Propane on 2 stroke turbo idea.

[Wheel House Motorsports]

Just putting an idea i had out there for people to look at and maybe some who have tried similar to give me some feedback.

My current plan was to turbo my 1000 sdi ski-doo summit next spring/summer. Now here is my idea.

Propane metered to boost injection. My buddy and his dad have a company were they install propane conversions on cars and trucks so it gave me the idea. The way i see it, the sled already delivers enough fuel to run the sled for natural air pressure, now as you add boost it increase the air in the cylinders so you need X amount more fuel, well my idea is to figure out how much more air would come in and then figure out a way to meter a propane injection system to add the perscribed amount of fuel. it would only work in lower boost applications, as propane is 104 motor octane i beleive, BUT the big helping factor is the cooling affect when you inject it, allowing the intake charge to be cooled down quite a bit, this combined with the higher octane should in theory allow the engine to be much less prone to detonation.

any thoughts or ideas?? I was really just curious about a way to meter the injection based on boost.

 

[winter brew]

Talk with Brad Story, he is a pioneer in the propane sleds, has great success on 4-stroke, I believe there are some issues with the 2-strokes, give him a call.

 

[06MXZXRenegade800]

I dont see why it wouldnt work, it would probably be easier (yet alot more expensive) to just convert it to run 100% LPG. That way your not lugging around a full tank of gas plus another propane bottle (dont even know where you would mount it)

It would be find of cool to convert it from speed density SDI to a mass air propane system...

 

[Wheel House Motorsports]

yeah, the cost of running straight LPG is the only reason i would want to do it, i cant justify the cost. and with the injection ratio still isnt to high, i think i could get away with a 35 pound bottle off a forklift, thats 7.4 gallons of propane, so i know it would last when running a 10.4 gal tank of gas, i would just rock it right on top of the gas tank with a custom highrise tank, probably something like a dirtbike seat, im gonna go look at it and just see how much room i have, Rev seets are really big, so i could carve out the inside and make it a tad taller, and it would look like nothing.

"from there the propane passes through a specially designed regulator which meters the appropriate amount of propane to be mixed with the incoming oxygen and diesel fuel. The oxygen is supplied via the air coming into the intake, at which point the propane is injected through a port mounted in the intake tube where it mixes with that incoming oxygen"

that is a quote from a Bullydog propane setup on a turbo diesel, from another artice on it that i read, i beleive its some sort of boost referenced valve, i would just have to adjust for the setup i was running.

at a tad over $3 a gallon right now for motor fuel (road tax added) that is a HECK of a lot cheaper than 6 bucks a gallon for comporable race fuel. and propane is EVERYWHERE, and with the regular gas tank and then the aux propane setup, i could go a lot farther per tank, meaning no bringing extra gas all the time.


whats brads name on here, i forgot. the reason the idea sort of worries me is that it seems to easy, just not sure why its not more common.

 

[06MXZXRenegade800]

It wont be 'easy' tryint to suppliment the boost with LPG rather than gasoline.

Both your LPG injection and SDI need to be perfectly in synch with the boost levels or your going to end up with lean/rich spots. Its not as easy as it seems.

Now, adding LPG injection as a MPG suppliment on a diesel is EASY, it can be done for $20 in parts and a regular BBQ bottle!

 

[Hairy Mark]

i heard from simmons who is working with brad that the m8 thatthey tried to run on propane lasted 14 seconds. not sure why but they even machined some titanium postons to put in it and they still melted almost immediatly. and propane is 116 octane equivilant from what i am told.

 

[Wheel House Motorsports]

see the question i have is about running propane as a supliment, so you still have normal fuel levels running through it.

im gonna PM brad and see what he thinks.

 

[Trashy]

We do SEFI propane conversions and diesel boosts. I'm not saying the 2 stroke deal is impossible, but it would be pretty difficult. I think you would be best off running it dedicated fuel, and the first hurdle would be getting a functional oil injection system that would look after lubrication duties. Do you want to remain injected, or would you consider running a mixer (carburation)?

 

[Wheel House Motorsports]

i cant run mix on the SDI motors as the bottom end sees no fuel, as its shot straight thru transfer ports into the cylinder, so the oil is the only thing that keeps the bottom lubed and cooled at all.

 

[Trashy]

Bearings maybe... but what about the piston/bore?

 

[rmkboxer]

I dont see why it wouldnt work, it would probably be easier (yet alot more expensive) to just convert it to run 100% LPG. That way your not lugging around a full tank of gas plus another propane bottle (dont even know where you would mount it)

It would be find of cool to convert it from speed density SDI to a mass air propane system...

would you premix?

 

[Wheel House Motorsports]

like i said above, not totally converting to LP, just injecting it to compliment boost, so the pistons get plenty of lube, heck i might even premix a tad bit o' oil in the gas to help compensate things.

just chatted with brad a bit, and he said the problem they have with straight LP is that that above 7psi the thing just falls apart as it gets so hot. then again hes injecting vapor, my idea was to run straight liquid right up to the injectors. seeing as liquid propane boils at right around -42*F its COLD, this should help drop charge temps a ton with the sled, i just happened upon some crazy info on propane, heres some stats

gas will ignite on its own at 428 degrees F
propane ignites on its own at 1004 degrees F, as far as preventing detonation, that looks pretty dang good to me.

 

[Trashy]

Injecting liquid is tricky business... for one you will need a pump, usually in the tank. You also need a vapor return line. And a sophisticated control system... Complex, and likely too heavy for a sled.
There have been many liquid systems the past few years, some more successful than others. Roush is currently marketing a system used by Ford, once again a dedicated LP deal...

 

[Wheel House Motorsports]

yeah, after my brain engaged and i realized what i was trying to do, it doesnt look to be such a great idea, may just stick with something else, im gonna keep looking around for ideas.

 

[moyiesledhead]

Something else to consider when injecting liquid....the expansion rate when propane vaporizes is 240 times its liquid volume. That might be why most systems vaporize first, then inject. Easier to control the quantity of fuel.

 

[triple7]

I wonder why Brads motor melted down above 7 PSI? I didnt think Propane burned that hot. As for a detonation suppressant, It would be better than very expensive race fuel. Its crazy stable.

 

[Trashy]

Something else to consider when injecting liquid....the expansion rate when propane vaporizes is 240 times its liquid volume. That might be why most systems vaporize first, then inject. Easier to control the quantity of fuel.

270 times, but close enough.
And you are correct, thats why even most injected systems, even the one on my race car, are vapor injection...

 

[Wheel House Motorsports]

yeah, when i was reading gas versus propane info the expansion rate came up, and you inject just a tiny bit to much and it would be WAY off. IM wondering if you could run LP through a fuel injector, that would allow some pretty precise control of liquid injection.

and i think the reason if he went above 7 psi it would cook itself was the lack of any liquid fuel pulling heat out of the motor. thats why i wanted to run gas and propane supliment.

 

[HANDSOME]

Bear Mountain Boy ran a Propane turbo 580 Cat in 95.

 

[Trashy]

yeah, when i was reading gas versus propane info the expansion rate came up, and you inject just a tiny bit to much and it would be WAY off. IM wondering if you could run LP through a fuel injector, that would allow some pretty precise control of liquid injection.

and i think the reason if he went above 7 psi it would cook itself was the lack of any liquid fuel pulling heat out of the motor. thats why i wanted to run gas and propane supliment.

Any of the liquid systems that worked have been injected... I wouldn't give up on the idea; I would love to develop something that works... but a 4 stroke makes things a whole lot simpler!!!
As for your 2 stroke, oil injection and a mixer would make the most sense to me. I have been working on a tank that has a decent capacity (WAY more than the dual setup Brad has been using) the problem is that there is no way I could legally sell one (it uses a 100 psi p.r.v. which is just fine for cold weather operation...)