DIY_EFI Digest Monday, 25 March 1996 Volume 01 : Number 086 In this issue: CNG/LNG Re: CNG/LNG Re: CNG/LNG LPG injection See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Darrell Norquay Date: Sat, 23 Mar 96 16:44:21 MDT Subject: CNG/LNG > I remember reading an article on natural gas injection that was put > in a 302cid Ford Mustang which, incidentally, utilized the FACTORY ECU. I > I also recall that the stated octane rating of the gas is > 130....could anybody verify this, and if so, why not run a 10:1 compression, > bump the timing up a little, and run 10 psi of boost???(can't do that with Compressed Natural Gas (CNG) does have an octane rating somewhere near to 130 - you can run 25 degrees initial advance, and upwards of 35 total. It's cheap, (at least here in Canada), and it has VERY low emissions. Having said that, it is stored in tanks at up to 3000 PSI, which means they are big, heavy, and they don't hold much fuel. Typically, range is very limited. It's hard to find fuelling stations, (getting a bit easier) and it takes half an hour to fill up. Plumbing and installation is very expensive, all stainless hard tubing (no hoses allowed). Doesn't have as high a specific energy rating (per lb) as gasoline, making fuel consumption much higher. All in all rather impractical for a street vehicle. There's no reason you can't run turbos and high compression with CNG, it's just that nobody does... (Taxis, couriers, etc use it somewhat, and our local gas company's service vehicles are all CNG - it figures) Propane (LPG), however, has a pretty good octane rating(110-115), is also cheap, clean, and the tanks and plumbing are much lighter and less costly since you only have to deal with a couple of hundred PSI. Tanks also hold more fuel since it is in a liquid state instead of a gas, and you can get it anywhere. Ideal fuel for use with turbos and superchargers. All in all IT IS a good fuel for a street/high performance vehicle. Both fuels promote long engine life because of the cleaner combustion and the fact that these fuels are not solvents like gasoline and don't wash the lubricating oils off cylinder walls and valve guides, etc, thus prolonging their life substantially. Half a million miles is not too unusual between rebuilds on a propane engine, if it was built specifically for propane in the first place... There are no stupid questions, only stupid answers... regards dn - -- - ----------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Voice: (403) 243-2220 Calgary, Alberta, Canada Fax: (403) 243-2872 "Absolutum Obsoletum" - If it works, it's obsolete - ----------------------------------------------------------------- ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Sun, 24 Mar 1996 19:36:25 -0800 Subject: Re: CNG/LNG natural gas is a great fuel for standby generators ------------------------------ From: robert dingli Date: Mon, 25 Mar 1996 16:32:21 +1100 (EST) Subject: Re: CNG/LNG > > natural gas is a great fuel for standby generators > While on the topic of CNG/LPG... There is a fleet of port injected CNG taxis running around in Brisbane, Australia as well as some in New Zealand. For our single fuel application, the compression ratio was raised from about 9:1 to well over 15:1, and the resulting peak efficiency increased from about 30% to over 40%. Natural gas in Melbourne is relatively consistent (but not available in CNG form) with a RON of 140-142. In Brisbane and NZ the methane ratio can be as low as 90% lowering the RON to about 130. To test various methane / propane ratios, we recently installed a second set of gas injectors with an adjustable pulsewidth proportional to the base injector pulse from the Ford EECV ECU. Could this be the ultimate dual fuel combination? The project was set back a little last week when the dyno drive shaft flex coupling decided to let go and hurl itself through the bell housing and steel safety cover, across the lab, through a window and into the car park onto an unoccupied Nissan. Luckily no one was hurt, but the mechanical casaulties include the drive shaft, engine crankshaft, dyno shaft, bell housing (now lots of little pieces of aluminium) and safety cover. LPG in Australia can have as much as 50% butane which lowers the octane rating to just under 100. Unfortunately this is little better than the leaded fuel that about half the cars on our roads still use. rambling on... Robert - -- Robert Dingli r.dingli@xxx.au Power and Control Systems (+613) 9344 7966 Thermodynamics Research Labs (+613) 9344 7712 University of Melbourne, AUSTRALIA ** he who dies with the most toys, wins ** ------------------------------ From: Bruno! Date: Mon, 25 Mar 1996 18:48:57 +1100 (EDT) Subject: LPG injection A couple of you have mentioned that when propane (lpg) is injected into the manifold, the manifold soon freezes. What about circulating engine coolant around the base of the manifold where the injectors are mounted? i.e. possibly by running another line from coolant system, in a similar way a car's interior heater works, or having another water system which runs across the exhaust, pumped by an electric pump, temperature regulated by pump speed, fan, etc. The latter system i was thinking of using for a hot water demisting system for when the going gets cold. Bruno. ( u933234@xxx.au ) "If you've gotta go, go with a smile" ------------------------------ End of DIY_EFI Digest V1 #86 **************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".