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westkill 05-20-2004 09:29 PM

propane + veg oil = vroom-vroom
I have finally gotten around to taking the digital photos of my propane injection system and have provided a link to them at the bottom of this post.
To refresh what I did was as follows:
I took a motor and tranny from a 83 SD and put it into a 1973 International Travelall (suburban looking). I boosted the turbo to 13.5 lbs, cranked up the fuel via ALDA and intercooled it using a unit from a Ford probe. I also added propane injection, an overdrive unit and started running it on used cooking oil. (SVO)
The addition of the propane was the single BEST improvement as far as power and speed and was probably the simplest to do. Propane is 118 octane and the MB diesel LOVES it!
Before I get into the particulars I must say that if you decide to do this, it is at your own risk and I am not responsible!
How I did mine was starting in the back of the truck I had a compt that used to store the spare tire, like old station wagons had. It is big enough to hold 2 barbeque tanks. Mounted on the tank is an adjustable regulator that I have set at 1-2 lbs. (You must find whats right for you, trial an error). I also have a gauge that reads tank amount (optional) see pic.
From there you run LPG rated hose up to the engine compt. You then must mount a 12V fuel lock solenoid. You want to get that as close to the air cleaner as possible.That way there is no lag when it gets the signal to inject. The hose from the tank goes on one side, an additional piece goes on other side and will go to air cleaner area. (see pic)
To inject into the engine I made up a brass fitting using a male an female hose barb and mounted it to the end of my cone type filter (pic). For a stock air cleaner setup. drill a hole through the "U" shaped piece that connects the air cleaner to the turbo inlet. Theres even a small flat spot on it thats ideal..
As far as activation, You need whats called a HOBBS pressure switch. Use the one that adjustable from 1-10 lbs pressure. On the rear of the intake manifols is a plug. Remove it and screw in the hobbs switch.(see pic) What this does is whatever psi you set it for, it will close contact at that psi,
there by energizing the fuel lock, opening it, and propane goes
To simplify, The fuel lock is grounded to the car. If you give it 12V juice it opens. I wired mine so that 1 switch energizes the system. When that toggle is on and I get to my preset boost amount (at hobbs switch), The lock opens and instant speed. I also added an additional toggle and what this does is power the lock manually. I use this coming off a light with a steep grade. Instead of waiting to build up boost, I hit the switch and propane shoots in instantly. (see pic)
As far as what boost psi I have it set at, I usually run at 5 lbs boost. I just lowered it to 3 lbs boost and now I have power instantly and haven't had to hit the manual button once.
As far as propane usage, I will tell you one experience I had. I drove from Ronkonkoma Long Island NY to Carlisle PA, approx 500 miles roundtrip and through a very mountanous area where the "juice' was on constant and I didn't even use 1 barbeque tank! The extra power is well worth the cost.
When I was setting up my pressure amount at the regulator,I initially had it set at 6 psi. WAY TO MUCH! You know your injecting too much when the engine pings. You only need to bleed it in.I like my 1-2 lbs setting.
AS far as the equiptment needed, My friend got me the fuel lock. Any large propane place should be able to help you out. He uses them on their fleet trucks as everything runs on LPG. Everything else should be easily obtainable.
Regarding the safety aspect, I will not get into it. There are tons of lpg vehicles on the road and I don't see them blowing up.. Also, although my vehicle once resembled a Suburban, I chopped the back, fused in a rear wall from a pickup and created a 4 door pickup. My LPG tanks are now outside the vehicle compt in the bed area
THis is all I can think of for now. I will leave you with this, If you want you Mercedes diesel to be a rocket of the line, do this. You will be amazed!!!!


05-20-2004 09:37 PM

from yahoo
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westkill 05-20-2004 09:43 PM

try the link again. It was set as "private"

boneheaddoctor 05-20-2004 09:49 PM

thats a lot of truck to haul with that motor......................

lietuviai 05-20-2004 10:55 PM

What type of veg oil filter set up do you have in that?

westkill 05-20-2004 11:26 PM

Oil is heated via a copper pipe heat exchanger in the aux. fuel tank tied into the cooling system. It leaves there hot and goes through a WEBB fuel heater/filter water seperator that has a 30 micron screen. It leaves there hotter and goes through a stock inline plastic clear MB filter.
It then goes through another stock MB spin on filter I salvaged from a wrecked MB.
The fuel then goes to a electric solenoid where either the veg or diesel is sent to the lift pump and then the injection pump. The diesel filtering system is totally seperate from the veg. The return line is also controlled by a solenoid. When on diesel, fuel is returned to tank. When on veg, its looped back to pump. If I delay switching the return solenoid after switching back to diesel, the veg filter gets back flushed with diesel making switch over to veg sooner next time.(return fuel has no where to go but back up the veg line)

lietuviai 05-20-2004 11:31 PM

It sounds sort of complicated, is it a "homebrewed" system? I'm thinking about making the switch to WVO in my 300D with the price of diesel being like it is.

coachgeo 05-20-2004 11:47 PM

for the Archives
1 Attachment(s)
THANKSSSSSSSSSSSSSS mucho for the pics and write up. I plan to do the same thing to my 617 Turbo and you have saved me COUNTLESS hours and brainstorming. Besides that you proved it works. In discussions in this forum about adding LPG to the 617A, some have been predicting potential doom to the engine because of issues about ignition of the LP in the prechamber.

PS. Could you kindly post the pictures in this thread using the attach file method. Reason being the odds are good this website will archive the pics and the related threads for the next hundred years where yours may be available only for a couple months, year etc.

Sorry, dont mean to sound like a Forum police. Just know what its like finding a GREAT GREAT thread like this one in the archives with all the pics no longer available.


PS (below is the pic of the Rig I will be adding this too)

coachgeo 05-21-2004 12:31 AM

HERE is the thread were we twisted Westkill's arm to get us some pics.


Hate to be a PITA but can you fill me in more on the intercooler you snagged from the ford. Also how you plumbed it into your setup?

Where do you live? What can I do to encourage you to get me/us an even more detailed account and pics of your setup? Dont know about others but I need these extra Ponies REAL BADDDDD and you got me all excited like a lonely dirty old man at a strip joint :p

westkill 05-21-2004 09:08 AM

The svo sysyem is not complicated at all. Read everything you can at the link I provided below. Everything from filtering to collection to installation is covered there. Mike

westkill 05-21-2004 09:14 AM

coachgeo , I sent you a PM

lietuviai 05-21-2004 04:36 PM


Originally posted by westkill
The svo sysyem is not complicated at all. Read everything you can at the link I provided below. Everything from filtering to collection to installation is covered there. Mike

Thanks Mike, that forum is great place to get my start.

dieselcruiserhe 05-21-2004 04:44 PM

Cool, I have a question, what is the "purge" switch for, is that a pump that somehow gets the SVO out of the lines? (if so cool!, how does it work?)

westkill 05-21-2004 07:38 PM

purge is nothing more than what I call my return line solenoid. It in effect purges any air in the line back to the diesel tank. for instance:
Say I decide to switch over to veggy. I throw both the veg and loop (purge) solenoid switches. Now I feel the truck starting to struggle. Possible air in line. What I do is shut off the "purge" switch and all return fuel, including vegy goes to the diesel tank. Once I smooth out, I flip the switch and I am back in a loop mode. problem solved.
When I am a few miles from my house ,I throw the Veg switch off switching back to diesel but I leave the return(purge) switch activated. The return fuel has no where to go but back up the veg line backwashing the filters with is now a diesel/vegy mix. A little hard to explain without a picture diagram. The next morning I can switch over sooner because the filters in the vegy system are really full of about 80% diesel.
The last three days here on Long Island its ben 70 during the day and 50 at night. I have not been flushing the system before shutdown as a test and the truck starts instantly on cold vegy each morning . Amazing!!!
By the way, The grease I got is from a chineese food restaurant and boy my exhaust smells good...... Mike

coachgeo 05-23-2004 09:37 PM

propane pics
1 Attachment(s)
here is his propane pics for the archives.

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