Ducati Monster Forum

Moto Board => Tech => Topic started by: EEL on August 24, 2009, 12:49:47 PM

Title: Questions about degreeing cams
Post by: EEL on August 24, 2009, 12:49:47 PM
I'll start with the simple ones first

1) What does it mean

2) What are the benefits

3) How is it done (general description)

I have no idea how this works and I'm trying to find out more info. I looked thru the tutorials and didnt see anything. Can someone clarify?

Thanks in advance.
Title: Re: Questions about degreeing cams
Post by: truckinduc on August 24, 2009, 12:54:43 PM
You cant do it unless you have aftermarket adjustable cam sprockets.

If you do, you can fine tune the position for power in different rpm.

A general rule is advance the cam, more low end power. Retard the cam, more top end.

You can really get into alot if you have a 4v 2 cam.

Also there are variances in the stock setup due to belt tension - play. as opposed to say gear driven cams.

Title: Re: Questions about degreeing cams
Post by: bigiain on August 24, 2009, 01:20:40 PM
Quote from: truckinduc on August 24, 2009, 12:54:43 PM
You cant do it unless you have aftermarket adjustable cam sprockets.

There do exist "offset woodruff keys" to let you degree non-adjustable pulleys... Brad Black posted recently about getting hold of a bunch of them...

Here's the first of a set of three articles which I found really interesting about cam timing:

http://www.docv.org/cgi-bin/news/newsscript.pl?record=17&template=site (http://www.docv.org/cgi-bin/news/newsscript.pl?record=17&template=site)

And Brads got a really good article here:

http://www.bikeboy.org/camdial.html (http://www.bikeboy.org/camdial.html)

and there's a bunch of model specific cam timing stuff in Brads article archive too - if you're really interested read up on all of that first...

big
Title: Re: Questions about degreeing cams
Post by: battlecry on August 24, 2009, 01:48:29 PM

Your bike may already have adjustable cam pulleys.  My '03 M800S does.
Title: Re: Questions about degreeing cams
Post by: bigiain on August 24, 2009, 01:50:53 PM
Quote from: battlecry on August 24, 2009, 01:48:29 PM
Your bike may already have adjustable cam pulleys.  My '03 M800S does.


Yeah, Brad says all the 2001 and newer 2 valves and testastrtta 4 valvers (which I _think_ is any 4Valver _except_ the S4 916) have adjustable pulleys as standard.

big
Title: Re: Questions about degreeing cams
Post by: truckinduc on August 24, 2009, 02:05:30 PM
well I didnt know that. Thats cool though, why to go Ducati.

I wish to order some vee 2 sprockets when I order my FCR's
Title: Re: Questions about degreeing cams
Post by: ducpainter on August 24, 2009, 02:16:22 PM
ducvet, a sponsor here, has offset keys also for those in the states.
Title: Re: Questions about degreeing cams
Post by: Speeddog on August 24, 2009, 08:04:00 PM
AFAIK, S4R have adjustable pullies, as well as what big referenced.

Offset keys are nice, as you know they're never going to slip.
But you've got to measure carefully before ordering.

Brad's done the most definitive work on cam timing IMO.
Title: Re: Questions about degreeing cams
Post by: scott_araujo on August 24, 2009, 11:34:44 PM
It seems most of the high points have been covered.  I have adjustable cams stock on my '03 800.  I had to degree them, one came loose shortly after i got the bike and it was running on one cylinder.  FWIW, once I did degree them to factory spec the bike definitely ran smoother. 

In almost every entry I've read here and on TOB where people degree their cams the first thing they do is measure to see where they are.  Most are around 5 degrees or more off one way or the other.

In general, on 2v bikes advancing the timing from stock gives more top end power but less low end torque.  On 4v bikes where the intake and exhaust can be set separately you have more variability and can do more things with tuning it. 

It takes some skill but more important is patience.  It makes for a good winter project.

Scott