12-11-2020, 06:30 PM
(12-11-2020, 02:17 PM)Charles P Wrote:(12-11-2020, 02:08 PM)Tom Coates Wrote: Thanks all, I have a stepped key on my current gear which allows for adjustment by half tooth. Depending on how it fitted I might have to try something more sophisticated, in which case I'll get in touch with Dave. Does he need the original outer part of the gear to start with?
Any thoughts on the profiles themselves? What is the max duration/lift you would live with on a car being used on the road? Not intending to do many hill starts but don't want to be burning the clutch out every few months!
Dave's are new steel gears. If it's a mag engine I'd replace the original gear - they do break.
I reckon 260 degrees will be fine in a lightweight road car and you probably don't want/need much over 270 lift. It really depends what you want the car to be. Until the development of variable valve timing technology camshafts were always an exercise in compromise.
If you're worried about the clutch then fit cast iron linings (as per the works). Makes a very nice clutch, long lived and no nasty smell if you do slip it.
Charles
My understanding is that extra lift beyond the point of maximum flow is still useful as it increases the amount of time the valve is open at the peak flow level.
What is the downside of extra lift? Is it just wear on the valve train and noise or are there other factors that I am missing?