Convert 1991 560SEL to CNG?
 

I have been reading a lot about Compressed Natural Gas conversions. The price of CNG is much lower than 91 octane; might it be possible to convert a 1991 560SEL to CNG?

Propane conversions are common in Europe and with propane, you can run a dual fuel setup. There are kits which have tanks that are the same shape as spare wheel wells so that you don't lose any trunk space. I have a 75 Jaguar XJ12 that runs on propane. I'm thinking of converting it back because it's not a dual fuel setup. It has a huge regulator that bolts into the intake on each side which is how the propane is fed. Much like throttle body injection.

I think propane for car use (not barbecue) is about $2.90 / gallon.

Nat gas has a lower energy content than propane but the concept of conversion is similar. Propane is held in a liquid form to save space. Liquid propane is run through a vaporizer / converter that is heated by engine coolant, the vapor is then run to a negative pressure regulator. ( Think scuba regulator where gas only flows when you suck on the mouth piece.)

Dual gasoline / propane isn't a big deal, the gasoline system is left untouched and venturi / mixer is installed between the air filter and throttle body. If you want gasoline, the fuel pump is turned on , if propane , a solenoid valve is opened.

CNG is Compressed Natural Gas. It is stored at high pressure but remains as a gas. ( you would have to use high pressure and lowered temperatures to have a phase change. ) The concept of engine conversion is the same. There are some conversion / factory systems that use solenoid type gasoline fuel injectors.

LNG is Liquefied natural Gas, this offers the dense energy storage of propane.

Y'all Gots a N.G. line to the "House" ?
 

For H.W. or HVAC heat or a N.G. Stove/Oven ?

Once you "Finish" deciding which CNG vendor to use for the Chassis Parts...

You can install an Electric High Pressure Compressor on your N.G. line in the
Carport or Garage that will "Fill" the H.P. CNG tank on the W126 overnight.
AT AN AVERAGE COST OF $0.85 per gallon (When compared with Petrol)

The only drawback is the OUTRAGEOUS retail cost of the Compressor, $4-5 K.
[The compressor is Italian,there are others]
http://www.ebay.com/itm/Phill-by-FuelMaker-CNG-Compressor-Refueling-Station-for-the-Home-New-/140727015413?pt=Motors_Automotive_Tools&hash=item20c3fbd7f5&vxp=mtr

Mercedes actually offers an E200 N.G.V. in the E.U. ...

The compressor cost is hardly "outragous" considering I've just speced out a 2200 PSI 1 SCFM 1.5 HP compressor for a nitrogen generator system I'm engineering. The compressor is $ 18,000 and that only includes the compressor sans piping / controls.

I'm very interested in this too. I've had lots of cars on propane in europe and once i moved to US, everyone looks at me like a weirdo, when i mention natural gas cars.

The price of installation is pretty high here though. I could get one installed in eastern europe for about 1000 euro, and it had injectors in the intake. Would start on regular gas first, and once warmed up will switch to propane automatically. Savings were huge on gas.

Not sure why americans hate it. I have a 5.0 Engine in my CL500 and i barely touch the throttle to save gas. I'm definitely not using all 320hp of that engine. I think between 2000-3000rpm i'm only at about 200hp. Why not convert to gas and save money.
Plus in CA you get access to the Carpool lane if you have natural gas.

I'll follow this thread and watch how it goes. I've done it myself once and routing the copper lines is a *****. Everything else is pretty straight forward

Threads like these show up more and more, unfortunately, none of the ones i'm subscribed ended up with success.

Other things to remember is the engine will run colder on NatGas. And NatGas doesn't have the lubrication properties of regular gas, so you need to look into using other oils. They had special oils in europe for these applications (same price as normal oils)
Someone mentioned that there's less energy in NatGas. The Octane number is much higher, i think it's somewhere below 110 Octane.
The systems let you adjust the flow of gas so you can turn it down a bit and have equal consumption on both fuels.

I really dig the idea. Just not sure if it makes sense financially to get the installation at 5000$.

Can someone with good math skills, calculate, how much time it will take to recover the investment ?

Subscribed. Interesting stuff. Recovery time would be based on driving I would imagine. I drive a lot each week so I think I could recoup the 5k investment in 2-3 years. Assuming the car would achieve an equivalent 35 mpg or so. (I used my original calculations for buying my 300D @ 35 mpg).

To make it easier to calculate.. this is what i need to know ( to convince my wife)

Filling up the tank 26 gallons @ 4.4$ is about 120$
And it will go about 350 miles

How much would i have to pay for NatGas to go 350 miles ?


one more thing i remember.. the smell of gas from cheap installations :) God it smells like gas in the garage, interior of the car, under the hood. Equivalent of a poorly maintained diesel engine, but add the smell :)

Well you're getting about 13.5 MPG with that information. As best I've seen so far CNG will often get 2-4 MPG below the gas number. (I looked on fueleconomy.gov and went year by year under car type and looked at bi-fuel).

The nearest station to me was at $2.10/gallon.

So going with 9-11 mpg at $2.10/gallon you will go, 230 miles to 286 miles. Cost will be about $55 to fill 26 "gallons".

To do 350 miles, $66.81 to $81.60.

So your savings would be, ~$50/tank. So for this to pay itself off (at $5k investment)you'd have to do 100 tanks worth or 35,000 miles. Given the average per year is like 15-17k...about 2-3 years.

That's enough to convince my wife.
Is anyone having different numbers when it comes to the 5.0 mercedes engine? Or am i the only one damaging the enviroment?
Can't i just buy those magnets you put on the fuel hose and double my mileage? :)

Many, many, liquid gas cars in Australia.
The government was even paying a subsidy to install it on cars and buses.

There really needs to be an infrastructure to be able to support this type of fuel. There are many gas stations in Australia that retail liquid gas as well as petroleum fuels.

Older Mercedes models (Carburetor or K jet models) convert quite readily to a gas installation. The best installs are gas only - no hybrid. A liquid gas powered car will suffer in the economy area by a couple of miles per gallon.

Without the government subsidy, to make a conversion worthwhile you need to do more than 15,000 - 20,000 miles per year.

Liquid gas in Australia is around 60% of normal standard fuel cost.

As far as the environment goes, Liquid gas is supposed to burn more efficiently than normal fuel however the loss in MPG compensates for the emission issues.

You can buy new factory Ford and GM cars liquid gas powered in Australia.
All main city taxis run on liquid gas.

All gas equipment must be certified and installed by a certified installer - no backyard jobs. The tank and equipment must be installed by the roads authorities every few years.

The down side is that gas conversions are done by "liquid gas enthusiasts". The resale value of a liquid gas powered car is very much less than a normal fuel powered car. Depending on the model you may not be even able to sell it.

I would not be doing any liquid gas tinkering in a home environment. The expansion rate of LNG is nearly a thousand times more than TNT. I worked at an LNG plant in Asia. We had a couple of 125.000 tonne storage tanks. Someone calculated that if by some freak accident both tanks blew up, a circle 12kilometres in diameter would be obliterated.

So what's better, Compressed Gas or Propane ? (CNG or LPG)
I know i europe people were a little apprehensive about CNG. I think you need the tanks to be much stronger and weight much more. I remember my LPG cars had one big tank were CNG cars had a few small but very heavy tanks. CNG will blow much "louder" then LPG too.
Just not sure about the financial part of it.

S320L LPG/Propane conversion build thread - Benzworld.org - Mercedes-Benz Discussion Forum

Here's someone that installed the LPG in a W140. An S320 :)
Looks clean. The guy is in UK and there might be some regulations regarding the LPG there that a different from the US.

Has anyone had any experience with Home Made LPG installations in the US. We have Smog Checks in California and they are every 2 years. I don't mind pulling the Front Pressure regulator once very 2 years if that's the only option.

EDIT: google helped


"California regulations prohibit conversion of emission-controlled vehicles with retrofit systems to operate on alternative fuels, such LPG, unless the retrofit systems have been evaluated and certified by the Air Resources Board (ARB). Assuming your vehicle was converted using a retrofit system certified for that vehicle, you will need to contact the manufacturer (based on your email, it would be IMPCO) and request a label. I don't know whether it's common practice for manufacturers to re-issue labels (i.e. if fallen off after long use) and if they do, whether they would require inspection/documentation (i.e. sales receipt)."

Basically if it doesnt have a CARB sticker saying it is approved by ARB your not going to smog your vehicle. I have been trying to find a loop hole for a over a year. Im at the point of selling my propane set up.

Anyone has any experience with HHO ?
Is it worth it ?

Yes. No.

Although there is some guy who used to post over in the diesel section about how he gets over 50mpg in a homebuilt HHO unit ;) and 100mpg with an HHO motorcycle. YMMV. I've messed around with some setups before and while its cool and fun to tinker with, it doesn't really do anything. You're still using energy off of the alternator to produce the electricity to electrolyze the water which is a greater resistance on the engine anyway. Based on physics and chemistry (i.e. conservation of matter), it simply doesn't work.