NITROUS OXIDE ( nos / n2o ) advice forum

Approx. 30 years ago I designed and manufactured a unit that pneumatically activated a pair of mechanical fuel and nitrous valves - I was told it was outdated and a useless option even then, because electrically activated solenoids were the future.
Here's a pic of my original version (please excuse the rust and lack of anodising but it does help to prove how old this unit is, as its been neglected for 30 years)



SORRY FOR PICTURE FAILURE - TO BE FIXED ASAP

Today in the USA a product based on the EXACT same principles as my ORIGINAL (side by side valves), is the latest and greatest new idea from Combo-Flo.

Despite the fact that the Combo-Flo doesn't come close to the final version of the valve I last manufactured some 15 to 20 years ago (that was based on the same principle but a vastly superior design and a quantum step forward), some people fail to appreciate the Combo-Flo valve is a backward step not a step forward.

Here's a pic of theirs



After extensive R&D work, my original side by side design ended up as my Duo-noid (a pilot solenoid activated a piston, which activated a fuel valve, that was stacked on top of the nitrous valve, all in one unit), which had numerous safety advantages over the side by side concept, as well as over pairs of individual solenoids.

Here's a pic of my last version (approx. dimensions 1.2" diameter x approx 3" tall, so although the pic on here is bigger than the Combo-Flo valve, in actual fact it is smaller)



Since the solenoid was only a 'pilot' it did not need to flow a great deal of nitrous and therefore was only a low current draw of approx. ONE Amp. This unit did not need a pneumatic supply as it used the nitrous to activate it (which makes the unit less complicated, more reliable and weighs less), despite being able to flow in the region of 1,000 hp of both fuel and nitrous through a single unit.

Some of the UNIQUE features the Duo-Noid offers are;
1) Solenoid activated pilot valve requiring minimal current
2) Valve can NOT be activated without nitrous supply (if the bottle is not turned on the system will not flood the engine with fuel)
3) The nitrous output can NOT be activated without the fuel being activated (NO risk of the engine getting nitrous without fuel due to fuel solenoid failure)
4) The fuel flow can NOT be cut off without the nitrous also being cut off (avoiding lean outs if a nitrous solenoid stuck open)
5) Auto purge capability (no need for restrictive fittings in the pipe line and no need for additional purge solenoid)

Furthermore, although it is not originally designed this way it can be modified to;
1) Prevent nitrous flow without fuel pressure being at the valve OUTLET.
2) Have twin nitrous and fuel outlets to avoid the need for restrictive T or Y fittings that might otherwise be needed.
3) Deliver progressive flow to some degree without any extra parts.


Since ceasing production approx 15 years ago it has come to my attention that there is a growing demand for such a valve to meet stringent class regulations and by those who suffer the problems caused by multiple high Amp solenoids, so I’m seriously thinking of re-starting the manufacture of these units.

I always thought that the duo noid was a beaut,I know a couple of scrutineers who loved all of the safety benefits and considered it the BEST piece of nitrous kit EVER.

Are they ok for pulsing?If so I would convert.

I'm sure Wayne still has some of your early cable operated valves,they appear to hold up well.

Well my initial thoughts when I first tried pulsing them on Wayne's bike on the Dyno was that they weren't but if I were to apply all I've leaned in the 30 years since then and redesign the whole unit, then they may very well be but I've long harboured the idea that a pair of REVO units on the outlets from the Duo-Noid would be the best and safest system in the world ever.

The only reservation I have with the original units is that whilst the majority worked perfectly and seem to be lasting forever, a small percentage would fail for no apparent reason, although having said that I'm quite sure I now know why that was happening and the re-design would solve that.

With all that said I don't think I'd advise anyone to switch from Pulsoids (which are 100% reliable) to the Duo-Noid just yet but if I go ahead with at least a rework of the units I've had in trade ins, that would be a different story.

Makes you laugh though when Combo-Flo turn out a pair of side by side mechanical valves operated by a separate pneumatic valve and the world thinks its the best thing since sliced bread, especially when I dropped the Duo-Noid all those years ago and that's ignoring the advances I've made with REVO technology.

Almost purpose made with REVO in mind
That would be a nice set up,especially if you can now iron out the last of the duo-noid glitches. Foolproof delivery and mixture control... nice

I discovered the 2 main causes of the Duo-Noid issues, just before I stopped manufacturing them;

1) The lengths of stainless steel rod that I used for stems, that were supposed to have a fine ground finish, had random longitudinal surface defects in them, which meant that SOME stems had their ability to seal seriously compromised.

2) The overall design didn't lend itself to repeatably consistent assembly.

Since then I've re-designed the unit and also found a supplier of good quality stainless rod, so those issues will be things of the past if I decide to manufacture them again.

Having a bit of a delve through some older threads, I thought this one was worth bumping up. For two reasons:

First, I'm curious about the resurrection of this fascinating product (I'd not seen one before this picture),

And second, because I've always thought that it would be really good in many ways (for installation, aesthetics and marketing) if there was a combined 'unit' of some kind rather than separate pulsoids to mount.

I'm sure such options have been exhaustively explored in Doncaster, but would be fascinated to hear about it.

Any further 'major' advances are on hold until the world economic crisis subsides and/or I retire, in which case it will be down to my successor/s.

For your interest, I do have a design which SOLVES ALL safety, operational and control issues which is based on the above valve (with additional units which include the REVOs), AS I DESIGNED IT APPROX. 30 YEARS AGO!!!

Just seen the cross section of the generic solenoids vs your pulsoid in your book Trev. No wonder the output becomes questionable on the generic noids.. The flowpath is ridiculous!

Exactly and that's just one bad aspect of what is an ENTIRELY FLAWED setup!!!