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propane conversion

I think 4Wheel and Off Road did and article a couple of months ago on propane conversions. IIRC is cost them a few ponies. You also have to think about the hassle of changing tanks and storage of the tanks. I think its a great idea for a trail toy but its up to you if the hassle is worth the $ saved. There are obviously benefits other than $ too. I would try to talk to people who have done the swap and get their thoughts.
 
"We now have a it to run the 4.0 and 2.5 motor on propane. They are designed to run strictly on propane. You no longer need the wiring harness or sensors. You will need to put a distrubutor in from an earlier carbed motor to eliminate the computer. Easily retrofit that older Jeep now without the worries of wiring,fuel pumps,etc. This is designed to re use your stock intake manifold. These are not approved for emissions controlled vehicles."

Does Washington state not have yearly vehicle inspections?
 
OBXJ said:
"We now have a it to run the 4.0 and 2.5 motor on propane. They are designed to run strictly on propane. You no longer need the wiring harness or sensors. You will need to put a distrubutor in from an earlier carbed motor to eliminate the computer. Easily retrofit that older Jeep now without the worries of wiring,fuel pumps,etc. This is designed to re use your stock intake manifold. These are not approved for emissions controlled vehicles."

Does Washington state not have yearly vehicle inspections?

States which only require federally mandated emissions inspections

  • Alaska (Municipality of Anchorage and Fairbanks North Star Borough) every two years, depending on age and type of vehicle
  • Arizona (Phoenix and Tucson metro areas only) annually, depending on age and type of vehicle [20])
  • California (for most ZIP Codes, every two years for all vehicles made after 1975 which are more than six years old)
  • Colorado (in some localities, every year or two, depending on age and type of vehicle [21])
  • Georgia (metropolitan Atlanta area only[22], every year, most recent three model year cars are exempt)
  • Illinois (Chicagoland and eastern suburbs of St. Louis, Missouri)
  • Indiana (Lake and Porter counties only, every two years)
  • Nevada (Clark County and Washoe County areas)
  • Ohio (seven counties)
  • Oregon (Portland and Medford metro areas only) [23]
  • Washington (urban areas of Clark, King, Pierce, Snohomish and Spokane counties)
  • Wisconsin (seven counties in Southeastern Wisconsin, every two years)
 
I did a ton of research on this. If you are going to be using this in a street legal vehicle, ONLY a certified installer can install it and then it has to be inspected to get the sticker that will allow you to drive up to a filling station and fill the tank while in the vehicle.

If you use removable tanks, you would have to take them out of the vehicle to have them filled. This is only for a non street legal vehicle of course.

BTW, I don't know what the price for propane is up there but in San Diego, it's only a few cents cheaper then regular gas. Remember, propane is made from oil so the price goes up as well.
 
propane is made from oil??
 
89xj said:
http://en.wikipedia.org/wiki/Propane

Propane is a three-carbon alkane, normally a gas, but compressible to a liquid that is transportable. It is derived from other petroleum products during oil or natural gas processing.

Yeah, what he said. :D Okay so I could have been a little clearer.
 
You will lose more than a "few ponies". Propane power was a big deal in Western Canada through the 80s/90s and is still popular/readily available. I had an old F250 with a 351 on propane, and it was a dog.

With the 4.0 you will lose some HP and your equivalent mileage will be lower. You need to factor this into the equation when you figure if this conversion will save you any money.

Propane, however, can easily manage much higher compression without detonation problems, so if you really want to convert, you could have the head milled as much as possible in increase your compression ratio and get back the power lost/increase efficiency/MPG.

IIRC, some purpose-built propane SBCs people used to run were in the 12:1 compression ratio range for propane.
 
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I dont think increasing the CR would be a good idea since propane doesnt help cooling the charge like gas, which will increase the engine running temp + high CR = Craked Head
 
I think federal regulations stipulate that the tank must be mounted outside the vehicle. This is OK in a pickup truck or a buggy, but not easy to do on a XJ.

Perhaps, you should ask your state representative why the EPA cannot change the regulations to allow European type approved systems to be installed. My 4.0L '93 XJ has been running on propane for eight years with an internal tank (vented to the outside). It has done more than 140,000 miles with the original catalytic converter and always passes the emission test.


tank2.jpg


tank3.jpg


filler2.jpg
 
Pharaoh XJ said:
I dont think increasing the CR would be a good idea since propane doesnt help cooling the charge like gas, which will increase the engine running temp + high CR = Craked Head

It's generally accepted that propane powered engines can run a higher CR. Propane burns at a lower temp, so even the stock hardened valve seats and valves will be OK to about 10.5:1 or so.
 
Its funny this thread came up now, yesterday at work a propane powered forklift engine came in for a rebiuld. The engine is out of a HYSTER forklift that used a Mazda 2.4 car engine block 3 valve notches in the pistons, but had the truck cylinder head with only 2 valves per cylinder. I'm not sure if there was a difference in chamber volume or maybe one was easier to work with. The valve springs looked like they were out of a Bic pen, I could open it by hand, its max rpm was probably just over 2000.

side note: Engines don't work very well when you put hydrolic fluid in the crank case.

~Alex
 
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