Hi everyone!

I have a "custom lpg kit" on my '92 mercedes 190D 2.5 turbo, inline 5 cylinder om602.96x engine.

Before the installation I had read about lpg injection in a diesel. I talked to a guy who converts petrol cars to run on lpg.

I have a donut in the trunk, plastic wrapped flash resistant lpg grade piping to the engine compartment and 2 lpg solenoids, 1 in the lpg tank and the other in the engine compartment.

The copper pipe is linked to a house regulator, then to an orifice in the air cleaner box.

The solenoid in the engine comp is controlled by a pressure switch set to open at ~12psi, max boost is ~14.5 psi.

The pressure switch and the solenoid in the tank are linked to a switch in the cabin. The switch in the cabin is linked to the ignition key.

First, you need to find a better regulator as the ones for home use are too small and they freeze if lpg is used for a long time. In converted petrol cars the regulator is heated by the engine coolant.

When you find a good regulator you need to experiment with the orifice size. The orifice size depends on the low pressure of the regulator. If you hear the car knocking, back off asap. That's increased pressure in your cylinders and you don't want that.

For now I'm looking for a way to increase the amount of propane proportionate to boost but haven't found out how. I'll also get a regulator that are used in fork lifts.

I also want to get a water injection system as it might help me increase the amount of injected lpg by delaying the detonation of lpg.


The question is: Hot to increase the amount of lpg injected proportionate to boost, i.e. more boost more propane?

Thanks!

Deni

How about making the gas flow based on the suction side of the turbo instead of the boost side? That's how my system works.

How about making the gas flow based on the suction side of the turbo instead of the boost side? That's how my system works.

This is how I have it now but I can't understand how this would resolve my question.

Added: I checked out the link you have in your profile. You talk about vacuum, but how do you get vacuum in a diesel? My engine is not throttled.

There is still vacuum pulled between the turbo and air cleaner. You can measure it in inches of water column or millibars. With my system, the engine has to suck the fuel in. The regulator starts delivering gas when it sees a vacuum, and increases flow as the vacuum increases as boost increases. The vac is proportional to the boost. At idle, the vacuum is so low that no gas is delivered.

There is still vacuum pulled between the turbo and air cleaner. You can measure it in inches of water column or millibars. With my system, the engine has to suck the fuel in. The regulator starts delivering gas when it sees a vacuum, and increases flow as the vacuum increases as boost increases. The vac is proportional to the boost. At idle, the vacuum is so low that no gas is delivered.

So, as the air filter gets dirtier, vacuum increases, amount of lpg increases, yet there's less air. Less because less air flows from the dirty filter, and less because since air is substituted by lpg.

Have you run into this problem?

Another question marcdeluca, is your regulator fuel heated?

Mine has a flow adjustment in the cabin that shifts the fuel curve. As the air filter gets dirtier it will draw more gas, but that happens very gradually. It is easy to adjust the flow, so it isn't a problem. This system is liquid withdrawal from the tank, so it has a coolant heated regulator.

Hi everyone!

I have a "custom lpg kit" on my '92 mercedes 190D 2.5 turbo, inline 5 cylinder om602.96x engine.

For now I'm looking for a way to increase the amount of propane proportionate to boost but haven't found out how. I'll also get a regulator that are used in fork lifts.

The question is: Hot to increase the amount of lpg injected proportionate to boost, i.e. more boost more propane?

Thanks!

Deni


The patented Powershot regulator is variable and proportionate to boost.

The patented Powershot regulator is variable and proportionate to boost.

That's way too expensive for me.

I might be able to come up with something for you using one of our water-methanol injection controllers. might be able to change software and control a proportional solenoid valve based on boost pressure.

Any idea what the mass flow rate is of the lg system and what type of fittings you are using for the lp lines?

best regards,

Dan

I might be able to come up with something for you using one of our water-methanol injection controllers. might be able to change software and control a proportional solenoid valve based on boost pressure.

Any idea what the mass flow rate is of the lg system and what type of fittings you are using for the lp lines?

best regards,

Dan

Hi Dan!

I've already asked in labonte's webpage if I could you the controllers to control the flow of lpg.

If I understand correctly your controller turns on and off the valve or pump to control the flow.

I have no idea how much lpg I'm injection in the engine, but I can limit the amount by using a smaller orifice.

I think I'll go the with the same setup marcdeluca uses as it's meant to be used with liquid lpg.

Thanks for the replies!

Deni

@ marcdeluca: From the pics on your website looks like you're using the same heated regulators that are used for lpg forklifts. Is that correct?

If yes, did you have to install a softer spring to use it on the diesel engine?

The forklift regulators can be bought for about $75 + shipping from ebay.

Alot of the regulators on ebay are Chinese copies of the USA stuff. I modify that regulator to work with the different fueling curves of the diesels.