Exhausts and Engine » Camshaft lobe indent.

LR? JPG? BMW R1200RS? Cam box? BCU Cam lobe? 18?09?20? -0609.jpg - Bild entfernt (keine Rechte)LR? JPG? BMW R1200RS? Cam box? 18?09?20? -0609.jpg - Bild entfernt (keine Rechte)I have just completed the first service that I have done (16000 miles) on my R1200RS and having taken the cam cover off, was admiring the nice shiny camshafts when I nearly had a heart attack on seeing a great chunk out of the lobe of one of the exhaust camshafts! When I had got the blood pump going again, I had another look and found that they are all like that! Why? I have never seen camshaft lobes with great chunks out of them and, assuming that I do not have the Friday afternoon special of the last 100 years, can only think that it somehow carries a local reservoir of fresh oil to the lobe when rotating.

Does anyone know or am I being stupid (possible!).

David.

Weird! What's the doohickey on the end of the exhaust camshaft?

Perhaps that is the chunk cut out of the camshaft to balance it? If it was on a Royal Enfield, it would be the place where the metal tongs are used to pick up the hot part when dropping the camshaft into a vat of water to cool it off.

Zitat von Ali-bear im Beitrag #2

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Weird! What's the doohickey on the end of the exhaust camshaft?

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Thanks for the answers and no, I don't know what the doohickey is either. It obviously is a locking pin to locate the camshaft onto the end thingy that carries the ..... hell, I don't know!

I am now slightly concerned that someone of an expert persuasion did not come straight back telling me that all BMW camshafts are like that - duh, obviously..... and stating the ludicrously simple mechanical principle that would explain such a loss of surface/contact area, while admonishing me for my engineering ignorance. Please could someone do that? Quickly please, before my paranoia gets any worse? Thank you.

Having thunk a little more, I think that the doohickey and attached thingy might be a centrifugal balancer for the camshaft but this is a guess. It is not associated with any sort of mortgage 'cos i don't have one.

David.

My local BMW Tech told me the doohickey acts as a compression release during starting and by idle speed is inoperative. The cutouts in the camshafts are on mine too and are of no consequence since the are on the low side of the cam and should have your valve clearance at that point. Maybe they are there to allow a little more oil between the parts.

Frank

Zitat von DJBee im Beitrag #5

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I am now slightly concerned that someone of an expert persuasion did not come straight back telling me that all BMW camshafts are like that.

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Thanks all. I feel better now that I know it is not just mine..

David.