E: Engine Comet cams followers and idlers

Martyn Goodwin

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Non-VOC Member
Hi photos attached show ATD, Cam and followers, the surface of the followers is worn I guess the hardened surface is worn away, the MK1 Cam end is best described as lumpy worn in ridges. The ATD looks ok apart from its movement being stiff, I note the comments made above, it will have to come off to be certain there are no problems, Given what Vibrac says about alloy idlers mine look pretty good and am now minded to keep them unless better advice comes forward. Remember that for most of its life this old gal from 1954 has been in a museum awaiting rescue.
From the photo's I would be strongly inclined to strip out the timing case as a motor in that condition may well have spindles that are also badly worn. And if you are going that far a complete disassembly , clean, inspection and careful reassembly using sound parts as needed would be in order.

Fear not, it is something you can do yourself there is no need for any fancy tools.

I am not suggesting that the following will be needed but about the only things you will need to get a engineering shop to help with is renewing the valve seats and or valve guides and rebuilding the crank assembly if there are issues with the big end bearing.

Work slowly and methodically making notes, labeling parts and taking lots of photos. You will gain great satisfaction from the process.
 

davidd

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VOC Member
The Megacycle camshafts that they make for me and the Club followers are harder than any of the Stellite grades that are available. It used to be that we had to use Stellited cams and followers when racing, but no longer.

I ran out of my cams so David Tompkins engine has a stock Megacycle Mk2 in it with Club followers and to date it they have performed fine. You can ask Megacycle about the hardness of the Mk1. This is why I said Stellite is not necessary on a street bike.

David
 

Black Flash

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VOC Member
Does anybody know if thin hardchrome [armoloy] plating or dlc [diamond like carbon] coating will be any good for the cam and the followers?
 

oexing

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VOC Member
Hardchrome on followers is not an everlasting solution as any SR 500 or Horex / Ducati owner can tell. Might be a try for Balzers hard coating , there are a few choices but I cannot say much about this yet. Stelliting should be allright for one partner in the valve gear but the corresponding part should not be the same alloy for good operation.

Vic
 

Chris.R

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VOC Member
Yes I think you would go many months before you found a new one

I have sent the Cam and followers to Bob Culver today to assess and treat/refurb I am taking the advice offered and will replace idlers with new in steel.
Chris
 
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