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[ V8 Engine Fitting Information ] [ Rover 3.5, 3.9, 4.2 to 4.6 Conversion ] [ LPG Conversion details ] [ Fuel Injection Section ]
[ Weber 500 & SU Carbs ] [ Mallory Ignition Systems ] [ General Engine Problems ] [ General Information ]

{short description of image}   . Front end kits The best for the V8. (Electronics)
. Vaporizers most suited for Rover V8.
. Specialist Systems Weber carb.
. Specialist Parts V8 applications

Front end kits (electronics) and Mixer.

Including: Emissions feedback loop, Principal of Computed & reactive LPG Fuel supply to engine management (Lambda and throttle position sensor driven).

The Lambda (In your exhaust) acts as a lean/over-rich sensor, and sends appropriate voltages to the LPG ECU to be computed, along with throttle position and reaction information from the throttle position sensor (TPS). We prefer to add an additional one as we find it difficult to rely upon the original aged ones.

Sorry no picture available as yet.
{short description of image} Emulators are there to trick the vehicle's original ECU (EFi Models only) into thinking it is still firing the injectors. It also prevents the ECU from getting upset and going into default.
LPG computer ECU (making the appropriate calculations). Whilst reliable info from the Lambda and TPS may be assumed, the accuracy of the ECU software brand means its (broad range) calculating abilities may be an issue. Some software types allow quite a range of adjustments to allow for large variations in vehicle type and use (as ours does), and others just rely on the 'Right for one, Right for all' way of thinking. This is why we have called to issue some of the most popular systems in favour of one that we now have fuller control of. {short description of image}
{short description of image} A. Mixer
B. Stepper motor
C. Emulators

In-line stepper motor (the slave device restricting or de-restricting LPG flow to the engine) Lambda TPS & ECU loop ) Quite simply, a restricting / de-restricting device (stepper motor driven) in the LPG fuel delivery line controlled by the LPG ECU, that is in turn provided with information from the TPS and Lambda probe. It is normally possible to adjust the base setting of these devices.

Throttle Pot Sensor (measuring throttle position and reaction), sited on the plenum chamber is a std. Rover fitment. Along with the Lambda sensor above, the 'TPS' sends information to the LPG ECU, which in turn makes appropriate calculations on engine emission values, so that the stepper motor can restrict or de-restrict LPG flow to the engine.

Sorry no picture just yet.


Basic Principal of LPG Fuel supply to engine (vaporizer).

The vaporizer works by having 'equal' atmospheric pressure on either side of it, one side being the feed pipe to the mixer (the bit on your intake) and the other side being a hole in the back of the vaporizer body. If you look, you can see and even touch the diaphragm. It only needs tiny changes in pressure to affect it (touch or air pressure). It's actually the same in principal as a demand valve worn by Divers.

How it delivers. Engine induction pressure rises on one side only ( the mixer side) and causes more LPG flow through it. That's basically how it meters the fuel at engine start up, idle and as RPM increases).

{short description of image} Mounting the vaporizer (A), in this instance to a Discovery. Make sure it is firmly bolted and is not in the path of fan wash (air pressure generated by the coolant fans), otherwise it may fail to operate effectively.
Connecting the water cooling pipes (A&B) to the vaporizer. They are essential to maintain operational temperature in the Vaporizer {short description of image}

Possible over-sight problems; If unit is assumed to be in good working order while set up with the vehicle static in a workshop, it's not unknown for it to be mounted in a position where, under-bonnet air flow or air pressure (affected by coolant fans etc) will cause the diaphragm to work in a biased fashion due to the extra air pressure. Also affected when out on the road, and even as the bonnet is closed.

{short description of image} Here you can see the other end of the water pipes have been 'Teed' (A&B) into the available engine coolant hoses. It is important to make sure good coolant flow will still be achieved in the original system.
It is now possible to see that the vaporizer (B) is securely mounted well out of the way of fan wash, you can also see the 'emulators' (A) mounted in the most convenient spot on this model. {short description of image}

Specialist Systems

This Unique (and invisible) LPG active mixer for the Rover V8 up to 4.6 Litre, when using the Weber, Edelbrock or Holley 4-Barrel carb system.
Inside the filter

Shown with the lid off.

Active Mixer

Shown with the "Active Vacuum" control switch

This unique Active Mixer, offers the essential part-closed Air intake for LPG running, with automatic vacuum-operated plenum control for unrestricted air-flow, essential for petrol performance, all within the small profile 12in air filter unit.

{short description of image} Active Mixer for LPG with Weber and Holley 4 barrel carbs
(up to 500cfm)
Top view of this unique Mixer. {short description of image}
{short description of image} We don't need this one :-)

Side view of the bigger Chevy type system. You can see this would present some difficulty with bonnet clearance issues on UK spec. cars.

Specialist Parts

The problem with the Rover V8 EFi engines (mostly) pre-1990 (flapper type) is easily resolved using our unique Flap opener. Controlled by a small vacuum pump (supplied but not shown) this device will automatically open the Air Meter flap, giving far better throttle response and alleviating the need to use a blow-back valve in line to protect from backfire.

{short description of image}

Why lose power & efficiency & risk great expense involving a new Air flow meter if ignored? (In some cases even a blow-back valve can't save it.) See below.

Blow back protection Blow back valve
Blow Back Valve

This nasty little device is the best most people can come up with to protect the air flow meter, you will see, above that we don't use it.

Don't forget to return to our main LPG Pages 'click'

links to other FAQ pages
[V8 Engine Fitting Information] [Rover 3.5, 3.9, 4.2 to 4.6 Conversion] [LPG Conversion details] [Fuel Injection Section]
[Weber 500 & SU Carbs] [Mallory Ignition Systems] [General Engine Problems] [General Information]

Prices do not include local EU.Tax.(VAT).
Prices & stock are subject to change without notice. Information and advice, as always, is free.

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