Nitrous Oxide and tubing cleanliness
DGo...@alum.mit.edu
scooter at 5 bar, around 75 PSI.
Will it blow up--that is my question.
If it will, I will try propane. If not, I'll work it out and do a
nitrous run on this tiny scooter.
The air line is contaminated by "spooge", an oil-water mix generated
by the onboard injection air compressor operated by crankshaft cam and
processing engine air which is mixed with an oil mist at the reed
valve intake, after the throttle body. "Scootnfast" has outlined a
spooge filter; I have one and the engine runs cleaner and better with
it in place. I drain my filter every time I have a SLOP (Sudden Loss
of Power). I should do it more often than that.
I get 96 mph driving hard, and well over 100 mph on cruises. Synerject
invented and provides the components for Aprilia's Ditech
impementation of the direct air injection technology, which atomizes
gasoline to 8 microns. I hope to build a direct air injection
airfcraft engine one day, because the economy would be world-class;
aircraft economy is a real big factor in air travel for light air and
some for experimental, not so much for ultralight.
Sure, if I ran O2 in this line, it would explode very likely, but how
"strong" is N2O as an oxidizer at 5 bar?
If I disassembled all lines and the injector body, and cleaned out the
oil traces, would N2O injection then be safe? You see, if I did that,
I could run an onboard oilless electric powered air compressor and
have some fun switching between air and nitrous oxide.
Always some fun to be had around here.
Doug Goncz
Replikon Research
Seven Corners, VA 22044-0394
erik litchy
to introduce the fuel now?
Louis Ohland
takes a dim view of 100+MPH.
What is your mileage?
Does this approach scale up to larger vehicles?
DT
>I plan to run N2O into the air/fuel injector of my Aprilia SR50 Ditech
>scooter at 5 bar, around 75 PSI.
Well, the nitrous by itself won't do anything. It is used as an oxidizer to
burn extra fuel. You need to also inject more fuel, and the nitrous/fuel ratio
needs to be carefully controlled.
Automotive systems use controlled pressures and fixed orifices to maintain
proper ratios. Your small engine is going to need a really small orifice. Here
is a chart with orifice information:
http://www.diy-nitrous.fsnet.co.uk/nitrous-fuel-jetting.htm
--
Dennis
Stan Weiss
> Will it blow up--that is my question.
That is up to you. How much HP / nitrous are you going to add and will
you be able to keep the air/fuel correct.
After reading the web site, you will see that the ratings he has for the
jet sizes are at 800 psi this rating / flow will change with bottle
pressure. One thing that is sold is a bottle warmer. Also as the
pressure /flow changes for the nitrous so does the fuel requirements.
Terry
>I plan to run N2O into the air/fuel injector of my Aprilia SR50 Ditech
>scooter at 5 bar, around 75 PSI.
>
>Will it blow up--that is my question.
Hello Doug,
N2O is not merely an oxidizer, it is a monopropellant; it can act as
fuel and oxidizer simultaneously, though it must be heated to a fairly
high temperature to do so. Yesterday's explosion in the Mojave (three
dead now) appears to have involved a large tank of nitrous oxide.
All that being said, 75 psi is much lower than the 500+ psi often used
in rocket motors.
Best -- Terry
spamT...@yahoo.com
I'm assuming you mean 96 and 100 MPG, there...
Anyway, when you introduce nitrous oxide, you must also introduce more
fuel. The N2O breaks down into N2 and O2, and that O2 is gonna make
you lean.
Dave
Jim Chandler
If you want a good idea of what nitrous can do, take a look at today's
news. Yesterday at Scaled Composites (the group that launched the first
private space ship) over in Mojave, CA. workers were testing a nitrous
injector when something went WRONG! Now three are dead and three others
are in critical condition. That's some nasty stuff in the wrong conditions.
Jim
spamT...@yahoo.com
Very commonly used in motorsports, though in very much smaller
bottles!
Contemplated nitrous in my time, really wanted a supercharger, cash
flow never did quite allow.
Dave
DGo...@alum.mit.edu
>
> - Show quoted text -
Riiight. And lean mixtures knock, right? So, um, that would mean a
holed piston crown? Yuck. I only have one SR50 piston and it's already
inside the engine! Maybe propane is the thing to try; at 135 psi at
ambient temperatures, it is easily regulated to the 7 bar design
pressure, around 75 psi
Thanks to Dennis, Eric, Jim, Louis, Stan and Terry, too,
The SR50 atomizes fuel to 8 microns (revoulationary surface to volume
ratio) by co-injecting air at 7 bar through an injector designed and
marketed as a component by Synergect, who recently opened a pant a few
hunderd miles south of hear in Norfolk. It's amazing. My mileage is 96
driven hard, over 100 mph at cruis (near 50 mph) , the muffler is
always clean, there is no visible smoke at all, even on cold idle, and
it uses much less oil as well.
The problem is the engine air with oil mist is compressed to run the
mixing injector which fires only when all ports are closed, so there
is no unburned mixture scavenging and associated waste. Well, Aprilia
forget that water vapor doesn't compress without limit. I call the
result "spooge" and just drained an ounce today from my miniature
Norgren filter. That was first suggested by a user called Scootnfast
on the AF1 Aprilia board where I am user name DGoncz. See the board
for more. I was thinking a reed valve on the injector air compressor
crown would allow fresh air in and then there'd be no spooge, but how
would I keep the injector compressor piston lubed properly then? You
see, this engine has two pistons; there is a small one for injector
air, and the usual setup for combustion and power.
Here's Synergect's definitive paper on the system:
From
http://www.apriliaforum.com/techtips.htm
at the bottom is
http://www.apriliaforum.com/techtips/sr50/orbital.pdf
Doug Goncz
2007 Smithy Super Shop
P.S. Nice to be back here in rcm.
Doug
DGo...@alum.mit.edu
Well, look what you get when you post to rcm at like 1 AM. A
repetition of the OP. Poor form, that.
The Synergetc link was new, though, right? (checking) Yes, that bit
was of value.
Doug