johnr9q

What experience or opinions do people have on this forum regards CNG fumigation in their Cummoins? This is using diesel as the primary fuel but adding CNG up to 50% and more into the air intake to supplement the Diesel. I know of a fellow that is selling a kit primarily for the Duramax but has also equipped the Cummins. One problem is no kit is certified by EPA or Cal EPA for the Cummins so they may not be legal but some are getting around this by calling it fuel supplementation not engine conversion because the primary fuel is Diesel and no changes are made to the engine. As I understand it, there are true Diesel conversions available that actually run on 100% CNG but the modifications are very expensive and includes things like adding spark plugs. There are people working on EPA certified kits but it will probably be at least a year away and may be pretty expensive as the certification costs $250,000 or so. If you have Natural Gas at your house you can purchase a unit that will fill the tanks on your vehicle and and the cost may be less than the equivalent of $1.50 per gallon of Diesel. So, assuming a 50/50 fumigation, if half the fuel you use (Diesel) costs $4.00 per gallon and half the fuel you use (CNG) costs $1.50 a gallon there would be a considerable savings. Of course there is a significant cost to do this in equipping the vehicle and purchasing a home fueling unit and added inconvenience in messing with the whole proposition plus if the entire proposition isn't exactly legal (you would need to keep the tanks under wraps etc). There also might be some issues with insuring that running CNG/Diesel doesn't damage your engine. Preignition (pinging) and higher engine temperatures have been mentioned and maybe other problems I am not aware of. People claim they have additional power running CNG/Diesel and this may have long term negative consequences. I have been looking into doing this for awhile so have done some research but would like feedback from others.

DiezelSmoke

https://www.dieseltruckresource.com/...d.php?t=219083

duratothemax

ask banks!!

ronbros

I know of 2 diesel engines running Propane injection with the diesel fuel,they use a spray bar almost like a gas enigine with a regulator. run great and no smoke. but propane is not cheap as CNG. Thx ron

utvaquero

I'm running CNG. Just started. I filled up once after doing 430 miles and saw a diesel-only improvement of 25%. I'm 120 miles into the new tank and it looks to be doing about the same. My mechanic wants to fiddle with the regulator some more to try to add more CNG into the intake. I'm taking a road trip (600+ mile round trip) this weekend and he's hoping I'll be 35-40% better when it's all said and done. I should be able to do the whole thing on one diesel tank.

infidel

I'd love to use natural gas, it's very cheap in my parts. Some of the farmers here even drill their own wells to supply themselves with their own NG to run the entire farmstead.

My question is how would you go from piped in natural gas to compressed gas?
It seems like a device to do so would be very expensive and because of potential danger not something you'd want to build yourself.

There was an outfit that came though my area last summer that was converting diesel powered irrigation pumps to 100% natural gas. Way cheaper to run when diesel prices were high.
The conversion didn't involve or cost much and allowed you to switch back and forth between NG and diesel easily depending on which was cheaper.

Problem with the conversion as far as a vehicle goes is that the engine couldn't idle on NG, only diesel. No big deal on a pump that runs at higher speed 24/7 but not good when you're stopping and going.

Answered my own question, only $17,000 for the NG to CNG compressor below.

dieselman2300

Check this one out infidel. its a residential unit.

http://www.myphill.com/

utvaquero

Yeah, those Mr. Phill units are an option and, frankly, the gas company charges less per GGE than a fill station but a $4,000 initial price will keep me going to the fill station for my CNG for the forseeable future. The conversion was already pretty spendy. And, those units only fill about 1/2 GGE per hour so you're looking at plugging your vehicle in all night to get a good fill. Not bad, though, if you have the time to wait.

dieselman2300

I just talked to a distributor for the Phill units. He said that you will recoup the 86% of the costs in less than a year just from Federal and State incentives.
Where I live there isnt many if at all CNG filling stations.
BTW, what do you pay for a Gallon of CNG?

utvaquero

Last week it was at $0.799. Haven't driven by this week yet but it should be about the same. It's great to pay less than $1.00/gal. Almost makes me wish the old Cummins ran COMPLETELY on CNG!

dieselman2300

I wish I could find a site that locates CNG stations. Do you know of any?

joe189man

pdi diesel sells a unit for our trucks i saw their add in diesel power this month the thing isnt cheap i think 5K or more :0

infidel

I never found the price?
One thing I didn't like

"How long does Phill take to fill a vehicle?
On average it will take approximately 4 hours to replenish the fuel consumed in 80 km / 50 miles of driving based on a vehicle consumption rate of 8 litres per 100 km or 30 mpg"

Here in the wide open spaces where I live it would take me all week to fill up enough to get anywhere.

RCinMesa

Here you go:

http://www.afdc.energy.gov/afdc/stat...nd_station.php

Also, there's a guy in the February issue of Diesel World with an '08 dually that's getting 24mpg in town and 31mpg (claimed) hwy after CNG conversion. The truck also dyno'd at 490rwhp and 900 + lbs of torque without any other modifications. EGT's were claimed to drop 200 degrees (were the same while towing heavy though).

If this is all true, CNG conversion is a great idea.

1. Diesel prices will go up again
2. Diesel/CNG combo burns cooler, cleaner, with more power
3. Cleaner is better for the motor internally, air externally
4. No other mods for mileage and power are needed
5. Large, useable vehicles can be made fuel efficient and "greener"

Again that's all if the claims in the article are true. If they are.....better mod those trannys!

utvaquero

OK, I just got back from a 700+ mile road trip this weekend on CNG. Before I left, my mechanic installed a 2nd supply line in my intake running from the regulator. It probably added 1/3 again more CNG than the single line. He also adjusted the regulator settings to apparently allow more flow. Whatever the changes were, they were BIG TIME noticeable in the throttle department. And, I called him 200 miles into the trip to say, "dude, my fuel gauge is STILL above the full mark!"

Normally, my truck runs 100 miles between a fill-up and when the needle actually falls back to the full mark and then 100 miles each quarter-tank tick mark. So, I go about 300-350 before the needle reaches the half-tank mark at which point the truck will take 18-20 gallons.

This weekend, I drove 330 or so miles and the needle was between the 7/8 and full marks! I re-filled it because I had to fill my CNG tank anyway. Calculated mileage was 32.04 mpg based on my GPS, because my speedo is off by 4%.

I then drove another 460 miles and my needle is still sittin between 5/8 and 1/2 tank. I also drove with the CNG off for about 150 of that because the extemely cold weather in Salt Lake this weekend apparently froze up the regulator.

We're going to be swapping a new regulator on that can be plumbed for engine coolant to keep that from happening again.

Overall, I could not be more pleased with the power, performance and economy that CNG is giving me. I'm already a CNG-***** and it ****** me off I had to run diesel-only for so many miles, knowing I was loosing so much fuel economy!

A big thanks to Kevin at Affordable Fuel Solutions in St. George, UT.