Pitted camshafts

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Pitted camshafts

Post by Miles » Tue Dec 27, 2011 10:56 pm

Hello folks, is it possible to fix the slight pitting on my camshafts or is it better to just track down another set ?

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Re: Pitted camshafts

Post by Tirpitz » Wed Dec 28, 2011 12:20 pm

Don't worry about slight pitting, a lot of crap has been written about the horrors of this. A lot of Kwak cams have pitting issues as a result of poor case hardening. The pits don't necessarily cause any problems so long as there is sufficient remaining hardened material over the width. If anything they retain more oil in the pit well - which is 'a good thing'. All you need to do is keep photos and at each service compare - you may well find that there is no change in condition - i.e. the 'problem' has been there virtually from new and is not deteriorating. If things do get worse so that all the case hardening across the lobe width disappears then that's the time to look at replacement.

Regrinding and resurfacing a cam is expensive but if done well is the permanent solution. Buying an unpitted OEM cam is a pig in a poke - you might find after a short time that it too develops pits! So there's no point changing a slightly pitted one until you need to.

Don't take any notice of people telling you that pitting is caused by poor oil supply / thrashing from cold. Pitting is a metallurgical issue. Oil supply issues cause scoring, which looks quite different, like a severe scuff or scrape. Once you've scored the case hardening off the lobe surface then yes, your cam is fubared. Pitting is something else.

DON'T, whatever you do, try to remove the pit by sanding it. You will be removing the rest of the case hardening then the cam is buggered. The only way to remove pits is by filling with weld and regrinding.

Put the cam back in and ride it :smt001

You've posted this in the wrong section really, it should be in Engine & Transmission. If a mod can move it, it will be easier for people with similar concerns in future to find it.
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