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Fuel Solenoid:
All you need to know about using Air Solenoid Valves as Fuel
Solenoids!
Fuel Solenoid - DIY
Self Build Nitrous Systems
A pair of
identical standard AIR solenoids. The FUEL one is stock.
The one with the Braided hose is modified for use with
Nitrous Oxide
Gas. Otherwise they are both the same!
Required
Parameters
You can use any locally
available pneumatics valve if it fits the following specs:
-
They must
have a 1/8 inch (3mm) or bigger internal bore at the
smallest place - the "seating" inside.
-
They must be
simple two port type open/closed valves.
-
They must be
12v DC
-
They must be
1/8th inch BSP inlet and outlet threads.
-
They must be
VERY reliable at 140/150 psi for engine safety.
-
They must not
leak!
-
They must
have sealing materials and gaskets that are not effected by
Petroleum based fuels, alcohols, ands all fuel additives
Some Details...
Here is the
piston that the electro (12V) magnet "lifts" up
against the working pressure when you activate the
Solenoid's).
This
is the reverse way round compared to a household tap "washer
and seat" arrangement. The
top one has been modified to work with Nitrous Oxide at high
pressures. But the bottom one is from a standard air
solenoid as purchased. This works just fine for fuel as it
is!
The seat material and the valves "gasket" rubber seal,
have been tested in a mixture of pump fuel, aviation fuel,
race fuel (C16), octane boosters (mixed) methanol, ethanol,
diesel, paraffin, nitro methane, nitro benzene, propylene
oxide.
Over a period of 3 months
of "soak" tests, in a jar, the seat material
(some kind of rubber possibly NBR not sure) did not swell, soften, harden, change colour or change any
of its properties as far as I could tell! This is important!
If it fails you could kill an engine... Nitrous without fuel
spells disaster.
Interestingly
an old NOS (Nitrous Oxide Systems manufactured) fuel
solenoid from 1985 fails this test with the rubber "swelled"
up and expanded. This when operated then does not lift far
enough off the seat to allow full fuel flow! Now you
know why I sort out my own stuff...
If your solenoids
are not the same make as mine, I suggest you mix all these
items together and seal the piston in a bottle or jar with
them inside for an extended period and try it! See
what happens to the materials... If it blocks the
seat up, swells so the valve does not open properly or whatever
your engine may be melted! Be extremely cautious... I
may have just been lucky.
Here
is a stock Solenoid valve as I used to use. It is a simple
140PSI air solenoid valve with a 3mm or 1/8th
inch seat cross section. It only requires two fittings! These are shown, one is a "tail" that allows a hose (fuel
pipe) to connect to it. That's the thing that at the bottom
left! The other fitting is shown below.

This fitting
is plastic. The best ones to use are plated brass or plain
brass, or stainless steel if you can find them easily.
Chromed ones and anodised ones are available too at a
price! But use the ones with nuts and olives! The one
shown is "push lock" - for simple prototyping great! But
these are really only suitable for testing. After a few
months at extremes of temperature under a car bonnet, they
age, and the pipes can fall out! This fitting (now also the
jet holder) goes into the solenoids outlet. The other thing
is the brass fuel control jet.

Actually its
a 130 Weber carb jet (1.3mm) in this case. It needs to be
drilled and tapped and recessed into the fitting rear face
as below pictures show! This fitting is 1/8th BSP to 4mm O/D
Nylon pipe.

Once its screwed in fully
and "flush" it can be fitted to the solenoids outlet. Fuel
solenoid is completed! Simple stuff... Ten minutes work.
*Technically
the term NOS is incorrect as this refers to an specific
company (called Nitrous Oxide Systems, in the US) |