propane vs. NG
#1
#5
Propane (C3H8) is a heavier molecule than natural gas (mostly methane, CH4). It liquifies more easily and yields somewhat more energy, but otherwise has similar properties of combustion and by-products.
My guess is that an engine designed for propane would run on natural gas (although perhaps with less power) as long as the appropriate metering adjustments were made to keep the air/fuel ratio where it belongs.
Chris
My guess is that an engine designed for propane would run on natural gas (although perhaps with less power) as long as the appropriate metering adjustments were made to keep the air/fuel ratio where it belongs.
Chris
#6
I don't know if Drwoodchopper is on here but here is a quote from his setup elsewhere
I have had a bunch of PM's about my CNG supplemental set up so I thought I would start a new thread about it. First off I did tons of reasearch and came up with a very limited amount of information. CNG supplements the diesel fuel, "streatching it" to make you go farther by supplying an extra, much cheaper fuel. We can't run straight CNG because we do not have a sparkplug...duh. CNG is much safer than propane because it is able to compress much more before ignighting so thus the diesel ignighting creates the fire to ignight the CNG. The gas is drawn under vaccum from the regulator pre-turbo so you are using little to no CNG at idle. The amount of CNG used increases with rpm and boost (ie: vaccum pre turbo). I have been running the system for a year now and have only run out of CNG once so I have been using it all of the time even grossing 18-20k towing. You do have to keep a closer eye on your EGT's but I have only had to reach down and shut it off 2 times that I can remember. I constantly get 800-1200 miles out of a fill up of diesel and 200-280 miles out of 10 galons of CNG. The downside is the tanks are big and because it is a gas they don't hold much, so I have to fill up often. Tuning seems to be a non issue except for trans tuning. The truck has 50-75 more hp with it so the trans does not "know" this. Newer trucks have "adaptive learning" for the trans and this seems to be a non issue. I had Johnathan at Beans tune the trans to behave as if it had more HP than my mods would produce and it has been shifting great ever since! The system is quite simple you have a tank, regulator/controler, coolant lines to kep it from freezing a power wire, a supply hose to the intake, an on/off switch and a control valve to adjust the max amount of CNG to be used. I get asked about it almost everytime I fill up as the CNG fuling station I use is right next to the diesel pumps. I just did a blackstone oil analysis at 7k and they said I should go 10k on next oil..it was that good! Belive me I was very nervous to try it and turn it on the first time but I absolutly LOVE it now!! The inital investment is quite large $3000 is what I spent on mine I looked into having it done and it was $7500-10k The tanks are what kill you, a new 12 gallon one like I have is $3600!!! Some of you might remember a duramax that smoked the fuel economy part of the diesel power challenge a couple of years ago. That is what peaked my intrest and I am running that same system.
#7
Trending Topics
#8
#11
#14
HHO is a snake oil scam, because the amount of "gas" created is so minuscule that it has zero effect.
Setups such as propane and CNG are actually introducing higher amounts of combustable fuel into the intake. The issue with both systems here is that when a fuel is introduced into the combustion chamber of a compression ignition engine via the air intake, rather than being precisely injected at a pre-determined time, you lose all ability to control start of combustion (SOC).
An earlier SOC event can increase horsepower and increase fuel economy (by reducing the amount of diesel needed during the injection event). However, the side effect of that is a rapid and often very high spike in cylinder pressures. It's this exact problem that is the cause of bent and/or broken rods, with windows in the blocks.
That's the inherent danger of propane and CNG. That's why propane kits, although widely popular years ago, were also quickly abandoned by the masses. CNG is just the same thing, under a different name and a slightly different fuel. Still doesn't change the fact that it's a fuel being introduced into the air intake, creating the same effect as propane.
Thread
Thread Starter
Forum
Replies
Last Post
Tenn01PSD350
1999 - 2003 7.3L Power Stroke Diesel
27
12-21-2008 10:25 AM
13hondacr250
Bio-diesel, Propane & Alternative Diesel Engine Fuels
9
02-12-2004 10:01 PM