# Propane??



## azmike (Jan 4, 2015)

We found a great deal on a ex-u-haul F700 cargo truck. We will remove the box (fill it with junk etc) and gooseneck hitch the truck and use it as a hauler with the tandem dually trailer. Got to thinking about a propane conversion as this is the only gas burning rig at the farm and we are in at 1.69 for propane right now. Any success/disaster stories??


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## ARD Farm (Jul 12, 2012)

My propane supplier (and hunting bud) has his entire fleet on propane. It's not a cheap conversion but he still has to cold start on gasoline.. Not sure about the diesel engines.

Propane here is right at a buck and dropping.


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## 1oldphart (Aug 20, 2014)

converted an IH 345 to propane in the 70's, lost about 20% power and was a pain in the wazoo when it needed fuel in the here and gone. burnt up the valves about 70,000 miles( We still had leaded fuel) so changed it back to gas. the gas shortages of the 70's made it sound doable, just couldn't live with it day in and out...paul


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## PackMan2170 (Oct 6, 2014)

We've been thinking about converting some of our fleet to Natural Gas, given that it's so cheap these days. A compressor station is like $35K, but I think it would pay for itself in a couple years. I'm sticking with a diesel, but all our guys just need little half-tons at the most.

Just sold our very last propane truck (had like 4) last year. They were all gutless, and a couple were pretty tough on the valvetrain


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## ARD Farm (Jul 12, 2012)

About a year ago there was big talk in the heavy truck industry about going NG instead of diesel to get around the Tier 4 mandates and the God awful emissions components as well as the DEF because NG precludes all of that stuff. Actually all the engine manufacturers, major ones, offer NG engines, Cummins, Cat, MB for sure don't know about Vol-Mack.

Problem is the fueling aspect. One big drawback is tank weight because the vessels are heavy and another is fueling time. It's not a matter of opening the cap and filling it up, even propane is quick compared to NG because the pressure is so much higher, equalization gtakes a while.

Finally, not just any 'fuel jockey can fill an NG tank. Takes specific hookup appratus and a knowledgable fueler. UPS runs some NG units and has dedicated fueling personnle.

I was at the Louisville truck show 3 years ago and Freightliner had an NG prototype tractor on display. Behind the cab (was a daycab model), was a stack of high pressure tanks for the NG. I thought to myself...'What if that unit was in a wreck on the highway, what a huge explosion those tanks would make....

With fuel costs (diesel and gas) where they are today, I don't see NG becoming a viable alternative anytime soon.

The NG engines built today are primarily for oilfield work.


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## 1oldphart (Aug 20, 2014)

There are getting to be a bunch of co gen engines running on methane at sewer treatment plants and landfills here in the moonbeam state. they usually have 3 in a row. one running, one on standby and one being rebuilt. my son is a cat mechanic and says the methane just destroys valve trane, cylinders ect. If it weren't for the EPA crap diesel would stay the obvious choice. however with the massive improvements in gas engines and the expense of purchasing and maintaining small diesels we have gone to all gas pickups and light trucks. we have even setup a 78 peterbuilt with a 460 ford and 5&4 as a watertruck. seems to work well and keeps the air Nazis befuddled...paul


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## ARD Farm (Jul 12, 2012)

The reason why they get ate up is the NG and Propane is dry. There is no lubricant for the top end or the valves. Problem is, the tree huggers love it and who calls the shots today..... one guess.


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## Thumbtack (Jun 18, 2012)

On propane you usually lose about 10% on power. To take care of the valves you put hard seats in the heads when you do a rebuild. Used to work for a propane co. and all our Bobtail trucks ran on propane of course that was back in the 70's when propane was like .17 \ gallon.

I have a friend that has a propane co. and he put propane on his Semi's and says his power and fuel mileage really jumped. The biggest expense are the tanks.


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## luke strawwalker (Jul 31, 2014)

Yeah, a "cheap conversion" will really end up costing you in the end, usually from valve problems...

Like someone else said, "propane (and natural gas) are "dry"-- no valve lubrication (or cooling) unlike gas (and diesel to a lesser extent.

Propane is naturally 110 octane, so if one is BUILDING the engine to run on propane, you can REALLY kick the compression ratio up over the modern gas engines, where the compression ratios were greatly reduced in the 70's (and subsequently) to reduce combustion chamber temperatures to reduce NOX emissions... course dropping the compression ratio also lowers the thermal efficiency of the motor, which means the gas mileage sucks... only been in the last 10-15 years that compression ratios started going back up to increase fuel mileage and deal with the NOX by reducing combustion chamber temps with exhaust gas recirculation (EGR) and/or dealing with it in the catalytic converters...

"Gutless" propane engines are usually a result of a "cheap" conversion. Slap tanks and vaporizers and a mixer and valves and lines on it, tweak the timing (if they even bother) and call it good. To do it right, one should really AT LEAST put hardened valve seats and valves in it and heads with smaller combustion chambers, if possible.
Dropping or eating valves or receding valve seats due to lack of lubrication on the "cheap conversion" method is one of the main gripes...

Grandpa switched his "fleacatchers" (Ford NAA and Golden Jubilee tractors that he bought new in the 50's) over to propane (butane), back when propane was 4 cents a gallon and gasoline was 8 cents a gallon. We ran the Jubilee until the early 90's... In fact I learned to drive tractors raking hay with the old Jubilee... We only retired it when we didn't really need it anymore-- did everything with the 6600, 5200 row crop, and 2310 Ford diesels... We'd still have it but Dad moved it up to a piece of land he bought in Junction, TX, with an old 4 foot shredder to cut weeds down to the riverbank, and during a flood the river came up and swamped it... Brought it back and debated rebuilding it,
but we decided it wasn't worth the effort and cost (since we didn't really need it) and sold it to the tractor salvage company my brother worked for at the time. He was there when they stripped it down for parts...

He told me the inside of the engine was "clean as a whistle", which I believe, because one time when I was in high school on a lark I decided to 'tune it up' (more or less "for the h3ll of it") and found when I removed the plugs, which was the first time in MY lifetime that I could recall (I was born in '71) they were spotlessly clean with only a slight tan discoloration-- no "wear" or debris or deposits on them whatsoever! The pistons were like new, no cylinder scoring (propane/butane and methane "burn clean" with no ash/carbon deposits to foul the engine, coat the piston and valves, and eventually work down into the rings and wear out the cylinder walls). The hardened valves were in "like new"
condition, according to my brother, and very little wear on the hardened valve seats... the only REAL problem was that propane/butane and natural gas (methane) tend to form a lot of water vapor when burned, which got into the plug threads, and corroded them badly-- (I had a plug that was almost "stripped out" on me when I had tuned it up 20 years before... It would "jump a thread" when tightened up, so I "snugged up just short of it" and called it good-- it worked!) Other than that, the engine was in terrific shape and even the bottom end was totally carbon free and looked like a new rebuild... (Dad had wisely drained the crankcase after it was swamped and put fresh oil in, and cranked it over a very long
time several times to sling fresh oil up into/onto everything... The transmission had some problems and the rear end, but the engine was "flawless" for its age, my brother told me...

The biggest problem with propane/butane is fueling... we have a fueling hose and valves on my brother's bulk propane tank from those days,and the old "tank bleeder" still rides in the door pocket of the pickup... Course back in those days, to fuel the tractor, you pulled up next to the bulk tank, turned the valve on at the top of the tank, cracked the fuel hose valve to blow out any spiders or debris, took the cap off the tractor propane tank filler fitting, screwed the ring on the valve seat onto the tank check valve filler fitting, then cracked the valve on the hose, made sure the connection wasn't leaking liquid propane, and then opened it all the way to start filling... Then you unscrewed the smaller "bleeder"
cap from the fitting, grabbed the "bleeder" out of the toolbox, and screwed it loosely on the bleeder fitting. The hose would get cool from propane flowing through it into the tractor tank until the head pressure in the tank equalized with the head pressure in the bulk tank, at which point you had to gently tighten the bleeder down a bit until propane vapor started to jet out of the bleeder from the top of the tank... this would lower the head pressure in the tank and allow liquid propane to flow through the hose and into the tank... sounded like a rocket with all that propane gas jetting out of the bleeder, and if you opened it TOO far, it'd soon ice over from the refrigeration effect of propane boiling off inside
the tank... you soon learned not to do that again! There was a little "liquid level indicator" that you opened a small bleeder screw, then turned the "indicator" so that the little "straw" behind the bleeder screw would dip down-- when it blew frosty droplets of white propane liquid that flashed over instantly to gas out, you knew the liquid level in the tank, since the vapor propane blew "clear". Usually we didn't bother with the liquid level indicator-- we just fueled it with the main bleeder until it started to blow a little "frost" out of the bleeder, indicating that the liquid level in the tank was nearly up to the height of the bleeder fitting itself, since liquid propane droplets would start blowing out...
Then you closed the bleeder valve, liquid propane would stop flowing as the pressure in the two tanks equalized, throw the bleeder in the toolbox, turn all the valves off at the hose end and the tank end, "crack" the ring holding the valve onto the tractor's filler fitting to relieve the pressure (it'd frost over as liquid propane blew out and boiled off, refrigerating it). Unscrew the [email protected] cold brass locking ring holding the valve onto the tank fitting, point the valve in a safe direction, then crack the valve and let the remaining pressurized liquid propane in the hose blow out-- I'd usually "freeze dry" the weeds growing around the propane tank with this liquid, which would kill them the next day). Put the hose up,
Put the caps back on the fill and bleeder fittings on the tractor to keep out dust/dirt/debris/bugs, and then you were good to go... Worse thing was, you had to do this all in a cloud of about 10,000 flies that would magically appear once the rancid-smelling propane vapor started being bled from the head of the tank-- that Methyl Mercaptan REALLY stinks, and it seemed to draw every fly for miles around... Then you were good to go...

Course, that was the "bad old days" so to speak... the tree huggers would sh!t pine cones if they saw you do that today... Methane vapors are a 10X times more effective "greenhouse gas" than carbon dioxide... dunno about propane/butane but I'd think the same is true, although they're heavier than air... Modern filling equipment uses "vapor recovery" hardware and a return hose for vapors and PUMPS the propane/butane across, while letting the vapors return to the ullage space in the supply tank...

Anyway, I wouldn't be afraid of it... just have to realize, there's more to it to do it right than just the quickest "el cheapo" method you can come up with... Your oil and engine will stay REALLY clean, and with regular oil and filter changes (even at "extended intervals" compared to "normal") your engine should, if properly equipped, last virtually forever compared to gasoline (or even modern ultra-low sulfur diesel)...

Later! OL JR


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