NITROUS OXIDE ( nos / n2o ) advice forum

Hello,
can I inject downstream of the reed valve?
(A Maico 490 dragracer)
Do you prefer engines with reed valve or without?
Thank you
Mike

I have seen in this forum one of the successful racers is injecting upstream.
At first glance, you would think that injecting downstream of the reed valve can help the engine breathe some air. Can someone explain?
Thank you.

Reed Valve 2 strokes are an 'iffy' job and the amount of nitrous you're adding affects the choice of location etc. of the nozzle/injector.

If you're only adding a little, then no problems with fitting it as normal on a 4 stroke aiming directly at the reeds. However, if you get too greedy we expect to see the force of the nitrous hold the reeds open and play havoc with the running of the engine and we've assume (as we don't know for sure), that this has been the cause of some erratic results on large amounts of nitrous in the past.

When that point is reached or if it's anticipated, we turn the plume direction to fire round the intake bore, rather than straight down it, in the hope and expectation that the reeds will not be affected by the direction force of the gas and that 'seems' to work well.

It would NOT be wise to locate the injector AFTER the reed as the additional fuel flow would be reduced in comparison to the nitrous flow, as that's at a lower pressure which would be counteracted by the crankcase pressure, whereas the nitrous wouldn't be affected.

There's also the question of having more nitrous and fuel flowing in to the crankcase and through the transfer ports when that wouldn't otherwise be the case, plus it would still be flowing during the exhaust cycle, which may reduce the efficiency of the nitrous use or it could improve the efficiency of the engine. Unfortunately I haven't had time recently to experiment further with 2 strokes, so I can't say exactly what the overall outcome would be.

My 'GUESS' is that it would be detrimental to the results, if only because when we did do A LOT of R&D on 2 strokes, we found that the exhaust made a HUGE difference to the results (in a way I didn't expect) and as this will affect the exhaust cycle quite dramatically, it's likely to at least need a good deal of R&D to at least figure out what is needed to make it work well.

I'm happy to run nitrous on ANY engine and we've had GREAT results on both piston port and reed motors.

BTW nitrous on 2 strokes is a MAJOR TRANSFORMATION of the power delivery. No more massive gutless periods followed by spiky power, NOW it's HUGE amounts of torque from nothing, all the way through to peak RPM.

Thank you, Trev, for your kind response. Uncharted territory here, of course. The downstream of the reed valve N2O injected 2-stroke looks promising, but unfortunately I cannot be the guinea pig. Alas, an easy decision for the non reed valve Maico 490. I am otherwise a very modest person and I want to inject about 200hp into a single cylinder stroker. REVO needed. I will use Methanol and/or Nitro Methane as a fuel enrichment, carb stays on gasoline. I will also add a water injection system.
I expect that a 60 hp 2-stroke can be injected 200 hp worth of N2O but half the N2O with Nitro Methane might allow the engine to breath more air/gasoline and the bottle would last twice as long. I wonder how much oil must be added to the enrichment fuel since Methanol would be twice as rich as gasoline, and Nitro Methane about nine times as rich by weight.
I have heard of castor oil, Blendzall and UCON (Polyalkalene glycol). In case someone is interested here is a link to an oil that can be blended into Methanol and/or Nitro Methane (german language):

http://www.google.com/patents/EP0144922B1?cl=de

Another link, ignition promoter for Nitro Methane (english language):

http://www.freepatentsonline.com/2673793.pdf

How much oil would you use?

Cheers

That all sounds fine and I'd be happy to assist you achieve your goal.

If you are using this for Drag racing or some other short burst competition some of my top customers have found that REDUCING the amount of oil added to be beneficial.

No matter how much fuel you use, you ONLY NEED the same amount of oil to lube the engine and as oil lowers the octane of the fuel, adding more than is needed, just puts your engine at a greater risk of detonation.

Thanks Trev for this info. I am very-very excited about your offer to help me with my K.I.S.S. 1/8 mile dragbike project. I will start testing miscibility of a few certain fluids and buying some hardware (may take a little time). I would like to share any knowledge gained in exploring the outer limits of 2-stroke squeezing,
not sure if I can contribute anything new though.