propane

what do you gents think about propane conversions ? It would be going on a 74 with a 304. i was looking at fuel injection kits and my old man said why not go with propane. so i have looked at a few kits and just wanted some more input.

 

I asked the same thing not to long ago. Here's a link to my question about the subject with some pretty good details about it.

http://www.earlycj5.com/forums/showthread.php?t=50883&highlight=propane

 

They had a pretty good write up on it in the new Petersons 4wheel drive magazine. It also had a fairly decent how to step by step.

 

I was looking at propane and FI for a while. Its can get to be very expensive very quickly. If its what you want, definitely go for it and dont look back. The only issue with propane is that you lose some power, but i think you could advance the timing, and more extremely, bump up the compression to get your power back.
I've got my factory carb tuned in so well that I'm in no hurry to go FI anytime soon.

 

The only thing I'd give up my 'pane for is *maybe* a late-model computer-controlled multiport EFI motor.

I got it on a '73 258, along with HEI, and got plenty of power. Some of the good things, no choke, and no cold start headaches. No fuel bowl running dry (or flooding) on steep ups and downs. Propane never goes bad, my Jeep does good to go a couple of thousand miles a year. Oil doesn't gunk up between changes.

If you shop around, you can find some used stuff pretty cheap. I picked up a complete set up off a local 4x4 board, all of it new in box, from a guy that lost interest in the conversion. Including tanks and brackets, I had less than $400 in the conversion.

 

o0o0o0o.....Did somebody say PROPANE.......Now you're speakin my language. I've been through every single form of fueling these things, and propane is the only way I will ever go again, especially on trail rigs. For Jeeps that are driven on the road mostly, I would just stick with a carb, but if I'm planning on doing any serious offroading then I wouldn't go any other way. I work constantly with a buddy of mine installing them, and we've done everything from V8's to stock Samurai motors, as well as several 22R's in Toyotas. I can tell you that Got Propane offers a good kit, but it's way overpriced. I think their Samurai kit is around $900 without a tank, and we've been getting it all for around $500. V8's usually take around $700 or so without a tank. Easiest way I know of telling you how to do it is to get a decent 4 barrel intake, and get a decent base plate (bottom plate with the butterflies) off a Holley (non-double pumper) carb. From there all you have to buy is a 425 mixer (equal to around 600-700 cfm or something like that I think) and the regulator. Those two things run a little over $400, and then you can check around with a local propane distributor to get your hose and fittings, or if you're lucky like me and have an industrial rubber and gasket place close to you you can get it there. That stuff isn't cheap, but it only adds up to around $100-$200, and from there you just bolt it up and go. Only other thing is figuring out your throttle linkage, but that's been fairly simple so far on the V8's we've done. After you get the idle adjusted, there's no more adjustment to have to worry about. I've done so many now that I could just about walk someone through the whole procedure without even looking at what they have. R)

There are tons of benefits to it, especially when it comes to offroading. This is a hobby where we just about have to have FI or Propane for the engine to run in certain situations. This is also a hobby where we know things are going to get wet and muddy, like computers and wire connections and crap, so propane eliminates all the complicated stuff needed to keep a FI engine running. You have no wires, no sensors, no computer, no fuel pump, or anything like that to have to worry about, just your basic ignition or msd box and your distributor and coil. Some say that you lose some power with propane, but from what I've been told by someone that I would have to say knows what he's talking about, the 10% loss of power thing is with a different kit than what most folks are running these days, especially with alot of the kits that come off old tow motors and things like that. Like I said, we've put this on several different vehicles, and every time there is a very noticable gain in performance, especially throttle response. Plus propane is 118 octane.

First guy in our club to decide to go with propane was running Holley Projection, and had problems with it left and right, not to mention had a very well built motor so he was having to run higher octane fuel. He was spending around $55 a day on our rides in fuel, and now with propane he spends $21, so it pays for itself fairly quick.

I could say more, but I just realized I'm taking up the entire thread with my Hank Hillish propane pitches, so I'll shut up now.

 

(Majority of post cut to eliminate the Hank Hill propane pitch...) R)R)R)


OK, so I've read the threads on how to do it... and I know why I would want to do it on a trail rig, but you suggest a mainly road/mild off-road to stay with a carb.
Why?
Most of our Government rigs and cop cars around here are LNG (I know LNG and 'Pane are different...). And with gas/diesel prices climbing through the roof ('They' are figuring over $4/gal for regular here by late spring early summer) and with propane a hellava lot less, even if the power/MPG was a little bit less than gasoline, it would still be economically feasible to convert, even for a DD. Or am I mentally impared from sniffing too many fumes from my leaking gas tank? R)R)R)

 

Propane requires a big tank that needs to be filled often, that's why it's not a great idea for a DD CJ5 which doesn't have a lot of room to begin with. And propane does cause a loss of power, it has little to do with the kit. It has a lower BTU content per unit of volume, hence lower power and lower fuel mileage. Sure, it has 118 octane, but unless you build the engine to take advantage of that, so what? May as well be the same as pump gas except you can run a little more timing.

I agree that for mainly offroad 'pane is great, I'm considering it myself as things go along. I don't think I'd go that way if I was driving the Jeep every day just due to lack of space to put a reasonably sized tank and the hassle of finding a place to fill it if you travel very far. There's also the dual fuel setup which does work great as long as you remember to use the carb from time to time. Most problems I've seen with dual fuel setups is that the carb dries out and the tank gunks up so the gas system doesn't work any more.

 

Biggest reason I say that is because it would be cheaper in most cases to rebuild a carb if it were on a vehicle that was mostly gonna see street driving. The other thing is having to mount a tank as NorCo mentioned. As to the power loss, I've never even looked into the logic behind it, because it really doesn't matter much what the numbers say, I've just heard that the loss comes in mainly with the setup you mentioned that goes along with the carb. I base the power differences on the facts of how well a vehicle runs, because if one isn't running good, then you will definately gain HP when you put propane on it. The guy I mentioned in our club as being the first one with it started with a carbbed 350, and it ran a certain way. Then he switched to the Projection, and it ran about the same. From there he went to propane and it was like having a whole new engine. We've done this on older V8's, brand new crate V8's, even took a TBI 305, swapped on a carb intake and put it on there, old 1.3 Samurai's, and 22R Yotas, and in every case there was a noticable gain.

 

Thanks for all the input. I think after taxs come back I am going to start getting the parts I need. How does the propane run in the winter since i use the jeep to go to work (5 miles round trip) when it snows.

 

I've heard some say it doesn't run good in the winter, but on our trail rigs we've run it when it was down below 20 degrees, and the engine compartment is mostly open, and the tank is out in the weather as well, and never had any trouble with it. It's all in making sure everything is hooked up good, because if you have a small leak somewhere the tanks will freeze up sometimes.

 

I spent some time driving a fork lift in Salt Lake City . . . In the winter it would be well below zero and the propane engines fired right up!

 

Cool to hear stuff like that, because that's really the only thing we've ever wondered about with it. There are tons of things you hear from people out there on why they wouldn't go with propane such as hearing the one about how they don't do well in cold weather. 90% of these arguments come from people who have never run propane on anything, and only have experience with it from what they have heard through the grapevine. I don't pay much attention to what I hear, or even half of what I read, I just go by the way it works.

 

I'm headed in that direction . . . I now have all the parts I need, picked up a piece here and there on EBay (need to clean them up) and just got a tank for free (need to have it tested). So far I've spent less than $100 bucks.
For me the big issue is how I want to deal with the tanks. I'd like to find a decent size tank that I could fit between the frame rails and not lose my back seat.
My second choice is to mount one or two smaller tanks (lift truck size) on my rear bumper. The idea being that you could have a spare or two and swap out the tank(s) as needed. Not much protection there, however and it might make a mess if you went over on them. I'm not worried so much about an explosion (I think gasoline is more dangerous than propane) but if you ripped your fuel tanks off it might make getting home more of a challenge!
I also have a problem that the tanks are damn ugly! The new plastic tanks are cooler looking (and it's neat that you can see how much fuel is left in them) but they are $pendy!

 

Running two tanks is alot better than running one most of the time. We run two in most of our trail rigs for many reasons. 1. If you are back in a trail, and run out, all you have to do is switch tanks. 2. Alot of places you have the tank filled at charge you the same amount of $ no matter how much it actually takes to fill it up. When you're on the trails and only have one tank mounted, alot of times you'll swap that tank out with as much as a gallon or so left in it to make sure you don't run out back in the woods. When you go to have it refilled, you get charged for that gallon again. Being able to just run it til it quits, and swap tanks and start it right back up saves all this trouble.

We run the bigger tanks though because we don't have back seats, but if you found smaller tanks you would still have this benefit. When we are making up our hoses we put a T in the line so we can connect both tanks at the same time. When it runs out, all you have to do is shut the valve off on the empty tank, and turn the valve on on the full one.

Stay away from the clear tanks. I've got a buddy that works at the place where they started making these, and they ran a batch of these back last year that there were safety issues with (I heard they were blowing up but don't know for sure). Now around here there are very few propane places that will fill these. They look uber cool, and it's great to be able to see how much fuel you have left, it's just gotten to where most places wont fill them. Even though they got rid of all the problematic tanks, alot of the propane guys I've talked to say they will never go back to filling them at their location because of the liability from it.

 

Anyone have pic's?

(Don't want to hijack your thread but Pic's are always good . . . )

 

Hope this helps, it's the only one I've got right now.




I've looked around for a decent pic of some of the ones we've done, but can't find anything that shows the mixer/regulator set up. There's also a safety shut off switch that shuts off the fuel in case there's a fire or something, but we've pretty much gotten away from running that. The switch, whether vacuum or electric, is mounted close to the regulator anyway, so that means either way the fuel line is right there where the fire is anyway, so I don't really see how it adds much safety to it. Plus, propane is pressurized gas anyway, so it will just shoot a flame out the end of the line until you shut the tank off, so it's not like the fire will make a trail towards the tank and build up pressure and blow up like a regular fuel tank can.

 

Hey, MCSCOTT...

I'm next door in NC. I'm hunting for a bigger tank for my M715 since I converted it, like a 20x60. Got any leads on a cheaper one...new tanks are pretty steep, plus shipping.

 

The tanks are the only thing I don't really have any good leads on yet. I've eliminated the clear tanks, and I don't want steel, so somewhere over the next few months I've gotta round me up some aluminum ones. I've got a lead I'm checking into with a guy that's suppose to be getting some cheap down in Alabama somewhere, but I think alot of these are gonna end up being steel. Usually if you check around with some of your buddies, they can round up tanks cheaper than you can get them new, but I don't even know where to start on a tank that size.

 

I've got 8 aluminum forklift tanks. If you are patient and watch 4x4 boards, they come up, I have paid $30 to $50 each for what I have.

I might stick with my plan to run the forklift tanks in the 715, but since they are not ASME, they are not particularly legal on-road.

The 20x60 (appx 74 liquid gallons) tank will run me about 1250. I just got a quote from sleegers for $936, plus 250 shipping. My local propane dealer can get also, but it ends up about $75 more (worth it cause I got Net 30, and he'll have to deal with the truck freight delivery. If I buy from him, he'll set it in the back of my truck for me.