INTERNAL COMBUSTION ENGINES.

This invention relates generally to lubrication/ cleaning of internal combustion engines in automotive, forklift, boating, agriculture or stationary engines

(generators/pumps etc) and relates in particular to upper cylinder lubrication/cleaning of internal combustion engines running on LPG (liquified petroleum gas) or CNG (compressed natural gas) fuels. Automotive petrol engines are not necessary designed for gas operation and problems develop when such engines are converted from petrol to gas operation. Problems are: Higher oil consumption due to the fact, that gas does not have the cooling properties of petrol and generates higher combustion temperatures whereby an engine runs hotter, hence more oil

(sump oil) is drawn down inlet valves and past piston rings.

In addition, LPG (liquified petroleum gas) normally contains wear-inducing olefins (unsaturated hydro-carbons) and as a result, ash deposits plus oxides from break down of oil and gas components accumulate in the upper cylinder region

(valves, valve seats, piston rings) . Additional problems are: exhaust valve and seat recession due to the fact, that unlike petrol, gas fuel lacks any additives to lubricate and clean valve faces, valve seats and upper piston rings. Most modern engine oils (sump oils) contain additives such as calcium, barium and magnesium compounds which remain in the ash (carbon built-up) as abrasive oxides when the oil is burnt. Due to higher combustion temperatures of gas, lack of lubrication, increase of ash and oxides, adds to the wear of exhaust valves and valve seats to such an extent, that there is a danger that valves do not close any more (burn¬ out) . Unburnt fuel escaping through these valves can burn¬ out catalytic converters (if fitted) by the temperature increase. The deposits on inlet valves can severely restrict the flow of air/gas mixture plus unburnt fuel escaping through exhaust valves will degrade the performance of the engine. In addition, premature upper cylinder failure often

occurs due to the absence of any lubrication.

It is an object of this invention to provide a device for upper cylinder lubrication/cleaning for internal combustion engines fuelled by LPG (liquid petroleum gas) or CNG (compressed natural gas) .

According to one aspect of the invention there is provided an in-line, upper cylinder lubrication/cleaning device for internal combustion engines run on gas fuels, also suitable for leaded/unleaded petrol or diesel fuel. The device comprising a lubricant/cleaner reservoir container with a refuelling opening at the top, closeable by an air- vented cap, a lubricant/cleaner supply line tube with one inlet end thereof fluidly connected to the reservoir container via a sight glass and the other end or outlet delivery end thereof adapted to be connected to a suitable vacuum port of the inlet manifold leading to the upper cylinder region of an internal combustion engine, lubricant/cleaner supply flowmeans being interposedbetween the inlet and outlet ends of the tube, whereby when an internal combustion engine to which the device is connected is operating, engine suction causes a vacuum in the device whereby lubricant/cleaner enters the upper cylinder region of the said engine. Preferably, an inlet end of the lubricant/cleaner supply line to the engine is adapted to be immersed in the lubricant/cleaner within the reservoir container just above the bottom thereof and the outlet delivery end thereof is connected to a vacuum port of the inlet manifold of a gas- fuelled, internal combustion engine and a transparent sight glass with lubricant/cleaner inlet and outlet is interposed between the reservoir container and a vacuum port of the inlet manifold of an internal combustion, gas-fuelled engine. Preferably, the device is at least a semi¬ automatic lubricant/cleaner metering supply device where an adjustable metering means is provided to vary the flow rate

or amount of lubricant/cleaner from the reservoir to the engine and more preferable the metering means provides an intermittent flow of upper cylinder lubricant/cleaner for LPG or CNG gas-fuelled, internal combustion engine. In a preferred form of the invention, the manually adjustable andpre-setable upper cylinder lubricant metering means is in the form of a needle interposed in a lubricant/cleaner flow line between the transparent sight glass and the lubricant/cleaner reservoir container, the sight glass being interposed in the lubricant/cleaner flow line between the needle valve and an intake end of a lubricant delivery line to a vacuum port of the inlet manifold fitted to an internal combustion engine; the needle valve is accessible from outside of the lubricant/cleaner reservoir container and the intermittent flow of upper cylinder lubricant/cleaner is in the form droplets supplied from the needle valve into the sight glass.

A non-limitative example of a practical arrangement of the invention will now be described with reference to the accompanying drawings in which:

Figure 1 is a sectional, elevational view of the upper cylinder lubrication/cleaner device according to the invention.

Figure 2 is a partial view similar to Figure 1 on an enlarged scale.

Referring to the drawings and first of all to Figure 1 there is shown an upper cylinder lubricating/cleaning device for delivering lubricant/cleaner into an LPG (liquified petroleum gas) or CNG (compressed natural gas) stream for lubricating and cleaning of an automotive internal combustion engine, the device includes a reservoir container 10 which can be square, cylindrical or of any suitable shape and manufactured of any oil- resistant, solid, transparent or translucent material for example glass, metal, synthetic polymeric thermo-plastics or resin material such as polyethylene. The reservoir container 10 has a beaded rim 10a and a shoulder portion 10b

and is provided with a refilling opening closeable by a cap 11 which has internal integral circular flanges comprising axial flange 11a and radial flange lib. The cap has an external skirting portion lie and an air vent which is preferable in the form of an open-celled, porous plastic vent plug (12) in an aperture extending through the top of the cap to prevent the container collapsing under vacuum from engine suction when the device is in operation and connected to a vacuum port of the manifold of an internal combustion engine when the engine is operating. The container 10 is adapted to hold a special liquid upper cylinder lubricant/cleaner designated by "L" in Figure 2 of the drawing. The reservoir container 10 has mounted therein a flexible or fixed siphon or lubricant/cleaner intake tube 13 the bottom end of which is suspended a short distance above the container bottom, the upper end of the tube 13 is attached to a longer leg of a tubular brass (or other suitable material) connector T-piece 14 at an externally- threaded inner end 15 thereof. When installed, a major part of the T-piece is adapted to project through the wall of the container via a hole 16 formed or drilled in the container wall between the rim 10a of the container neck and the shoulder portion 10b. The externally threaded inner end 15 of the T-piece 14 is clamped to the interior surface of the container wall by means of a nut 17 and sealing washer 18 and when the nut is screwed tight against the interior surface of the container wall, the T-piece is also held firm against the external surface of the container wall and hole surround by means of the external integral flange 19. An external sealing washer is also preferable provided to lie against the exterior surface of the container wall. The outer and shorter leg of the brass T-piece 14 is provided with an internal screw thread and is fitted with a rotable and manually-adjustable, screw-threaded, cross-headed, tapered needle valve screw 20, preferably of brass. A tight diameter silicon rubber sleeve 21 which is mounted on the internally threaded outer and shorter leg of the T-piece 14

provides a vacuum seal and locks the needle valve screw 20. The needle valve screw is adapted to be turned by a screw driver to increase or decrease the gap for the lubricant flow down into the right-angled lubricant delivery leg 22 of the T-piece, is external to the container and has a transparent sight glass 23 mounted thereof by means of the bung 24. The bottom end of the sight glass 23 is mounted upon a tubular brass connector piece 25 by means of the bung 26 and a manifold supply line flexible tube 27 is mounted upon a connector T-piece 14 and which forms a lubricant/cleaner outlet from the sight glass chamber and into the flexible supply line tube 27. It will be observed that when it is installed in-line interposed between the lubricant/cleaner reservoir container 10 and a vacuum port of the engine manifold, the sight glass vessel or tube forms a liquid flow interruption within the lubricant/cleaner supply tubing but forms a suction/vacuum chamber when connected to an engine and this feature in conjunction with the manually adjustable needle valve 20 is designed to produce a visible flow of lubricant/cleaner droplets, such as the one labelled 28, of adjustable flow rate through the sight glass vacuum chamber and thence into the vacuum port of the inlet manifold of an internal combustion engine to enter the upper cylinder region of an internal combustion,gas-fuelled engine entrained in the air/gas stream to mix with combustion air/gas mixture but with a residual amount of lubricant/cleaner remaining after combustion as an upper cylinder lubricant/cleaner when the flexible supply line tube 27 is connected to a vacuum port of the inlet manifold. Upper Cylinder lubricant/cleaner is thus delivered continuously and automatically in the form of droplets into an LPG or CNG air/gas stream or vapour stream or of other "unlubricated" fuels such as petrol or diesel entering an internal combustion engine by engine suction whenever an engine to which the device has been fitted is operating due to the vacuum created in the inlet manifold. Once the engine stops the lubricant/cleaner flow

cuts off automatically.

Although the invention has been described by way of example as applicable to an engine fuelled by LPG (liquified petroleum gas) or CNG (compressed natural gas) stream, the invention may also be useful for use with other fuels for internal combustion engines such as methanol, petrol or diesel engines.

The upper cylinder lubricant/cleaner reservoir container 10 for the upper cylinder lubrication/cleaner device of the invention can be mounted at any suitable location under the bonnet of an automobile or truck such as the fire wall or mudguard, body panels or any other suitable location by using a suitable cradling bracket with bottom support such as that is used to mount windscreen wash liquid reservoir or radiator coolant reservoir.

In operation with the upper cylinder lubricating/cleaner device of this invention connected to a vacuum port of the inlet manifold of a gas, methanol, petrol, diesel or any other suitable fuelled internal combustion engine, once the engine is in operation there is a vacuum created within the lubricant supply tube and this within the sight glass and upper cylinder lubricant/cleaner is sucked up from the lubricant/cleaner reservoir container via the adjustable needle valve from the reservoir and into the sight glass vessel or tube and then into a vacuum port of the inlet manifold. The lubricator/cleaner flow (drops per minute) is viable and fully adjustable to suit various motor sizes. Once the engine stops there is no vacuum and the upper cylinder lubricant/cleaner flow then stops. A film of lubricant/cleaner adheres to the upper cylinder and valve surfaces and is not completely burned off during ignition thereby remaining to protect critical surface.