Chris Brooks

Variable Cam Timing in a Clevo.

Think of it. A centrifugal advance system on your cam timing gear that advances the cam at low revs and gradually retards it at high revs.

Or if a centrifugal device would be too bulky, how about an electronic stepper motor to do the job. You'd have to remanufacture the timing cover and move the waterpump but it's not entirely crazy, is it?

If it was possible it would spread the torque curve pretty nicely.

Just another crazy, far fetched idea that I thought I'd share with you guys. One of you is probably skilled enough to pull it off. I know I'm not.



Chris.

__________________
Chris

There are two types of fools.
The first, who thinks that because it is old, it is good
And the second, who thinks that because it is new, it is better.

xacoupe

I think that the problems you will have will be to do with durability. The pressure required to turn all the stuff that the cams do would be immense.
The theory is sound but I get the feeling it would be a long and tough road to get it to work and be durable.
I would love to see it though :)

Chris Brooks

Yeah. Me too.

Maybe with a roller cam and lifters it would reduce the amount of pressure required. Also the cool thing is that as revs increase, the pressure on the cam gear increases and the desired effect is to have the cam retard. It would be worse if we needed the cam to advance as revs increase. How do they do it in modern engines like Honda V-Tec and Ford's new VCT engines? The problems you speak of have to be able to be overcome in those engines so I'd have thought that it's possible but would have to be adaptable to the clevo.

Chris.

__________________
Chris

There are two types of fools.
The first, who thinks that because it is old, it is good
And the second, who thinks that because it is new, it is better.

Chris Brooks

I got this of Ford's website.

"If conditions require earlier valve opening and closing, for example to achieve more low speed torque, the Powertrain Control Module commands solenoids to alter oil flow within the hydraulic cam timing mechanism, which rotates the camshafts slightly. If the valves should open later, to generate more high-speed power, the mechanism retards the cams as needed."

So they do it hydraulically. Clever dicks.

Here's an interesting article about a product called "Smart Valves"

I have no idea what car engines they make them for (they do Harleys) but it's an interesting concept which claims to achieve similar or better results to variable cam timing but it's done at the valve seat.

http://www.aatap.com/generic4.html

Chris.

__________________
Chris

There are two types of fools.
The first, who thinks that because it is old, it is good
And the second, who thinks that because it is new, it is better.