Racing safety issues with propane injection
 

Who knows the requirements to run this setup for road racing (lets say NASA unlimited for example). You are essentially driving around with a high pressure bomb. This kit for example, http://www.onlygoodstuff.com/product.asp?intProdID=51 no trunk to put it in, and I can't imagine they would let you on the track without some sort of shielding or full enclosure.
Comments?

Never even heard of propane with gas motors. It's one of the hot setups for diesels anyway. Dunno...

Chris

For turbocharged cars, it is injected typically right b4 the the tb. Inreases octane rating with pump gas to around 105 or so and is atomized upon injection and cools intake charge to freezing temps to prevent detonation. Safely run higher boost, in theory at least. Works same as with diesels. Bottle lasts longer than a tank of gas will. Some drag racers are using it but I'm just curious if you could get away with using it for road racing if someone wanted to (not me).

a friend of mines is running it on his 600+rwhp stealth, he says its much better then water injection (with water injection, he says he got bad ignition breakup at higher rpms).

The SCCA does have fuel rules. Must be gasoline of certain dielectric rating. Yada-yada-yada. Don't know what NASA would say.

Chris

Your propane cylinder should be D.O.T. rated. Most people are using 5 gallon bottles used for barbeques. Not a good idea in your car. Thin steel ( GO BOOM ON IMPACT if it sparks and air is supplied ) you will have no car left. I have seen pictures of people whose houses have been leveled after one has exploded, 3 - 4 bedroom houses flat to the foundation. Also if it doesn't blow up you have an extremely cold liquid which turns to a freezing gas when not under pressure blowing into your car and probably on you. ( Frost bite, becoming blind if it goes in your eyes, ECT.) Bottles ( D.O.T. rated ) are heavy and usually expensive ( lighter than natural gas bottles though). They can be purchased or custom made. Check with Manchester Tank / Bruner, Hanson Tank, or any other manufacturer on the INTERNET.

Yes the tanks are D.O.T. approved, as stated in the link that supplies the kit. I'm wondering if they are NASA or SCCA approved.

Sorry should have checked the link. NASA is pretty lenient. I would contact both organizations and ask for rule books. The minimum would be locating the tank separately from the driver just like a regular fuel cell.

I'm pretty certain a pressurized bottle is a HUGE no no in NASA or SCCA.. I don't think having a side impact into a 1000psi bottle is going to be contained in a fuel cell.

I'll look over the rules tongiht, but if you're in a hurry, you can download NASA's Competition Rules on their website www.nasaproracing.com.

PaulC

Propane is liquid at less than 100psi, NOT 1000, but the point is well taken as fuel cells are not designed to be pressurized. The HALON in your FIRE bottle is under much greater pressure (and COLDER) than the Propane would be.
SCCA pretty much restricts you to PUMP GASOLINE. So even if the TANK were to be approved from a Safety standpoint, the Propane itself is NOT ok under the compitition rules

Granted that Halon is under pressure as well, but it's not flammable, so a bottle failure wouldn't cause an explosion if a spark hit it. OTOH, freezing halon on my skin isn't exactly a pleasant thought. Oh well, what can you do :)

PaulC

I think it's funny that we here propane and think. "bomb"

But a half empty fuel tank isn't a "bomb".

I think that exposing a spark or flame to either of those fuels would have a very similiar result. Desirable or undesirable depending on the location.

Desirable in the combustion chamber.

Pretty bad out side of the combustion chamber. ;)

Llew

Could you use a nitrous bottle if you found the right fittings?

Do you mean using a nitrous bottle filled with propane to fool people? I don't see why you couldn't disguise it.

A standard gas tank isn't under high pressure as is a propane tank. Don't get me wrong. I like propane even though it doesn't have the BTUs of gasoline you can make up for the loss by raising compression or running higher boost. + you can inject it at a very cold temp. if you can figure out how to keep your nozzles from freezing up. GREAT for turbo or supercharging applications. The only draw back is the weight of the bottle and location of fueling stations.

I didn't mean as a disguise:) I meant that a nitrous bottle is made for high pressure and NHRA doesn't complain about them being on the track. I guess this means they don't automatically explode on impact. If they are protected by a cage they should be relatively safe compared to a BBQ tank.

NHRA doesn't have a huge potential for getting tagged by another car (or multiple cars) like roadracing does, and you're a hell of a lot closer to help on a drag strip.

Plus is a 20lb bottle (i.e. pretty small) anywhere big enough to contain enough propane to fuel a car for 20 minutes of hard track driving? How big of a tank are we talking here (no idea, never used a propane fuel'd car)

Anyway, it really doesn't matter. Until you convince the SCCA/NASA organizations to allow it, it's not allowed, and why bother worrying about it. If you're convinced it's safe, I wish you luck :)

PaulC

Propane is and has been used in RV's for years as a backup and/or independant fuel system. When you run out of gas, you turn a switch and on comes the propane. It is plumbed directly into the intake air filter, no need to change anything else.

Basically propane and nitrous will do the same thing but propane is corrosive and will pit valves on pistons, don't know what it'd do to rotaries. Probably pit the rotor face and maybe start to break down the apex seal...

DO NOT put propane into a nitrous bottle. You're talking about putting a liquified gas that vaporizes at a given rate, vs. a compressed gas under high pressure. In a propane tank, there is plumbing inside so that it is either a liquid or a vapor draw. 20 pound tanks for grilling, etc, are setup as a vapor draw so if you ever tip one over while it's running, watch out!!! Liquid propane will cause a much greater flame to occur!!! As the liquid comes out first the vapor is on fire, then the liquid expands to vapor (at ~800 times its own volume).

A compressed gas cylinder is setup differently so there is no liquid draw, only gas so the guts of the valve are all at the top. All compressed gas and cylinders have a little fusible plug as well (generally made of lead) that will melt in the event of a fire so that the tank will not explode like a bomb. That is, considering, that you do not rupture the whole thing at once in a collision.

Lastly, whatever compressed tank you put in your car better be extremely well tied down so that in no manner can it come loose! Ever hear stories of compressed gas cylinders (like an oxy-acetylene torch setup) that had their valves broken off? Imagine a high speed missle/torpedo going through the car (literally through it) in an instant.

Have fun and do more research before jumping into something you're not aware of all the hazards or you'll make a good story for firemen to laugh about :)

Basically propane and nitrous will do the same thing but propane is corrosive and will pit valves on pistons, don't know what it'd do to rotaries. Probably pit the rotor face and maybe start to break down the apex seal...
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Turbo 3 -

I don't think propane is corrosive. The interior of propane tanks made of carbon steel will last indefinitely if no water is introduced into it. I have opened several motors that have run on propane only and they are very clean. The only thing I have seen that is even close to this is a car that runs water injection. Propane burns very clean - no carbon deposits. As for corrosive, I have seen no evidence of this. If you have any literature I would love to read up on it.

When an RV or other vehicle runs propane and gas there is a trade off. The only way for a car to make the same power on propane that it does on gasoline is to raise the compression or to raise the boost. You have to set the vehicle up to run either one or the other. There just aren't enough BTUs in propane. Propane has a much higher octane rating so 14 or 15 to 1 compression ratio is not unheard of. That is how you can make more power with propane as opposed to 91 octane gasoline. Also since it is injected in gas form, you don't have to worry about fuel atomisation. It can also be injected extremely cold but when I tried for an extended time my nozzles would start to freeze up limiting fuel and causing lean a condition. "This was in Early 1990s" New delivery techniques might now be available. Lastly all intake tracts and combustion cambers can be ported & polished to a to a mirror finish for optimum flow and flame travel with no worry about your fuel separating and puddling in the lower RPM ranges.

Propane is corrosive in an internal combustion environment. It is not corrosive just sitting in a tank under "normal" atmostpheric or pressurized conditions. I should have stated that better but you're right, it's not corrosive such as ammonia, SO2, chlorine, etc, are.

I agree there is a trade-off which by trying to remember my autometer A/F instructions, says gasoline stoich is ~14 and propane is in the mid 15's. I don't understand how having a different A/F requirement would create the need to increase boost or raise compression? Add more fuel or air to create proper combustion...

I know that police cars (Ford LTD's) were propane-only for awile in the mid-80's (had a friend with one, the tank was in the trunk and it was a pain to fill it). I wonder if anyone can get us the compression specs on the 5.0L 302 used in that application?

Again, RV's have been doing this for years as separate/redudent systems where you turn off your gasoline supply and go strictly off of propane. They are not forced induction engines running off of pump gas normally and, (my assumption) is that running off of pump gas, they are not high compression motors. Compression/boost is not a factor here in that, you'd just need more fuel to run it.

I agree also with the injecting at extremely cold temperatures would cause a freezing condition at the nozzle. Under "normal" flow conditions, your cooling will occur at the fuel source or tank because that's where the liquid is vaporizing and therefore pulling heat (energy) out of the surrounding area for that physical change. Go put your hand on a propane tank while you're grilling for instance and feel where it is cold.

If you try to draw too much vapor too fast, which is identical to what you did of pulling cold vapor, which was still nearly liquid fuel through the plumbing. This caused the physical change from liquid to vapor change to occur later in the system and freeze up at that point, nothing special. You can make mechanical changes such as polishing up the port to reduce the negative effects of this like you said. In this instance, too cold is not beneficial unless you could do something like direct fuel injection like the new gasoline direct injection systems. Maybe the combustion temps would help keep the nozzle warm enough?

I think we agreeing partially but on different points. I also agree with you about having to raise compression and/or boost...but only if it is an additive used in the same manner as nitrous.

Give me a couple days and I will speak with the gentleman working on my car about getting some technical information about the subject. He's the one who told me about the RV's from his own experience with being a factory-certified mechanic working on those systems.

Good discussion :)

Propane & Nitrous DO NOT do the "SAME THING"

PROPANE is a FUEL, equivelant to very high Octane (114+) Gasoline and adds FUEL to the Fuel side of the Air/Fuel ratio equation adding Propane acts as an octane booster much like Toluene but with additional Charge cooling benefits.

NITROUS is an OXIDIZER an adds Oxygen to the AIR side of the Air/Fuel ratio equation. Adding Nitrous LEANS out your A/F Ratio. hence the need for adding fuel at the same time.

Ugh...you're absolutely right. Didn't even think about that. Thanks Max.

Can you contribute any information about the valve pitting?

I can't comment on the valve pitting except to say I know that Propane & Natural Gas burn much HOTTER than Gasoline, and a lot ov industrial engines that are designed to burn Propane and/or CNG use sodium filled exhaust valves, and run very "COLD" Plugs.

maxpesce / Turbo 3

Propane is not equal to 114 octane gasoline. The octane ratings are about the same but propane does not produce the same energy. The BTU are quite a bit less. ( British Thermal Units. ) It does burn hotter than gasoline so colder plugs are necessary. As for corrosiveness in an internal combustion environment, I am very interested.. So if you can find any literature, please post. I would like to read up on it.

True Propane has a lower ENERGY DENSITY (BTU/Pound), So propane requires a higher Specific Fuel Consumption (Lb/Hp/Hr) than gasoline. However it is capable of producing Peak Torque & HP on par w/ Gasoline, You just need MORE of it to produce the same amount of work.
The amount of Torque an engine produces is directly proportional to BMEP (Brake Mean Effective Pressure), Piston Surface Area and Stroke. and When taking into account the fact the high Octane Rating of Propane allows Higher Compression ratios vs/Pump Gas - It is capable of producing equivlent BMEP's. when using Propane in a "DUAL FUEL" motor w/ Pump gas (in a Either/Or mode) , you will get Higher Torque & Power with gasoline b/k you won't be running high enough compression to optimise the combustion of the propane.