I know the basic forumla for the LS1, but does it change for different cubic inch engines? Thanks, I'm just a little confused about something.

 

- No, it is independent of Cubes.
Does depend on # of cylinders..i.e. 8cyl = 15 factor/constant, 10 cyl is 12 factor/constant and 12 cyl is 10. FWIW.
joel

 

So, I'm confused.

What is the determining factor or equation?

8=15, 10=12, 12=10...it's not consistent?

So an 8 cylinder that's 232 cubic inches would use the same equation as a 600 cubic inch big block?

Thanks Joel, I've been reading your's and NoGo's posts for my information lately

 

Your inital units are Grams / second / ( Revolutions / minute), or

Grams * Minutes / (Revolutions * Seconds)

Multiply by (60 Seconds / 1 Minute) and you get

60 * Grams / Revolutions

(seconds and minutes cancel out).

Now we have A 4 stroke engine with 8 cylinders - with 2 strokes per revolution we have 8 intake valve events in 2 revolutions - so 4 intake valve events in 1 revolution - so multiply by

( 1 revolution / 4 intake events)

And you get 60 / 4 * Grams / Intake Event

or units of 15 * Grams / Intake Event

1 Intake event is the filling of one cylinder, so this is the same as Grams/Cylinder


So we started out with MAF / RPM - the 15 is essentially a "conversion factor" that will put us in the correct units.

So, as binksz06 posted above, for a 4 stroke V8 it would be Maf * 15 / RPM.

If the cubic inches change then the MAF reading will change - so you will be at a larger final value - but the formula is the same.

The only thing that will effect the formula is whether the engine is a 2 or 4 stroke, and the number of cylinders (which effects the number of intake events per revolution).