Hi, anybody knows about adding lpg or cng to diesel engines? More power, better fuel economy, cleaner ?
Its used a lot in the states on big trucks to give them the edge going up long gradients etc. i have been researching it for ages. It does work well to clean up most of the unburnt fuel on acceleration and when towing, does little when cruising on tdi's at least due to the better control of fuelling compared to mech pump older systems. As a cost excersise, the additional lpg usage and cost per litre of lpg used serves more as a power booster than a mpg saver. It works a lot like nitrous, you can pump as much as you want into the engine but without additional fuel its pretty useless. The main problem with lpg diesel fumigation systems is the control of lpg, how much to flow in, at what rpm and load vs boost and engine temp etc. A dumb system that just ramps up the flow dependant on boost alone is ok, the extra lpg over what the engine needs tends to be expended. But there are a few safety issues etc.
i've got a Zone1 kit i havn't fitted yet to my 2.4D Turbo IDI Engine you can make a cheap kit using a Nitrous Solenoid with a 1mm jet and Propane bottle with 30mb regulator this will give 10bhp more and reduce emissions and increase mpg
Additional Fuelling i have now decided to go for my first plan on the additional fuelling under boost LPG T: I've sourced the parts required and basically i will have a LPG Vapourisor adding the Fuel controlled by an Adjustable Pressure switch. so when i get upto 0.3bar the LPG will kit in and add 10% LPG this will also give me a 100% burn of the Veg Oil / Diesel and lower emissions and EGT's. The Current IDI Engine design only burns 80% of Fuel injected so the LPG Enures a more efficient burn some info here - http://www.mrsharkey.com/lpg.htm :ILU: How it works: Introducing LPG gas into the combustion air intake of a diesel engine acts as an accelerant, promoting the even burning of the diesel fuel, and more complete combustion, resulting in more power being produced. Many web pages and forum posts will call LPG a "catalyst" but this is not correct, as LPG creates no change in the molecular makeup of either the air or the diesel fuel. Propane by itself resists self-ignition inside a diesel-fuel compression-ignition engine due to it's high flash point and narrow fuel-to-air ratio. During the compression stroke, the air/LPG mixture is compressed and the temperature is raised to about 400C, not enough to ignite the LPG, which has an ignition temperature of about 500C. In the small concentrations that LPG fumigation uses, the LPG mixture is not rich enough to be overly flammable and is more difficult to ignite. When the diesel fuel is atomized into the cylinder under high pressure, it immediately self-ignites (diesel ignites at about 385C.), and causes the LPG to burn as well. Since the LPG is in mixture with the air, the flame front from the diesel spreads more quickly, and more completely, including igniting the air/fuel mixture which is in contact with the cylinder walls, which are cool in comparison to the super-heated air inside the combustion chamber. Much of the cleaner burning of the fuel is attributed to this ignition against the "cooler" components of the engine, and accounts for raising the percentage of combustion from a typical 75% for a well-tuned diesel engine running on pure diesel fuel alone, to 85-90% with the addition of LPG. Obviously, this more complete combustion also gives a nice boost in power, with an accompanying increase in fuel economy and reduction of pollutants. Turbocharged diesel engines are able to realize a significant increase in power by using LPG fumigation. While the usual suggested increase is considered to be approximately 20%, by careful management of the gas introduction, power gains of up to 40% are possible
Is 10% lpg, the percentage compared to the cylinder volume, or 10% of the total amount of fuel injected per stroke?
10% of fuel injected per stroke The Zone 1 kit i have was a victim of it's own success, it increased efficiency (mpg) and power but people got too excited with the power and started increasing the LPG mix and melting pistons when the EGT's got too high so the company stopped making them.
Iv read that 37% is the max you can run but that is very risky. How does it maintain 10% fuel ratio throughout the rev and load range using just boost as a reference? Sorry for the questions, im just trying to fill the gaps in what I already know haha.
my kit has a diaphram that adds the fuel amount by vacum on the diaphram , so on a Turbo Diesel you have to fit it before the Turbo Compressor.
