CNG Vehicle in Perth, bit of an update

[Mike (Perth, Western Australia)]

Hi Bill (and copy to EFI list for comment),

Further to my last email, spoke to local tech at local gas company (govt
owned at moment - plan to privatise soon) - thanks to DR :)

Now this is interesting :)

The ford they run is a six cylinder, (4.2L?) and runs the *same* fuel rail
as the original petrol variant. The additions are:-

a.	Injectors are high flow methanol units supplied by Bosch, I
	will try to get a part number. Note: They operate at 200KPa
	fuel rail pressure and the fuel rail is only dense gas (methane
	mostly) at that pressure.

b.	Standard ECU was reprogrammed to take the larger injectors other
	controls are unchanged - AFAIK - but will check.

c.	There's no fuel pump, high or low pressure, though might still be
	in the vehicle... Not sure if there's a safety run/stop solenoid
	valve.

d.	Two stage pressure regulator, drops from tank 20MegaPascals to
	the 200KPa used by the injectors.

e.	Regulator is plumbed with hot water from cooling system as the
	methane has a small amount of water (hope there's no hydrates)
	when it comes from the refinery. Nothing to worry about its just
	that its enough to ice up the regulator on higher flows...And I
	suppose a single stage 20MPa to 200KPa might not be so stable ?

f.	Injectors only work for 60,000 Kms before failing. Reason suggested
	by Ford is that they are designed for fluid with that cushioning
	effect - running dense gas makes them wear and fatigue more.

g.	Vehicle doesn't have dual fuel capability, injection system being
	tuned/setup/fixed only for CNG.

h.	Not sure of size of tank, will check out later this week if at all
	possible, I udnerstand wall thickness is 1/2" though and *HEeaVY*.

There is some suggestion that a suitable solvent could be found for methane
in a storage format similar to acetylene tanks (Acetone I think, or is this
just acetone to wet the catalyst the acetylene sits on in the tank) ?

Comments ?



Rgds


Mike Massen

Ancient Sufi saying:
        "Should your God save you from adversity, choose another God"

Pictures of site installation at Mendulong near Sipitang, Sabah (Malaysia) for
container based RAPS...   http://www.wantree.com.au/~erazmus

Vehicle modifications on GMH Turbo, twin tyres, possible 175Kw at wheels
Preliminary pictures at http://www.wantree.com.au/~erazmus/Twin_tyre_vehicle/

My editorial on twin-tyre opinion and good reference about tyres:-
http://www.geocities.com/MotorCity/2195/ttyreopinion.html

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