Re: old design was oilheads-digest V1 #47

[Tpcutter@xxxxxxx]

In a message dated 1/6/04 10:12:11 AM Eastern Standard Time, 
ABSDoug2@xxxxxxxxxxx writes:
    I remember in my Corvette days, I used roller rocker arms.
Never did understand why the Oilheads didn't have roller
rocker arms. So we are back to considering SOHC and pushrods
as a less than idea set-up all around vs. DOHC.
    Oh and Tom, it is good to hear from you. Those that follow
your posts know you and value you vast knowledge.>>

Thanks for the kind words, Doug.

The Krauser 4-valve head kits for Airheads had roller rockers. They lose 
adjustment constantly. We tried making a set of 1.5:1 roller rockers for our 
racebikes may years ago ('77 or '78, IIRC) and they opened a whole new can of 
problems. Of course if the manufacturer started with the design, those problems 
wouldn't happen. But rollers are heavy, and ANYTHING that increases valve train 
mass is a BAD thing. It takes a lot of horsepower to overcome valve springs. 
That's the primary benefit of Ducati's desmo system, not the over-rev safety, 
which is secondary, because piston speed is the limiting factor in that engine 
design.

Tom Cutter

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