LPG Installation - The Grand Experiment

[Quickstop [UK]]

Ok guys here goes....

As gas/petrol in the UK is so F*&^$ing overpriced I am going to install an LPG / Autogas kit which means that the charges will be 1/2 what I am paying. Whilst the install is not cheap, neither is running normal gas, and I can see several advantages of having an LPG tank onboard.

1. LPG is a higher octane (105 - 110). This will prevent knock.

2. As it is so compressed, it actually cools considerably as it expands in the cylinders again decreasing knock.

3. It is 50% cheaper than the standard pump gas (95 octane) here.

So the plan...

There are a few components that need to go in, so some need to come out.

AC - I have ordered an AC delete kit and after some searching have decided to go with the RPM kit.

I would like a heaterbox though if anyone has got one to make more room on the passenger side. PM me please if you can help?

Fuel injectors -

The LPG injectors are different from the normal gas ones (you can get dual injectors but read $$$$$$$$$$$$). Looks like I will have to have the manifolds drilled.

It will be a tight fit.

Fuel mapping - The LPG injectors are wired to the same pulses as the normal gas injectors so they will be putting the same amount of fuel etc so tuning will be easy. The only difference I can see is that I could run a leaner LPG tune as the octane is higher - I will tune for gas though and just keep that safety margin.

The tank - I am going to put a large tank in the rear of the truck opposite the spare wheel. I will lose some space but that is not the point.

With any luck I will end up with a truck that is 50% cheaper to fill than at present (1 tank here costs me $110) and has better performance and is less prone to engine knock.

I am also open to taking out the ABS to create more space in case the turbo / exhaust heats up the mixer. At present, the mixer unit is to go in place of the AC but that may not be an option.

Any suggestions on this would be appreciated as I am going into somewhat uncharted territory....

I will keep you all posted

 

[bezerk]

Re: LPG Installation - The Grand Experiment

this is so freaking cool, you're going with 6 injectors first? you can always add some, or install alky injection if you're to lean with 1 injector per cil.
if this is going to be as great as i think it will, i will see myself daily driving the Ty.
better get everything done soon, so the next ride over to my place will safe you $200.-

 

[Quickstop [UK]]

Re: LPG Installation - The Grand Experiment

just spoke to a guy that had it done to his BMW by the guy I am using and he is very happy with it and it sounds like an easy job.....(for a pro!)

 

[Quickstop [UK]]

Re: LPG Installation - The Grand Experiment

here are some pics of a guy who had it put into his BMW. Looks pretty discrete.

The mixer/vaporiser will go nicely where the AC used to be

$2000 install - $50 saved per tank unless the US nukes Palestine / Lebanon...... :rant:

 

[QUICK STORM]

Re: LPG Installation - The Grand Experiment

did yout ty get hit in the rear, cuz your bumper is pushed in

 

[Robert Lone]

Re: LPG Installation - The Grand Experiment

LPG is some good chit...

You won't have to change your oil until something like 25,000 miles b ecause it never gets contaminated. No soot w/ Propane.

 

[Quickstop [UK]]

Re: LPG Installation - The Grand Experiment

cool.

QS - got a pic of a non dented car?

I am not sure if LPG is actually propane but apparently it does run cleaner.

I am going to do this in August!

 

[Fin[uk]]

Re: LPG Installation - The Grand Experiment

Im watching this one!

I will have the space the ABS leaves

 

[Don W.]

Re: LPG Installation - The Grand Experiment

Question: Do you have a link to the injector you plan to use? For that matter the entire kit.

Comments: For Quickstpop, propane and butane are both LPG. LPG stands for liquefied petroleum gas. Propane has a lower boiling point than butane hence a slightly lower BTU content. Commonly they are mixed at the refinery to control the pressure in the tank. Little less butane in the winter, little more in the summer.

Mounting the tank in the passenger compartment caries some risk. Be sure to pipe the pressure relief valve to the exterior.

:2cents: Unlike gasoline propane has -0- cooling effect in the combustion process. Unless the injectors are actually injecting liquid propane (the BMW photo seems to indicate it is not) there is not going to be a cooling effect in the intake manifold either. My experience is that a different spark advance curve can be helpfull. More initial, less total. :2cents:

 

[fahrfrumwurkin55]

Re: LPG Installation - The Grand Experiment

yeah, to actually inject liquid propane requires a cooling system to keep the lpg below the boiling point even through the injector. I looked into it alot, and the only actual car I have found that runs on liquid injected propane is some school's science team entry into some "environmental challenge", and it was just a chrysler van with some setup they invented to be able to inject liqiud propane. http://www.kettering.edu/~lpgvan/SAE-LPG.html
The only realistic option for actually injecting lpg with injectors is vapor injectors, or gas mixer (Carb).

When you tune it, you will want to start out lean and adjust towards rich because tuning for propane is the exact opposite as tuning for gas.. stoich is around 15:1. Once you get rich enough to where power starts dropping off, lean it out a tad and that's where your max power will be.

Lastly, be cautious of the power capabilities of your propane system, because one tank will only support so much power. I'm doing a turbo VH45DE that is going to be propane fed, and the best setup that I found that would reliably support over 400 horsepower was a dual tank setup with two impco model E's and dual OHG 450's. OHG's work better than impco 425's under boost and one model E converter only supports 325hp.

here's a good site to read up on and decide the best propane system for you.. their propane section has alot of good info, and they have a forum specially for alternative fueled cars that you can get alot of info from too - http://cars.rasoenterprises.com/

 

[Don W.]

Re: LPG Installation - The Grand Experiment

:rant: The folowing is subject to edit.

I've been out of the propane buz for quite some time. That being said, having looked at one web site showing a OHG 450 it looks like a mixer that goes on top of the carb. Also another site showing a model E.

It appears that basic theory, as I know it, still stands. Liquid propane is vaporized in a vaporizer/converter (using engine coolant) that converts liquid to a vapor and delivers it to the engine as needed in a vapor state. You should not need two tanks. Just a tank configured to deliver liquid propane. Believe me you will want a vapor line teed into the line as well to for when the vaporizer freezes. And it will freeze one day. (All propane MOTOR FUEL tanks that I've ever seen are configured this way.) Attempting to operate on propane vapor as delivered by the tank is impractical even for low power engines. A single propane motor fuel tank will easily supply upwards of 400 HP provided you're puling liquid not vapor from the tank. The limitation is at the vaporizer & carb setup not at the tank. I would REALLY like to see a blown propane engine! I see no reason not to do it, just have never seen it done.:rant:

 

[fahrfrumwurkin55]

Re: LPG Installation - The Grand Experiment

Yeah, the power level depends on what kind of tank you use and what brand. I've seen some that say 250hp, and some that say 350hp, and inbetween. I was advised by a guy who has almost the exact setup that I am doing to use two tanks. (http://home.iprimus.com.au/promotive/_Personal/Patrol.htm) He went on and on about how his multivalve mounted on the tank would always freeze up because of so much liquid flowing through it and the safety shutoff valve would shut fuel supply off and stall his motor. He went to two tanks, and now he can run at his 550hp+ level without freezing up.

Also, carb sizing is important too.. and drawthrough vs. blowthrough has different sizing requirements. Drawthrough, you size the carb for the amount of cfm the motor makes n/a, while blow through you size for the cfm of the turbo(s).

 

[Don W.]

Re: LPG Installation - The Grand Experiment

He went on and on about how his multivalve mounted on the tank would always freeze up because of so much liquid flowing through it and the safety shutoff valve would shut fuel supply off and stall his motor. He went to two tanks, and now he can run at his 550hp+ level without freezing up.

Also, carb sizing is important too.. and drawthrough vs. blowthrough has different sizing requirements. Drawthrough, you size the carb for the amount of cfm the motor makes n/a, while blow through you size for the cfm of the turbo(s).

What this tells me is he's not using a tank configured for liquid withdrawal. If the tank is freezing up then he's pulling vapor. In a high HP motor this is what's gonna happen. Kinda hard to explain in a short post but the way to do it is to pull liquid from the tank, run it through a vaporizer (the thing that has coolant hoses going to it) and you won't have this difficulty. The coolant lines are there to HEAT the propane (and turn it into a vapor state) not to cool the vaporizer. Years ago we used to run large 350-400 HP truck engines that ran on propane with no freezing tank issues.

I can explain this liquid vapor mymbo-jumbo if you'd like...

And yes carb sizing will be an issue.

 

[fahrfrumwurkin55]

Re: LPG Installation - The Grand Experiment

yeah, I know what a converter is and does.. im no stranger to propane fueled engines, but I've never had one that made any more than 200 ft/lbs of torque. I'm just going off of what the guy said in reply to my e-mail about high power applications. Have you ever ran a single tank over 400 horsepower?

 

[Don W.]

Re: LPG Installation - The Grand Experiment

Have you ever ran a single tank over 400 horsepower?

Nope! But on the other hand, based on the multi valve setup I'm still leary that he's trying to pull vapor off the tank. As you prolly know it takes a tank configured for liquid withdrawl. Any ol' propane tank won't do.

So: Some research. Gas (as opposed to diesel) engines burn approx .45 lbs of fuel per HP. At 400 HP this equates to about 42 gals per hour for propane and 30 gals per hour for gasoline. Or .7 gals per min for pro and .5 for gasoline. Easily supplied by any propane tank configured for liquid withdrawal. The conversion to vapor for propane is 270 to 1. 1 gal of pro converts to 270 gal of vapor. Hence the freezing tank issue as the propane in the tank tries to "boil" to keep up with the demand.

 

[Don W.]

Re: LPG Installation - The Grand Experiment

Just for smiles here's a photo of a beautifully restored 1947 Peterbilt with a Hall Scott model 400 propane engine. These engines were 1091 cu inch, and produced 350 hp. Notice the single propane tank on the side. There may, and often would be, another one on the other side but only for range. These engines got lousy MPG.

http://www.sonic.net/~donpris/Peterbilt.jpg

 

[Neo]

Re: LPG Installation - The Grand Experiment

I think that many of my motor problems are due to my LPG system,since the installation of the LPG,the truck did about 5K,and now is running bad and has lack of power,probably due to improper management.So now i'm getting it back to petrol.
If i can give some advice:keep an eye on the stoïch when your TY is running on LPG

 

[Don W.]

Re: LPG Installation - The Grand Experiment

Is this a Sy you're running on propane? If so I'd like to see pics. Propane can be hard on plugs, have you looked at them lately? For straight pro (as opposed to dual fuel) you'll want to run 1 or 2 heat ranges colder than stock. Sometimes the coldest you can get is not enough. You just have to keep them fresh.

 

[libertysyclone]

Re: LPG Installation - The Grand Experiment

Wow, I brought up this topic about a year and a half ago with nothing but people telling me that it couldnt be done, or that it has been done but people have failed miserably.

I have been piecing together my set up for a while now. I have 2 model E evaps and a single 425 mixer over a 4bbl carb adapter, I ordered my self the carb/EFI intake from summit that a lot of guys seem to be using for their efi setups for their vortecs. I only plan on having a single tank, it is all you need, you do have to increase you feed line size though and your tank HAS TO BE A LIQUID TANK!!! there is a turbo'd SBC willy's jeep that makes 700+hp on straight LPG, it only has one tank.

lets keep this thread up to date I am glad to hear that I am not the only crazy person in the world LPG for the win!!

Also for those people in the states that are looking to do this or are in the process of doing it. There are grants and tax credits($2000-$3500) for converting your vehicle to an "alternitive" fuel source. Also in most states this conversion allows you to drive in the HOV lane by yourself

I am going to have dinner with Dig Wednesday and discus tuning with this since teh ECU will have no control over fueling only timing. I am also not doing this by the seat of my pants, I have several peoples help/input on the LPG conversion, all who have or have had LPG experience. First off is my uncle Brad Story who has been LPG/Turboing snowmobiles/sandrails for the last few years and a good friend of his Steve Benson that currently has a LPG Rotary powered sandrail.

 

[Don W.]

Re: LPG Installation - The Grand Experiment

This is very cool. Keep us posted... Nice that someone agrees with me on the liquid tank question. One of those things that's kinda hard to explain in a post.