25 replies to this topic

[Rorf]

Whistler I think the main question is how did you bed the new camshaft and cam followers in. One needs to have a good cam lubricant on the lobes and followers and on initial start up the engine must be idled at 2000 rpm for 20 minutes continuously.

[Spider]

Whistler I think the main question is how did you bed the new camshaft and cam followers in. One needs to have a good cam lubricant on the lobes and followers and on initial start up the engine must be idled at 2000 rpm for 20 minutes continuously.

 

While the advise of the Cam supplier should be followed, this is generally the typical type of instruction given. The speed must never go below what ever figure they give not even briefly. This is because the only Oil the Cam Lobes (and the followers) will receive is what's thrown off the Big End Bearings. It needs this moderate speed not only for the Oil 'fling' but also to be sure the Oil Pump is supplying higher quantities of Oil.

 

The reason for 'breaking in' new or ground cams, is fresh ground steels don't absorb oil too well.

 

The Cam and Cam Follower, in regards to it rotating, behave in a very similar way to a Roller type bearing that has a Cup, Ring and Rolling Elements. For this reason, the type of 'break in lube' needs to be chosen carefully. Some of the greases, like some molly greases can in fact cause the lobe to slide over the follower without promoting any rotation. This is why Molly greases are not recommended for Bearing with rolling elements (like wheel bearings).

 

" If such greases are used in high-speed bearings, problems can be experienced with roller “skidding” where the bearing roller fails to rotate through the full 360 degrees due to reduced friction. As a result, the roller develops flat spots, and its service life is reduced. "

 

https://www.machiner...se-right-grease

[whistler]

Whistler I think the main question is how did you bed the new camshaft and cam followers in. One needs to have a good cam lubricant on the lobes and followers and on initial start up the engine must be idled at 2000 rpm for 20 minutes continuously.

That's exactly what I did. I've not built that many engines but never seen followers shaded like this or indeed cam lobes on a new cam with what I call striations (stripes).

Attached Files

•  20190428_115553.jpg   67.74K   2 downloads

[Rorf]

 

Whistler I think the main question is how did you bed the new camshaft and cam followers in. One needs to have a good cam lubricant on the lobes and followers and on initial start up the engine must be idled at 2000 rpm for 20 minutes continuously.

That's exactly what I did. I've not built that many engines but never seen followers shaded like this or indeed cam lobes on a new cam with what I call striations (stripes).

 

I hope I do not have the same problem as I have just installed the minispares cheap followers onto an old cam. These new followers appear as flat as the 35 year old followers that came out of the engine. 

[gazza82]

These???? https://www.minispar...sic/AEG584.aspx

[whistler]

https://www.minispar...84.aspx|Back to
These are the ones I fitted.

[DeadSquare]

I always use coarse emery paper to 'scratch' the bottom of new followers, with a circular motion, to try and hold a little bit of oil until the engine is run in.

[Rorf]

I fitted these http://www.minispare...px|Back to shop

[whistler]

Been away for a few days, out of range of all mobile signals.

Here's 2 images. The marked followers are the ones that didn't rotate.

 

The bottom image shows the scuffing on the 'stationary' followers.

The top image is when I rotated the 3 followers 180 degrees. Little scuffing.

 

Attached Files

•  1.jpg   38.61K   2 downloads
•  2.jpg   36.35K   1 downloads

[gazza82]

https://www.minispar...84.aspx|Back to
These are the ones I fitted.

 

I hoped you wouldn't say that .. they are the ones I fitted. Luckily (if you can call it that) the engine isn't finished and has not be run so I could pull them out and start again. The engine is in dry-ish build mode .. in that those cam followers were lathered in cam lube, as were the cam lobes.

[whistler]

 

https://www.minispar...84.aspx|Back to
These are the ones I fitted.

 

I hoped you wouldn't say that .. they are the ones I fitted. Luckily (if you can call it that) the engine isn't finished and has not be run so I could pull them out and start again. The engine is in dry-ish build mode .. in that those cam followers were lathered in cam lube, as were the cam lobes.

 

Going to fit these https://bullmotifmin...am_follower_set

 from bullmotifminispares instead once I've had a clearer idea of what has happened to the M/S ones from the engineers amongst members.