Dirt Cheap Supercharger
By Steven A. Richmond Sr.
OK, here it is. Please don't laugh until you've tried
this, it really works. We've used these things for many different jobs where we
needed a lot of volume at low- to moderate pressure levels, and they almost always work
out very well.
All you need is a "smog pump"! I assume everyone knows
what I am referring to. In the USA, at least, almost every new car has been required
to have one of these since around 1970, (by government regulations) to pump air into the
exhaust manifolds, which supposedly facilitates more efficient conversion of the unburned
hydrocarbons as the mixture passes through the catalytic converter.
If we build them into a machine, we by them new, but there are piles of
them in junk yards which you can actually
get for as little as $5.00 each. People don't realize just how efficient these
little pumps are. At 8,000 rpm you can feel a strong air blast from a one inch pipe
attached to one of these standing over twenty five feet away, they will actually produce
up to sixty pounds or more (for a VERY short time), and if you block the air flow
completely the pump will stop a five horsepower electric motor.
Most of them take in air though an impeller right behind the drive
pulley, which is fine for most purposes, but some are equipped with a separate inlet port
complete with a small air filtering device,- which can prove useful in certain
circumstances.
You can even hook these things up "back to back", and the
first one will drive the second,- with amazing efficiency. If you get the kind
equipped with both inlet and outlet ports, you can the make a closed loop and either one
will drive the other,- in either direction. There's a novel way to transmit
power! If you do try this, be sure to include an intercooler in the plumbing,- the
only thing I've found that will ruin these pumps, is heat!
Some of the pumps I'm describing have more capacity than others.
I like to play with the ones from 350 cid Chevrolet police cars, or 454 cid trucks.
It takes four to six of these to provide ample boost for the average V8, but one or two
should suffice for most motorcycle engines. I built a setup using these on a small
V8 once, and used a automotive air conditioner pump, electric clutch & pulley, so that
it was not necessary to wast fuel driving the arrangement until it was needed.
90% of the pump body is aluminum, so they are relatively light, and
it's not difficult to polish them up and radically alter their appearance. By the
time you've done that, and added a aluminum timing pulley,- no one will ever guess what it
is/was, or how little you have invested.
Be careful how much intake pressure you apply to a high compression engine. You
probably shoudn't try to go over 8 - 10 pounds on any engine with a 9 :1 compression ratio
or higher. We attached one of these to a friend's son's go-cart engine (Briggs &
Stratton) and the power increase was very impressive,-- the kid decided he'd like even
more power, and changed to a larger primary pulley. I'm not sure if it was the
extra compression or detonation, but it didn't run very long after that before the
complete cylinder assembly separated and exploded off the engine block (no kidding!),--
kind of reminded me of pictures I've seen of Blown(up) top fuel drag engines.
If anyone is not familiar with these types of pumps, or has any trouble
understanding how they can be attached,- driven, etc..., let me know, and I'll post a
photograph of one mounted on a prototyping test setup.
Steven A. Richmond Sr
richmond@RICHMONDLABS.COM