Compressed Natural Gas

[Grizzly]

My wife and I visited the Grand Canyon NP, Bryce Canyon NP and Zion NP last month. All three parks had buses to take visitors from one observation site to another. I never saw the engines on these buses, but they sounded just like a diesel engine. All buses displayed a large sign that read Natural Gas Powered Engines.



My question is, could they have been diesel engines powered by CNG?

 

[Ross]

Grizzly: YES!



Back in the 90's there was a pretty hard push towards CNG. There were fueling stations in certain areas, and municipal vehicles (garbage trucks, buses, etc) were often converted. To help with this, Cummins converted both B and C series diesels (and maybe more). I remember reading in Diesel Progress magazine several articles about the Cummins engines that were converted to run on CNG. I believe that they had to integrate spark plugs into the head, probably located where the fuel injector is currently located. (my memory may be wrong about this).



Cost/lack of fueling infrastructure, consumer reluctance, and cheap fuel prices (then) ultimately contributed to a loss on interest in the conversions.



To me, using CNG makes WAY more sense than current energy "alternatives" like turning animal and human FOOD (corn) into ethanol (a topic that deserves it's own thread).

 

[RustyJC]

One can either replace the injectors with spark plugs (and an ignition system, and an A/F ratio control system, and a gaseous fuel governing system) and run what is called a "spark gas" configuration, or one can use the fuel injectors as pilot fuel (just enough diesel is injected to initiate combustion) in a "dual fuel" configuration. With the standard injectors, the BTU mix will be around 95% gas/5% diesel, but with precise, low volume injectors, the BTU mix can be brought down to 98. 5% gas/1. 5% diesel.



Rusty

 

[Grizzly]

Grizzly: YES!



Back in the 90's there was a pretty hard push towards CNG. There were fueling stations in certain areas, and municipal vehicles (garbage trucks, buses, etc) were often converted. To help with this, Cummins converted both B and C series diesels (and maybe more). I remember reading in Diesel Progress magazine several articles about the Cummins engines that were converted to run on CNG. I believe that they had to integrate spark plugs into the head, probably located where the fuel injector is currently located. (my memory may be wrong about this).



Cost/lack of fueling infrastructure, consumer reluctance, and cheap fuel prices (then) ultimately contributed to a loss on interest in the conversions.



To me, using CNG makes WAY more sense than current energy "alternatives" like turning animal and human FOOD (corn) into ethanol (a topic that deserves it's own thread).

Thanks Ross, Good explanation.