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Corky Bell's Book[2]



All,
	I just thought I'd mention a few things that I
find interesting about the book.

Corky's opinion on what NOT to spend time/money on:

1. Big cams, heavy port work, expensive high RPM parts.

	He points out that the forces due to combustion
are only about 20% of the load on the pistons, crank, and
rods on a naturally aspirated motor.  Everything else is
stress due to RPM and simply compressing the charge.  
Since the RPM related stresses get squared every time you 
double the RPM, you only have to drop your peak RPM about 
10% to put yourself at 80% loading, which gives you the 20% 
margin you need to double your horspower without any additional 
stress on the motor(assuming you're not causing any pre-ignition 
or detonation).  The point is just that for a given strength of 
motor, you can gain more power by running more boost and less
RPM than vice-versa (doing both is not an option once the motor
is maxed out).
	To me, this sounds like an argument for putting better 
rods in our motors (the weak link) which would make them good 
for about 7000 RPM, but leaving the stock redline
alone and buying efficient turbos and intercoolers and
running lots of boost (and good enough gas for that boost).

Corky's opinion regarding porting:  It works, but taken to the 
extreme, it reduces low RPM driveability and there's no need for
it if you have (once again) the right turbo and IC.  The
problem is that most turbos are only efficient to about
3:1 pressure ratios.  For you guys at sea level that'll
get you to about 30 pounds of boost, probably as much
as you can use even with race gas.  Up here at this
elevation, that only gets me to about 24 pounds of boost.
I'd probably need to do some porting if I were trying to
max the motor out on race gas and keep the boost within
the turbo's efficiency range.


Corky's opinion of what TO spend time/money on:

1. You guessed it, turbos and intercoolers.

	A turbo that will run in the 70% efficiency
range at 400-500cfm, and a good, large frontal area
fairly thin low restriction front-mount intercooler.
This, combined with a fuel system that will deliver
a consistent 13:1 A/F ratio will make monster power
on our motors, without huge internal motor mods.
**********************************************************

I guess this should all be taken with a grain of
salt, but I do find it all interesting, I consider
the source to be as reliable as any other I know of...

-- 
Carl_Morris@StorTek.Com