Setting cam geometry, Peak cam lift or peak valve lift? Options

[VaccaRabite]

Jake's site is down it seems, so I am going to ask this here.

I am about to set my pushrod geometry, but I am having a brain fart.

Do I use the peak cam lift or the peak valve lift.

I think that it has to be within 5% of peak valve lift, but I am just not sure, and I don't want to mess it up.

Also, does anyone have a copy of Jakes article for setting geometry? I pretty much remember the procedure, but I'd like to re-read it before I continue to make sure I have it right.

Zach

[DNHunt]

Zach

That's not anything like I did.

I ran the shaft of the dial indicator parallel to the valve stem shaft so I could measure total lift of the valve. I then divided that number in half and used the adjustable pushrod to find a length that resulted in the adjuster screw being parallel with the valve stem at half lift. Changing the length of the pushrod would change lift some so it was a trial and error kind of thing.

I also used shims under the rocker assembly to help with how much thread I had for moving the adjuster screws in the rocker arms.

As I understand it the most important issue is lateral forces on the valve stems causing wear of the valve guides. Having the adjuster screw parallel with the valve stem at half open results in the least amount of wear. As I remember, it is better to give up a little lift to have the right orientation at half lift.

Dave