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This is off topic, but I hope the collective engineering brains here might have some thoughts.

This is a camshaft made new for a 1925 Frazer-Nash, which is a side valve (L head) engine with roller cam followers. After less than 5000 miles this damage was found on several of the cam lobes. The hardening has just peeled away leaving soft metal below (soft enough to file/dent with a hammer). It seems as if two of the rollers may have been slightly misaligned. But is it normal for the hardening on a new cam to be so thin? On original pre-war cams it is generally thick enough to carry out quite significant cam-reprofiling without penetrating the case.

The cam was supplied by a third party but is believed to have been made by a reputable UK manufacturer. The thought is that modern cams are design for use with big flat followers which spread the load much more evenly than is the case with the relatively small profiled followers used pre-war and are therefore not tolerant of any kind of abuse.

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Richard Jemison
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This is off topic, but I hope the collective engineering brains here might have some thoughts.

This is a camshaft made new for a 1925 Frazer-Nash, which is a side valve (L head) engine with roller cam followers. After less than 5000 miles this damage was found on several of the cam lobes. The hardening has just peeled away leaving soft metal below (soft enough to file/dent with a hammer). It seems as if two of the rollers may have been slightly misaligned. But is it normal for the hardening on a new cam to be so thin? On original pre-war cams it is generally thick enough to carry out quite significant cam-reprofiling without penetrating the case.

The cam was supplied by a third party but is believed to have been made by a reputable UK manufacturer. The thought is that modern cams are design for use with big flat followers which spread the load much more evenly than is the case with the relatively small profiled followers used pre-war and are therefore not tolerant of any kind of abuse.

View attachment 1604167 View attachment 1604168
This kind of erosion commonly happens when there is a mis-match of contact surfaces between the follower and cam lobe. Both of these lobes have issues that are propagated at the edges of their followers. First thought is poor surface on the cam follower from angularity between surfaces.

Use of the wrong oils (Synthetics, or too low viscosity, or with little zink can cause wear.
Pitting of cam lobes is generally a result of inadequate control of the valve (spring weak, floating valves, or bouncing valves on closing.

It is more likely in cams built with softer wear surfaces like billet cams with surface hardening, or welded cams using common steel alloy for build-up. For builders specializing in all out high rpm Stellite is the material used to build up the lobes.
 
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