DirtRider . Net MX, SX, Arena Cross, Off-Road Community
Dirt Rider . Net Text Version Home
Dirt Bike Dirt Bike Dirt Bike Dirt Bike

This is the text version of DirtRider.Net
Click Here for the Full Version


Pages: 1

Oxygen injection?

(Click here to view the original thread with full colors/images)

Posted by: Kav

Dirteater and I were having a discussion about the post about the Vacuum Cooled Intake and we got to talking about using compressed oxygen to power a dirt bike, by having a onboard supply of LOX (Liquid Oxygen) and injecting the oxygen into the bike like nitrous to supplement the air coming into the bike and jetting accordingly, or to run the bike only off the compressed oxygen and fuel alone. He is thinking that the oxygen will be much cooler entering the combustion chamber thus allowing for more physical oxygen and fuel into the combustion chamber, and being that three things are needed for combustion, (Oxygen, a fuel of some kind, and Heat) having only oxygen, fuel and a spark to light it off this would be better because there would not any non-productive “stuff” introduced into the combustion chamber, it would be ideal to use. And to some extent I see (And agree a little with) his logic. But I think this would be a very bad idea because...

1. Oxygen is an accelerant like an Oxygen/Acetylene torch the oxygen would raise combustion chamber temps far past their melting point.

2. Pure oxygen would cause too violent of combustion in the combustion chamberand destroy the engine.

3. Even if it could be done, too much fuel would need to be used help keep the piston, cylinder, head, etc. cool enough so they don’t melt making for a very rich mixture

4. Too be strong enough to handle the oxygen, the bike would be so over built that it would weigh a ton. And it would not be reliable.

5. God forbid that in some freak accident the LOX container would explode, I don’t think there would be much to pick up. http://dirtrider.net/ubb2/eek.gif

In closing I think that if oxygen were such a good thing someone would be using it on a stronger engine that is used very little before it is rebuilt (Drag racing?). What do you guys think?


------------------
'01 YZ250
'92 DR350S

Lessons will be repeated until there are learned.

[This message has been edited by Kav (edited 02-17-2001).]


Posted by: dirt bike dave

I agree with you that it is dangerous and impractical. To your list of problems, I'll point out that the weight of the oxygen you would have to carry would be a big problem. Using air, many engines consume about 10-14 pounds of air per pound of fuel. With pure oxygen, that would be less, but I'll guess you would need 2-4 pounds of oxygen per pound of fuel.

On the plus side, if the bike was totally self contained with it's own pure oxygen supply, you could ride underwater. Aqua-Cross, anybody?


Posted by: spanky250

They have engines that use this set-up. They are called rockets.


Posted by: MACE

Mickey Thompson built a funny car that used either compressed air or o2 (not LOX). That was about 1970, about the same time as his monocoque car. He must have been bored with just winning all the races..... I never heard much about the car. Probably considered dangerous by NHRA or something.


Posted by: FMX_novice

I think that using oxygen on a dirtbike as something like an afterburner would be good, you know like used only when you press a button or your accelerating heavily.

Or you could use it as a supplement to the air thats entering from the environment, to raise the % of oxygen


Posted by: WWR

You're kidding, right??
Do you know that when LOX comes in contact with any oil, fuel, or other combustible material, what usually follows is an explosion?! I can see it now. "Poor little Jonny was killed in an explosion while trying to service the LOX on his CR125".

I work with LOX every day, we have to service our aircraft with this stuff. It is NOT something you just mess around with. Extensive safety precautions must taken when servicing or handling it.

It is much safer to deal with Nitrous, which has a higher O content than air, but has the N to keep it less volatile.

------------------
Paul '97 YZ250, '86 VFR400R Mechanical "nut"


Posted by: spanky250

I would think running an accelerant like NOX in an otherwise stock two-stroke would be equivalant to taking a torch to the piston. It takes a massive amount of extra fuel to run NOX in an engine, and even if the fuel is rich enough, you risk blowing the head right off of the engine from the increased combustion pressures. Car NOX setups use an extra fuel rail and a pump to provide the extra fuel when the NOX is in use.

It would be quite a rush, though, to see just how quickly you could plant the back of your helmet into the ground as the bike loops out.


Posted by: Dirteater

As might be aparent in his post I refuse to listen to Kav's logic. In fact I won't listen to anyone's logic. Dangerous,,, gasoline, NO2 at 500hp boosts not regulated? Come on now. If someone wanting the baddest bike around spend the appropriate time on a dyno, and manufacturing a bulletproof engine how much horsepower would it be worth? 100 maybe 150 horsepawer out of a 250. Ox is what accelerates the burning process, air has about 30% oxygen in it. Were talking 70% more accelerant to burn. And, more consistant jetting.
Did you actually mention fuel consumption? If that was the only thing I was concerned about I would sell the Suburban, the two dirtbikes, and the Harley and geta a Geo. It is a proven fact the less you have to full throttle an engine the better "gas mileage" you will get.
I'm not saying this would be a go out and buy it at the local K-Mart bike. The new YZ250 has a experianced rider only sticker on it for heavens sake. We're basically talking a Seth Enslow "I'm going to jump the moon" bike.
I seriously believe everyone is to set in their ways of monotany. Just because it has been don't since the beginning of your time doesn't mean that is the right way. And just because it didn't work 20 years ago doesn't mean it never will. Think how far tchnology has come in the last five. A ceramic engine might be what it takes, but would you buy a 150 hp CR250. Don't worry just lean on the tank a little harder and you'll be OK.
And when you jump a backflip will be a beginners move.
Of course I could be completely wrong, but as soon as I admit it someone will do exactly what I am thinking of. In that, I have faith.

------------------
Ridin' till I can't
'98 RMX250
'84 XR250r
Laid to rest:
'73 TC125


Posted by: MACE

So how hard would it be to run nitromethane?

I'm serious!

------------------
MACE

Does my dirt bike make more air pollution
than the soccer moms waiting at the McDonalds
drive through?


Posted by: Kav

Ok Dirteater... My ‘01 YZ20 makes about 45 peak horsepower, the air around us has about 20% oxygen in it, now lets say for fun and giggles that if we increase the ratio of oxygen too every thing else in the air HP will increase proportionally. So in theory if at 20% oxygen we have 45hp peak, then at 100% oxygen we would have 225hp. Ok so now I have a 225hp 250cc engine. (0.9 horsepower per cubic centimeter not bad http://dirtrider.net/ubb2/tongue.gif ) Now I want to put it into a dirt bike, I’m going to need to change a few things...

1. The engine will need to be much stronger to handle the 400% of extra HP. Its weight and bulk will reflect this. Alummimn I think will out of the question to use in the construction of the engine. Steel and titanium alloys or ceramics may feasibly be used to build the engine.

2. The engine would produce so much heat that a water-based cooling system may not cut it. You could use a radiator and water to help out, but I think more cooling will be needed. If you use LOX, you may be able to use its cooling properties to help cool the engine by injecting it (as a gas) into secondary cooling passages in the head that are parallel to the water passages. But this may be counter-productive as stated in a post above LOX is very dangerous, and the temp difference may be to extreme. A tranny cooler would also more then likely be needed

3. Internal engine components would need to be beefed up to handle all the extra power. (It would suck to launch a piston thru the bottom of your engine. http://dirtrider.net/ubb2/eek.gif ) The clutch would have to be the strongest one out there. Literally!!

4. The drive train will need to change. Think of the chain stretch! I think two counter-rotating drives shafts running down the insides of the swing-arm may be a better idea. This would allow for a bit of safety in that if one or both of the shafts self-destruct http://dirtrider.net/ubb2/eek.gif you have some protection. CV-joints could be used on the front of the shafts to allow the rear suspension to move freely.

5. Think of what will need to be done to the frame and the suspension to handle all of this extra stuff. I have no idea what that would entail. Ok, ok, ok you’ll have stiffer springs (sorry for the lack of detail it’s getting late)

With all the things listed above what ever I haven’t thought of the bike is going to weigh a ton (well... maybe closer to a quarter then a full ton http://dirtrider.net/ubb2/eek.gif ). There goes the “flick-ability” of the bike, and if I wanted that much weight I would have gotten a quad. (At 6’3 and 155 with all my gear on if I got pinned I’d be in a world hurt and in more ways then one!)

Dirteater I’m not changing my mind, it still is unpractical, and way too dangerous for any thing except for maybe the drag strip. And for 500hp NOS kits, I would put something like that on a Ford 460 (7542.5cc), 351 (any) (5771.7cc), or maybe a 302 (4947.2cc) those engines are about 30.3, 23.2, and 20 times bigger then my bike respectfully. Building an engine that could take a 500hp shock takes a little work, and a lot of money to build and maintain it. I would never put it or any thing like it on a dirt bike. What happens if the engine explodes when you are riding it? The more extreme the engine the more damage it does when it goes sky-high. And the more power you pull out of an engine the more expensive and time-consuming it is to use it.

One the other hand Aqua-Cross does sound like fun dirt bike dave. They already make paddle tires! http://dirtrider.net/ubb2/biggrin.gif

MACE could you elaborate on the nitromethane a little more. I don’t much about it.

------------------
'01 YZ250
'92 DR350S

Lessons will be repeated until there are learned.


Posted by: Bicentennial Man

LOX to increase performance? NASA has already done it. http://dirtrider.net/ubb2/smile.gif Seriously, LOX is nothing to play with, or maybe it is... http://ghg.ecn.purdue.edu/~ghg/
Good luck at your next cookout!

------------------
Furious activity is no substitute for understanding..


Posted by: MACE

Info on compressed air dragsters (google is a great search engine!) http://northernthunder.com/airforce.html

Quote:
Originally posted by Kav:

MACE could you elaborate on the nitromethane a little more. I don’t much about it.


Don't know nuthin' 'bout nitro either. Bet ol' Rich does though. Can you enrich gasoline with nitro? All I ever hear is "don't do it". Seems like a cheap thrill. Who wants to be the first to pour a little model fuel in their tank?

------------------
MACE

Does my dirt bike make more air pollution
than the soccer moms waiting at the McDonalds
drive through?

[This message has been edited by MACE (edited 02-18-2001).]


Posted by: Boit

Dirteater: Air, at sea level, has no more than 21% oxygen content...and I've never seen it quite that high. I use sensitive instruments for testing several different gases where I work and the highest I've ever recorded was 20.3%. It fluctuates according to different factors such as barometric pressure..ambient temperature...and hunmidity.

I like to play what-if. What if a small compressed pure oxygen bottle was mounted on a YZ 426 and it was piped thru a flow controlled valve to bleed a precise amount of oxygen into the intake....say just past the air filter....and this was metered to raise the oxygen content of the intake by just 5%? To maintain the same fuel/air mixture, richer jetting is used.

Supercharging is just air intake forced under pressure by an air pump which raises the amount of air/fuel intaked and gives an increase in power. Seems that a small increase in oxygen content, in conjunction with an increase in fuel, would approach this same result. Maybe even an increase as small as 1 or 2% increase in oxygen might make a difference. Surely someone, somewhere has played around with this.

[This message has been edited by Boit (edited 02-19-2001).]


Posted by: jake949

what would be the volume of that? How much O2 would you have to pack? at the flow needed to make a 5% increase in O2 would it need a reed valve before the carb to keep it going in the right direction?


Posted by: Boit

I suppose the tuner would need to know the volume of air being drawn into the engine throughout the RPM range......which is probably already known by the original manufacturer. Why would a reed valve be needed when the normal vacuum caused by the intake wave will draw the O2 in? Why couldn't this be tested on a small scale with short dyno runs? I'm simply curious as to what what happen.


Posted by: WWR

Boit,
what you are explaining is exactly what nitrous oxide does. Nitrous has a higher oxygen percentage than normal air, so the mixture of air and nitrous oxide is somewhere in between. Pure nitrous (N2O) has 33.33...% oxygen, while air is around 20%. Mix the two 50/50, and you have air with somewhere around 27-28% oxygen content. The nitrogen does nothing, it is a nonflammable gas which makes up about 75% of the earths atmosphere.

Using nitrous oxide is just a "safe" way to do exactly what you are asking about.

------------------
Paul '97 YZ250, '86 VFR400R Mechanical "nut"


Posted by: flyinzuki

Does anyone want to talk about Methanol? It brings more Oxygen into the equation! I know jetting, timing, and compression must all be increased, but it must be easier than trying to run liquid Oxygen or even a N20 setup.
Once you get methanol figured out then you can go to the hobby store for the nitro blend.


Posted by: Boit

WWR: Thanks for the info on nitrous. I wasn't sure how much oxygen was in nitrous. Seems like I read an article some time ago about nitrous and that the big downside was that nitrous is pretty corrosive. Is that true? Does that mean that continous use os nitrous would virtually eat away at the top of the piston and combustion chamber? Would increasing the oxygen content of "regular" air have the same result?

flyinzuki: We're just playing "waht if" here. I think Rich probably can relate his experience and knowledge of methanol...if he can pick himself up off the floor after having his laughing cramps... http://dirtrider.net/ubb2/biggrin.gif

Rich: I KNOW you are grinning like a mule eating briars at some of my musings. I can feel it.


Posted by: Dirteater

OK, if you were to inject the correct amount of pure O2 in to a cyclinder to raise the percent of O2 5%, how would that affect emmisions?
I know relativly nothing about emmision production, except is is cause by impurities in the burn process (bad jetting, usless crap in the air???). Maybe we can get the EPA to start funded research in an effort to reduce the emmision production of vehicles.
Methanol, maybe I'm crazy, (nod yes), but does anyone know of any conversion charts to use to convert. This sounds like a viable alternative to the oxygen injection. If I were to learn enough (read: to much) I may try it on the XR. THat would be a selling point. A fifty HP XR250. Hmm,,,,,,,,,
Time to surf for knowledge.

------------------
Ridin' till I can't
'98 RMX250
'84 XR250r
Laid to rest:
'73 TC125


Posted by: Kav

Quote:
Originally posted by Dirteater:
I know relatively nothing about emission production, except is cause by impurities in the burn process (bad jetting, useless crap in the air???).


Emissions are caused by the combustion process its self. If emissions were only made by “impurities in the burn process (bad jetting, useless crap in the air???)”. Then removing all impurities, and having perfect jetting would make for a zero emission engine. Some emissions are caused by impurities in the air, but most are caused by the chemical reaction of the fuel being burned. i.e. hydrocarbons, carbon-dioxide, carbon-monoxide, and some times depending on the application, unburned fuel, among other things.

Quote:
Originally posted by Dirteater:

Maybe we can get the EPA to start funded research in an effort to reduce the emission production of vehicles.


Huge amounts of money have been spent on emissions testing some examples are… the catalytic converter, the 14.7:1 air to fuel ratio for use with the catalytic converter, electronic fuel injection, (look at the new REV! dirt bike posts in this forum) and small compact cars.

And Edelbrock has NOS kits for Harley-Davidsons. http://dirtrider.net/ubb2/tongue.gif

Any one try to retrofit one of there kits yet http://dirtrider.net/ubb2/eek.gif


------------------
'01 YZ250
'92 DR350S

Lessons will be repeated until there are learned.

[This message has been edited by Kav (edited 02-20-2001).]


Posted by: Jim Crenca

In regards to methanol as a fuel; having used it in drag cars & go-carts the following is pretty much documented data:
1. You will get more horsepower; dyno testing 4 stroke go-carts shows about a 20% power increase; drag cars make less (based on time slips, never dyno'd)
2. Engines run much cooler & allows for much more agressive tuning (jetting, timing, etc.)
3. Fuel usage is about doubled
4. Pure metahnol (required for go-carts) is very corrosive; oil gets changed after each race & aluminium oxidizes easily (carbs get hosed down with WD40 after each use); drag strip methanol has oil added as a top end lubricant and is not as bad
5. Octane number or methanol is higher than all pump gas & many types of race gas
6. Price here in MD is about $3.50 per gallon
2.


Posted by: Tony Williams

I'm not sure that you could just double the size of the jets (and air bleeds) in my YZ400 carburetor and run alcohol, but who knows?

Sounds like a lot of tinkering, which I'm not against, but I don't like to wonder about the fuel performance on the face of a jump.

I've had TWO ideas tinkering around in this regard...

Oxygen injection for the rider. There's a company that makes little O2 bottle that fit in the palm of your hand, with regulator. At max flow, they last 12 minutes or so... about a typical vet moto, say at 7000 feet Mammoth Mountain.

Nitrous Oxide for the engine. I would only want to use it for the start of a race, so the super small pressure vessel would have NOX with a switch to discharge the entire amount over 8 seconds or so. A second pressure vessel would have the corresponding fuel to accomondate the increase in O2. It's small, relatively simple, and relatively inexpensive.

Tony


Posted by: KXaggerator

I think a practical N2O system would not be that difficult with a current KX250 if you tied it into the Power Jet circuit for fuel enrichment. All you would need is a small regulated bottle of N2O, metering orifice, selonoid, a larger power jet, rejet the carb so that it jetted as a normal non Power Jet carb, and a buddy dumb enough to let you tool with HIS bike.
The first problem would be that the boost would be in the wrong range if you let the black box run things. The N2O would come on at 4,000 rpm and sign off at 8,000 rpm. This would over-stress the rod. If you could find someone to build a second box to run the enrichment and N2O and to come on from say 7,000 and sign off at 10,000 it might work and it would be a hands free system. If you did not need the extra power you could just ride at a lower rpm, or have an over-ride switch. Some day I may have to check this out on a G2D goped motor to see if it might work. I have been thinking about a blower for a ped motor, this may be easier. Yes, some day I will stop eating leaded paint chips, but for now it's just too damn good.

------------------
The truth only gets in the way of the facts!

'98 KX250
'90 KX500


Posted by: Henk

OK
To take this one step further (or maybe sideways). How about Hydrogen oxygen engines. Inject a 2:1 mix directly into the combustion chamber, The only by product of combustion is water so the eco nazis would be happy. You get as much super charging effect as you like by varying the injection pressures.
I believe torpedos use this sort of engine and that the main drawbacks are
1. Immense temperatures generated, no problem in a torpedo as you have the entire ocean as a cooling medium.
2. The engines don't last long before they self destruct, again not realy a problem with a torpedo as they don't have to last a 45 minute moto.
3. The bottles are rather large and ungainly, I'm sure this coule be solved.

Just interested if anyone else has heard anything about this.



------------------
Illiterate trail slug



This is the text version of DirtRider.Net
Click Here for the Full Version

Text Version Home





vBulletin Copyright ©2000 - 2009, Jelsoft Enterprises Limited.
vB Easy Archive Final ©2000 - 2009 - Created by Stefan "Xenon" Kaeser