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CNG semi truck engine type

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
Frito Lay near me has been switching to interesting semi trucks. They will be trying 15 tesla semi trucks and I think tesla forklifts?
They have some big semi trucks running on compressed natural gas. I could not finds any good information are these diesel engines or spark ignition engines? I know some are Volvo trucks.
Bil lD
 
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Frito lay near me has been switching to interesting semi trucks. They will be trying 15 tesla semi trucks and I think tesla forklifts?
They have some big semi trucks running on compressed natural gas. I could not finds any good information are these diesel engines or spark ignition engines? I know some are Volvo trucks.
Bil lD

"AFAIK" . the first natural gas engines were Bessemer or similar hot-bulb type for their own pipeline compressor power. "Not new" IOW. Diesel LOOKING ones have pumped sewage about, run off the methane from the processing. Also "not new".

Dual-fuel gen sets are generally LPG/Gasoline based in the smaller sizes, Diesel/LPG in the larger sizes:

LPG diesel dual fuel engine – A critical review - ScienceDirect.

Cleaner Long-Haul Engines Guzzle Diesel or Natural Gas - MIT Technology Review

YouTube
Nothing new about electric forklifts, either, except optimization around a Tesla battery instead of older types.

Among the first of electric vehicles, many-stops route delivery trucks:

Baker Motor Vehicle - Wikipedia

Food & beverage majors could be a better fit for a modern-day return to that niche than to long-haul, much as electric and hybrid taxis and buses have been appearing in crowded Asian city spaces.
 
They are diesel engines converted to CNG by either using a different head with a spark plug or just utilize a manufacturers conversion system that replaces the injector in the standard head with a spark plug.
 
They are diesel engines converted to CNG by either using a different head with a spark plug or just utilize a manufacturers conversion system that replaces the injector in the standard head with a spark plug.

So no longer diesel, compression ignition. CNG requires at least 15-1 compression ratio. Diesel already has this CR or in most cases a higher ratio. This makes the CNG efficient.
 
So no longer diesel, compression ignition. CNG requires at least 15-1 compression ratio. Diesel already has this CR or in most cases a higher ratio. This makes the CNG efficient.

Per the article(s), either a sparking plug OR injection of a small amount of Diesel is needed to control the timing of ignition more accurately - CNG being an easy-peasy pussycat in gasoline-range compression with spark-ignition [1], but less predictable by itself in a compression-ignition situation.

All that must be pretty well "solved" by now if Penske has fleet rentals of them and You Tube instructions (as linked). BTW, Mercaptan is no longer all they use for skunkification, long years, already.

[1] An HAVAC tech of my acquaintance had converted his GMC 350 V8 service truck to CNG as dual-fuel with gasoline.

UNlike dirt-common LPG (Propane or Butane) as is commonly sued for portable generators, OR mains-supplied natural gas NOT compressed, there was only ONE fill-point for CNG (Methane, mostly) in the DC Metro area back about 12 or 15 years ago.
 
City transit been doing CNG for years so nothing special.

Did observe a Tesla 18 wheeler along i5 in kettleman city charging station the other day.

Slick looking rig.

Sent from my SAMSUNG-SM-G930A using Tapatalk
 
Crowley Maritime in Jacksonville has recently started using their newest ship that runs on CNG and stated that it can run on conventional fuel.They have another in the works.
There is a new CNG plant on the westside and a storage facility by the port.I suppose that the CNG industry is expecting a boom in usage.
In the past year 4 m/sq ft + of warehousing is being built in the park our plant is in.
I'm guessing everyone is expecting a lot of growth when the river is deepened for the new container ships.There are 18k 20ft container
ships afloat now and talk of 20k unit ones being built.That will require a heck of a lot of trains and semis(maybe CNG powered?).So maybe it is all connected somehow.
 
Thee months ago, I purchased an almost NEW Cummins 8.3 litre CNG engine that was used as a training engine for Puget Sound transit in buses. Built in 2002. I bought it as I can no longer drive my over twenty year old Freightliner truck into California. Figured I'd convert my Diesel truck into a CNG. BUT there's not ONE station in the Portland, Oregon area where you can fill up a truck. Add to that the storage tanks for CNG have a twenty year lifespan, and I'm looking at almost 30K for tanks, and I decided this just wasn't viable. It IS a Diesel engine with spark plugs. Haven't found any manuals on it yet. Very little information available on it.

It runs and sounds like a big gas engine. Exhaust smells like my propane forklift. In the 25 minutes I ran the engine on a test stand, the fuel storage tank went from 2000 pounds of pressure to 700 pounds. I don't think this is a viable alternative for any long haul trucking. Two stations in southern Oregon, then a three hundred mile gap before the next one in California. Run out of fuel- you're toast.

So I'm thinking of CONVERTING it back to a diesel. I really like the Cummins 8.3 litre engines! I was REALLY excited at first, but reality sucks.
 
The City Council bus fleet here were being changed over to CNG,think they may have had 1000 gas busses......however after a number of tank explosions,they have quietly dropped the big enviro speak,and gone back to diesel buses exclusively.The price of CNG has risen exponentially here due to export markets seeking green fuel,and is a source of considerable political disturbance ,due to its influence on electricity costs..(and retic.gas cost)
 
NZ had a functioning CNG system for light vehicles during the late 70's and early 80s. Cars were converted with a mild subsidy to dual fuel, these were standard cars albeit leaded fuel cars, so compression ratios of 10:1 to 12:1 at very most. CNG stations drew gas from the main and compressed it for transfer.
It did work, but CNG produces best power at high compression so vehicles were underpowered.

There was also a trial system of diesel trucks which used diesel and CNG together to achieve better economy and power, effectively using the diesel autoignition to ignite the natural gas.
 
There is still some work being done here to recover the compression work by expanding the gas thru two stages to drive auxillaries and refrigeration plant on B double trucks,with about 1/2 of the A trailer taken up by the gas tank to allow depot to depot interstate running.....Paccar were paying for at least some of it,a couple of years ago,but the high gas price and shortages are issues......its pretty ridiculous the we are one of the biggest gas exporters ,but there is no gas for domestic use,due to multinationals having tied up all the gas in preproduction deals.............Another strange fact.....no government can touch the gas deal,yet the same governments have no problem stealing landowners rights without compensation when it suits them.
 
Frito Lay near me has been switching to interesting semi trucks. They will be trying 15 tesla semi trucks and I think tesla forklifts?
They have some big semi trucks running on compressed natural gas. I could not finds any good information are these diesel engines or spark ignition engines? I know some are Volvo trucks.
Bil lD

CNG engines are spark engines, just like LPG. The only difference is the fuel/air induction system. Any given hydrocarbon fueled engine will make the relatively same power with any of the fuel types when measuring pounds of fuel consumed per horsepower/hour. The stoichiometry of all the fuels is about the same, roughly 15 parts air to 1 part fuel by weight. The real differences is all about energy density by volume and partial throttle efficiency. This is where diesel engines rein supreme, as there are no need for air controls. All the other lighter fuel types must maintain the correct fuel/air ratio to burn correctly without damaging the engine. Once the engine is forced to run under a vacuum is when the efficiency falls off. The down side to diesel is higher Nitrogen Oxide emissions when running at partial throttle due to excessive air and high combustion temperatures.
 
The City Council bus fleet here were being changed over to CNG,think they may have had 1000 gas busses......however after a number of tank explosions,they have quietly dropped the big enviro speak,and gone back to diesel buses exclusively.The price of CNG has risen exponentially here due to export markets seeking green fuel,and is a source of considerable political disturbance ,due to its influence on electricity costs..(and retic.gas cost)

The public Transit buses in the Whistler, BC area are CNG powered.

No local source for their environmentally friendly fuel, so they truck it out from Quebec, pretty much on the other side of the continent.

Makes perfect sense to me....Gotta be keeping up the house payments for at least a couple long haul truckers.

Have not heard of tank explosions. Yet.
 
Tank explosions are probably VERY rare, as the tanks are probably many times stronger than the vehicle. BUT, CNG tanks are designed to hold 3500 pounds of pressure.
My tank is carbon fiber. Since they DO hold so much pressure, they have a life span of twenty years. A person CAN get a compressor and actually fill their vehicles up at home using natural gas supplied. BUT the compressor at this point is not readily available, and pretty expensive. It's also very slow since it's compressing a two pound pressure up to 3500 pounds.Considering the litigious society we seem to live in, I can see why a company WOULDN'T want to manufacture these in America.

CNG would work for a local hauler, where their vehicles DON'T go long distances, and they have economy of scale. For a ONE truck business, I think it doesn't pencil out. I bought my engine because CNG engined vehicles are exempt from the California Air Resources Board rules. At this point I should just buy a Prevost Bus and just call myself an RV. A forty five foot diesel powered bus can pull a twenty foot trailer and just WAVE at weighmasters at the scales.
 
Around here after the Marcellus boom hit, some of the well tenders
are driving CNG pick up trucks.

They use an army surplus scuba compressor, driven with an engine
running off NG right at the well, IIRC they are Davey 5 stage units.

As far as 2Psi, most wells around here have a tap at around 150 psi
coming off the little joe.
 
Starting in the mid 90s, the Argentine government decided to encourage the use of locally produced natural gas. They actually have almost 2 million cng vehicles now in Argentina, including all 40,000 or so taxi cabs in Buenos Aires. There are CNG only gas stations thru out the metropolitan area. They banned any gas or diesel taxis in the city limits about a dozen years ago.
The reason this works is local CNG, sold by the big national oil and gas company, to a chain of gas stations, density, and government regulation.
You need a certain scale of adoption before it makes sense. Although there are CNG cars and trucks thruout the nation, most are within a few hundred miles of the capital, which is probably where 80% of the CNG vehicles are used. Plus, the daily distances are low. Most are taxis, or in city deliver vans and, soon, buses.

It cant be very expensive or hard to switch over, as taxi drivers there are notoriously cheap.
Before the changeover, most of the cabs were old Peugeot diesel 504s, and they put out copious clouds of black smoke. The city is much happier with the CNG cabs.

Scania Argentina unveils CNG bus, it will operate soon in Buenos Aires | NGV Journal
 








 
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