CNG and LPG conversions

Crookedaxle said:

I had a 2005 GMC C6500 with an 8.1L... ...It was an old Schwans truck in it's former life. .

Click to expand...

Funny. Years ago, I bought a couple of gasoline in-tank fuel pumps, gasoline injectors and rails, and some sensors from a company that converted 8.1L Schwans trucks to LPG...or CNG...or Bovine Farts...or something.

A buddy works with CNG trucks and power generation equipment. When asked about using CNG for cars, he just laughed. The real expense is the tank at $10K, not to mention the lower efficiency of CNG versus gasoline, something like 70% less energy from each gallon. You can multiply the cost of CNG by 1.4 to get near the actual cost.

E.g. 1.75 x 1.4 = 2.5 equivalent dollars per gallon. That's more than the $2.25 for gasoline!

David89gmc said:

A buddy works with CNG trucks and power generation equipment. When asked about using CNG for cars, he just laughed. The real expense is the tank at $10K, not to mention the lower efficiency of CNG versus gasoline, something like 70% less energy from each gallon. You can multiply the cost of CNG by 1.4 to get near the actual cost.

E.g. 1.75 x 1.4 = 2.5 equivalent dollars per gallon. That's more than the $2.25 for gasoline!

Click to expand...

What you are forgetting is cng is sold in gallon of gasoline equivalent. So it is equal comparison. Just takes up vast amounts of space.

GM has made the CNG available on Vans since 1992 or longer. It is like the S10E that used the EV1 drivetrain and sold to East Coast Electric Companies for use to read the meters. Never knew that either, but I was in Torrence CA at a GM hydrogen fuel cell facility in 2004 with a group of 50 ACDelco personnel. Very interesting as they had everything in house, including software to design circuit boards. Spent an entire day...but the project was cut back from 4 facilities to? I am sure the project is sit-in in the "Alternative Technical Vehicles Center" highly guarded near the Berlin Township. Yep, they still had EV1...they did not crush all of them.
(CNG) Besides the tanks, the had to use heaters, to keep regulators from freezing up. The intake have two sets of injectors, one for gasoline, the other for CNG. A dash mount switch would allow the fleet driver to switch between either fuels while driving down the road with no interruptions. These vehicles are in every boneyard around town, but there's a lot going on.
As for LPG, during the 80's in Omaha, the Carl Anderson company installed these systems, then dial them in on a dyno. They have been out of business for decades, as they rebuilt turbo, diesel injectors and had a massive part house. Never understood the entire process but as a tech at a local repair shop, I was the import tech, but worked on everything. Took the chance to tour the facility and it was impressive to see naked turbos on balance machine at 100k speeds, but the CNG side was described as a dry fuel carb of the beginning of the induction. With regulators, valves and a round canister to ensure the liquid was always in gas form, then into the engine. While they did mostly cabs, but a lot of Fleet vehicles came thru with the addition. In 1983, it was still a 4-5k investment, but engines never wore, oil was as clean as the day they change it last and other than the cost, I was very impressed. Especially after working on 5.7L diesels in Oldsmobiles and others. I alway hate the oil as it did not wash off...at least with the stuff we had.
Our city has a larger population than St. Louis, still has no facility to add either fuel delivery system. Best of luck!

Ford offered Crown Vic.'s back in the '90's with factory CNG. Dual fuel. Fleet vehicles. Many of the local police forces used them for cruisers. But, the gas-powered Suburbans were the high-speed-chase vehicles.

G’day from down here.
I have owned a ‘93 7.4 crewcab dually for 14 years with 430,000 kilometers now on the clock and never been touched. It has had 2 water pumps, a pair of valve cover gaskets and a new distributor. It is dual fuel ( pump gas/ LPG) I start it every morning on pump gas and when we are about 1 mile up the road I switch it to LPG and it runs on that for the rest of the day.
Down here the price of all fuel is stupidly high.
Over a two year period i did between 1400 kilometers a week to 2 kilometers a day, and the results were that it averaged out at $8.00 cheaper to run per 400 kilometers on LPG than pump gas. WITH NO LOSS OF POWER.
The electronic control equipment (Technocarb)that was fitted in the USA before coming to Australia is now out of date and I am about to go from 7.4 to 8.1 crank kit, so the current mixer is not big enough. So i am deliberating weather to upgrade or remove.

Very interested in what everyone else has done!! Keep this thread alive.

Terrick down Under said:

G’day from down here.
I have owned a ‘93 7.4 crewcab dually for 14 years with 430,000 kilometers now on the clock and never been touched. It has had 2 water pumps, a pair of valve cover gaskets and a new distributor. It is dual fuel ( pump gas/ LPG) I start it every morning on pump gas and when we are about 1 mile up the road I switch it to LPG and it runs on that for the rest of the day.
Down here the price of all fuel is stupidly high.
Over a two year period i did between 1400 kilometers a week to 2 kilometers a day, and the results were that it averaged out at $8.00 cheaper to run per 400 kilometers on LPG than pump gas. WITH NO LOSS OF POWER.
The electronic control equipment (Technocarb)that was fitted in the USA before coming to Australia is now out of date and I am about to go from 7.4 to 8.1 crank kit, so the current mixer is not big enough. So i am deliberating weather to upgrade or remove.

Very interested in what everyone else has done!! Keep this thread alive.

Click to expand...

Very interested. I have been watching your 6.5 thread. I would love to hear more about your LPG experience.

"Edit" I just realized i was refering to someone elses thread. But i have read all your comments on that thread. ☺

Been a while since i have posted. It is summer here and i work on air conditioning so i have been scrambling.
I am still thinking about this. I have met a mechanic who has lots of spare parts but he does not recommend lpg he much prefers cng and he may have a tank to sell me. Cng is far cheaper here so if i can ever afford it i want to setup a work truck with dual fuel cng and gasoline.
I am looking into dually gmt400s because i found a utility bed that i may be able to get that belongs on a gmt400 (not the ford its on).

Sent from my LM-X210APM using Tapatalk

So what do youall think what year, model, and specs should i look for?
I am wanting a truck that will get "good" mileage and be rock solid reliable.
I dont need a lot of power and i wont be towing but it will have a loaded utility bed. Also i would plan on running only 4 tires if the weight rating was good enough.

Sent from my LM-X210APM using Tapatalk

Also how reliable are the 1 ton front ends compared to the 1/2 tons because i have had a bad time with a 1/2 ton gmt400 front end.

Sent from my LM-X210APM using Tapatalk