Bill McLeod wrote:
> This is a question from a friend who is running a DOHC 4 cylinder with a
> supercharger (it's not British, but what the heck) and a DCOE sidedraft
> carb. The car has awesome power, and idles fine, but when he hits the
> go pedal, it just flat dies. Sometimes it is the infamous WAAAAH and it
> will go if he nurses it. Other times it just quits, dead. He says the
> accelerator pump is putting out gas. The car also has factory
> electronic ignition. Once he gets it up into the higher RPMs, he says
> it is scary, scary fast! Any suggestions from those of you who run
> superchargers or work on them? Thanks,
Here are a couple of WAGs:
Accelerator pump may be working, but it may not be the right stroke, or may
need larger pump jets and orifices. My
general guess about this carb in combination with a supercharger would be that
mixture distribution isn't very good just
off idle--that may require copious amounts of extra fuel to get it going.
Gasping and dying would indicate that there's
just not enough supplemental fuel just off idle when the throttle is opened
sharply.
A shorter stroke on the pump, combined with larger jets will get more fuel into
the engine in quick order, but mileage
will really go down.
The other thought is that a DCOE isn't the best carb for this application. A
DCOE works best when it has a nice sharp
vacuum pulse on intake--the low-end metering really does need this sort of
sharp pulse--and that's not likely with the
carb mounted upstream of a supercharger. A large constant-depression carb or
fuel injection would be among the possible
fixes.
Cheers.
--
Michael D. Porter
Roswell, NM
Never let anyone drive you crazy when you know it's within walking distance.
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