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GMP Cricket |
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GMP Cricket |
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Motor drive assembly |
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A new .25 cubic inch two stroke engine was the chosen power plant. Modern engines often have the mixture control behind the cylinder head for safety reasons on fixed wing models. On the Cricket the radio tray is close to the back of the engine and did not provide enough room for the mixture control. Both the carburettor and the back plate were sourced from an old .28 cubic inch engine. The picture shows the new engine, note the highly polished restored carburettor and an old (discoloured) back plate. |
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To gain familiarity with the engine prior to installation it was mounted on a test stand and operated for about an hour to run in. |
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It is important to align the clutch and flywheel as accurately as possible. Note the lack of a cooling fan on this model. It was designed so that the cylinder head derived its cooling from the main rotor wash. The primary belt is still in production today by a power tools manufacturer, please email john_neasham@hotmail.com for details. |
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Once the clutch assembly was complete it was ready for installation onto the chassis. Additional cooling for the engine is provided by the use of aluminium engine mounts that were designed to draw the heat away from the engine. |
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The standard aircraft muffler with a baffle was the traditional exhaust. |
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To maintain fuel hygiene a new tank was used with three pipes, one for the fuel clunk to the engine, another for the pressure coming off the exhaust and one for filling. |
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To prevent the engine bolts from rubbing against the fuel tank and potentially creating a leak a small foam block was placed between the tank and the chassis. |
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Webmaster: John Neasham |
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