In the photos you see a clear top
on the combo Airnoids.
This is a dual purpose thing that
keeps dirt out of the workings
and allows you to monitor
plunger wear, if any.
More on plunger wear later.
This photo shows the T bar
and a space between it and
the lock nut.

This is similar to your valve to rocker arm lash and is set at .020.
The .020 ensures that the plunger is seated properly. If the plunger
wears in the lash will decrease and you simply reset the clearance and
race on.
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Nitrous Master.
Urbana, IL  USA     217-531-1770     M- F   9-5   CST
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Combo-flo adjustment
A Review of Combo-Flo  Air Operated Solenoids
Pressure Capacity
The nitrous Airnoids are rated at 1250 psi maximum so naturally I tried
them at 1350 psi.

They opened and closed repeatedly with no drama. Granted, there is no
sound reason to be at 1250 psi since the nitrous is in a supercritical phase
(a bad thing) beyond 1060 psi but the Airnoids can handle it as advertised.

The fuel Airnoids are rated at a maximum of 90 psi which is way beyond
any system requirements that I have worked on, seen or heard of so life is
good and they can be used with low or high pressure fuel systems including
EFI. Naturally I ran them at 100 psi. No problems whatsoever, thus proving
that they are correctly rated.
Flow Capacity & Results
Flow capacity is pretty impressive. The nitrous side far exceeds what we
normally use via the electrical solenoids and the fuel side meets and
exceeds what it was intended to replace.
CF400 Silver 2630
CF450 Gold 2970
CF NS500 (monster) 4750
.116 Electric Solenoid 1620
CF400 Silver 602
CF450 Gold 789
CF FS600 (red) 596
CF NS500 (monster) 1127
.157 Electric Solenoid 559
Nitrous Results were obtained at 900 lbs w bottle topped off each test. Fuel
Results were obtained @ 8lbs of pressure with .740 specific gravity test
Progressive Use
At the moment the Airnoids will not function with a progressive
controller. In the previous article on the Racing Instrumentation
PROgressive box I used a rotating door analogy to show what the flow is
doing during the pulse phase. The flow and corresponding pressure
never actually falls back to zero. The same thing happens here with the
co2. While the little electric Actuator handles the pulsing just fine, the
actual flow of co2 does not have enough time to dump to the
atmosphere allowing the plunger return spring to do its job. The system
will pulse 1 to 1 times before it goes into a float mode so there is not
enough pulsing spikes for our purposes. There may be some hope. A
couple of ideas are being tested to allow the pulsing to be utilized. Stay
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machine shop engine industrial balancing, fuel injection  flow tesing urbana IL
Urbana IL, USA 
217 531 1770  
M-F  9 - 5 CST

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Combo-Flo 500 plate air operted solenoid
By David Koehler
copyright 11-30-05