adding propane to gasoline engine?

[BrooklynBay]

Thanks for the link! According to that article, it seems like you need a vacuum controlled valve to regulate the flow of propane into the intake manifold. Maybe there is a way to do it with a MAP sensor, and an electric solenoid valve connected to a controller?

 

[Charlie]

You might also want to check this link:
http://www.gotpropane.com/

I looks like there is no way produced yet to work with the fuel injection. There has got to be a way though..

 

[BrooklynBay]

I'm sure that the conversion for LPG could be used on propane too.

 

[Charlie]

What vehicle of yours had you tried the propane on?

 

[BrooklynBay]

My 89 with a 3.0L V6. It has multiport (not sequential) fuel injection without a MAF or a coil pack. It uses a regular distributor, and a MAP sensor. It has EEC-IV.

 

[dlk]

Thanks for the welcomes and replies!

Sounds like I'm not the only one interested in doing this. My biggest fear (besides blowing up my engine) is that I won't increase my gas mileage enough to make up for the propane I'll use. Accelerating normally and driving 70mph during the summer I get around 15mpg, if I accelerate slowly and set the cruise on 55 I can usually get around 19. During the colder months, I'm lucky to get 15 if I baby it and cruise 55.

I don't think it makes much difference if the propane is injected before or after the MAF sensor, as I don't think it can tell the difference between propane and air.

I've tried using E85 before, but when the concentration in my tank hit about 40% my engine started acting dumpy, and mileage went down, so I stopped using it.

I wouldn't be considering this if I didn't think I could jerry-rig up a system using parts I already have, like off my camper. I wonder where I can find a 12 volt on/off propane switch?

 

[Charlie]

I want to do it, not so much for mileage, but just because I can

I like to try things, to see if they will work

 

[BrooklynBay]

You could try a nitrous solenoid. An air horn solenoid might work too.

 

[dlk]

It Works!!!

Well, I tried it out today. Yesterday I took the 20# cylinder and regulator off my camper and stuck the hose into a hole in the side of the airbox of my Ex. I had the engine warmed up already, and I opened the valve a little and my engine stumbled and idled slower. Then I opened the valve more and it quit. I was disappointed and decided not to go through with it, but I changed my mind. Curiosity got the better of me, and I had to find out if it would work.

Today I added a valve downstream of the regulator, and an adapter for 1/4" vinyl hose, and ran the hose out the door and under my hood to the airbox, securing it with duct tape(Red Green would be proud!). I opened the valve on the tank, then opened the ball valve until I heard it hissing, and I'm using the main valve on the tank to turn the system on and off.

I drove 128.6 miles on 5.913 gallons of gas, or about 21.75 mpg. I took it easy and set the cruise on 55, I've been getting about 15mpg driving like this. I estimate I saved about $7 on this tank alone by using propane, but the last variable is how much propane did it take to do this? I have no idea. The tank on my camper is an old pre-OPD tank, so I couldn't get it topped off before I started, and I don't know how much fuel was in it when I started. I might've used $1 or $13 worth of fuel, I have no way of knowing. I'll have to run this tank until it's empty, then get a full one and use it up before I will be able to tell if it's worth it or not, and I only drive about 120 miles a week, so that'll take awhile.

I'll post back when I find out whether it's cost-effective or not. If I'm saving enough to make it worthwhile, then I'll need to figure out how to mount the tank OUTSIDE the cab of my Exploder. I couldn't really smell it today, but I could taste something under my tongue, so I think there was a little bit of gas seeping through the 5' hose on my tank. Just another reminder of how dangerous this idea is....DON'T TRY THIS AT HOME, FOLKS!!!

I plan on letting my engine reach operating temperature before turning on the propane, and shutting it off a couple minutes before I park it. I've heard of people having a leak in their nitrous systems and blowing their engine up literally in the parking lot. That's all I need is to forget to close the valve and blow the intake through my hood when I turn the key!

 

[BrooklynBay]

Well this is a good start. The valve you would need is a normally closed valve. It will close when it loses power.

 

[dogfriend]

I might've used $1 or $13 worth of fuel, I have no way of knowing. I'll have to run this tank until it's empty, then get a full one and use it up before I will be able to tell if it's worth it or not, and I only drive about 120 miles a week, so that'll take awhile.

Weigh the cylinder before and after using - the difference is the amount you used.

And, yes, Red Green would be proud. :

 

[dlk]

^Now that says class!

 

[Charlie]

That's not spraying through your sensors, right? Edit: I would also pull that duct tape from your paint before it leaves permanent marks.

 

[dlk]

You think it'll damage my sensors? Which sensors?

 

[Charlie]

I can't imagine propane going through the MAF and all that is good. I would put it higher up than the sensors as much as possible.

 

[Donner]

Don't know if this helps, but Charlie, how about some type of insulation for that tubing? Would it help to run the tubing through inside (in between) the fender, and use some of those small horseshoe style clips to secure it?

 

[dlk]

So far I haven't had any trouble, but I'll keep that in mind.

Donner-I don't see any need for insulation. What I have so far is just a cobbled-up system that I am using to test a theory. If it works I'll invest in improvements like mounting the tank on the outside of the cab, remote valves, and running the line along the framerail or something.

 

[Donner]

Got it... you know your stuff! Alright then, I'll check it out again later...

 

[dlk]

Update: I've used the propane on two more trips, the last one I got 20.07 mpg cruising at 55mph. The other one I drove 70 the whole time, it was below zero and I had a really nasty headwind on the way back, so I only got 14.26 and was glad to get that. I'm going to try opening the valve more while I'm driving at speed and see what happens. I don't know how much my little 1/4" tube will deliver with the regulator.

Before I started this, when I first put the "big" hose in the airbox and opened the valve, I expected the motor to rev up. I now think the engine didn't rev up because the throttle stayed closed, and all I did was flood the motor by putting too much fuel in it when it couldn't get any more air through the butterfly.

Charlie and Brooklyn Bay, If you don't mind, I think I know why your two experiments didn't work. The one that was plumbed through the fuel injectors probably couldn't deliver enough propane to do more than idle the engine, and opening the throttle leaned it out and it quit. Charlie, I think your "ghetto" style system put too much propane in because you didn't use a regulator, and weren't able to regulate the flow. Using a propane system this way is tricky because the propane is delivered at a rate independent of the motor's needs, which is why I'm trying to just put a small amount in and let the engine's fuel injection system regulate the motor's speed. As long as I don't put more propane into it than the engine requires to run, I think it will work fine.

It seems filling the small cylinders costs $0.65 per pound. This is probably more than $2 a gallon, anybody know how many pounds a gallon of propane weighs?

My full cylinder weighs 35 lbs, so I'll try to figure out how much I've used this weekend.

 

[dogfriend]

5.1 lbs / gal @ 60°F

http://www.propane.ca/Resources/propane.asp