About a year ago I was completing a semi rebuild (with assistance from Shadetree) when carb problems surfaced. Not a fan of gasoline anyway so just converted it to propane. I have plenty of experience over many years doing conversions but first atv. It turned out great, plenty of power, starts right up(down to zero) and uses half the fuel. Spent about $250 on the adapter, converter, hoses and fittings. I had 2 horizontal 20# cylinders and mounted them on the rear rack. With all the problems those old girls have with bad tanks, fuel pumps and carbs, I think propane is a viable option. Now I'm trying to figure out how to convert my Rincon!
Propane powered 1987 TRX 350
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Well I have the pictures on my phone and laptop but cannot figure out how to get them on this site. There is an aluminum "adapter" mounted directly in front of the carb, using the oem rubber boot originally going to the air filter. The propane goes from the tank(s) to the converter at tank pressure. (100 psi-summer, 40 psi winter) The converter reduces the pressure to 11inches water column (1/2 psi approx) the same as a 2nd stage regulator on a house. The converter has an idle adjustment and a high speed adjustment. Also has a primer button. Since you want as straight and short a hose as possible from converter to adapter, I mounter the converter in the space vacated by the gasoline tank. Right next to the converter is the new air filter connected to the adapter by 2 inch rubber hose. Propane is high octane but less explosive than gasoline so it likes high compression, high lift,long duration cam profiles, and the timing advanced. All I could do was have G&H rebuild the head, bore the cylinder and install 10.25 compression piston. I used one heat range colder than stock NGK Iridium plug. To start I open the throttle wide open as I give a shot of fuel with the primer button on the converter. slide the choke lever full on and hit the starter button. It fires right up but takes about 5 minutes to warm up enough to drive. I plowed snow with it all winter. Below zero I had to warm up the engine with a small infrared heater for half an hour. It uses less fuel than gasoline and the oil is undiluted by gasoline improving lubrication. Oil still needs to be changed as regular due to the breakdown due to heat. I mounted 2 tanks so when one is running out I can switch over to the full one.
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So, LPG (liquid petroleum gas) here in the UK is a complete and utter failure. Very common conversion fitted to V8 4x4's due to the fuel costs over here.
I'm a V8 lover, especially rover 3.9 V8's however.. I've bought several now that have LPG conversions and all have had issues and a serious lack of power over petrol/gas, I've removed all of them and thrown them away, literally!
My questions and concerns are...
Loss of power (I know from experience it will be high)
Issues...
The carb freezing
Spitting back (backfiring) when cold and when on and off the throttle.
On EFI motors a very common, almost guaranteed issue is blowing the airbox to pieces and trying to adjust the timing to allow both LPG and gas.
Due to the ignition properties of both fuels it's virtually impossible to be able to switch between the two.
My personal opinion on this is NO, a big NO!
I do look forward to hearing any results though
I'm a V8 lover, especially rover 3.9 V8's however.. I've bought several now that have LPG conversions and all have had issues and a serious lack of power over petrol/gas, I've removed all of them and thrown them away, literally!
My questions and concerns are...
Loss of power (I know from experience it will be high)
Issues...
The carb freezing
Spitting back (backfiring) when cold and when on and off the throttle.
On EFI motors a very common, almost guaranteed issue is blowing the airbox to pieces and trying to adjust the timing to allow both LPG and gas.
Due to the ignition properties of both fuels it's virtually impossible to be able to switch between the two.
My personal opinion on this is NO, a big NO!
I do look forward to hearing any results though
I am still using the stock carb so it's the enrichment valve but looking at it,it seems to be a choke with a butterfly that reduces air to the combustion chamber. It does take some futzing with the idle knob when it's cold (ambient) increasing initially and then backing it off as it gets warm. As far as propane conversions on cars, propane and gasoline have different properties and running propane in an engine set for gasoline, propane generally suffers in comparison. But if you modify the engine(high comp, loppy cam, advance timing) propane is great. Now with modern engines they install a new ECU that changes the settings in the ignition/fuel delivery for each fuel. Back in the 1960s my Dad ordered high performance engines in his work cars and they screamed on LP. I know, as teenager I surprised guys in their camaros and mustangs. Also I've done dozens of conversions on fork lifts, commercial lawn equipment etc. and they run better on propane. Generac builds a number of engine for their generators(that they sell to other manufacturers of lawn equipment) that were designed from scratch to run on propane/naturel gas and they perform at least as well as gasoline counterparts.
I not trying to talk anyone into propane, I'm just saying it is a viable alternative and has some real advantages. By the way to the guy talking about propane freezing up. That is in liquid propane delivery systems, where liquid propane goes to a converter where (in a separate chamber) engine coolant circulates to vaporize the LP into vapor prior to entering the engine. So once again in colder temperatures, before the engine warms up, the converter (years ago they called them vaporizers!) would frost up and cause difficulties. An engine heater, heated garage or start on gasoline til warms solves that. What I'm running in the 350 is a vapor system. The concern then is the tank frosting up because the surface of the tank(cylinder) cannot vaporize the liquid in the cylinder as fast as the engine is using it. I had that one time when plowing in 10 below zero. The engine starts losing power(I guess obviously) and I just opened up the other tank and finished plowing, by the time I was done (20 minutes) the frost had melted.
I not trying to talk anyone into propane, I'm just saying it is a viable alternative and has some real advantages. By the way to the guy talking about propane freezing up. That is in liquid propane delivery systems, where liquid propane goes to a converter where (in a separate chamber) engine coolant circulates to vaporize the LP into vapor prior to entering the engine. So once again in colder temperatures, before the engine warms up, the converter (years ago they called them vaporizers!) would frost up and cause difficulties. An engine heater, heated garage or start on gasoline til warms solves that. What I'm running in the 350 is a vapor system. The concern then is the tank frosting up because the surface of the tank(cylinder) cannot vaporize the liquid in the cylinder as fast as the engine is using it. I had that one time when plowing in 10 below zero. The engine starts losing power(I guess obviously) and I just opened up the other tank and finished plowing, by the time I was done (20 minutes) the frost had melted.
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You've just described/explained factors that were understood 20 years ago...
I hate to be the argumentative one but physics has proved that LPG in place of gas (petroleum spirit) is not viable.
BOC (British oxygen company) did several written articles on this subject, I assume all are available online.
There are to many time consuming (potentially down time) factors that go against LPG for me.
I hate to be the argumentative one but physics has proved that LPG in place of gas (petroleum spirit) is not viable.
BOC (British oxygen company) did several written articles on this subject, I assume all are available online.
There are to many time consuming (potentially down time) factors that go against LPG for me.
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something in the back of my mind, or shall I say two 20lb propane bottles behind my back ?..says helllllllllllllllll no !!!..lol.
As I said not trying to talk anyone into converting their atv. But shade tree , last year when I did it,you told me to post it because guys would be interested. After 7 or 8 tries to download photos I decided post w/o pics. But I guess I'd rather have danger behind me than under or between my legs. lol As far as SamUK your fellow commonwealth citizens in New Zealand and Austrailia are cutting edge in propane. I saw a video on youtube where a company built a Chevelle with a 572 crate motor injecting liquid propane directly into combustion chamber! 2000 hp. There is a lot of developement going on in America (like both Ford and Chevy factory nat.gas/ propane trucks available at dealerships) due to clean emissions and the largest reserves of Nat. gas in the world are here in America. I'm not crazy about electric cars or fuel cell cars but its a free country (at least for now!) I don't have to own one. As for me I'm very happy with the results. And in 5 years the conversion will be paid for in fuel savings. lol So to each his own fellas
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my friend owns a propane company, about 20+ yrs ago he converted a few dozen of his delivery trucks over to propane thinking he would save money
that idea didn;t last long and he went back to regular diesel fuel in his trucks
trucks had poor fuel consumption, and much less power on propane, so, he bailed on the idea
and that is him getting fuel at COSTS the public doesn't and it wasn't worth the effort he told me
I gather anything can be done if one wants it bad enough, has the time, money and skills
but I cannot see this being a worth while mod to anyone that isn't just looking to make something ODD!
NO offence meant here either
I like seeing folks make things out side the box, so best of luck if your still going forward with it
that idea didn;t last long and he went back to regular diesel fuel in his trucks
trucks had poor fuel consumption, and much less power on propane, so, he bailed on the idea
and that is him getting fuel at COSTS the public doesn't and it wasn't worth the effort he told me
I gather anything can be done if one wants it bad enough, has the time, money and skills
but I cannot see this being a worth while mod to anyone that isn't just looking to make something ODD!
NO offence meant here either
I like seeing folks make things out side the box, so best of luck if your still going forward with it
It works and makes sense in some applications, but not all. About 14 or 15 years ago one of my brothers bought a new 5th wheel camper and a new diesel pickup to tow it with. He wanted a genset in the 5th wheel permanently mounted, so I took a like new 7.5kva Onan gasoline generator, fabbed some mounting brackets and cooling vents for the fan-cooled motor in the front cargo area of his 5th wheel and shoehorned that Onan in there. I run a new exhaust pipe with a muffler and a turnout across the undercarriage to the right side.
I hung one of those long, round propane bottles crossways up on the frame behind the axles. Then I put a propane conversion kit on it that was matched to that application that I found on the Internet. It was a bolt on adapter/spacer affair that allowed the original carb and air cleaner to stay put. The propane shutdown relay/valve was wired into the remote start/stop panel that I mounted on the wall inside the camper. The tank was plumbed to the genset using the supplied hose run through cheap conduit.
That setup works great. The generator has always started easy and it runs good. No engine mods were necessary. But it is only used during the summer. In cold weather I'm sure things could be different.
In a camper application propane fuel begins to make some sense since the exhaust is mostly water vapor and CO. I wouldn't try to use it in most other applications though, liquid fuels (gasoline & diesel) provide much greater energy densities (BTUs per pound oxidized) than gaseous propane or methane does. Plus the extra carbon oxides in liquid fuel exhausts benefits plant life, its immediately consumed for oxygen production.
I hung one of those long, round propane bottles crossways up on the frame behind the axles. Then I put a propane conversion kit on it that was matched to that application that I found on the Internet. It was a bolt on adapter/spacer affair that allowed the original carb and air cleaner to stay put. The propane shutdown relay/valve was wired into the remote start/stop panel that I mounted on the wall inside the camper. The tank was plumbed to the genset using the supplied hose run through cheap conduit.
That setup works great. The generator has always started easy and it runs good. No engine mods were necessary. But it is only used during the summer. In cold weather I'm sure things could be different.
In a camper application propane fuel begins to make some sense since the exhaust is mostly water vapor and CO. I wouldn't try to use it in most other applications though, liquid fuels (gasoline & diesel) provide much greater energy densities (BTUs per pound oxidized) than gaseous propane or methane does. Plus the extra carbon oxides in liquid fuel exhausts benefits plant life, its immediately consumed for oxygen production.
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Would it be possible to convert a raptor 660? And would it loose power or stay about the same ? Cool idea
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GLAD to see this, have a 93 here in Florida & i'm fed us with the condensation that builds in the take & cans I fill from, about every couple of weeks I have to add 4 oz of seafoam to run the crap through, I've had success in converting gas Gems to propane, fill me in on yours, is it till running good? WHERE did you get YOUR kit? When you wrote the article you could not post pics have you figured out how yet?? ANY help appreciated
Sorry, I don't check these forums very often. This will be my fifth winter plowing snow with the propane 1987 350. It works wonderful. Starts fine down to 25 degrees, when colder I station one 12k btu infrared heater on one side and a 7.5k btu on the other and after 10 minutes it fires right up. I got the converter(regulator) and the carb adapter from Carb & Turbo in Shakopee MN. I sent the cylinder and head to G&H supply (Tenn) They rebuilt the head and bored the cylinder .060 for the 10.25 : 1 Wiesco piston. I mounted 2 horizontal 20# cylinders on the rear rack. I was in the propane business for most of 50 years and probably converted 35 engines of all different types. Having said that it is not difficult and any reasonably competent mechanical person could do it. Mounting the tank(s) is the most challenging part. I am very familiar with TRX300fw and one concern I will mention is because propane runs hotter than gasoline you will have higher head temps. Especially in Florida. Years ago I installed and oil cooler w/2 6 in x 6 in fans (Radio Shack) in a 1995 TRX300fw my kids were running to death in 85-90 degree temps. Worked great. I do know how to send pictures attached in text message or email. Will be happy to help if you decide to proceed. I will check this site more faithfully.lol
Truth is I don't know. I have a Rincon I'd like to convert but it has a frame crossmember 1 1/2 inch from carb and I can't fit the adapter. I think the Raptor is "high performance" (higher compression, more lift/duration cam profile) which propane likes. Propane produces higher head temps but Liquid cooling handles it and an oil cooler mod for air cooled works. The problem is mounting the tank. A 20# cylinder works fine but the bulk is an obstacle in an ATV.
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