Hi Jack,
I used Vizzard's information to modified the 2 x 1 1/2 inch carbs on my
1275 cc street mini. I don't have any before- after performance
comparisons because I did the modifications as I was building up the
engine the first time. However is drive ability is still excellent and
judging from how the car runs I believe his recommendations work.
The modifications I did were these:
- 1/4 inch ram pipes in K&N air cleaners
- Streamlined protruding metal on the bottom of the piston
- Blended out all casting parting lines within the I.D. of the air
passage
- Blended the inside of the air passage where it goes from round to
square and back to round.
- Drastically cut away the throttle shaft leaving only a thin section
on one side of the butterfly
- Removed all protruding butterfly screw ends sticking out of the
throttle shaft
- A partial job of knife edging the butterflies but not quite down to
the full thin edge Vizzard suggests. My reasoning was that I wanted
good sensitivity in the idle adjustment on a street car and I was not
sure this could be maintained with knife edges. Still don't know.
Regards,
Carl Braun
Jack W Drews wrote:
> Out of curiosity, has anyone on the list modified their S. U.
> Carburetors per the David Vizzard book on BMC "A" engines?
>
> --
> uncle jack
> I ama curious -- blue
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