse

The stock plates do the same. There is a difference between anodizing missing and a deep groove.

FWIW, this is the plate from my bike.

The mark you see is a current picture after 4 years and about 25K miles
At less then 1 year and 3-4000 miles it looked the same.

The wear can barely be felt with a fingernail. Plate changed color too, from black to this nice burgundy.



The oil pump looks real good. And the crank run out is still the same as it was 4 years ago, .003" I really expected it to be worse, considering that I tend to be a little low in the RPM's at times.

The original cam plate had a lot of wear on the crank shaft bushing. The bushing looks real good on this one.

http://www.cvoharley.com/smf/index.php?topic=84030.msg1126786#msg1126786

[INDEPENDENT_1]

My guess is the same as everyone else's.

This may put it into perspective a little better.

http://tmanperformance.com/?page_id=944

[HILLSIDECYCLE.COM]

What is the actual deapth of the scuff?
A deapth micrometer will tell you, but as others have said, the fancy anodizing probably enhances the look.
A fixture locating off the pinion shaft bearing bore could be manufactured, allowing the face of the cam plate mounting surface to be indicated/measured/machined to insure dead-balls perpendicularity to that pinion bore.
Just sayin'.
Scott

[bikerboy53]

I don't have the actual depth of the scuff, but it is definitely wear, not just removal of the anodizing. When we got back from our trip this summer (with about 8,000 miles on this cam plate) the oil pressure was very low. According to the gauge on the dash we had about 16 psi at 2,000 rpm when the motor was at 230F. The dealer checked it with their calibrated mechanical gauge (also at 230F) and found that the gauge on the dash was spot on! (Bad news actually...)

After verifying the low oil pressure they looked inside the cam chest and found the badly worn cam plate -along with wear marks and grooves inside the oil pump housing (see earlier posts). It's hard for an amateur photographer like me to capture the depth of the damage -I was just happy that the pictures were more or less in focus...  My mechanic just happened to have the cam plate out of his bike with several thousand miles on it (don't know the actual miles). We compared them, and his showed scuffing and removal of some of the anodizing, but no real wear into the cam plate. My cam plates all have noticeable depth to the damage. Even the one with 11 miles on it will easily catch a fingernail. 

The T-Man approach to the Timken conversion looks pretty thorough, but I didn't see anything about whether they correct the pinion shaft bearing bore if it is off in relation to the plate they use. I assume they must do something if they find a problem there though. Overall, I like his approach very much! 

I really appreciate all the input, and plan to investigate the ideas brought up. I think this has to be a result of some kind of case machining error and will investigate accordingly. As Johnsachs, and Sadunbar pointed out, the wear on the pinion bushing looks like it shows some kind of problem. Not to mention the wear inside the oil pump body is all on the same side as the pinion bushing wear too...

[johnsachs]

Here's a stock low mileage cam plate. 
John

[porthole]

Here's a stock low mileage cam plate. 
John

I see John has the latest hi-tech Harley tools nearby 

[Beak Boater]

Genuine Harley Davidson high tech tools. Not to be confused with regular hammers.

[JoeSDE]

The hammer next to the crescent wrench looks like a stainless steel surgical hammer used in operating rooms for orthopedic procedures.         JoeS