What rocker arm ratios do people see? Options

[stugray]

I am adjusting the valve geometry while putting in a Raby 9700 cam and I am seeing .38 on the exhaust cam lift and .496 at the valve (an exh rocker ratio of 1.3) and I have a .39 on the intake with a .546 at the valve ( an int rocker ratio of 1.4) is this what everyone else gets for rocker ratios:

Intake rocker ratio = 1.4
Exhaust rocker ratio = 1.3

These are the 1.7 (1.8?) rockers that accept the 911 swivel feet.
I am using the swivel feet, have modified the rocker faces, adjustable push rod, and zero lash to do the meaurements.

Do those rocker ratios look like stock?

I want to take 50 thousandths off the Combustion chambers to increase the CR, but my measurements say I wont have enough clearance on the Intake valve once I shave off 50 thousandths.

I only have ~0.075 clearance now from the piston to the Int valve as it is with a deck of 0.030 and everything else (crank & rods) stock - flat top 96mm pistons.

That Intake valve travel of ~0.55 looks huge to me. Anyone else care to comment?

Stu

[stugray]

Ok, so after some measurements, I get the whole "shim the rockers" thing.
I thought the main purpose for shimming the rockers was just to get more clearance for the swivel feet to have room to work.
What previous threads about this topic fail to do is explain HOW shimming the rockers can make a difference in the actual rocker ratio.
It turns out that by moving the pivot arm of the rocker geometry up & down it gives more room to adjust the push rod length.
If the rocker-arms had a fixed rocker ratio throughout their travel then this wouldnt change their ratio.
However, the rocker arms have a very different ratio depending on what the "start angle" & "end angle" is through the "throw".

If the rockers start mostly flat and rotate through ~15 degrees. there will be a totally different ratio than if the rocker started at 15 degrees and rotates to 30 degrees.

Here is a pic to show the concept:

(IMG:http://www.914world.com/bbs2/uploads_offsite/i366.photobucket.com-10819-1356308971.1.jpg)

The very top pic shows a perfect rocker, at zero degrees, and a ~1:1 rocker ratio:

The next pic down shows a more represantitive pic of our rocker geometry.
Each pic down represents how the geometry is affected by shimming the rockers UP away from the valve seats.

Now I understand HOW shimming can affect the rocker ratios.

(I Still cannot get to the required Intake valve clearence without changing rockers However...)
Stu