R 50 cam follower question

[cghanson]

My first post, back before Christmas, concerned information regarding right cylinder oil galleries. I appreciate the help you folks provided. Just to recap. I am the owner of a 1958 R50. A very quiet and smooth runner when purchased, the odo shows 24K miles. As the history of this bike is a bit sketchy a tear down and slinger exam is in progress. The right piston has a bit of scuffing in a couple of places and it looks like there is a matching rough spot on the right cylinder wall. Left piston and cylinder are perfect.

On careful examination the right cam followers have what appears to be paint of some sort on the interior surface, almost looks like the red material lining my fuel tank. The left cam follower interiors are simply bare metal. All of the cam followers look good, no pits or cracks.

I had planned to ignore the paint, buff the follower faces and reinstall them but the red paint stuff is flaking off. I wouldn't want chips of paint drifting around in my engine oil. I will probably scrape it out with dental tools and then glass bead the interior surfaces after protecting the faces and bearing surfaces with painters tape.

Do any of you gentlemen know anything about red paint like stuff in cam followers?

Thanks very much for any possible information.

Chris

[schrader7032]

I too had the red interior on my R69S cam followers. There were some flakes, but all I did was pick at the loose stuff and then reused them. I don't think I've heard of a reason for the material. I can guess that it might be some kind of damping material to keep the lifters from vibrating or something...don't really know.

Are you original followers the 4-window type, or do they just contain 2-windows. Attached is a bad picture of my 2-window type:



I believe you want the 2-window types. If yours are 4-window, you might consider getting new ones. The 2-window types are stronger.

[cghanson]

I have 2 4-window and 2 2-window followers. The 2-window followers are on the right side and painted inside with red paint. the 4-window followers are on the left side. I will measure the OD and check if any are oversize. I will try and include some photos.

Is there a problem with the 4-window units collapsing or in some way failing?

Thanks.

Chris

[schrader7032]

Is there a problem with the 4-window units collapsing or in some way failing?

Chris -

I don't have any personal experience, but that is what I've heard other experienced at this say. The 4-window ones were weaker and prone to fracturing...makes sense given the material removed to create the extra windows. With that information, I'd replace all four just to be sure and start with the same style on both sides.

[cghanson]

Thanks for your thoughts on the relative strengths of the two cam follower styles. I had a close look at all of mine. I think I will reuse these however.

Here is a photo of the two styles of cam follower in my R50. The 2-window style has, as can be seen, red flaking paint on the interior.

Both measure .7850 inch O.D. In fact all four cam followers measure the same. My digital caliper increments in 0.0005 inch increments so they all fall in that range.

No pits or cracks anywhere so with a bit of cleaning the red paint will be gone and then back into service.

Thanks again.

[sithot]

Glyptal: used for rough castings. Has been used in engine blocks to "seal" them keeping potential contaminants from getting into the oil (casting sand etc). Also helps by allowing oil to find its way back to the pan more quickly since it is slick.

Tom