Fwd: Another thing about throttle bodies...

["Doug Johnson" <doug_johnson@rscnwm.com>]

JG wrote:
<<One thing I didn't mention is that of the six throttle bodies I've checked -- 
four MC and two Ur-Q -- only one would open far enough for the throttle plate 
to reach 90 degrees to the bore.  With the degree wheel I use to align cams, 
I found that of the rest, one hit the WOT stop at 85 degrees, another managed 
86 degrees, two of them would do 87 degrees and one made it all the way to 88 
degrees.    

Fortunately, a few strokes with a file was all it took to correct this and 
it's probably irrelevant on a stock car.  Still, it's definitely something to 
check out if you ever have your throttle body off the intake manifold.  You 
don't need to use any fancy tools, either, since one degree of error across 
the 60mm throttle plate works out to .52mm and you should be able to get 
pretty close to 90 degrees just by eyeballing it.  >>

Keep in mind that a 90 degree throttle plate opening may not be the most effective for passing air.  Turbulent air is a funny charachter...as is laminar air...

FWIW,

 - Doug