Anybody have cam specs?

[CaptonZap]

I just finished a degree wheel, and I have a surface grinder, so I would like to dial in the valve timing.
The manuals I have don't give any info.
Does anyone have factory specs that they can share?
Thanks, CZ

[crazy steve]

Cam specs are very hard to come by.... as you noticed, there isn't much in the manuals.

The numbers I've heard (not personally verified) are...

'78-79 cams: .327" lift, 262 degrees duration

'80-82 cams: .347 lift, 235 degrees duration.

The lift numbers are good, as that is in the manuals. The duration numbers were gotten by guys checking what they had. I haven't seen any numbers on lobe centers/overlap, so you're on your own there...

[XS1100_OEM4ME]

Specs

I just finished a degree wheel, and I have a surface grinder, so I would like to dial in the valve timing.
The manuals I have don't give any info.
Does anyone have factory specs that they can share?
Thanks, CZ

Don't know if this helps or not

http://xs1100.com.au/forum/index.php?topic=235.0

[TADracer]

Stock lobe centers are 101 degrees for both cams and overlap should be in the close neighborhood of 40 degrees.

Oh, goes without saying that if you change your cam timing do not forget to check your piston/valve clearance at 5 degree intervals from 20 degrees before to 20 degrees after TDC.

[CaptonZap]

Don't know if this helps or not

http://xs1100.com.au/forum/index.php?topic=235.0

Thanks, OEM,
That is as good as I've found. It will give me a basis for comparison.

Thanks for the input Steve. The question with those numbers is, at what lift were they measureing duration?

And Mike, advice taken. I don't intend to change the timing, only to play with tappet clearances to obtain the same valve timing on each cylinder, ala <http://www.motorcycleridersforum.com/forum/f16/suck-squeeze-bang-blow-878/>
I am trying to get rid of an annoying vibration at 3300-3750 RPM, under load.
Thanks to you guys, I know more than I did last night. If I come to any conclusions, other than it was a waste of time, I'll let you know.

CZ

[crazy steve]

Thanks for the input Steve. The question with those numbers is, at what lift were they measureing duration?

At those duration numbers, I'd be reasonably sure that these are from the first moment of valve lift until the valve is fully closed, or fairly close. That would be typical of how it was measured in those days. The '@.050" of lift' measurement came later...

Looking at the specs from the AU site, one thing caught my eye; the peak acceleration numbers. With the higher lift but shorter duration of the later cams, it makes me wonder how much additional stress the later cams put on the valve guides. With the 'faster' ramps, you might get just a tad bit more wear with the late cams.

[skipper]

Steve, doubtful there would be much accelerated guide wear from the faster lift due to the shim/bucket design. No side wear as would happen with a rocker actuation. Only increased wear would come from the increased travel.