If you're planning to use the car on the street, I'd avoid changing the
throat of the carb's at all - while it improves ultimate HP potential, it
really screws up low speed and part throttle running. Basically, the other
mod's you mention - the butterfly stuff, and thinning down the shaft - won't
make a difference you can feel, or measure without a dyno, so I wouldn't
bother. A half point in compression ratio will get you more...unless, of
course, you're building an SCCA race motor, in which case every possible mod
is required!
How do I know this, you ask? He points silently to the fully modified pair
of SU's lying under the workbench that flow beautifully, but don't run worth
a damn under 6000 RPM...I went back to the Weber.
Brian
At 08:13 PM 3/14/98 -0500, you wrote:
>Dear Crash:
>
>Yes, I'd be interested to get a copy of the book. I have a couple of other of
>Vizards books and have been using them as a general guide, but now I'm at the
>carb/manifold part and need more specific info on the SU's, I'm gonna use the
>1 1/4 carbs, thin the shafts and knife edge the butterfly, and I've seen some
>vague references to to reshaping the transition area of the carb from opening
>to slide, but I'm not clear on that part. I've already ported the head. Does
>anyone know a good source for a quality complete gasket/engine rebuild kit w/
>valve stem seals etc.? Seems like there's lots of horror stories about wrong
>gasket sets, poor quality...
>
>Thanks in advance,
>
>Terry Heffron
>
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