12valve@heart

Does anyone know what all besides the head is different about a Cummins 5.9L natural gas motor? I'm just wondering what it would take to pull the 5.9 diesel and put in a 5.9 CNG motor. At less than one dollar/gal., CNG sounds pretty attractive. I'm eyeballing a 5.9L CNG bus as a donor.

DiezelSmoke

Basically the same motor just lower compression. Keep in mind if your going to fill at home it will take like 8-10 hrs.

Desert Dually

i'm just curious here, but why would fueling take up to 10 hours?

capt.Ron

Probably not enough pressure through the home regulator.

Desert Dually

yeah, that'd be a pretty serious drawback!

maybe you could employ the use of a small air compressor to facilitate the process? Or would there be a serious explosion hazard?


I saw a photo somewhere on the web of a Cummins 5.9 natural gas SC engine, factory supercharged no turbo'd! It mounted the supercharger on the passenger side of the engine i think. I didnt see a closeup of it, so i couldnt exactly tell what type of drive the supercharger had. It looked super cool, but was painted a bizarre shade of green.

DiezelSmoke

At home your pulling a vapor and if you went to a station your filling with liquid. I might be wrong on the 10 hrs. but I know it is a long time 6-8 maybe.

logskidder

The block, crank, rods, front cover and most accesories are the same. You could use everything from a bus, however with CNG the biggest problem is making room for the tanks. The reason a small home type compressor takes so long to fill (6-12 hrs) is because, they dont have any type of holding reserve and they use a very small unit to compress 25 psi inlet press, in 4 stages to about 4000 psi....so it takes awhile. If you need any info just ask, I have done about 50 5.9 and 8.3 conversions in the last 2 years.

capt.Ron

Can they be converted into a dual fuel setup?
Diesel or CNG?
Diesel and CNG?

logskidder

From what I understand......yes, however I have not done one yet. I may look into a dual fuel setup for my shop truck.......just to many thing going on right now to give it 100%

capt.Ron

So how do we go straight CNG on a 12 valve?
Is the injector pump removed or somehow disconnected?
Not sure how big my tank would need to be but I have a tool box that fits flush with the top of the bed. I might be able to install the tanks in the tool box with a false bottom over the tanks.
What kind of price tag can I expect for a conversion?
Self installed if that's possible.

logskidder

1) change the head, pistons and cam
2) remove the complete fuel system, install block off plate for injector & lift pump
3) install needed sensors
4) install new electronics
5) install new intake horn & throttle valve
6) I use a water cooled HX35 14 cm turbo
7) install fuel tanks, high press reg, low press reg, pri filter, sec filter, fuel shut off, mixer, fuel control valve and change throttle pedal to fly by wire

I use 4 carbon fiber tanks that are about 2' round x 8' long......they are good for about 250 miles in a 20,000 lb bus...all stop and go traffic.

Using all new parts...without labor.....cost is around 20k. If you can find used parts and know what your doing......maybe 3-5k. You would also need Cummins Insite software to read faults and program default settings.

One more thing....you want the B Gas Plus, stay away from the B Gas(1st series) many, many problems.

capt.Ron

Ok well that decided it for me.
No way!
It would take forever to make up that investment.

logskidder

Maybe a low pressure system like propane or LNG fogged into the engine could be home built for a fair $$$.

Gary Emerald

why spend $20k to convert when an engine costs half or less new? I have some natural gas Cummins engines, and we run Alltronic Magnetos or ignition boxes on them. They're pretty gutless compared to their diesel counterparts... and you think your EGT's are high now?!?!? LOL!

I think I'd rather set one up to run on gasoline than natural gas, and I HATE gasoline

logskidder

Do you run LNG or CNG?