Tech: How to Propane a 2F

[LT]

This has been a process in the making for me. In February I decided to convert my ’76 FJ40 over to propane. The main reason behind this was that I was sick and tired of carburetors and flooding out on inclines. My Land Cruiser is mostly a trail only rig these days so I tow it to the trail. Going to propane was a viable option because I don’t have to worry about finding gas stations that have propane to fill up between the trail and my home.

Why Propane? First of all Mace was a big reason why I did it. It is something unique that a lot of people haven’t done to the 2f, plus it is super cheap, reliable w/o the hassle of electronics and it’s the poor mans version of fuel injection. Here is a list of Pros and Cons of converting over to Propane.

Pros:
1. LPG will run at any angle. Propane when entering the engine turns from a liquid to a gaseous state. There are no float bowls or fuel delivery problems. LPG is under constant pressure from the propane tank.
2. Propane is just plain simple. There are very few moving parts and can be rebuilt on the trail with just the use of a screw driver.
3. Propane makes your engine run cooler. On the trail my 2f will probably sit at the most around 150* to 160*.
4. A clean engine. There are no hydro carbons in propane and no oil properties. Your engine will effectively run cleaner and longer because of this. Some claim that because there is no oiling affect that the valves will harden. But I have yet to experience that.
5. Easy to tune. The propane mixer has a variable venturi which restricts or adds more propane as needed when you are under acceleration/deceleration. LPG is rated at a 104 octane so you can run an extremely high compression ratio, though your 2f will never see the likes of 11:1 compression.

Cons:
1. Hard to find refill stations. Like diesel you have to know what gas stations carry LPG. Here in Oregon I do not have a problem finding a gas station that carries LPG. But that varies from state to state.
2. Loss of power. Because the 2f is not designed to run a high octane gas like propane there is a slight loss of power. You should expect a 10% - 20% loss and about 1 mpg less in performance. The power loss is pretty minimal and the gas mileage is still comparable to gasoline.

 

[LT]

Installing the propane system is extremely simple. First of all I bought everything I needed from Propane Guy. It came with the propane mixer (200A rated at 345 cfm), two radiator Y lines, an adaptor from the mixer to a Holley throttle plate, fuel pump block off plate, a model E regulator/vaporizer, a model vff30 fuel lock off valve (vacuum operated), and 3ft of low pressure vapor hose from the vaporizer to the mixer.

Here is a step by step instruction of how to assemble the mixer to the Holley throttle plate. First you will need to find one of those dreaded Holley carburetors that you could never run right. All you need is the throttle plate with the butterfly valves. It is 5 simple screws that you can find at the base of the carburetor. You will also need the adaptor that was made to mate the 2f intake to the Holley carb. Don’t worry all of this stuff is relatively easy to find. There are a lot of people that have these old carbs and adaptors lying around on their shelves collecting dust.

Now this is a very important step. Once you have the throttle plate separated from the main carb unit you will need to use some JB Weld. Propane is very sensitive to vacuum leaks so you will have to block every vacuum port. In the picture everything you see that is solid gray is where you need to fill with JB Weld. Let the JB Weld dry over night before going on into installing the rest of the propane mixer/throttle plate.

Next you mount the propane mixer to your adaptor.

After that you simply mount the Holley throttle plate to the adaptor.

Install your Holley adaptor plate.

Finally put your propane mixer/Holley throttle plate on.

*As a side note you will have to convert to a cable operated gas pedal. For those of you running a Weber or a Holley that won’t be a problem. But for people running the stock aisin mechanical throttle linkage you will need to seek out a new/used gas pedal.

 

[LT]

Onto the next stage. After you have installed your propane mixer next comes the installation of your vaporizer/regular and fuel lock off valve. You can mount these two items wherever you want in your engine bay. The propane will not care since the whole system is under pressure. Since I am running Metal Tech tube fenders I didn’t have any inner skirts to mount to so I had to make my own custom mount.

Once you have mounted your vaporizer/regulator and fuel lock off valve you will need to route two radiator hose lines to the regulator. How the propane converts from a liquid to a gas is at this state. The vaporizer/regulator uses your own engine temperature to do the conversion. So while your engine might run a little rough when cold it will perform better as the engine warms up.

Using your heater lines in the picture below you will cut the radiator hoses and install the Y junctions that came with your kit. Make sure that they are pointed in the same direction. One should be pushing and the other pulling. The red radiator line indicates the “in” flow and the black is the “out” flow.

After that mess you have one more line to hook up in the engine bay. My particular fuel lock off valve is vacuum operated. You can get an electric solenoid one, but I prefer the vacuum operated. Reason being that when your engine dies it cuts off all flow of propane into your engine until your engine starts cranking over again creating vacuum. For my vacuum source I used one of the blocked off vacuum ports on the intake. You need a full manifold vacuum for the fuel lock off valve to operate properly.

That last thing you need to do in the engine compartment is block off your old mechanical fuel pump with the block off plate. Make sure to use some RTV silicon to have a good seal. Don’t want any oil leaking!

 

[LT]

Now the important part, your propane tank and high pressure line. The most commonly used propane tank is a fork lift tank. They are readily available new or used. I bought two used ones because I was on a budget at the time. You cannot use a BBQ propane tank. They are not designed for automobile use. There are other propane tank options but for the size and space a forklift tank is the best application. There are two size options with fork lift tanks, 8 or 10 gallons. The general rule being that a 4cyl requires an 8 gallon tank and 6 & 8 cylinder engines need a 10 gallon tank. You will also have to acquire the mounting brackets or clamps for your fork lift tank. You should be able to find them at a propane supplier or fork lift dealer. They cost roughly around $60 - $80 brand new.

The final part to your conversion is the high pressure line that leads from your propane tank to your fuel lock off valve. Propane coming out of the fork lift tank is at 300psi and requires a special hose. You can get this hose made at your local propane supplier or fork lift dealer. It costs roughly $40 to have one made at around 10ft in length.

 

[projektdotnet]

what is your MPG since this conversion or do you know yet. I am trying to figure out a good mix between wheelability and cost

 

[72cruiser]

looks awesome man...makes me want to do it, ha ha

i haven't been to propane guy yet, but how much would you say the whole conversion ended up running?


oh, and i think we all expect some pics of you driving your cruiser on the ceiling. just to prove that it can run upside down.


malphrus

 

[LT]

I would say... 10 - 12mpg not really sure. I am running 37x14x17 bias ply Iroks which aren't the best road tire. I average around 1 gallon of propane an hour on the trail. Haven't had an issue yet running out in the middle of nowhere.

I do trailer my FJ40 though so I don't daily drive it or have it on the road a whole lot these days.

 

[Tigerstripe40]

I was thinking about running propane dual fuel style.

How difficult would it be to run dual fuel?

 

[LT]

looks awesome man...makes me want to do it, ha ha

i haven't been to propane guy yet, but how much would you say the whole conversion ended up running?


oh, and i think we all expect some pics of you driving your cruiser on the ceiling. just to prove that it can run upside down.


malphrus

The Kit cost me around $550. I bought his stage II option which had the brand new mixer which supposedly gives your around the same mpg when on gasoline.

Used 10 gallon tank was $110

Holley carb and adaptor $30 - $50 depending where you get it from.

About... $5 - $10 in radiator hose

$40 in the high pressure line

$40 on a K&N air filter.

$75 in the fork lift clamps new.

Basically around $800 you can get it converted over, give or take with how crafty you are in finding good deals on new or used stuff.

Too bad no one took a picture of me vertical on dump bump standing on my rear tires. The 4 second vertical time I was staring up at the air my engine still ran

 

[RHINO]

the cool setup for me would be dual fuel so i have the option to run gas on long trips or when propane is not near.

 

[pbuschbeck]

The dual system is very common here, you run a switch on the dash that controls fuel or gas. One of the biggest brands is the italian Beddini, but I dont know if you are going to find them in the states.
As for the tanks, they are making ones that look like spare tires, with up to 18 gallons.

There is an issue when using propane. After spending a long time on the road generally at highway speeds, the valves tend to stick on their guides, many saying the cuase is lack of liquid ( gasoline ) against vapor ( propane ).
The problem is solved by changing to gasoline for 5 minutes every hour of gas operation, and to warm and shut off the engine using gasoline.

Peter Buschbeck
Crushin in Peru

 

[andrewfarmer]

I was thinking about running propane dual fuel style.

How difficult would it be to run dual fuel?

Easy. only variation on what is posted is you fit the mixer to the top of the std carb, and a lock off solonoid to the petrol line between pump and carb, and a switch to swap over.

 

[andrewfarmer]

LPG is rated at a 104 octane so you can run an extremely high compression ratio, though your 2f will never see the likes of 11:1 compression.

It can be done

The other advantage is you can advance the ignition timing (= more power) without pinging. This can almost compensate for the power loss of LPG vs petrol

 

[cruiser88]

trully thank you for this thread.every time i buy a old cruiser as you well know there is problems with fuel delivery.so i will give this kit a try .all kinds of filling stations around here

 

[Beaver State Bogger]

Bump.

So, how's the kit working out? Anyone rocking one as a daily driver? This sounds like a great idea to me, especially since I have access to the commercial account which provides fuel for our lift trucks at work... I think our price break puts it around $1.60 a gallon, though that's not certain.

Also, I'm thinking of putting a new head on my 2F--is there a way to remedy sticky guides during the rebuild process?

I'm hyped in this idea!

 

[pbgbottle]

i've been contemplating switching to propane myself for the last year.now that i saw your pictures .i've been thinking about it again . never heard of sticky valve guides here (CAN) .but who knows ,most of our taxi's and limo's run propane year round . guess i will have to go visit the propane guy ,he is only 20 mins from my house , see what he recommends . i've heard of the exhaust valve seat burning away if your heads don't have hardened seats .

 

[LT]

Bump.

So, how's the kit working out? Anyone rocking one as a daily driver? This sounds like a great idea to me, especially since I have access to the commercial account which provides fuel for our lift trucks at work... I think our price break puts it around $1.60 a gallon, though that's not certain.

Also, I'm thinking of putting a new head on my 2F--is there a way to remedy sticky guides during the rebuild process?

I'm hyped in this idea!

My cruiser runs like a banshee with the propane with little power loss notice. But for some reason I have an really good running 2f, I am always getting compliments on how well it runs.

If you want to check out my set up I live in SW Portland off of Barbur and Terwilliger. And if you need some propane help, I know the guru of the area at Suburban Propane in Tigard.

 

[PUPTLAM]

I have no reason or desire to try this mod. However if I wanted to, this would be my tech source. This was very informative and the pics brought it all together. I learned some stuff from this thread. Thanks LT.

 

[TemeculaTim]

One thing I think most have overlooked is that propane powered vehicles are exempt from smog regulations. Could be cheaper for some to convert than correct.

 

[LT]

One thing I think most have overlooked is that propane powered vehicles are exempt from smog regulations. Could be cheaper for some to convert than correct.

Yeah it is true you become smog exempt running on propane. However there are some states that won't allow vehicles on the road running on 'pane. I believe California is one of them.