Cam degreeing and valve adjustment - Ducati.ms

ducdom · Apr 15th, 2009, 9:38 am

Hi
A question for all of you mechanics and techs.
Will a cam degreeing throw off my valve adjustment? In other words if I adjust my valve clearances and afterwards have the cam degreeing done ( I assume some adjustment is needed), will I need to readjust the valve clearances again?
Thanks for your info
Dom

NoMAD · Apr 15th, 2009, 9:46 am

I'm no tech, but here's my $.02

The valve clearance adjustment is setting the amount of free-play between the rocker and the valve.

The degreeing is changing when the valves open.

The two should not affect one another.

ducdom · Apr 15th, 2009, 9:51 am

Now that I think about it it makes sense. Degreeing may change when the cam lobe hits the rocker with regards to the piston position but doesn't change how close the rockers are to the shim. So degreeing should not affect the shim clearances. It's fun to use the brain.

tye1138 · Apr 15th, 2009, 10:21 am

It surely won't make any difference in terms of your clearances. All it does is actuate the valves at a different time. Now if you were to CHANGE cam's entirely, yes... that could change your clearances.

Cam timing is worth the money, but unless your racing the bike, just have the mechanic set them to Ducati factory spec. When you start getting into more aggressive timing changes, the bike won't idle very well or it could loose some top-end.

ducdom · Apr 15th, 2009, 10:46 am

Thanks for clearing this up for me.
Love this message board.

Shez748 · Apr 15th, 2009, 10:50 am

I've read that many bikes aren't close to factory spec. And once you have the cams degreed to factory specs the bike runs smoother and is much more responsive to throttle. If I can dig up enough info on how to do it i'll be degreeing my cams at the next valve check.

tye1138 · Apr 15th, 2009, 11:12 am

The timing is done at the factory, very quickly. I'm also not quite sure if they time the cams in the bikes, or just have sets of cams that are pre-timed.

Needless to say, your right, the timing from the factory is less then stellar. But the timing in the service manuals is spot on. Its actually really easy to time the testastretta's, all you need are the proper gauges and some time to pull the bike apart.

flash1034 · Apr 15th, 2009, 11:22 am

Quote:

Originally Posted by tye1138

The timing is done at the factory, very quickly. I'm also not quite sure if they time the cams in the bikes, or just have sets of cams that are pre-timed.

Needless to say, your right, the timing from the factory is less then stellar. But the timing in the service manuals is spot on. Its actually really easy to time the testastretta's, all you need are the proper gauges and some time to pull the bike apart.

Tye, what do you think about setting the timing/degreeing cams on my 998 at the tech class? Are you up to that?

Flash

tye1138 · Apr 15th, 2009, 12:27 pm

I don't got the tools sadly, they're VERY expensive. I've been trained on how to do it, so if you wanna buy the tools, bring them along and we can do it... but its a grand to buy the proper ones. I could half-ass some home-made tools, but I'd need a mill and thats something I don't have.

I think Tom was working on a jig to adapt standard gauges for doing timing. If he ever finishes, I'd love to get my hands on it. Wink-Wink, nudge-nudge

TomTom · Apr 15th, 2009, 12:54 pm

Tye, the jig has been ready for a while now.

It does not fully follow the angle of the valve and may upset someone, but if you are using centerlines it will work just perfect. The upside is that you dont have to remove the airbox, and that is one thing you dont want to do on the 999 for example.