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Old 12-09-2012, 11:25 PM   #2
Tosh Togo OP
Beastly Adventurer
Joined: Nov 2010
Oddometer: 1,594
Originally Posted by BOETJE View Post
Even the factory manual doesn't mention opening and
closing angles. I have made valve lift curves in the past for standard and special cam : If you set them on the standard timing marks, you'll be fine.

I once had a Yamaha manual for my XJ750, and it listed the opening and closing numbers for both camshafts, just like it does in my XJ650 manual. Unfortunately the 750 manual was loaned to a friend, and never came back.

The head that's going on has been milled .020", and the top of the cylinder block may get the same treatment, so "setting them on the standard timing marks" will only guarantee that the valve events will all be late.

Over the years I've degreed in about a dozen cams, and have yet to find ANY that were close enough (<2 degrees from spec) to suit me. I've seen two DOHC engines (both a were XJ Yamahas) that had one cam within one degree, but the other was worse.

It's my engine, and "close enough" isn't going to work.

Opening/closing numbers or lobe centers are welcome.
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