Hi trying to get info on the short comings of CNG .I have experiance with propane ,and wondering if there is any concerns other then the high pressure tank .what kind of maintenance is required ?? does it respond to ignition upgrades as in multi spark ignition , any problems you have had ?? and how complicated is the factory Ford unit , or should I be looking at aftermarket kits?? and is there any differance in the mixer compared to an impco propane setup??thanks ..

 

Since no one else has answered, I'll give it a try. There is much confusion about LPG vs CNG in that many think they are similar. There are huge differences in physical properties.

CNG (mostly methane) behaves more like hydrogen and LPG (propane, butane) is actually more like gasoline. LPG is a liquid and dispensed by the gallon, just like gasoline. Pressure in the tank is very low. CNG never liquefies at room temperature and is dispensed at over 3000psi. A huge tank is required to get any significant range.

The Ford factory setup (we had a CNG Crown Vic) uses the EFI system with bigger injectors, but with high pressure plumbing and valves. The only maint. item is a filter, but factory valves are breathtakingly expensive to replace.

Aftermarket conversion? I dont know because our "fleet" has been all factory, Ford, Honda and Chevy. The Cavalier is dual fuel, the rest dedicated. Dedicated has the advantage of higher compression in order to recover some of the power loss. Exotic ignition systems would be a compete waste because it already burns much cleaner than gasoline on the stock ignition system.

 

thank you..still trying to get answers from people that have used it ,it seem's the intrest has faded ,but no real reason why ..are you talkin engine valve or flow control valves??

 

Flow control valves.

 

see I do pay attention..how are ford's flow control different then Ipco's control ??and yes I know they are propane ..is it just the high pressure differences?

 

Please dont confuse propane and CNG systems and components. As I stated in my first post, they are drastically different. Yes, its because the pressures differ by several orders of magnitude. Another thing is there is no need to vaporize CNG. Its not a liquid to begin with.

IF Impco makes a CNG conversion system, I know nothing about it, but it cannot be physically identical to a propane system.

The other issue is that factory parts are more integrated into the vehicle electrical system and due to limited production plus much higher development cost in a big corporation, replacement parts can be very expensive. A prime example is the $4000 Ford dual fuel "Compuvalve".

 

HP fuel components should not be expensive, diesels have been running higher pressure than 3000 psi for years now. They're operating with ten times that pressure. CNG is just getting started.

 

I understand the basic differences.it just seams anything that may save you money ,like a clean burning available fuel like cng has so many barriers put up by the government ,thank's guy's

 

The big difference here is that diesel fuel sits in the tank at no elevated pressure, only the short lines from the pump to injectors are in traditional and common rail systems. In the case of unit injectors, or the early PowerStroke, the high pressures are only at the injector itself.

A large storage tank at high pressure is much more difficult/expensive. Also, a crack in a high pressure line containing a liquid is usually a much less dramatic event than with a gas.

 

Yea, but CNG handling equipment is not as new as you'd think. The tanks are safe, that's not an issue(if it were, they'd never get certified), and even having a traffic accident should be no different than dealing with a ruptured (plastic) gasoline tank, afterall the fumes are the dangerous part, not the gasoline itself. The oil and gas industry has been handling CNG for decades and aside from a relatively few incidents, CNG has been no more dangerous than any other fuel. Lots of cities have been running CNG buses for years now too, how many bus explosions have made the evening news ? (other than the intentional explosions in the middle east?) The extreme high pressures in the diesels exists not only in the injectors but also in the lines from the HP pump to the injectors.

 

As far as the feds are concerned, I haven't heard anything done to prevent the use of CNG. I do know that several states are moving on making the filling stations easier to get built. Here in Louisiana, this has been given the high ball by the Governor, there are a dozen or more stations already in use in north Louisiana. I know of one in a little hole in the wall place along LA Hwy 1 and US 371 that's been in service now for a couple years, right next to the gas well the gas comes from. Right out of the ground, right into your vehicle. No refinery needed, no pipeline needed. Can't get more efficient than that.

 

I'm in canada , we have a lot of tree huggers here ..and a government that listen's to the EPA , and the California level of red tape ..what I want is a home filling station ..plug in at night drive all day..got any pix's of your merc'?? I have 68 Ranchero 390 about to be 428 tri-power ..or CNG...

 

Yea, I have a few pics of it, but sold it a couple years back. (can't post em here though)There are home filling stations available here in the US. Don't know what they cost though. I've heard it all on a statewide talk radio program several times. Seen some of it first hand (I hauled the diesel fuel to the drilling rig that drilled that well the CNG station is located next to) North Louisiana was litterally booming with gas well drilling for the past 5-6 years, it's somewhat tapered off now, but they're moving forward with marketing the gas that's in production now. I don't know how the mileage figures translate to compare it to gasoline, but at $1.55 per gallon, it looks pretty good to me if and when I buy a new vehicle.

 

still have the Stang??

 

Gosh no, sold that 22 years ago. Got a few pics left that's all. Worst part about selling it was when the prices on the 67-68 FB's took off a few years ago. What I sold it for wouln't buy a rolling shell now.