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Dudes.. casually looking at possibly buying another rig down the line, and seeing some LNG trucks for a very reasonable price. I do see that county has quite a few running around.

Is this something to stay away from, like the Maxforce engines? Possible to convert back to diesel?
 

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I was going to correct you thinking you meant CNG until I googled it. I had no idea LNG vehicles were a thing.

HTF does that work? I though LNG was cryogenic and had to either stay cold or be constantly vented/compressed to stay liquid.

What happens in an accident/rupture/tank failure since LNG is compressed to something like 600 times its gas state density. I remember working on proposals for LNG terminals and storage facilities and seeing some of the worst case scenarios - like if a vessel on an ocean tanker leaked, it could put a "layer" of gas over the water surface for miles around until it found an ignition source.
 

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Dudes.. casually looking at possibly buying another rig down the line, and seeing some LNG trucks for a very reasonable price. I do see that county has quite a few running around.

Is this something to stay away from, like the Maxforce engines? Possible to convert back to diesel?
I don’t have any real world experience with one. But virtually all of the local garbage trucks here have been running them for a while now. Also the long haul fleets have been running them from the la area into slc for a while too. They have put in the infrastructure between the two to support them. If they are like a gas engine running on propane. You might get a lot more life out of one. You tear down a gas engine that’s run on propane it’s whole life and they look new inside. I’d be interested for others with real world experience to s chime in.
 

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I was going to correct you thinking you meant CNG until I googled it. I had no idea LNG vehicles were a thing.

HTF does that work? I though LNG was cryogenic and had to either stay cold or be constantly vented/compressed to stay liquid.

What happens in an accident/rupture/tank failure since LNG is compressed to something like 600 times its gas state density. I remember working on proposals for LNG terminals and storage facilities and seeing some of the worst case scenarios - like if a vessel on an ocean tanker leaked, it could put a "layer" of gas over the water surface for miles around until it found an ignition source.
I've always wondered how they work, too. Maybe a small compressor that captures the vent gas and compresses it into a low-pressure CNG tank? As far as the expansion ratio, that's always a concern. But, it's twice as bad as propane. And you don't see many of those blowing up in accidents. So maybe it's not as bad as it seems like it would be. This would also be lighter than air, so I'd think that would help in the case of a rupture.

ETA--When I said "twice as bad", I meant that propane expands at ~300:1. So, this is worse, but not by an order of magnitude.
 

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I would look into availability of fuel, and power per btu. I don't see it making sense at the current time. With the proper infrastructure and engine development it might at some point. There is a company that makes diesel conversion kits, but mostly for city buses to cut down on pollution not for the economics.
 

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As stated. Lng is different than other gases. I have a friend that is a plumber that helped put together a couple of these stations. The trucks are literally carrying liquid natural gas. Super cold and under a lot of pressure.
 

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Volvo has LNG in Europe, and we build CNG trucks here in the states. I'm only familiar with CNG builds. They use 12L Cummins ISX12N or the 9L Cummins L9N

The infrastructure for CNG is much more common these days in the US than it is for LNG. CNG powered Class 8 trucks have been around for awhile now
 

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My main concern is that people seem to say they have half the power of a diesel rig on the hills.. 20k load feels like 40k. Also have to change spark plugs during oil changes


The upside is, they appear to be very cheap..
 

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For the Cummins 12L CNG the specs are 400hp @1800rpm/1450lb-ft @ 1200rpm. Spark plugs every 50K per the Cummins manual

Estimated range up to 448 miles with dual 45 DGE (diesel gallon equivalent) tanks, or 796 miles with 45 DGE on RH rail and 120DGE tank behind the cab. Both of these with slow fill. Fast fill = less mileage. These are day cab numbers on our new trucks

CNG is approximately 15% less efficient than diesel. The above mileage is based on a diesel baseline of 6.5mpg

No DEF or DPF required obviously, just a catalytic converter essentially as far as emission equipment. Again I'm talking a brand new truck. I don't know about what older trucks have.

These are not meant to be long haul trucks. More for regional work or deliveries from distribution centers (think Coca Cola, UPS/Fedex, Frito Lay, etc).
 

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I was going to correct you thinking you meant CNG until I googled it. I had no idea LNG vehicles were a thing.

HTF does that work? I though LNG was cryogenic and had to either stay cold or be constantly vented/compressed to stay liquid.

What happens in an accident/rupture/tank failure since LNG is compressed to something like 600 times its gas state density. I remember working on proposals for LNG terminals and storage facilities and seeing some of the worst case scenarios - like if a vessel on an ocean tanker leaked, it could put a "layer" of gas over the water surface for miles around until it found an ignition source.
Nothing to really add, read this years ago:

https://www.amazon.com/Deadly-Frost-Terrence-Moan/dp/0345289471

may be complete bs, but was a good read.
 

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Which LNG system does the truck you are looking at have? Westport? If it is the Westport LNG system run for your life! They went bankrupt and getting parts is tough and stupid expensive and having someone with the software and know how to work on them is difficult also. I have a customer here in northern Colorado that has 6 of them and would love it if they went away due to the cost of maintenance to keep them up and running.
 

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Which LNG system does the truck you are looking at have? Westport? If it is the Westport LNG system run for your life! They went bankrupt and getting parts is tough and stupid expensive and having someone with the software and know how to work on them is difficult also. I have a customer here in northern Colorado that has 6 of them and would love it if they went away due to the cost of maintenance to keep them up and running. To convert the engine to diesel, especially if you live in an emission area is not cost effective. ECM, head, wiring harness's, DPF, SCR, DOC will all need to be purchased.
 

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Dudes.. casually looking at possibly buying another rig down the line, and seeing some LNG trucks for a very reasonable price. I do see that county has quite a few running around.
About half the power, half the range. (Check the BTUs.)

We have ships running on it. Some of the fuel suppliers run their trucks on LNG. Tanks are insulated, not refrigerated. Pressure is relatively low when in liquid form. LNG is normally used at a rate faster than it boils off... or it vents. Not feasible to have 'onboard' cryo reefer plants - ship or truck.

Better figure out what the ongoing maint/repair cost is to keep a LNG rig going. Probably a key reason these things are cheap.
 

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LNG and CNG work pretty much the same except for how the fuel is stored. LNG has vacuum insulated tanks, like big thermos', CNG is in high psi (typically 3600) tanks similar to any gas bottle. LNG draws vapor as the fuel changes from liquid to gaseous and goes through a regulator to the engine. CNG is just high pressure gas to the regulator and then to engine. The LNG tank is problematic if you use the truck sporadically. The fuel will continue to vaporize in the tank and when it hits the bleed-off pressure it will off-gas. If you leave your truck parked for weeks, it will eventually run itself out of fuel by bleeding off. CNG will stay in the tanks pretty much indefinitely.

Having dealt will both for a long ass time in a municipal fleet, I would not recommend either one to anyone who isn't a large fleet or gov't fleet looking for air credit type bullshit. They are very expensive to repair, and typically very limited availability of shops with anyone trained or have the tools/software to even work on them. I would buy a Maxxforce before a natural gas powered truck. A CNG car or pick-up used locally would be a different story, there could be benefit there if you have infrastructure nearby.
Travis..
 

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Discussion Starter #17
Which LNG system does the truck you are looking at have? Westport? If it is the Westport LNG system run for your life! They went bankrupt and getting parts is tough and stupid expensive and having someone with the software and know how to work on them is difficult also. I have a customer here in northern Colorado that has 6 of them and would love it if they went away due to the cost of maintenance to keep them up and running. To convert the engine to diesel, especially if you live in an emission area is not cost effective. ECM, head, wiring harness's, DPF, SCR, DOC will all need to be purchased.
What cost am I looking at if I am not in an emissions area? ECM, head, wiring harness? Does the turbo, exhaust manifold, cooling, etc. stay the same?

I am seeing a few 2012 Pete 386 with under 100k miles for 30k, if it costs 10k to convert I am still long way ahead

Thanks
 

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I put a quote together 6 months ago for the customer here that owns the 6 trucks and he asked what it would take to make it a diesel engine again. If you leave out the emission stuff and build it to an older engine (CM870 style ISX) it will take cylinder kits, head, 6 injectors, fuel pump, ECM, wiring harness, fuel lines, fuel tanks and mounting brackets and some other odds and ends. Just the parts I listed will run you $15,000-20,000 and many hours of labor. The cooling system is the same as far as radiator and fan hub. If they gave you the truck for free and did all of the work at the end day you still have more into it than what a 2012 386 is worth.
 

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I put a quote together 6 months ago for the customer here that owns the 6 trucks and he asked what it would take to make it a diesel engine again. If you leave out the emission stuff and build it to an older engine (CM870 style ISX) it will take cylinder kits, head, 6 injectors, fuel pump, ECM, wiring harness, fuel lines, fuel tanks and mounting brackets and some other odds and ends. Just the parts I listed will run you $15,000-20,000 and many hours of labor. The cooling system is the same as far as radiator and fan hub. If they gave you the truck for free and did all of the work at the end day you still have more into it than what a 2012 386 is worth.
got it.. well that answers my questions.. thanks!
 
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