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Discussion Starter #1
After reading the whole topic on How to Degree your Cams, I wanted to check the cam timing on my GPZ500. In the topic it is stated that the cams are symmetrical. That is why it is easy to find the lobe center. But after looking at the cams in my GPZ, the do not seem to be symmetrical at all. I've try to make clear pictures of the cams:





There does not seem to be any damage or scourging on the surface of the cams or the forks:





The cam profile does seem to be the same on both the IN and the EX, but than opposite. So the inlet has a "soft" start of the lift and a "hard" cut off. The exhaust looks the other way around: a "hard" start and a "soft" cut off.

Does anybody know what kind of cams these are? And how should the cam timing be approached in this case?
 

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In order to get symmetrical movement at the valve with this type of valve train, the profile of the cam lobe has to be asymmetrical. This is due to the fact that as the lobe "wipes" across the surface of the follower, the the rocker ratio continually changes. The intake and exhaust cam lobes are mirror images of each other because the intake and exhaust valve trains are mirror images of each other. They are most likely stock cams.

FOG is right; the lobe center technique will work fine.
 

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Discussion Starter #6
One more question about degreeing the cams. I quote from the How To from Fog:

I can add here that you can use different settings that the stock ones but I’m not going to tell you, except to say expanding the spread of the cams will move the power up in the rev range, and closing the settings will do the opposite.
What is ment by the 'spread'? Is that the same as the overlap between the exhaust and inlet? Sorry if this seems a silly question. Because English is not my native language, I sometimes miss the nuances.
 

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Have a look at webcam camshafts
how to degree your cams. If you don’t have much experience in this area I wouldn’t mess around with your cams.
 
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