Pålidelighed og ydeevne er en af hovedårsagerne til succesen for LASER motorer. Detaljer i designet såsom det direkte brændstofflow fra karburatoren er med til at øge motorens præstationer og følger praksis på fuldstørrelse motorer. LASER motorer er designet til at give høj trækkraft og derved anvendelse af store propeller. Dette nedsætter støjniveuaet og forøger levetiden for motoren. Nitrometan er ikke nødvendigt for normalt brug, men vil væsentligt forøge motorens præstationer. Nitrometan er meget dyrt og hovedårsagen til rustdannelser inde i motoren. Oplysninger om trækkraft kan være meget misvisende, idet det er afhængige af mange faktorer, herunder indholdet af nitrometan og hastigheden hvor motoren opnår maksimalt trækkraft. LASER motorer lader konkurrenceresultater tale deres eget sprog og offentliggør derfor ikke oplysninger om trækkraft. I mange år har op til 50% af top-ti piloter ved verdensmesterskaberne i skalaflyvning anvendt LASER motorer, herunder har de udgjort trækkraften på adskillige modeller, der har vundet verdensmesterskabet. I England er de totalt dominerende. Normalt flyver samtlige deltagere ved de engelske nationale mesterskaber med LASER motorer. Det taler deres eget sprog. LASER motorer er designet til den seriøse pilot, der kræver kraft, pålidelighed og lang levetid. Motorerne anbefales at bruge brændstof med 15% olieindhold, helst fuldsyntetisk olie, da det nedsætter risikoen for at ventiler sætter sig fast og karburatoren stopper til. Der kan tilsættes op til 12% nitrometan for forøget ydeevne. Det fleste standardbrændstoffer giver tilfredsstillende ydelse. Jeg har i mange år selv anvendt 12% syntetisk olie (ML70) med et meget godt resultat. LASER motorerne er designet af Neil Tidey, der selv er en passioneret modelflyver, så LASER motorer er designet af modelflyvere til modelflyvere. Succeshistorien starter i England i 1983, hvor de første motorer blev lavet. Hurtigt spredte rygtet sig om en usædvanlig motor med stor trækkraft, pålidelighed og meget lavt støjniveau. Allerede få år efter var LASER motorer den dominerende kraftkilde for alle skalapiloter i England og også internationalt. Brian Taylor har i udstrakt grad brugt LASER motorer til sine modeller, hvilket også fremgår af hans byggetegninger.

Også deres to-cylindrede udgaver med Vee-placerede cylindre er blevet meget populære. LASER Vee Twins kører usædvanligt roligt, meget stærke og pålidelige. Vee-designet giver en perfekt balance og den synkrone tænding giver motoren en specielt og realistisk lyd. Den rolige motorgang giver få vibrationer og påvirkninger af din model og din elektronik, der resulterer i længere holdbarhed og lettere konstruktioner. Motorerne laves på fabrikken i England under anvendelse af højkvalitetsmaterialer og der anvendes den seneste teknologi inden for CNC fræsning og drejning. Hver motor er samlet i hånden og testkøres inden afsendelse. LASER motorer er dyrere end andre mærker, men langvarige fornøjelse ved at bruge disse motorer opvejer den kortsigtede økonomiske besparelse ved at vælge andre og billigere mærker. Her får du kvalitet for alle pengene.

SPECIFICATIONS Inclined OHV pushrod design operated from rear of engine. Wedge shaped cylinder with vertical plug. Twin camshafts. Hardened stainless steel valves. Separate replaceable valve guides. All valvegear is fully hardened steel. Twin piston rings for compression and oil control. Aluminium parts fully machined from solid internally and externally, polished or bead blasted finish.

LASER	70	80	100	120	150	160V	200v	240V	300v
Bore mm	27.7	27.7	27.7	33.5	33.5	27.7	27.7	33.5	33.5
Stroke mm	18.8	22.2	26.9	22.2	26.9	22.2	26.9	22.2	26.9
Weight grm	560	645	770	785	835	1050	1160	1160	1660
Propeller	12x8	14x7	15x8	15x8	16x8	16x8	18x6	14x14	20x8
Height from crankshaft
to cylinder head	84	92	100	93	101	92	100	93	101
Width between
engine bearers	35	40	45	45	45	Backplate mount on vees
Crankshaft thread	1/4x28unf	--------- ( M8) --------					M10	M8	M10
Engine built before 2002 will have unf crankshaft threads

FUEL 15% oil preferably full synthetic 85% methanol. Nitromethane may be added up to 12% for increased performance. Most standard commercial fuels will give satisfactory performance.

PLEASE PHONE IF YOU NEED ADVICE TO SELECT THE CORRECT ENGINE FOR YOUR MODEL

Power output is one of the key factors of the success of LASER ENGINES. Design features such as the straight gas flow from the carburetor improve performance and follow full size practice. They are designed to give high torque enabling large efficient propellers to be used reliably. This also reduces noise and increases the life of the engine. The NITROMETHANE is not needed for normal running but will significantly increase performance. Nitromethane is very expensive and the major cause of corrosion. Power figures can be highly misleading as they depend on many factors including nitromethane content in the fuel and the speed the engine achieves maximum power. Laser engines let competition results show performance and do not publish power figures. LASER ENGINES are designed for the serious modeler who demands power with reliability and an engine with exceptional life.

LASER-70 Exceptionally compact and light, similar height to other 48 - 52 4-stroke engines. Best power range 9-10,500rpm static. Ideal for sports aerobatic models and multi engine models. where power to size ratio and reliability are important.

LASER-80 similar height to other 65-70 4-strokes. Wide useful power range from 8-10,500rpm. A direct replacement for the very popular Laser 75 fitting the same mounting but giving greater power.

LASER-100 Long stroke engine giving huge torque at low speeds for large propellers. Useful power range 7,500-9,000rpm. Ideal for the larger scale model and exceptionally quiet at low propeller speeds.

LASER-120 Very compact engine shorter than any production 90 4-stroke engine. Not as powerful as other 120 4-stroke engines but will fit into small cowls. Useful power range 8-9,500rpm. Always use the LASER-150 if a 120 is called for.

LASER-150 Lighter and shorter than any 120 4-stroke but with more torque. Useful power range 8-9,500rpm. Our best selling engine, powerful, reliable, ideal for sport and scale models with proven international competition success.

LASER Vee Twins. The Vee twins are exceptionally smooth running very powerful and reliable. The Vee layout gives perfect primary balance and the offbeat firing gives the engine a distinctive and realistic sound. The smooth power of the Vee twin puts less vibration and stress into your model and radio gear resulting in longer life and lighter airframe structures.

LASER-160v A compact engine with a wide power band between 8-9,500rpm.

LASER-200v The most successful competition 4-stroke twin ever produced. Will fit easily into scale radial cowls and in Continental and Lycoming cowls. The engine gives best power between 8-9,000rpm.

LASER-240v Smaller but similar weight to the 200v the engine is designed for FAI aerobatics. The engine has the highest power/weight ratio of all Laser engines. Due to the small size it is essential that good cooling is arranged in the model, it is not as tolerant as the 200v.

LASER-300v Designed for the larger model, the 300v is the most powerful in the Laser range. Performance between 7,500 and 9,000rpm. it has excellent running qualities and will suit the new 12Kgs FAI rules.

All Laser engines are test run and the carburettor has been set. Slight adjustment may be necessary to suit your fuel and installation. The Laser engine does have some different characteristics to other engines and the following notes are the result of experience gained from the use of Laser engines in our own models and, more important those of other Laser owners. We want you to enjoy using your Laser and ensure reliable performance.

The carburettor and silencer for the single cylinder engines are packed separately to avoid damage.

The main needles are removed on the Vee Twins. They should be fitted 4 turns open for initial adjustment.

THE LASER DESIGN The design of the Laser engine followed an intensive study of all types of full size 4-stroke engines and model engines. Since the first Laser ran in 1983 the design has been refined with continuous development. New materials, processes and machining techniques have become available and improved the engine further.

For a model aircraft, the engine has to have a high power to weight ratio and be very reliable. Compact, especially from the front profile. It has to meet noise criteria which means a silencer has to be fitted. A silencer fitted externally would spoil the shape of a model so it has to fit behind the engine within the cowl. The carburettor also has to be within the cowl, again the only place is behind the engine.

All modern high performance engines have the carburettor in a straight line to the valve port, you can see this feature on any motor cycle engine. Air and fuel are different weights and if the mixture is forced round a bend, centrifugal forces affect the mixture and also reduce velocity. The carburettor on the Laser engine is fitted near the cylinder head to give a straight line to the port.

The carburettor size is conservative. This is a compromise between maximum power output and response to the throttle setting. Silencer pressure is not needed but the open tank vent should be faced forward to avoid a venturi effect over the vent. If it were left hanging from the cowl it could create a variable suction on the tank.

Silencer pressure is not needed with Laser engines. Pressure is used on many engines to increase power by increasing the size of the carburettor. Pressure reduces throttle response as pressure has to build up when the throttle is opened. It can be a source of fuel contamination as burnt oil can pass back into the silencer and adjustment to the main needle can be more critical. In the event of the pressure pipe coming off or fracturing, the engine would stop. A larger carburettor makes the needle setting more critical and reduces reliability.

The ?Wedge? shape combustion chamber is recognised for performance providing good air flow characteristics and large ?Squish? areas for efficient combustion and minimisation of detonation. This allows the Laser engine to run on zero or low nitromethane and have excellent fuel efficiency.

The valves are inclined to the rear of the engine reducing the height of the engine. Although more complicated as a separate drive has to be taken from the crankshaft, the rear pushrods have two major advantages. The maximum height of the cylinder head is further back following the profile of most aircraft cowls and there is less chance of damage in a crash.

Just like ?Full size? engines the Laser engine has separate valve guides. These are longer than the combined guide and seat fitted to model engines and give greater accuracy in seating the valve. With hardened valves wear is negligible but the guides can be replaced and the valve seats can be reground.

Cooling fins are machined integral with the aluminium cylinder barrel giving superior cooling and far less distortion than a separate liner and fins. Nickel Silicon Carbide is electro plated directly into the aluminium. This process is similar to the plating used on Formula 1 racing engines and car manufacturers such as Porsche, BMW and Jaguar. It is very expensive and should not be compared with electroless plating used on some engines which is less than one tenth of the thickness.

Long beams are machined onto the crankcase for extra strength and support. The cylinder head bolts fix direct to the crankcase giving more strength and rigidity. As the engine warms up the steel bolts tighten further against the expansion of the aluminium cylinder so it is impossible for a the cylinder head to come loose when the engine is running. This ?Fail safe? system is used on many full size engines, the Rolls Royce Merlin is an example.

A pinion drive is engaged with the crankshaft to drive the twin camshafts fitted at the rear of the engine. Flat headed cam followers are used to drive the pushrods and rockers. The camshaft profile is computer generated and like all performance engines there are two camshafts.

The crankshaft is made in one piece from nitride hardened high tensile steel supported in the front housing by two ball bearings. The bearings used are standard and can be obtained anywhere in the world. The propeller driver is secured with a taper collet so there cannot be any movement between the driver and the crankshaft which could loosen the propeller nut.

The basic layout of Laser engines has not changed from the original in 1983. New engines have been introduced and the design has been refined and developed as a continuous process. New materials and machining techniques have become available and introduced to production. Testing has always been essentially practical through bench development and extensive use in flying models. The ultimate purpose remains the same, simply to power model aircraft. We hope that you enjoy owning and using Laser engines for many years in the future.

RUNNING IN

Careful running in will ensure a powerful and reliable engine with a very long life. LUBRICATE as described. Run the engine for 15 to 30 minutes at varying speeds up to full power before flying. Do not allow the engine to overheat. Do not overload the engine with a large propeller. Check valve clearances and LUBRICATE. Run for 30 seconds at full power. If the engine maintains full power go and fly. Only use full throttle for short periods for the first hour running. Full performance and reliability will be achieved after a minimum of 3 hours running.

OILS, FUEL and general LUBRICATION

Laser engines do not demand special fuels.

The ideal fuel is: 85% Methanol 15% Synthetic oil.

Oil is essential to prevent excessive wear and seizure. It keeps the engine clean inside by removing particles created by normal running including by-products of combustion.

SYNTHETIC OIL will generally give better performance than castor oil as it does not produce carbon or lacquer. Used correctly, synthetic oil is preferred to castor but it will not withstand overheating and may not protect as well against corrosion. 1 - 2% Castor oil added to synthetic oil can give additional protection against corrosion and seizure. Make sure the engine is LUBRICATED as described below.

CASTOR OIL gives better protection against corrosion and overheating than synthetic oil but creates carbon that can clog the exhaust ports and silencer and a lacquer that can cause the valves to stick. An excessive build up on the piston and cylinder can cause overheating. It can burn on the outside of the engine and reduce cooling efficiency. LUBRICATE the rockers and through the breather nipple to lubricate the crankcase and bearings.

LUBRICATE through the BREATHER NIPPLE on the rear of the crancase before and after the initial running in and after every 3 hours running. Lubricate the engine if it is not to be used for some time and before running again. The breather nipple can be extended with tubing. Oil may come out of the front bearing if the breather is restricted, there is a lot of oil in the crankcase or the engine is left with the nose down. This will not harm the engine.

Methanol does not vaporize if the temperature is near freezing and the engine may not start. 5% Nitromethane or 5% petrol will improve starting in these conditions.

GLOW PLUGS

Most standard 2-stroke 'Hot' plugs work well. We use Super Tigre and Model Technics F5-7 but experiment with your favourite type first. O.S. and Enya 4-stroke plugs work well. The Fox Miracle plug and some others do not work with the Laser.

Make sure that the plug is in good condition, the element is bright and not distorted. Change if in doubt. Always use a separate glow battery for starting.

If the plug is faulty or not a suitable type the engine will not achieve or maintain full power or will miss fire. A faulty plug can cause detonation which may cause overheating or severely damage the engine.

VALVE CLEARANCE

Set valve clearance .002" - .004"      .05 - .1 mm.          Clearance will increase as the engine warms up. Check after every 3 hours running when you lubricate the engine. Clearance is not critical.

PROPELLERS and FUEL TANKS

Engine	70	80	100	120	150
Propeller	12x7	13x8	15x8	15x8	16x8
Fuel tank	7oz	8oz	9oz	11oz	12oz
	200ml	250ml	300ml	350ml	400ml
Vee twin	160	200	240	300
Propeller	15x8	16x8	16x12	20x8
Fuel tank	200ml x2	250ml x2	300ml x2	350ml x2

Only use glass reinforced plastic propellers. Propeller and tank sizes are a guide only. Experiment with propellers to suit the performance of your model. For maximum power run the 70 and 80 at 9-10,000rpm and the 100, 120 and 150 at 8-9,000rpm on the ground. Good makes of propeller do not need balancing unless damaged. Do not exceed propeller manufacturers speeds.

For general reliability the fuel tank should have an open vent, pressure is not necessary. Ensure that the open tank vent is facing forwards. If the vent is facing to the rear, side or down a vacuum may be created in the fuel tank which will cause erratic running or the engine to stop. The tank should be as near the engine as possible and on the centreline of the carburettor. Position is very important if the model is highly aerobatic.

If you prefer to use silencer pressure you may fit a pressure tapping on the silencer. Using silencer pressure will not overcome an incorrect tank position but can sometimes help. Contaminated oil can pass from the silencer to the fuel tank, pressure will be lost if oil blocks the connecting pipe and the engine will stop if the pipe is broken or destroyed by heat.

CARBURETTOR

The carburettor is a conventional twin needle type. Screwing in the needles leans the mixture. Once the main and slow running needles are set little adjustment should be necessary unless you change fuel type or there is a fault such as a blocked spraybar.

The main needle assembly can be removed for cleaning by undoing the hexagonal nut. The fuel nipple can be removed but do not attempt to remove the spraybar. If the screw holding the throttle barrel in position is removed it should be re-secured with 'Locktite'.

If an extension is needed on the main needle it should be made from 20 gauge piano wire soldered onto the existing needle. Brass tube or heavy extensions should not be used as they may case the needle to fracture or vibrate causing the mixture to vary.

STARTING THE ENGINE

The engine will  start easily if  it is at idle position and is well primed. Make sure that the model is fully restrained for safety.

Make sure the plugs are disconnected during priming and before running at full power. If the carburettor is accessible it can be primed by blocking the inlet with a finger and turning the engine over a few times. If the inlet is not accessible open the throttle fully and spin the engine over with an electric starter to prime the engine. The throttle should then be set to idle position and the glow plug connected for starting. If the carburettor is inaccessible fuel can be forced into the carburettor by blowing into the open vent of the tank using a piece of fuel tubing.

If silencer pressure is used the engine can be primed by placing a finger over the silencer and spinning the engine over. This will pressurise the fuel tank and force fuel into the carburettor.

FAULT FINDING and DISMANTLING

WARNING - Do not remove the backplate or the timing may be lost.

Most erratic running or reliability problems are caused by faulty glowplugs, fuel blockage in the spraybar or the tank vent not facing forwards. Check the glowplugs and replace if in doubt. Check power supply to the plugs. A supply from a 12v system often gives problems, always use a separate 1.2 - 2v supply to suit the glowplug used. Check fuel supply and clean the spraybars. Check tank vent position and fuel lines

Poor performance can be caused by a build up of carbon in the exhaust port or silencer if castor oil is used. The engine will sound very quiet if restricted. If the silencer is restricted by carbon it should be replaced.

Overheating is often caused by poor cowl design. Baffles should be fitted in the cowl if necessary like ?full size? engines to force cooling air through the fins on the cylinder and head.

The air outlet should be at least 1.5 x the area of the inlet. In some model designs the outlet is on the bottom of the cowl and actually faces forwards preventing air flow through the cowl. A lip should be formed on the leading edge of this type of outlet to give a venturi to extract the air from the cowl. The full size 'Pitts' has this arrangement. Overheating can also be caused by poor lubrication, running the engine lean, carbon build up, faulty glowplug causing pre-ignition or using a propeller that is too large and overloads the engine.

Overheating can seriously damage an engine, this is not covered by guarantee, do not allow your engine to overheat.

If the cylinder head bolts become loose this is a positive symptom of overheating.

Lack of compression can be caused by lacquer build-up on the exhaust valve if castor oil is used, causing it to stick, or dirt on the valve seat. The engine can often be started with an electric starter which may cure the problem if it is through dirt. Check valve leakage by putting a finger over the exhaust outlet and turning the engine over. If you feel slight pressure then the valve is leaking, Repeat with the inlet.

If the problem persists the valve must be removed and cleaned. When removing the valves work with the cylinder head in a polythene bag. This will contain the springs, collets and retainers. Mark all the components so that they are replaced in exactly the same position. The rocker shaft is retained by the special screw that also holds the rocker cover. The valves are released by compressing the springs and releasing the collets just like a full size engine. Use a nylon scouring pad to clean the valves and seats. Do not use grinding paste as this is likely to get into the valve guides and cause severe wear. Reassemble using plenty of 2-stroke motor oil. Never dismantle unless necessary..

The backplate fitted to single cylinder engines can be removed provided the cam followers are in position as they will hold the cams. If the cams are removed they can be reset so the inlet valve starts opening at approximately 40⁰ before top dead centre (TDC) and the exhaust closes at 30⁰ after TDC. There are no markings on the cams for timing.

Do not dismantle the engine unless absolutely necessary. Always tighten screws in sequence, head bolts 1,3,5,2,4, and front housing and backplate 1,3,2,4.

Occasionally check the head bolts and the bolts holding the front housing.

Vibration on single cylinder engines can be affected by the engine mounting. We suggest a Glass filled nylon engine mount which will give slight flexibility. The mount may be cut into two halves to suit the width of the crankcase. Metal mounts are not recommended. You will have to experiment if soft mounts are used, they can create more vibration and cause the engine to shake. Good quality propellers should not need balancing unless damaged. An out of balance propeller may cause vibration and it is possible that vibration may occur at certain speeds due to harmonics set up with your engine mount, model and propeller. Vibration may be reduced by rotating the propeller through 180⁰ or changing or balancing. A faulty glow plug will also cause more vibration.

VEE TWINS Installation and setting carburettors.

Laser Vee Twins are designed to be mounted direct to the firewall. They are much smoother running than single cylinder engines. Each cylinder should be considered as a separate engine and a separate fuel tank should be used for each cylinder. If a single tank is used it should have two ?clunks? so the fuel feeds are not connected.

The carburettors must be carefully synchronised to close together. It is very important that each carburettor has the same amount of opening at idle position. The barrels can be closed onto a piece of copper wire used as a gauge to check the positions.

When you receive the engine the main needles are removed to avoid damage, they should be fitted about 4 turns open. The engine has been test run and the slow running needles will be set. Slight adjustment may be necessary to suit your installation and fuel.

Start the engine at idle position and allow to warm up. Open up to full power and tune one carburettor for maximum speed. Next adjust the second carburettor. Re-adjust the first carburettor and then re-adjust the second. If a cowl is fitted to the model the needles must be adjustable from the outside as airflow through a cowl will often affect the settings of the main needles. The cowl will not affect the settings of the slow running needles.

The same procedure is used for adjustment to the slow running needles. Adjusting one carburettor will affect the other.

Vælg antal: