OkF-BIRD'88 wrote:

I did add on .045 to .9 deg LSA (for compression ratio above 10.5:1) to the result of the math in brackets subtracted from 133.5

To get 105.16 LSA to 105.6 LSA recomended.

it is very interesting what DV is doing here with this. But I'm not yet convinced it is absolute......

But interesting...I hot rod little cheap $$$ motors. Its seems to work pretty well with the SBC if what you are after is a very hot torque curve....

I am going to go back to this one more time

What am I missing in the formula as written in the first post

THERE IS NO .9 MULTIPLIER AS WRITTEN UNLESS MY ENGLISH IS COMPLETELY FUBARED UP,,,,,,,,,,,

Doing the math as shown & I still come up with 102.35 for a 11.0 582

The formula as written

For a 10.5/1 motor the required LCA will be LCA = 133.5 - (CID of one cylinder/Intake Valve dia Inches).

For each whole ratio above 10.5 the LCA needs to be spread by 0.9 of a degree.

Now maybe it is just me but I read that line is saying add .9° per point of compression so:

582/8/2.3=31.63

133.5-31.63=101.87

101.87+.45 for 1/2 point of compression=102.35

The example as written is

500 inches so one cylinder is 62.5 cubes. That number divided by 2.55 for an intake valve gives us 24.5.

Subtract that from 133.5 and you have a base line LCA of 109 degrees.

But our Pro Stocker is going to be a 16.5/1 CR motor not 10.5 so we need to correct it for that.

This means we have to add the six extra ratio’s x 0.9 (6 x 0.9 =5.4) onto our base 109 and that gives us a LCA of 114.4