View Single Post
Old 01-07-2013, 05:24 PM   #33
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,804
Quote:
Originally Posted by Hookalatch View Post
I have been running my R1200GS cams 9 crank degrees advanced for 5 years and 25,000 miles. Doing so gave me more midrange power (which is what I wanted) with the possible expense of some top end. I rarely go 7,000+ rpm's anyway so I wouldn't notice.

Modern auto engines with variable valve timing, while not Airheads, advance cam timing as much as 7 degrees and retards it up to 45 degrees for a total of 52 degrees variability. Having been involved in drag racing for several decades I am very familiar with the effects of advancing, and in my case more often retarding cam timing to change power characteristics. In my experience cam timing changes of more than 3 degrees are commonly done but usually for reasons other than producing maximum peak horsepower.

Chuck
I didn't say that three degrees was maximum. I said it was the 'classic' amount. It certainly seems to be with BMW and then some from what I have heard and read.
supershaft is offline   Reply With Quote