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(N2O) Nitrous Oxide and Lycomings

gmcjetpilot

Well Known Member
Looking for opinions or experience of anyone who has used NO2 with a Lycoming or any engine. Good idea? Bad idea? Pros Cons?

I have an O-360A1A, with stock compression and special exhaust and electronic ignition. I would like to install a dry or wet NO2 system that I can remove and install fairly easily.

The main use would be cross-country racing and getting a little edge at altitude. I would prefer a dry system (no added fuel inlet) for ease of installation but realize that I need assure a richer mixture when using NO2.

I am interested in things like: where the injector would go, bottle location, manual valve or solenoids, bottle size to duration of use, safety, brands and places to buy equipment.

Thanks George
 
George, No auto systems available that I know of. We have done this on some high compression parallel valve 540?s and trust me you should think about other ways to get what you want. Trashed some engines along the way. It is very easy to trash one without really trying hard.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts
are hopefully helpful to you. Please use the information provided responsibly and at you own risk."
 
Thanks

Yes, I was thinking about the same thing, can be but way too easy to blow engine.

I read about and a failed attempt in 2000 at the Sun `n Fun EAA Fly-In, when his nitrous oxide-injected Mattituck-Lycoming engine failed catastrophically, forcing him to make a deadstick landing.

http://www.jsfirm.com/onenews.asp?ID=24

Any other ideas or ways to add HP safely with NO2 or other method (alcohol water injection).

G
 
Somebody is trying it.

A guy named Al Paxia from out west built a Murphy Moose on amphibs.Powered by a Lycoming 540,with No2 boost.Sorry,no other info as to reliability or performance.
 
You got guts to put the 'gas' on an airplane!!!! In a former life I was very into drag racing/street racing street cars. Many had nitrous. Few motors survived. Personally I would exhaust every other avenue for power before spraying an airplane engine (high compression, advanced timing, ported/polished cylinders, different cam, roller cam/tappets, bigger engine, turbo/supercharger, etc). If done right nitrous can really help, but you need good bottle pressure and temperature for it and can NEVER run lean. It won't last long depending on how much you are going to spray? I guess if you are only looking for 30 horsepower or something you will get a little bit out of a 10 pound bottle (that's 10 pounds of nitrous, plus the 20+ pound bottle). If you are going to try a dry shot I doubt a "stock" fuel injection system will work.

Plus I would definitely have 2 nitrous solenoids at least. It ain't pretty what happens if a solenoid sticks open.

I could see spraying to get extra takeoff performance for a short (10-15 second) shot, but sustained use and you'll need a BIG bottle and it still does not last all that long.

All that said, it is THE most bang for the buck when looking for horsepower. That is unquestionable.

Water/alky injection is more a liquid intercooler if you are boosted (super or turbocharged).

Scott
RV-9A - N598SD Flying - ~93 hours
 
Rod-be-gone

Hi George,
My former boss used nitrous in his Bearcat at Reno and also had around 50 gallons of ADI fluid, a 50/50 mix of alcohol and water for a race. We ran nitro methane racing go-karts years ago and had a 1/2" thick aluminum plate on top of the head with two long bolts going down front and back to the engine base. Its purpose was to keep from separating the cylinder/head assembly from the block. We made around 25 HP from a 5 horse Briggs and Stratton, turning 10,000 RPM, up from the original 3600!!

Yes, you can get a whole bunch of extra horsepower from a bottle or tank but the end result ain't pretty.

Others have been known to just kinda let a little nitrous escape from a disguised fire extinguisher bottle in road course racing and have it leak near the intake....just for passing ya know... :D

Regards,
 
George

I talked with an engine guru a couple of years ago. He ran a few numbers and just to "normalize" at 15k ft a std 20lb nitrous bottle would only last 60-100 seconds or so, forgive me I am going by memory. Since a very large bottle would be needed I moved that idea to the scrap heap.

I am sorry I still don't have the emails, but I think you could get a jist of what he said by searching the RV=8 yahoo group archives for nitrous.

Good luck and If you find a way to make it or something else work let us know.
 
Keep in mind as well the increased horsepower (although temporary) results in increased heat rejection requirements - you're still gonna fight CHT gremlins, regardless of whether or not you succeed in avoiding trashing the engine with a lean mixture.
 
How about supercharger driven by a second, small engine in the back seat (basicaly a gigantic leaf blower)? For some reason I just thought Will Mathews' setup at reno a couple of years ago was so cool:) - pics of it in the march 2005 kitplanes issue.
 
consider RPM

The horsepower gain from NO is in a different realm than most folks are use to thinking about.

Although I dont have the SPECIFIC numbers, it goes something like this.

A pound of NO, with correctly proportioned quantity of gasoline, per minute=100 HP.

This is without regard to the RPM. Strictly a matter of fuel + NO over a set time. Remember that HP is a function of RPM times torque, divided by a constant (5250, if I remember correctly).

In the world of auto engines, you set up the system to come on at full throttle position, minimum RPM------5000 or more, and most systems have timing retard also,-----not to mention that the extra fuel dumped in brings the mixture way rich.

Now, if you consider that the Lycosaurus is turning less than 3000 RPM, the same shot that your neighbors kid uses in his Honda, at 6000 RPM will produce more than double the torque. In milliseconds--------and will try to accelerate that old long throw crank way past what the poor thing will be happy with. Not to mention all the things mounted on, or driven by, the crank. And I can conjure up some wild images of what it will do to those poor cylinders, which are only held to the block by a few bolts at the base.

All in all, while it can be made to work, I doubt if the "pleasure would be worth the all the pain".

There are a couple of race engine builders ----car type---- on this forum, perhaps they will chime in with more details.

Happy gas can be fun, but it makes its own rules.

Mike
 
I want to fly chase with him when he hits the button the first time. I've never seen jugs punch through the cowling before. :cool:
 
I'm thinking to do this right, you would absolutely HAVE to use a CS prop, and you would need to have your cylinders and pistons (and maybe crank) upgraded to make sure they can take the additional chamber pressure. The biggest worry then is EGT, roasting the piston or valves due to a lean mixture. To my way of thinking, you could eliminate that by knowing EXACTLY how much NOS you are injecting when you hit it (regulated pressure, known orifice size), and supplying an additional EXACT quantity of fuel (again, known pump-regulated pressure, known orifice size), and have both those systems triggered on the same NOS button, with an interlock to prevent activation unless the throttle is wide open. A simple microswitch on the throttle link would serve, and failure mode is normal engine with no NOS.

That way you have no issues - normal operation at any given power setting, hit the button and your NOS and additional fuel input will balance stoichiometrically, no problems with total mixture going lean. You would need to be quite certain about your NOS/fuel mixture ratio, but that can be had with some good testing. Just have to be careful with your CHT - short bursts for acro would be OK - long racing runs are another story. Maybe spray bars? Reno anyone? :rolleyes:
 
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I've thought about this a fair amount and have come to a couple of conclusions.

N2O systems don't have to destroy the engine. It all has to do with a managable feed rate. What's that rate? Somewhere between zero and enough to blow the heads off the cylinders.

N2O is real good for drag or short duration racing. Even better for something that doesn't have to fly due to the weight of bottle(s) and hardware.

My interest in boost comes more with altitude normalizing or boosting at cruise altitudes. This means 1+ hr flights. The complexity and volume limitations don't make N2O worthwhile for me.

Want it for fast climbs or say 100 mi races? May well be a viable choice! Let us know what you learn.
 
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Want it for fast climbs....

Can't you see the expression on the Rocket jockey's face when he's outclimbed off the runway by a 180HP, fixed pitch RV-8 ???
Can you say.. Priceless!
 
georgie...

NOx is the bestest fastest cheapest way to convert an air cooled 360 into "fully vented" 270 or 180.

consider yourself lucky if you achieve TBO after you land.

If the "highly engineered popoff valves" (jugs) don't let go, you need to pray the "highly engineered shear pin" (crankshaft) will shred before you throw a blade off the propeller.

the good thing about NOx is you save money on an engine monitor....the hottest cylinder always explodes first.

Oh, and bring a clean pair of shorts....you'll need 'em :D
 
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The most amusing thing about this thread to me is that George was one of the loudest and longest-winded at taking me to task for wanting a diesel engine, and here he is talking about NOS.... :rolleyes:
 
I'm thinking of what happened to Bruce Bohannon's plane with nitrous and Rare Bear. Kabooom. The amount required even for record attempts for a meaningful power boost is staggering and expensive. Nitrous is best applied to engines which can take serious increases in specific power output. Aircraft engines don't fit in that category IMO. Air cooled opposed engines are hard pressed to last very long above 1 hp/ cubic inch.

Turbos offer a continuous supply of power, better suited for long distances.
 
Now it's all fun to talk about cylinders blowing off, but if jetted well, say 20-30 horse gain, then you are not just going to blow cylinders off I doubt. But, it's still a big potential risk to pay. I'd much rather spend my time creating a custom turbo system and then just control the wastegate for how much power you want to make. A much more reasonable solution for an airplane in my opinion. I'm sure the guys that have or do run nitrous on airplane engines most already have turbo's and part of the nitrous use is simply for the chemical intercooling effect it has. The guy with the Pitts probably uses it for some vertical penetration for a couple seconds and then done.
 
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Scott--------I think you may have misunderstood my comment about LB/time/HP.

I stated that I DIDN'T remember the exact numbers, but that there was a specific ratio there, and that the numbers I used were only an example.

As I recall, these figures were generated from research done by the Air Force somewhere in the WW2 era.

The really important fact I was pointing out there is that the HP gain is strictly due to the flow of juice and fuel. It is independent of the RPM that the engine is turning. And at the RPM we run these engines at, the torque hit is massive.

The comment about blowing off jugs was just a bit of humor. But if you consider that the entire mass of the cylinder is only supported on one end, and that there isn't any structure keeping the other end from moving around, it isn't hard to imagine some really strange things happening if/when you start adding liquid HP.

Mike
 
An old WWII buddy told me that NO was used in Spitfires during the war. The activation switch had a break seal. If the seal was broken when the plane landed the engine was torn down and inspected, period, no exceptions.
 
To my knowledge, nitrous was never fitted to Spitfires used in service although RR experimented with Lox (liquid oxygen) injection for high altitude intercepts on the Merlin 61s used in the Westland Welkin.

Nitrous was fitted to many later marks of BF-109s and FW 190s/ TA 152s using DB and Jumo liquid cooled engines and called GM-1. These engines were also fitted with water/ methanol injection to help deal with the often low octane fuel the Germans had. The K series 109s and D-9/ D11/ TA 152 FWs were very formidable opponents with this technology. Some later versions of the R2800 powering the P-47 and F4U also had WM injection.

Makes great sense on a combat aircraft to have nitrous to escape or launch a climbing attack from below for a couple of minutes, not much sense on a cross country race aircraft.
 
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kevinsky18 said:
An old WWII buddy told me that NO was used in Spitfires during the war. The activation switch had a break seal. If the seal was broken when the plane landed the engine was torn down and inspected, period, no exceptions.
All the info I have (several books full of archival stuff from the Rolls-Royce Heritage Trust + several books on Spitfires) is that nitrous oxide was not used in operations. Yes, there was a seal you could break, but its purpose was to allow higher manifold pressure for combat or emergency use.

RR got the Merlin up to 1,980 hp combat power (Mk 130 and 131 for the DH Hornet at 3000 rpm & 81" MP on 150 octane fuel) in mid 1944 and had run it at over 2,600 hp (3,150 rpm & 101" MP on 150 octane fuel + water injection) by the end of 1944 in the test cell.
 
In fact, some sources rate the Merlin 130/131 at 2030hp or 2070hp, one of the highest specific outputs of any piston engine developed for operational use in 1945. (1.25hp/ cubic inch) Levels that air cooled aircraft engines were unable to approach.

It should be noted that the German liquid cooled engines had very impressive specific outputs considering the sub 100 octane fuel generally used and generally simpler supercharging technology. Direct fuel injection, MW-50 and GM-1 contributed significantly to closing the hp gap with Allied powerplants.

It's interesting to note that liquid cooled engines dominated in German fighter aircraft in the last 2 years of the war.
 
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Yep can be done but worth it?

UPDATE:
Original post in 2005, Consulted with manufacture of NO2 systems technical dept. They where very helpfull. I'll tell you want I learned. Its interesting and have hard numbers which I'll in address comments below:


Scott DellAngelo:You got guts to put the 'gas' on an airplane!!!! Few motors survived.

No guts, for altitude use only, aka normalizer.



Pierre Smith: We made around 25 HP from a 5 horse Briggs and Stratton, turning 10,000 RPM, stock RPM 3600! Yes, you can get a whole bunch of extra HP from a bottle but the end result ain't pretty.

Thanks Buddy, yep, just looking for may be sea level hp at say 8,000-10,000 feet. Not practical per below.



RV8RIVETER:I talked with an engine guru a couple of years ago. He ran a few numbers and just to "normalize" at 15k ft a std 20 lb nitrous bottle would only last 60-100 seconds or so, forgive me I am going by memory. Since a very large bottle would be needed I moved that idea to the scrap heap.

Here is what I learned about NO2 from "NO2", normally it goes in as a liquid. Part of the HP gain is the rapid cooling as it vaporizes and makes the incoming air denser, as well as acting partly as an oxidizer itself. My research and input from Tech support at NO2 is to run the NO2 in the gas state, for many reasons. There are some challenges but its doable. Practical? Read on.

NO2 typically is used for mass HP for short periods. My spec was say 5-10 hp for 1.5-2 hours. Feeding liquid NO2, duration will be short. Also liquid flow is so small for 10 HP, the orifice is too small for practical purposes. Further with liquid you waste a lot in the bottle. You buy 20 lbs of NO2, you only get a fraction of that in liquid out of the bottle. When the liquid is gone, the bottle has lots of gas remaining. Going with NO2 gas-state you can use all of the NO2. Again this only works for small small HP gain, but this is what I want. It is indeed unusual.

The down side of using NO2 in Gaseous state is you loose the COOLING effect. The KEY idea behind NO2 is the liquid becomes gas, vaporizing in the induction, inside the engine. This cools the incoming air charge and the higher air density increases HP further.

The only worry with running gas from the bottle/valve/regulator/jet is freezing, because the expanding is going on in the bottle or down stream. However at the low flow it should not be an issue. There are "heaters" to help the bottle freezing issue. Normally you want liquid only going into the engine, so that is why you see cars with NO2 systems BLOW off the GAS, to bleed the lines and fill them with liquid NO2.

The idea of course was to get an edge in a cross country and pick up a handful of MPH and not peal the paint off, while I could remove it, leaving may be a fire wall penetration and air box hole to plug.



RV8RIVETER, bingo on the duration. To get not even get 2 hours and 5-10 HP, and would take at least two 40 lb bottles, I recall from my calcs and the numbers NO2 engineering gave me.

The most I could HOPE and dream of getting would be 4 to 4.8 mph? So over 2 hours it would shave may be 2-2/3 minutes off? Just flying cleaner and navigating better would help more. Trying to get more than 5-10 HP for 1 or 2 hours with NO2 is not practical in my opinion. HOWEVER some crazy guy might try it, but it will take a BIG bottle.



airguy:increased horsepower results in increased heat rejection........ avoiding trashing the engine with a lean mixture.

Right, see above, normalizing to get say from 65% power back to 75% power.

I was also going with a DRY system, no separate GAS line/jet. Mixture is manually add the mixture control, since it would be leaned at altitude. Again 10 hp is not much at 8,000 feet. However Id have to be careful with the mixture and NO2. I'd have more enough mixture control with the carb to accomodate small about of NO2.

For those who don't know, NO2 systems are usually WET systems. Usually they have TWO lines, one injecting NO2 (liquid) and another injecting RAW gasoline into the induction. The extra fuel balances the denser air charge. The NO2 wet systems are really about making 100-500 HP or more not 10 HP.



BikePilot: How about supercharger driven by a second, small engine in the back seat (basically a gigantic leaf blower)?

I saw a "Lightning" (4 place composite, retract) at Reno years ago with the Aux engine and blower in the cockpit. Heck yes, interesting.



Mike Scan be made to work, I doubt if the "pleasure would be worth the all the pain".

Roger that. My conclusion as well. I might try a small prototype with used borrowed parts some day for fun.



Yarddart Ray Lettrell:Pitts has NOS, flew the Lakeland show . He had it for years , no problems.

Interesting thanks. The NO2 technical department was more than happy to help me and I was NOT the first to call. He had no problem with it being for an airplane. He was also intrigued with my 10 hp for 2 hours requirement. NO2 would engineer the parts and send me a kit for I guess under $1000. I think I could find some used NO2 parts and make a small prototype for limited flight test, for $200?



Airguy Greg you would absolutely HAVE to use a CS prop, have your cylinders and pistons (and maybe crank) upgraded to take the additional chamber pressure.

Yea see above, idea is say normalizing 70% back to 75% power.



Low Pass Bryan: I've thought about this a fair amount and have come to a couple of conclusions.

N2O systems don't have to destroy the engine.
N2O is real good for drag or short duration racing.

My interest in boost comes more with altitude normalizing or boosting at cruise altitudes. This means 1+ hr flights. The complexity and volume limitations don't make N2O worthwhile for me. Want it for fast climbs or say 100 mi races? May well be a viable choice! Let us know what you learn.


Yep we are on the same page and conclusion, but would not use it for climbs my self. My mission, airshow cross-countries like Oshkosh Airventure or Aircraft Spruce Dashes. Did them years ago and they a blast, win, place or show, its fun. Funny thing is more times than not flying high is a waste. Flying LOW negates the need for NO2 all together, since my criteria is not to exceed 100% rated HP. Wide open on deck strategy works, unless the winds are very favorable (and known) at altitude.



RVpilot Bill:Can't you see the expression on the Rocket jockey's face when he's outclimbed off the runway by a 180HP, fixed pitch RV-8 ??? Can you say.. Priceless!

Now that would be fun. :D



bumblebee:... NOx is the bestest fastest cheapest way to convert an air cooled 360 into "fully vented" 270 or 180.

Not sure what a fully vented 270 or 180 is, but you are right I think? There is no substitute to getting say a IO390 210 HP engine. Of course turbo charging would be the gold standard. However for a daily flyer I want a basic O360 (180HP). The idea was a bolt on, bolt off, quick add on to make a little difference. Per the bottom line, and NO2 tank fills are NOT free, tt's expensive, its not worth it to me, but........3 min on a 150 min race may be worth it to some hard core racer.



Bottom line: IT WOULD WORK, but the difference is little, may be 2-3 minutes faster time, for a one-tank X-C race. Its not worth it, but the mental exercise and learning about NO2 was fun. :D Thanks for the input. If any one wants details, contacts, cost let me know.
 
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gmcjetpilot said:
Not sure what a fully vented 270 or 180 is,

My guess----------

Start with a 360 cu in, four cylinder engine.

Remove 90 cu in cylinders one at a time.

Mike
 
I like the idea, but I would choose a turbonormalized induction first and foremost. An electronically controlled wastegate would give the option (with a little tinkering) of setting the desired MP for the turbo to maintain - if you wanted to maintain a max of 75% power at any given altitude for example. Ideally you would be able to electronically adjust this MP target in the cockpit, from sea level MP to about 22" (~65% power) to suit the particular mission du jour. That would allow full MP climbs to cruise altitude, and then dial it back for safe LOP operation at 70% power and excellent economy.

I think I'll start the R&D on this project with my SECOND million.... :cool:
 
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Seeing a friend's supercharger on his Egg pkg pretty much cinched it for me. I think that a supercharger is a much more elegant solution for an airplane. Much easier to install (lighter), maintain, and plan around failure.

The Lancair guys have a great option, http://www.aerosuperchargers.com/ but boy is it pricey.

I feel I may have the urge to play around with one after I fly for a few hundred hours. Darn, I spend alot of time thinking in the future tense, I better get back to work and actually finish the airplane. :)
 
If you have ever looked at the supercharger system on the Egg STI, you will see it is far more complicated and maintenance intensive that a turbo system which is why Egg has gone to turbos. There are no supercharged GA production aircraft any more for good reason. Turbos are way more elegant and efficient for aircraft.
 
Supercharger vs Turbo

If Eggenfellner comes up with a turbo option for my STi I will swap out my supercharger. I might even roll my own turbo.
 
Not trying to convert or argue with anyone. Big believer in to each his own.

So, that said, what am I missing? Maybe I am blind but how is a turbo simpler?
Since they are both "pumps", they differ in their power source. For a supercharger you need a mechanical means to provide power. For a turbo you have to rout the exhaust to the impeller (alot of pipe), you have to provide alot of oil to the turbo, account for the high temp oil coming out, takes up alot more space under the cowl, ect. More modes of failure.

I am not using an Egg, so I have not kept up to date on their engines. But that would make sense for him to take essentially a stock set-up, he is buying turbo engines, and run with it. I know his earlier supercharger was a custom job. Probably less headache from a manufacturing standpoint. I made mention because the space taken and components added were small. Se also the link above, very small component list and space used. Much smaller than a turbo would be.
 
Turbo and supercharger

Well I'll just say WEIGHT, COST, COMPLEXITY and MAINTENANCE.

Yes a turbo would be great for racing, but you have to live with it 365 days a year. No thanks. Turbos have been done to death on Lyc powered planes. Its nothing new. I've flown a hand full of turbo planes. It is not a panacea. There is no free lunch.

If I really wanted more than 180 hp, I'd go to higher compression pistons or add more displacement (XIO390), before turbo charging. There ain't no replacement for displacement.


Eggy and Subaru supercharger (belt driven) is not trouble free. In fact there has been one accident I know of written about in the RVator year or so ago. Also TEMPS are a real issue with the Subie supercharger in RV's. Its not all sunshine, flowers and puppy dogs.


Turbo? Yea that works, but it does add weight, cost, complexity and maintenance. Lycs have been turboed and supercharged or both for a long, time. It's not new, but designers and plane manufactures call for normally aspirated ATMO engines. Why? Its all trade offs. High altitude performance in a little single engine non-pressurized plane is usually not a priority. Where flying in Flight levels is important, than turbo away.


Compressing air raises the temp. With out inter-coolers you run into temp limitations on most engines as you climb. The higher you fly the less cooling you have (less air). On a Lycoming that can be an issue.

A turbo allows you to fly at higher True Airspeed's, but than you run into flutter issues.

ECI or Superior (forgot which one) was working on a Turbo Kit engine. They dropped it. The cost was going to be like $20,000 more than a ATMO engine (atmospheric, no boost). I guess you can make your own Turbo set-up from auto technology, but its not cheap or light weight.

Bottom line: Turbos for a "Sport Plane", for everyday flying, on Lycs, is a PAIN in the back. I know, as a CFI and Freight Dog I flew: Mooney 231's, Aerostar's, C421's, P-210's, Seneca II's, all with turbos. Turbos are Great but BIG money. I did not own any of these planes but they needed constant maintenance on the turbo systems. The P-210 was the most problematic. The TSIO-360 (continental) had operational weirdness but did not fall apart (unless you did something wrong). The Big Lyc TSIO54O in the Aerostar and other large twins was fine, but it was complicated. There was one Aerostar that broke an exhaust stack, melting the spar. The plane broke up in flight. All Aerostars had to add fire/exhaust leak warning sensors in the nacelle and spar area after that. TURBOS have lots of LONG HOT PIPES to fail and cause a fire. How many turbo race cars catch on fire?

I'll never own a turbo, at least if I have to pay for it (unless I win the lotto). If I had that much money and wanted a "transport" I'd skip the turbo charged pistion plane and buy a turbine (jet) powered plane, by-passing the piston all together.

Ross will say he can do better Turbo set ups than Kansas birds, using automotive Turbo parts. I don't doubt that, but I don't think most people will find a Turbo worth it. Do you want to fly at 17,500 feet sucking O2. That is NOT my idea of fun. For a race yes. For fun or normal operations? No. Turbos are more suited for the Lancair IVP type planes, ones made to fly straight and level, high, pressurized, going from point A to B.



Again the idea of NO2 was for RACE only, a "helper". As discussed not really practical unless you want to carry 100'bs of NO2 tanks. Even than you only can get a small boost for long periods. On the other hand for $200-$400, putting the tanks in the baggage area (good for aft CG and better speed) NO2 could be a cool RACE only thing. Once done you can take it out 100%. It would shave a few minutes. To hard core racers that's a lot. Look at the X-C race results, sometime a minute or two separates several finish positions.

However my motto is LOWER DRAG FIRST, add HP last. NO2 would give me say 3-4 mph max. You can get 3-4 mph with clever aerodynamic mods. Also as someone said over Revving the engine would get more HP, True! I do that already in a limited way. I am not willing to turn over 2,800 rpm. Some Reno formula racers turn their engines well into the mid-high 3 grand range. Remember this is a daily flyer not a racer for me.

Thanks again for those with the good input, for those who who just talked silly, you know who you are............ (insert raspberry sound). :D
 
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RV8RIVETER said:
Not trying to convert or argue with anyone. Big believer in to each his own.

So, that said, what am I missing? Maybe I am blind but how is a turbo simpler?
Since they are both "pumps", they differ in their power source. For a supercharger you need a mechanical means to provide power. For a turbo you have to rout the exhaust to the impeller (alot of pipe), you have to provide alot of oil to the turbo, account for the high temp oil coming out, takes up alot more space under the cowl, ect. More modes of failure.

I am not using an Egg, so I have not kept up to date on their engines. But that would make sense for him to take essentially a stock set-up, he is buying turbo engines, and run with it. I know his earlier supercharger was a custom job. Probably less headache from a manufacturing standpoint. I made mention because the space taken and components added were small. Se also the link above, very small component list and space used. Much smaller than a turbo would be.

No drive belt on a turbo, way easier to control boost, less parasitic drag, available power to turn compressor increases with altitude (which is what you want), modern Garretts have compressors up to 85% efficient and can operate at pressure ratios up to 3.4. Most turbos require less than .5 gallons of oil/ min. The turbo takes the exhaust bark out without a muffler which has been troublesome on the Subes so far.

The present EZ30 does not come in turbocharged form from Subaru, the EJ257 (STI) did but that was all taken off when the Eaton blower was added. The footprint of the supercharger installation was much bigger than an equivalent turbocharger. The crank drive pulley is over 1 foot in diameter! The belt has so far proven to be a liability and tensioning and tracking a big concern. The support bracketry is complex from a manufacturing standpoint.

Turbos have less failures modes when properly executed and themselves are very reliable, weigh less and are more efficient than superchargers- exactly why you don't see many superchargers on GA aircraft.

For Reno, the latest word is no nitrous for the Sport Class, it is reduction gears. DG is rumored to be installing a planetary setup on his Conti to spin it to 4000 rpm and the prop at 2500, more hp and better prop efficiency will give higher thrust. John Parker and Jon Sharp better have some new ideas this year. Should be a great race! :cool:
 
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Use a Turbo with an adjustable waste gate.
Although, NOS is the cheapest HP it is violent and can break pistons, blow off heads, ETC, ETC, Before you can blink an eye. If all was PERFECT it would be fine, BUT it is not.
The car guy's smash down and let up, the airplane guy's smash down and hold it for much longer times, this form of extra power is not worth the disproportionate risk.
 
Properly executed, nitrous is entirely safe on an engine which is strong enough to take the higher loadings. Dual fuel and nitrous solenoids can guard against a lean out problem if a single fuel solenoid fails to activate.

These days, it is relatively simple to proportion the two components properly. Hp increases are in direct relation to the mass of nitrous/ fuel added- to a point. Unfortunately at high mass flows, the hp increase would quickly overload the relatively weak design on typical air cooled aircraft engines. The base bolted cylinders, lack of crank pin overlap and poor crank support with the low number of mains per throw make for a willowy structure. On top of this, the high power increase means much higher rates of heat transfer are required to maintain proper cooling, this is the crux on air cooled engines.

The sheer mass flow required for useful power gains make nitrous a short duration power booster. Rare Bear was fitted with four 50 lb. bottles (200 lbs) used intermittently during the 10 minute race. If you figure a 4000 hp engine is processing around 500 lbs. of air per minute, you can see that even in a 10 minute race, 200 lbs. of nitrous would result in a very small power increase for the whole race duration. I think the thought was to use it in spurts to gain a tactical advantage on the course. Unfortunately the R3350 did not like the diet of nitrous too well. :(

Equal distribution of the mix to individual cylinders is critical for reliability, a radial makes this more complex and difficult. Individual nozzles on an opposed 4 or six make this quite possible.

Fixed ignition timing with nitrous makes for a hand grenade in many cases. Modern auto engines use specialized ignition retard boxes or do this through the EMS upon nitrous activation.

Nitrous alone, would simply lean out the mixture unless extra fuel is added and this can cause the instant engine obliteration at high power settings- nitrous solenoid opens, fuel solenoid does not- big lean out and kerbang!

The Continentals in the Sport class suffer from a lack of fuel delivery at high manifold pressures using the standard injection setup. The Lycomings don't suffer this affliction apparently. At least one of the Contis is being fitted with EFI to solve this problem for this years race. Now combine nitrous and more spray bar water.... :cool:
 
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pierre smith said:
Hi George,
My former boss used nitrous in his Bearcat at Reno and also had around 50 gallons of ADI fluid, a 50/50 mix of alcohol and water for a race. We ran nitro methane racing go-karts years ago and had a 1/2" thick aluminum plate on top of the head with two long bolts going down front and back to the engine base. Its purpose was to keep from separating the cylinder/head assembly from the block. We made around 25 HP from a 5 horse Briggs and Stratton, turning 10,000 RPM, up from the original 3600!!

Yes, you can get a whole bunch of extra horsepower from a bottle or tank but the end result ain't pretty.

Others have been known to just kinda let a little nitrous escape from a disguised fire extinguisher bottle in road course racing and have it leak near the intake....just for passing ya know... :D

Regards,
We used Nitro in our Hydroplanes back in the 60's & 70's. That plate Pierre speaks of was fondly referred to as a "head-catcher" It would keep the cyl heads from blowing off.
Nitro & Methanol was used for fuel. Nitro Oxide (laughing gas) was only used as an accellerant. A trigger was hooked up to the steering wheel and when needed, you pulled the trigger and held on. A 5 sec burn was about all that the engine would tollerate. Usually used coming out of turns or to get around someone in front of you. Very hard on engines and if the heads held together pistons would melt.

In an airplane? I cann't imagine! Our attitude was 'So what if the engine blows This is the Nationals or World champ. its now or we wait til next year. And we always had rescue guys to hall us back in. In an airplane? the whole idea is scary.
 
rv6ejguy said:
At least one of the Contis is being fitted with EFI to solve this problem for this years race. Now combine nitrous and more spray bar water.... :cool:
George,

Now here is a good idea. Cool your induction plenum with a mist of methanol and H2O. The blue windshield washer fluid contains methanol and you could just put a washer nozzle in front of or behind your filter.

The water would cool the mixture AND expand upon mixture detonation, giving you boost.

This was used in WWII, mostly with turbo compound engines to help keep detonation under control but should give you some extra HP in an NA engine, with the correct (small) spray.
 
Yea I remember AWE now you mention it!

N941WR said:
George,

Now here is a good idea. Cool your induction plenum with a mist of methanol and H2O. The blue windshield washer fluid contains methanol and you could just put a washer nozzle in front of or behind your filter.

The water would cool the mixture AND expand upon mixture detonation, giving you boost.

This was used in WWII, mostly with turbo compound engines to help keep detonation under control but should give you some extra HP in an NA engine, with the correct (small) spray.
Interesting. Ya that reminds me of my commuter days. I can attest to AWE - Alcohol water injection. The Swearingen Fairchild Metroliner III, a 19 seat turboprop commuter had two Garret TPE331's (1000 hp dry). However with AWE it would go to about 1,100 HP (wet) each. You'd use it for high altitude airports, hot and high gross weight takeoffs.

I'd warn the passengers before takeoff power would cut back abruptly after takeoff. When you turned the AWE off, you actually felt like the engines where shut off. When you lose 200 hp all at once, it's surprisingly dramatic.

So AWE, I forgot about that. It works. The down side is carrying it. To do what I want would probably not be practical from a volume and weight stand point. Even on the Metroliner, keeping the AWE tank full was a pain. It would only last a like a minute or so, but its effectiveness was obvious.
 
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airguy said:
I like the idea, but I would choose a turbonormalized induction first and foremost. An electronically controlled wastegate would give the option (with a little tinkering) of setting the desired MP for the turbo to maintain - if you wanted to maintain a max of 75% power at any given altitude for example. Ideally you would be able to electronically adjust this MP target in the cockpit, from sea level MP to about 22" (~65% power) to suit the particular mission du jour. That would allow full MP climbs to cruise altitude, and then dial it back for safe LOP operation at 70% power and excellent economy.

I think I'll start the R&D on this project with my SECOND million.... :cool:


Hmm? Sounds like my Turbonormalized IO-550 in my Bonanza. Only, I use 87% power in cruise, LOP. Can't figure any reason to slow down. I like 205 ktas.


You guys have ruined this whole thing. I wanted to see him "light the wick!" <vbg>


BTW, we used gaseous NO2 in a race plane at Reno. Wasn't worth it--except for a few second burst to pass someone. THEN, you tore the engine down anyway.

Ya know what all of that smoke is behind those Reno Racers? Hundreds of thousands of little, bitty, tiny hundred dollar bills!
 
Walter Atkinson said:
Ya know what all of that smoke is behind those Reno Racers? Hundreds of thousands of little, bitty, tiny hundred dollar bills!

Speed in airplanes requires power. Power is measured in cubic dollars. How fast you wanna go?
 
No Nitrous, No win!

Old NO2 thread ....

Just returning from the 2021 Reno races. Helped a friend in his pit with his nitrous equipped Sport Class racer. It's safe to say if you DO NOT have nitrous, you will not win, or even be competitive. A certain RV-8 Fastback was extremely competitive in his Heat races and won the Bronze class with his O-360 powered motor. Rumor has it putting out 400 hp with gas😳
 
Old NO2 thread ....

Just returning from the 2021 Reno races. Helped a friend in his pit with his nitrous equipped Sport Class racer. It's safe to say if you DO NOT have nitrous, you will not win, or even be competitive. A certain RV-8 Fastback was extremely competitive in his Heat races and won the Bronze class with his O-360 powered motor. Rumor has it putting out 400 hp with gas😳

Maybe in the lower echelon of Sport Class but not at the top. None of the aircraft which have done over 400 mph laps in Sport have used nitrous to my knowledge.
 
This whole thread seems to ignore the demonstrated experience of many at Reno. Adding 50 Hp with a wet N2O system is pretty straightforward, with a couple of bottles it lasts for the duration of a race (about 10 minutes). At least one was running as much as 125 Hp additional N2O to an IO-390 -- the main issue being carrying big enough tanks to last for a significant fraction of the race. These engines typically also add cooling by spraying water on the exterior of the cylinder heads and oil cooler.

To the comment about the robustness of these engines, the Sport Gold class racers are turbocharging IO-580s and Conti IO-550s up to something in the vicinity of 900 Hp.
 
I am glad new life has been injected (pun intended) into this thread. I watched Reno and got to see some Pit videos of the top Gold Class Sport planes with cowls off. Yes many of them use TWIN turbos or superchargers vs N2O. WET N2O systems making so much HP is a little scary to me. I'm glad it was a safe week of speed with no major malfunctions.

As far as being competitive many just want to qualify and go racing, doing their best time. However to just qualify for Sport Gold or Silver Class you need retractable gear and 6 cylinders or more. Turbos, Supercharger or N20 on winning and top placing planes to be sure. However there were a lot of RV's out there in the Medallion and Bronze race. The winner of the Bronze was an RV8 with average course speed over 253 MPH!!! I am sure he had some happy gas. I suspect the slower planes may have not had any power adders, except high compression pistons, stroked etc. The race rules I believe allowed to juice up with race fuel. The slowest RV to race was about 190 mph, but most RV's to race and place in the upper half of the pack were in the +225 mph range.

1st and 2nd place in Sport Medallion class were two RV8's with speeds around 234 MPH. Well done!

Fun fact, I was wondering why the top 3 finishers in Jet Gold class were the older L29's not the faster newer L39's? Why. Well they take the old turbojet out of the L29 and put a bigger engine in, e.g., Armstrong Siddeley Viper (Rolls Royce Viper), resulting in a 70% increase in thrust over original engine! The L39 came with a modern efficient turbofan. I remember you could buy a L29 for $30,000 with a spare engine. L39's also use to be fairly cheap when they first were imported decades ago.

FUN TIMES... Great to get back to normal somewhat. :D

This whole thread seems to ignore the demonstrated experience of many at Reno.
No my friend. I'm the originator of the thread , and no one is ignoring anything at Reno or use of N2O in RACE airplanes. N20 use in airplanes has been around since WWII (Germans used it). Drag racing has used N2O since late 1950's.

My original question was about using a simple dry N2O for an extended cross country race 300 miles at altitude (eg +8000 ft) to add 5-20 HP. It would be simple and could work. However after finding the correct data and formulas, crunching numbers, it would be barely practical to add 5 HP for 1.5 hours. It would take a large tank. However you could use a wet system to improve time to climb part of the XC race. In a XC race a turbocharger is the way to go, Many Reno racers use turbos and superchargers not N2O as mentioned above. For fairly short Reno races lasting under 10 minutes, N2O is more "practical". It is the cheapest way to add HP to a stock engine. It is also easy to blow your engine if you don't do all the right things. It is fairly easy to add 50-100HP, but over that I am chicken. In a drag racer fine, but airplane no, not for me.
 
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As far as being competitive many just want to qualify and go racing, doing their best time. However to just qualify for Sport Gold or Silver Class you need retractable gear and 6 cylinders or more. Turbos, Supercharger or N20 on winning and top placing planes to be sure. However there were a lot of RV's out there in the Medallion and Bronze race. The winner of the Bronze was an RV8 with average course speed over 253 MPH!!! I am sure he had some happy gas. I suspect the slower planes may have not had any power adders, except high compression pistons, stroked etc. The race rules I believe allowed to juice up with race fuel. The slowest RV to race was about 190 mph, but most RV's to race and place in the upper half of the pack were in the +225 mph range.

Bob Mills won the 'bronze' heat on Saturday and was gridded #7 in Silver for Sunday with a RV-6S (Rocket-6). So fixed gear can get you into Silver.

He has a Lycon IO-540 (parallel valve) with CR=10:1 (with 2000 hrs!) and a 50 hp (0.028" jet) of wet N2O. He is turning laps at 263.5+ with our new wingtips. He held a little back on Saturday because it was so rough and windy. We would have been faster on Sunday for sure, cuz we taped up the flaps and wing root fairings, and it was cooler. He scratched because of a low fuel pressure indication which turned out to be a bad sensor.
 
Bob Mills won the 'bronze' heat on Saturday and was gridded #7 in Silver for Sunday with a RV-6S (Rocket-6). So fixed gear can get you into Silver.

He has a Lycon IO-540 (parallel valve) with CR=10:1 (with 2000 hrs!) and a 50 hp (0.028" jet) of wet N2O. He is turning laps at 263.5+ with our new wingtips. He held a little back on Saturday because it was so rough and windy. We would have been faster on Sunday for sure, cuz we taped up the flaps and wing root fairings, and it was cooler. He scratched because of a low fuel pressure indication which turned out to be a bad sensor.



I saw that and had high hopes for the race, really sorry to see his DNS on that race, it seemed to be looking good for Fast Bob.

Did everyone see Bobs video comments as President? Thumbs up !!!
I loved it even if it is 2 yrs old!

OMG the cylinder pressures!!! Hope the piston skirts (& crown) are thick.
 
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Bob Mills won the 'bronze' heat on Saturday and was gridded #7 in Silver for Sunday with a RV-6S (Rocket-6). So fixed gear can get you into Silver.

He has a Lycon IO-540 (parallel valve) with CR=10:1 (with 2000 hrs!) and a 50 hp (0.028" jet) of wet N2O. He is turning laps at 263.5+ with our new wingtips. He held a little back on Saturday because it was so rough and windy. We would have been faster on Sunday for sure, cuz we taped up the flaps and wing root fairings, and it was cooler. He scratched because of a low fuel pressure indication which turned out to be a bad sensor.

I enjoyed watching most of the weekend on YouTube and was particularly impressed by the Sport Class. Steve, can you explain how most race planes, and especially the Sport Class, are flying well beyond the manufacturer's Vne (...laps at 263.5+...) without flutter issues? Do they have thicker skins, additional control surface counterweights, did they do a ground vibration survey, or...?
 
I enjoyed watching most of the weekend on YouTube and was particularly impressed by the Sport Class. Steve, can you explain how most race planes, and especially the Sport Class, are flying well beyond the manufacturer's Vne (...laps at 263.5+...) without flutter issues? Do they have thicker skins, additional control surface counterweights, did they do a ground vibration survey, or...?

Have been very curious myself. Would love to hear the approach. Surprised no one has eaten a canopy to date.

This following link was cut out of a post I put in the general section which I understand. I hope the moderators will permit this one to stay. Even though no RVs were in this category, it's related to the thread here. Really.Enjoy (if it stays). Don't comment.

https://youtu.be/pAHdfZ2OB_Y
 
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