Propane Power

[BigblueC]

I have no current intentions of doing this but I watched this video this a.m. and was wondering if anyone here had converted something over to propane, like an old car or truck.



I'm guessing there are kits out, but I've never really looked or even thought about it until this video. I've driven propane fueled equipment before so I know what that's like, just not in a vehicle. What's yall's thoughts?

 

[thethee]

Over here in the Netherlands a lot of these older cars are converted to running liquefied petroleum gas or LPG for short, basically a mixture of different flammable gasses but I think you guys call it propane. Mainly because of running costs since E10 is around €1.80/liter and lpg around €0.70/liter.

Generally with lpg you have a bit less mileage, but if properly set up there is just a little power drop compared to regular gas. Also, around here these cars are almost always bi-fuel systems so they can run both lpg and regular gas so you can pretty much go twice the distance without stopping for fuel. But since lpg is available pretty much everywhere around here stopping for fuel is hardly an issue.

It is run with both carbs and injection systems but I have NO idea how well it behaves with non stock engines.

 

[BigblueC]

Looks like you are correct in saying that LPG and propane are the same gasses.

I know propane/LPG fueled engines make less power than when run on gas, but I don't know how much less, or what the drivability is like.

After a quick search it looks like the off-road community here in America has been running these conversions for years now. Obviously that's due to issues with carbs when bouncing around and leaning over for extended periods.

 

[Big_John]

So, am I the only one that thinks of Hank Hill when propane is being discussed?

 

[thethee]

Looks like you are correct in saying that LPG and propane are the same gasses.

I know propane/LPG fueled engines make less power than when run on gas, but I don't know how much less, or what the drivability is like.

After a quick search it looks like the off-road community here in America has been running these conversions for years now. Obviously that's due to issues with carbs when bouncing around and leaning over for extended periods.

I also don't know how much less power exactly since N=1 but my drivability is pretty good. How my car is setup is I start on gas then when the engine is warm shut off the fuel till the carb is drained and switch over to lpg. This way I can just run gas in the city and cruise on lpg on the highway, where any power drop is not really noticeable.

One drawback to mention though, when running bi-fuel systems, you need to kinda choose which one you want to optimize. Don't really know the specifics but propane and gas need different ignition curves for optimal performance. IIRC propane wants more advance in lower rpm and less advance in higher rpm compared to gasoline.

 

[thethee]

With carbed engines easiest thing to do is get her running good on gas and for propane bump up the initial around 2-3 degrees I think. Not that I'm an expert but that is what I found online. It's better to have the right setup at low rpm over higher rpm otherwise it will be an ABSOLUTE DOG to get her going and you need to really feather it from standstill or it will stall.

 

[NY69]

I've been running the 440 on lpg for the last 20 years without any problems.
Pro's: simple and reliable system; clean fuel for the engine internals; cheaper fuel; no carburetor problems.
Cons: not original; extra weight/ less trunk space; initial investment; additional engine wear (especially the valve seats; they are not lubricated like when running on gas) at high rpm's; any problems with the ignition, timing or air leaks in the engine will give sooner and bigger problems than when running on gas, so it is essential to keep the engine in perfect shape.

So it is a good and smart conversion if you're using your car just for cruising/every day use, especially with the quality of fuel nowadays.

Running on lpg makes my engine at least 15% less fuel efficient, due to the lower caloric value of lpg.
I can hardly notice any loss of power compared to gas, but that also depends on the lpg system that is used.

 

[Alchemi]

LPG likes compression, if you can build a dedicated engine, 14-15:1 will get you to the similar power as petrol.
The other way to get to the equiv compression is via forced induction, they get on well as the lpg has a natural cooling effect.

We even have some places doing lpg into turbo diesels here, runs a 20% feed of lpg into the system, the efi comp automaticly takes care of how much less diesel to use via afr. Our propane is 2/3 to 3/4 the price of diesel or petrol these days so you have to be doing the miles to make it pay

 

[Big_John]

Popular Science did a propane conversion on a Charger 500 back when in 1969 or so. Some googling might find more info. This car is still around.

 

[BigblueC]

We even have some places doing lpg into turbo diesels here, runs a 20% feed of lpg into the system

I've known about the diesel guys injecting propane, but here in America I think it's used more like a nitrous shot, and not as a running fuel. It's interesting that you say it likes higher compression. I would have guessed that propane was more susceptible to premature detonation. I guess the cooling effect counteracts the heat?

 

[thethee]

What cooling effect exactly? I thought only gasoline has a cooling effect since it transitions from liquid to gas but since LPG is already gas you actually don't have a cooling effect?

 

[BigblueC]

What cooling effect exactly? I thought only gasoline has a cooling effect since it transitions from liquid to gas but since LPG is already gas you actually don't have a cooling effect?

I was making an assumption that the gas was under pressure (still liquid) until it is injected into the system/air stream. This is all new to me so I'm kind of winging it.

 

[thethee]

Ah my bad, I ment to quote post from @Alchemi

 

[Alchemi]

The 14:1 was a bit on the extreme side, 12:1 is more reasonable for a petrol engine. The research octane of lpg varies a bit by location and brand, but is generally listed at 110 RON here in oz, much higher than even our high $$ premium.
So same deal as a normal car - you dont get what you should out of using race gas in an daily driver as it doesn't have the compression to utilise it effectively.
Where ever the lpg enters the system it will expand and pull a lot of temp as it dose so (the pressure regulators in the old systems are just a simple diaphragm and can actually freeze up in cold weather, they usually have engine water run through them to combat that), subsequently the best systems are a direct injection of the actual liquid, not the already expanded gas like the older style mentioned, in a turbo car it will drop a bunch of heat out of the charge air.

 

[cuda hunter]

There was a factory ford Futura in 78 or 79 that was propane.
You can also use natural gas in an old car. Tank needs to be pressurized to 265 whereas Propane needs to be pressurized to 250.
Same equipment with exception of the natural gas eats the rubber parts quickly.
Must have a pop off valve for over pressurization and possible fire.
Just need a mixer on top of the carb or a specific propane carb. Several different types of carbs.
Propane runs waaay better with a 12:1 motor than it does with an 8:1 compression motor.
These sucks in cold weather as you loose pressure in the tank with the cold weather. However, even when it's cold my buddy has a truck that will start easier than all of his other gas trucks.
Irrigation motors can be made to use propane. Somewhat popular depending upon circumstances.
Lower gas mileage. Less stores with propane. Not as useable here as in Europe.

 

[TobiasM]

Hi!

I am running my dailydriver on LPG since about 10years. Here in Germany the LPG thing got “mainstream” quite late, about the time I got mine converted.

At our neighbours, the Netherlands, it was common decades earlier to run LPG on cars, since the 70’s think. Maybe more Dutch members can confirm on that more precise.

In Japan Taxis run on propane since the 80’s, as per NGK-homepage. Did not knew that, learned that when I searched their homepage and found special spark plugs for LPG-use and some comments on how much history/experience this (Japanese!) company has with LPG through the Jap. Taxi-business.

As @thethee explained correctly, the older/original systems worked with an evaporator, so the lpg was not liquid anymore but a gas, when sucked in. Could be used with carburated, mechanically injected and electronically injected cars.

A major producer of the old days is US company IMPCO, still in business.

The most modern LPG systems are fully electronically controlled and do have injectors, so your engine breaths liquid LPG. Thus less power-losses (example is the JTG system from ICOM, that I am running in my 92 BMW 535i).

As mentioned: the LPG technique is nothing new, works good if the system (and the installation!) is a quality one and saves you money. My personal breakeven was after about 20,000mls. The more fuel your engine consumes, the earlier comes the break-even.

The system can be installed if desired without robbing you trunk-space: there are smaller tanks available that get installed instead of the spare-tire.

Also I have a 2003 Chrysler Grand Voyager 3.3 V6 (think is named Town&Country or Pacifica or Caravan or Minivan in the US) that also runs on LPG. Manufacturer in this case is very reputable company PRINS.

Longterm reliabilty depends on what make/engine you have: mandatory are hardened valve-seats, which any catalytic converter equ. car should have.

But still no guarantee to resist, if engine-materials-quality is low: e.g. modern OPEL or many French cars.

Usually: the older the car the better ;-)

Also there are systems injecting a valve-saving fluid, most popular is FLASHLUBE.

MOST IMPORTANT LAST: Chrysler did build Propane-cars from factory!!! As early as 1981! Look here: Chrysler Propane Cars: Dodge Diplomat, Plymouth Gran...

 

[BigblueC]

So for you guys with a propane/LPG setup, what does it look like in the car? I assume a large tank/bottle in the trunk, some plumbing and a "mixer" regulator type setup on the carb, or just a special carb.

 

[thethee]

I'll get you some pictures of my setup tomorrow

 

[TobiasM]

Buddy of mine from our MOPAR-regulars-table owns a 67 Fury Station with Propane...runs for years, uses it as daily and even for his business.

 

[TobiasM]

Here some pics of a 70 RR from the Netherlands that attended our 2018 German Mopar Nationals: runs a dual quad setup that is fed by 2 IMPCO-propane-evaporators.

Oh, and as being a Dutch vehicle: it is of course equipped with a trailer-hitch