HPDI parts are available if you buy a cummins Westport system.
I built some DI cng parts a decade ago using solenoids... Forget solenoids, the turndown is inadequate and closing bounce is another issue aside from tip coking due to aerosols and fuel with >-50 dew point fuel.
The best path is using magnetostrictive actuated common rail and constant temp glow plugs.
I am going to start development of a system to provide supplementary cng for diesels. I already have a kit to do it for lp. It will use a regulator that requires vacuum to open it, and the fuel will go in before the turbo.
Sorry for the slow response, I've been really busy and haven't had a chance to get on the forum. Anyway, I want cheap fuel! I have a gas well and even though I'll have to get a compressor, the gas itself is free. I think there is a small market for a system like this for people that either have their own wells or can get cng cheap. A company in Canada called FuelMaker has a residential compressor that will pull from the low pressure house line and compress it to 3600 psi. It does an equivalent gallon/hr, meaning around 125 cu ft/hr. The bad news is that it is $5100, so it is a long term payoff.
I have a 12 yr old fuel maker that has seen better days but it works. I drove a few cng vehicles for a decade and mostly refueled with the fuel maker. It was not less costly when the fuel, electricity, machine and maintenance cost were added up but it facilitated the demonstration and practice what you preach type work that I used handle. There are/were a lot of cng fumigation systems out there but they dont seem to offer enough return on investment over a short enough time to be worth it..
As for HPDI, the best known system on the open market out there is installed on the Cummins Westport ISX.
Have you tested to see what species are present in your natural gas? Some natural gas wells produce gas with high sulfur content. The sulfur would be an issue for engine catalysts and maybe some other components.
Honda is selectively marketing a CNG car for the California market in the US.
The drivers rent a fuel compression system called PHIL for 30 to 80 US dollars per month. I don't know what the purchase price of the PHIL system would be.
I haven't had the gas checked, but we heat our house with two ventless heaters and haven't noticed any sulfur. I worked up the numbers a few years ago, and I figured that the first 12K gallons equivalent of cng would cost me around 49¢/gal. That took into consideration the $5000 cost of the FuelMaker, about 10¢/gal of electric to run it, and 10¢/gal rebuild cost for the compressor. They say that every 4K gallons, the compressor has to be rebuilt, and at the time it was $400 to get that done. I would initially buy the gas, they are charging $1.99/gal locally.
The information I recall is every 2000 hours the compression end needs an overhaul, and the price was closer to $2000 USD. I think the TBO has been extended a bit since (late 90's). The total cost per mile for the end user product including cost of fuel, amortized cost of the Phil fuel maker, electicity for compression and whatever road use taxes you have to pay is very close to the cost of gasoline, maybe slightly cheaper. Dont look for the costs you are estimating, they dont exist. Somewhere you will have to calculate the cost of the vehicle fuel system too, they aren't free or cheap for that matter.
Franz
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When my very earlt generation fuelmaker shut itself down for a sevice interval I removed the Sulzer compressor head from the motor and fedexed it to the factory and they had it back the same week. Initially there was a short interval but it was lenthened for later models than mine. The rebuild was several hubdred, not thousands. It still did not make economic sense for me. It does make sense from a convenience perspective though.. Did not have to make an additional stop out of my way for fuel, the stop at home was enough. I added a pair of steel 11GGE tanks to the system and a priority valve with regulator. I plumbed the FM to the tanks via NGV1 connector. Initally got a partial fast fill then the FM would top off the vehicle before dumping back to the storage by the machine. Rarely had lack of range issues with that setup.
I installed supplementary cng to my Duramax diesel this week. I installed a weaker spring in the regulator so that it would pull more gas than with lp. It runs just the same as with lp, but is a bit more detonation resistant, which is to be expected since it is higher octane. I installed a 10 gal tank. I only have about 40 miles since install, so I will be collecting data on fuel consumption rates as time goes on.
No pyrometer installed yet, but at least I have one now. That is next on the list. I suspect that the egts will be lower at low load than straight #2, but higher at heavy load than with only #2. This is simply because of more power being produced because of extra fuel. Hopefully I'll find out soon.
Some business in the Netherlands just announced a home CNG re-fueling system (GTC Almere Pressurecontrols from Almere-The Netherlands). See these websites:
Just to clarify any misconceptions about Cummins Westport and HPDI, the Westport HPDI system is still in development and none have been sold commercially. Even when they are commercial it will not be something you can retrofit in your backyard.
Cummins Westport, a joint venture between Cummins and Westport, was restructured at the beginning of 2004 and is currently developing and marketing spark-ignited engines only.
For more information visit the Westport and Cummins Westport websites,
Can anyone tell me what the disadvantages of combined fuel systems are. Those are the systems where the gas, natural or propane is introduced into the intake manifold at low pressure with a simple valve and just enough diesel is injected to "Light the fire"?
Caterpillar has a businesss venture with a company that sells kits like the one you describe. The company used to be called "Clean Air Partners" (they have changed names a couple of times so I am not certain what their name is now).
NOX emissions are lower than for a typical diesel but higher than for a good spark ignition natural gas engine.
Maybe someone who owns such a system can give more info?
I have my truck set up to run lp and cng at the moment. The disadvanges are as follows:
You lose space because of another tank.
You have to get fuel two places instead of one.
If you hotrod, you better modify the tranny or you will slip clutches.
The advantages are:
Cleaner oil.
Better range on #2.
Quieter operation.
Lower emissions.
More power.
I took my first trip today with supplemental cng. I drove 220 miles and used a bit over 10 GGE. I'm not sure how much #2 I used, it was around 1/8 tank. I need to run it alot more to get some good numbers. It appears to be giving me about the same #2 consumption as w/lp.
