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Bus Nut
Join Date: Nov 2003
Location: Twin Falls, Idaho
Posts: 809
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Do it to yourself Adding propane
Propane Article with setup instructions and Pics..."
I first heard about the addition of propane to a diesel engine from some of the threads on the ford diesel website. The concept is that diesel fuel when it burns, doesn't burn completeley. In fact it only burns about 75%, so the total available power(in the form of released btu's) from a given amount of fuel is somewhat wasted, especially in a non-turbo deisel engine. The addition of propane(lpg) to the intake air, acts as a catalyst, and allows the diesel fuel to burn more completely releasing all the available power. The result is a cleaner burning engine(less soot, cleaner oil) and increased power for any given volume of fuel, and therefore, increased fuel economy.
I was intrigued, so I checked into it. There are a few companys that offer after-market bolt on systems, most of them in and around the $500 U.S. price range, but most of those are designed for trucks which are running a turbo on the engine. Since I don't have a turbo on mine, and don't really want to add one to my tired, old engine, I was hoping to find a system that would work on a non turbo application. A company named Bully Dog Technologies did e-mail me back and said their system would work on a non turbo application, but it was still $600 U.S.(about $900 Can.) and I figured I could build something that might work for cheaper than that. One guy described a system he made at home, and although his was also a turbo application, I thought it could work. So I built much the same system.
I would like to put a word of warning here! Propane can be very dangerous if not used properly. If respected, however can be very safe. Always check all fittings for leaks using soapy water prior to running the system. You can never be TOO careful!
My plan was to have the lpg setup so as to come on when maximum power was needed but not run all the time so as to conserve on the added cost of the purchase of lpg.
Equipment required...
Vapour-type propane tank(BBQ style 20lb'er works fine)
High to low Pressure regulator(Acetylene one works great)
Hobbs pressure switch
Electric solenoid Lock-off switch
Micro switch for throttle activation
Various hose & fittings
Dash mounted toggle on/off switch
My total cost for all this stuff was less than $250 Can. but I did scrounge some of it second hand, so to purchase it all brand new would probably run closer to $300 Can.
Setup
A long (10ft.) extension hose connects the tank sitting in the back of the truck to the Acetylene regulator mounted at the front of the box on the driver's side. I had to wire wrap the hose fittings to connect the high pressure hose to the regulator.(Don't want any leaks here!)
click here for tank pic
Next, I mounted the acetelyene regulator and the electric Lock-off valve in a box that was accesible, but safe from things bouncing around in the bed of the truck. I put the lock-off on the low pressure side of the regulator so that if it somehow didn't completely close off the flow, the leak would at least be a low pressure one. It has been suggested that maybe a second lock-off valve connected to a separate on/off toggle on the dash might be a good idea, to have absolute control. I can't see anything wrong with that idea. I have the regulator set to around 4psi pressure. This is the pressure in the line. When the flow is activated, the low side of the gauge drops to less than 1psi.
Click here for pic of regulator
I then ran 1/4" fuel rated hose from the Lock-off valve through a solid brass fitting mounted at the forward drivers side corner of the box down along the inside of the frame rail and up over the top of the engine along the firewall to the air intake hat. To connect to the intake I used the same type brass 3/16ID. fittings with 0-ring seals and a small 4" length of copper tube on the inside with some 8 holes drilled through one side to allow the propane to disperse into the incoming air stream.
Click here for pic of intake
The electrical connections consist of running a wire from battery power through a micro switch mounted alongside of the fuel injector pump, just barely coming into contact with the timing advance lever. As the throttle is opened, the advance lever moves out/away from the pump, and eventually when the throttle is at about the half way point, the micro switch is depressed and allows current to flow.
Click here for pic of micro switch
I then ran the electrical through a Hobb's style pressure switch connected inline with the oil pressure gallery. This switch is normally "open", and only allows current to flow when the oil pressure is above 15psi. The other one on the left in the photo is for my "idiot" light on the dash which is not related to the lpg setup, but is normally "closed" and only lights up if oil pressure drops below 15 psi!! (paranoia factor)
Click here for pic of Hobbs switch
Finally, the wiring runs through a toggle switch on the dash(the little blue one down low)which is also connected to the little green led up on the steering column to show when electricity is flowing, and thus indicate when the lpg is also being activated. From there the current runs to the Lock-off valve in the truck box mounted alongside the regulator.
Click here for pic of Dash switch
Well, that's it!
Does it work you might ask? You Bet! It took a bit of fiddling to get the micro switch set where I wanted it to be, and some fiddling to find the right amount of pressure to run the system at, but once I got it right, there was no turning back. The difference in power is immediate and impressive. It doesn't "snap" on, but kind of comes on smooth and strong. I think because the distance from the regulator to the intake is some 11 ft, there is about 1 second delay, but barely noticeable. I did a few tests to get some numbers. On the flat, shifting through all 4 as fast as I could, 0-60mph, without the lpg on, I could do it in about 22 seconds(3 tries averaged) When I turned the lpg on and did the same test, I spun out in 1st, but still made it to 60 in about 16 secs. Climbing a local hill, about 5% grade I had about 2,000lbs of gravel in the back, and without lpg, I couldn't hold 55mph in 4th, and had to shift down after about 1/2 mi. When I did the same thing with the lpg on, I had to back off the throttle at about 3/4 mi, because I was gettin' up to 65mph!!(speed limit 55)
So, for anyone who is looking for a way to get more power, at a reasonable cost, with some nice side benefits, without the added stress to an engine of a turbo, then lpg is a great way to accomplish this. Go for it!
I will mention again, this stuff is great if used properly and respected, but we know that propane can do some serious damage to life and limb if abused. Double check your system for leaks before using it, and better yet, have it inspected!
Happy Truckin'!.....Don
I thought I'd add a little update paragraph to this article.
It's been a few months now since I first had the lpg up and working on my truck. I have not been able to notice any increase in fuel economy, in fact, my fuel mileage has gone down significantly, and I know why. It's because I can't seem to be able to get my foot off the "go pedal" It's so hard with all that power!!
Actually I wanted to mention a couple things. One is that I finally had to fill the same 20lb'er that I started with, but that's after about 8-10 tanks of fuel run through. So, to me, for 15 bucks to fill the lpg tank, it's well worth it. Next though, I've had to change the setup somewhat. I'm finding that the single stage "acetylene" regulator that I use is a little difficult to control. I seem to be always adjusting it, to find the "sweet spot". I'm convinced that it is because of changes in pressure in the tank due to ambient temperature variations. So, I've put a second small regulator in the low pressure line nearer to the engine. This allows me to drop the tank pressure to between 10-15psi with the 1st stage, and then the second stage I am now running at about 5/6psi through a 5/32(instead of the original 3/16)inch orifice to the engine. As the tank pressure goes up and down slightly, the pressure at the engine remains more/less constant. One guy e-mailed me to say he had done much the same thing, but using a Sears craftsman model 359H 2stage regulator(from a welding rig) on his, but I couldn't find such a regulator here in Canada.
here is a pic of it
I also have found that if the micro switch is set to allow flow of lpg at very heavy throttle applications, it seems to smoke black a lot. Lots of power, but I found that if I set the switch so that the lpg flows at a throttle postion just over that required to lightly accelerate on the hwy from 60mph, then the lpg flows sooner, with lesser throttle application, but there doesn't appear to be the black smoke(overfuel), until I really get into the full throttle position, which is now often not needed except on the larger hills.
I also found that if the lpg hasn't been on for a long time, then the first time or two that it is turned on, there is often a lot of black smoke for a bit. I am not really sure what this is about, but it seems to clear up very quickly, and I am guessing that it is somehow built up carbon/soot deposits being "blown" out of the engine when the lpg is being used. Once lpg has been on for a few seconds, it clears up, and then there is hardly any smoke out the exhaust at all, even with fairly heavy acceleration.
Overall, I still feel that this is the single most significant thing I have done to my N/A engine with respect to getting more power without having to spend the big bucks, and have the added stress of a turbo.
Don
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