Anybody install a CNG (Compressed Natural Gas) kit on their Cummins?

[CSM]

I am going to be doing a lot of driving after I get out of training this next year... and I am thinking of ways to reduce my fuel costs other than buying a small car.  

 

I was looking at these systems, or building my own.  

 

http://mycngguy.com/product-category/diesel-bi-fuel-systems

 

 

[rancherman]

I've only seen the  propane kits,    around here they are getting very popular  with the  diesel stationary  power unit guys....     They are claiming  up to  $5 dollar per hour  savings in fuel.

 

Propane is  running about   $1.45 gallon right now,  I'd recommend   propane just because of the   amount of  fuel you can carry.   Plus  the fact  DOT  ready   cng  tanks  are pretty spendy...  and  finding   re fill  stations  are  far and few.   Maybe you are  sitting in a  cng  hotspot??

 

Don Hardy engine,  out of  Texas,  has  a kit  for   natural gas...     20%  diesel,  80%  dry fuel.    

 

http://www.donhardyengines.com/specials.htm          Kind of  a  cheesy  web page,   not  much  info on his kit,     but    has   email and phone info

[MnTom]

I would go with propane due to the availability. I am running propane and it gives me a flat 5 mpg increase across the board. At 65 mph empty I am getting 25.5 mpg diesel, but when you factor in the propane it is still more economical. I have also seen up to 17+ mpg towing my fiver with it. Running empty I can go about 900 miles before I run out of fuel. Towing I have had to fill up once in 900 miles. This is the system I have: PROPANE SYSTEM The way I have mine set up is to come on at about 2psi and the more boost the more propane. I use about 20 gallons of propane per tank of fuel towing and about 10 empty. Also it does increase your power!

[hex0rz]

Tom, I don't see anywhere it can be ordered?

[MnTom]

Tom, I don't see anywhere it can be ordered?

Looks like you click on the Dealer tab and call them. I got mine from a friend so I didn't order it from them.

[hex0rz]

So what did you buy the kit for? Did your buddy buy it from them? Trying to get an idea of what the overall cost would be...

[MnTom]

I got my kit for $200. I supplied the tank. I had a 10 gallon tank at first that I got for $50 full of propane, but it was too small for towing and got the tank I have now (almost the size of a 100# bottle) for free.

[TFaoro]

Interesting, but I don't like the idea of pre-turbo injection. Wouldn't it be better to inject it into the horn, after the intercooler? This way in the event of a crash you wouldn't have to run the risk of an explosion from the intercooler full of propane?

[rancherman]

these things are regulated  so  the more boost,  the more  propane  is  injected...     while nothing is   guaranteed  'safe'..    malfunctions  can and  could happen.   (as with  any fuel)   I've got  a couple  of  JD  propane  tractors,   50 years old,   and   the fuel system is  about  fool proof.  They  use   manifold vacuum to   run the  mixer.

 

I'd  bet the   amount of propane  is  pretty lean.   (for  the   guys  wanting  just  a  little  help  for   mpg purposes)    and   it  may  take  a  really dedicated   source of  ignition to  light it off.    Now,  for the guys   going-for-broke,   the  mix is probably  rich  enough  to  make   it  a little easier to  ignite

Tom  is  claiming about   5 gallons propane  to  a  tank of  diesel  for  daily driving type conditions...     about  15%  of   needed  fuel is supplied  by  his  propane...       I  wonder if  we could even smell  it,  at that  concentration..   Much less   ignite it  with a  spark..    But,  even if it  was  rich enough,   the  amount of  fuel  inside the  'cooler    at  any given time  is  pretty small...  there may be enough to  give a little  'wuff'  but  a  kerboom  is probably  not going to happen

 

your idea of  injecting into the  horn is probably safer,  but remember the propane  needs to  overcome  the  boost pressure...   and    we are talking  anywhere from  4-5 lbs of  boost  all the way up to  (insert your max boost here)..

 

most  propane  regulators  are  set up  in  OUNCES

Edited May 28, 2014 by rancherman

[mulcher812]

There is a guy out here that I've seen running around with a 20 lb propane bottle in the back of his truck. I finally stopped him and asked what or how his setup worked and it was a simple regulator out of a forklift that he had rigged up to a solenoid on a toggle switch I the cab. His system injected pre turbo also.

[MnTom]

Rancherman is correct on hte amount of propane, but when I had a boot leak just off the turbo I did get a whiff of propane, but like what was said, no boost=no propane so unless I keep my foot into it and the boost up there is probably about 0% propane in the intercooler during a crash. Also keep in mind that propane needs a fairly precise mixture of air and propane to ignite.

 

 

The lower and upper limits of flammability are the percentages of propane that must be present in an propane/air mixture. This means that between 2.15 and 9.6% of the total propane/air mixture must be propane in order for it to be combustible. If the mixture is 2% propane and 98% air, there will not be combustion. If the mixture 10% propane and 90% air, combustion will not occur. Any percentage of propane in a propane/air mixture between 2.15% and 9.6% will be sufficient for propane to burn. http://www.propane101.com/aboutpropane.htm

[CSM]

Im thinking here but in my mind, I would want CNG because I could fuel it up from a compressor from my main line at home each evening... (assuming when I move again I have gas service)  Otherwise, propane could be the best option.  Especially if it could be injected post turbo as a liquid, slightly cooling the gas mixture.

 

i would also want post turbo, as its already compressed and adding more mass to compress and cool through the intercooler is a waste of energy.   

[MnTom]

Im thinking here but in my mind, I would want CNG because I could fuel it up from a compressor from my main line at home each evening... (assuming when I move again I have gas service)  Otherwise, propane could be the best option.  Especially if it could be injected post turbo as a liquid, slightly cooling the gas mixture.

 

i would also want post turbo, as its already compressed and adding more mass to compress and cool through the intercooler is a waste of energy.   

First question, how would you be able to tap into the main by your house? Do you already have a compressor that is capable of producing 3000 to 3600 psi?

Second question, why would you  want to inject liquid LP? With liquid you will not have the same amount of control as you would with vapor. The liquid to vapor expansion rate is 270:1 In other words, 1 drop of liquid will give you the equivalent of 270 drops of vapor. Not only that, but it is easy to inject enough propane to have some real serious cylinder pressures and be replacing headgaskets.

[mulcher812]

Well since this has come up I have started looking into it and found out that the propane it's a kit that can be done rather cheap and easy. Apparently there is a gentleman in Vancouver, WA. that sells all the required parts and pieces. I'll do some more checking and if its a viable source. If so I'll post his info here.

[hex0rz]

I likewise have been doing some looking into. I called diesel performance products today. The same kit that mntom owns. I was chit-chatting with him about a few things, here is what we discuseed:

 

(from the subjects I can remember)

 

- His propane injection system only has an approx. 1% propane injection.

 

- This little % of propane pre-turbo is not enough to cause any problems, but helps facilitate in completing the diesel combustion process.

 

- He stated he is making 40mpg! Crazy, I KNOW! But he said his was an '04 as well.

 

- Mainly will only benefit at highway, cruising type speeds. City traffic will not be much help.

 

- His kit is on sale right now for $895!!!

 

- Depending on the size of propane tank, DOT approved, he said between 2-600 dollars.

 

DOT propane tanks are very safe. Safer than the fuel tank on our trucks. He said you could lop off all the valves on the tank and nothing would happen. Each tank has a check valve for safety. 3/16ths steel.

 

You do NOT want a liquid propane injection, you want a vapor. Much better, safer...

 

I'm just still a little shocked at the price of the kit he is selling. I do really like how he has it though!

[MnTom]

- His kit is on sale right now for $895!!!

 

- Depending on the size of propane tank, DOT approved, he said between 2-600 dollars.

If I had to pay full price I would not have done it. I only have about $200 invested in my system excluding my labor to clean and paint the tank, installation, etc. If you check the online classified ads in your area you can find DOT tanks occasionally.

[rancherman]

I agree with   NOT  injecting   liquid  anywhere..   It's  next to impossible  to  keep it  from  boiling  in the line..  unless it's kept  at least  200-250 PSI...  and   any degree of  accuracy  @  point of  regulation  is  going to be   very complicated  (EXPENSIVE)

Vapor is   much  easier, cheaper, accurate, SAFER.

 

I remember  HONDA  selling a   hydrogen  generator  that  would  hook up to  a  home  natural gas  supply,  and  it  would  crack  the  H  and  pump it   into their    fuel cell   cars...    But  I   wondered  about the   energy used to  do the  process  would   be more than   just  buying a  gasoline  car  and   tooling down the road? 

Which   brings me  back to the   amount of  compressed  cng  a person can  carry..  I suppose  a  tank about  10 'Q"  bottles  would  give  a  person  some  range,     but  the  main thing  is  the  compressor  is  going to be  SPENDY...  both  in price and   energy to run it...   I  wonder if  there  would  ever be  a  pay-off  date.   (  one  truck   would  really have  to  put  some miles  on..  Fleet  stuff  is  different)

[MnTom]

I looked at the availability of the product. There is a natural gas liquification plant not very far from me and yet there is not any place to get LNG around. Propane is available just about anywhere in the country.

[CSM]

First question, how would you be able to tap into the main by your house? Do you already have a compressor that is capable of producing 3000 to 3600 psi?

Second question, why would you  want to inject liquid LP? With liquid you will not have the same amount of control as you would with vapor. The liquid to vapor expansion rate is 270:1 In other words, 1 drop of liquid will give you the equivalent of 270 drops of vapor. Not only that, but it is easy to inject enough propane to have some real serious cylinder pressures and be replacing headgaskets.

 

I doubt that I would actually get liquid to work.  However, I was thinking of the small gain in energy there by adding a liquid that will turn to gas and also cool the intake system slightly.  

 

I don't have a compressor capable of that, however it is not an insurmountable task. 

[MnTom]

I don't have a compressor capable of that, however it is not an insurmountable task. 

I doubt that it would be 'profitable' for you to invest in a compressor and everything related for compressing your own LNG even if you kept your truck for 20 years.