Jerry E. Howell
3980 Becket Drive - Colorado Springs -
Colorado 80906 - USA
(World Wide Supplier of Quality Model Project
Plans & Kits Since 1992)
Howell 2-Jet Throttle
A shop made throttle for your favorite
engine.
These are the throttle plans that are included in my V-Twin
and V-Four engine plan sets. The fuel inlet is straight out
one side for the V-Four version. Both drawings are included in
the plans. It is small in physical size, very adjustable and not
nearly as difficult to build as it looks. The configuration and
size of mounting flange (or a spigot) at the base of the unit
is easily modified to suit your engine requirements. The two threaded
holes at the top are for mounting an air filter (included in the
plans) if desired. Otherwise, a trumpet shape velocity stack may
be used instead - or your own special treatment. There is also
a drawing of the throttle body with the fuel inlet parallel to
the throttle shaft which will suit most engine types.
The through air passage is .250" in diameter. The throttle
is large enough to operate engines up to 1" bore (25.4mm)
and 1-1/4" stroke (31.75mm) with a provision for higher performance
than I use on my V-Twin engine. This is the throttle recommended
by Lee Hodgen for his radial engines up to and including his 9
cylinder engine and included with his plan sets under license
from me. Multi cylinder engines don't need larger throttles than
a single cylinder engine because the throttle only supplies one
cylinder at a time and does nothing when there is no intake stroke
demand on it. For larger or smaller cylinders the plans can be
scaled up or down in size to suit.
The throttle has two fuel adjustment needles - one for idle fuel
mixture and one for high speed fuel mixture. In photo #1 above,
the fuel needle knob on the left is the idle mixture adjustment
and the fuel needle knob on the right is the high speed mixture
adjustment. Only one fuel inlet is needed to serve both fuel jets.
In Photo #2 the two socket head screws to the right of the high
speed mixture adjustment are the idle stop and high speed throttle
stop screws.
The throttle is .975" high including the mounting flange,
and .925" by .765" excluding the fuel needles.
The plans set consists of 5 sheets of drawings plus a sheet of
construction notes.
Howell 2-Jet Throttle Plans Set -
$6.00
(Use the Project
Plans Order Form to place an order. Otherwise, see the
"How To Order" page)
© Copyright 2006 - 2008 Jerry
E. Howell - All rights reserved