Cam Timing

[GSJimbo]

what it mean to set cam timing at 110/ex and 110/int??

 

[Anonymous]

Degreeing your cams means you install slotted cam chain sprockets and then rotate the cams relative to the crank to set the intake and exhaust valve opening points where you want them in the cycle. The 110 degrees number is the lobe center and is a measurement of how advanced or retarded your cam timing is relative to the crank position. 110I/110E would be considered a "top-end" setting, with peak power and torque occurring higher in the rev range. Many people like 108/108 for the GS, which is more of a mid-range setting. Some people go as far as 106/106 for more bottom end torque, but your peaks are lower then as well. On my 82 1100E the stock timing is 110I/109E, which is where I set mine when I did them this spring.

One of the best reasons for degreeing your cams is to have them accurately set. The timing has a very large tolerance from the factory and significant power gains can be had from setting things accurately. On my 1100, my intake timing was a good 6-8 degrees off what it should have been and this is a major misalignment for a cam. I expect I picked up 5+hp simply from correcting that problem.


Mark