0n the subject of cooling I have fitted a perforated aluminium rear floor in the powerdrive with foot wide air intake scoops ,I have also used a turbo type heater blower to cylinder 2 to aid cooling when stationary to hopefully deal with the lack of cooling
Going on memory I recall the engine having an installation with vanes directing air from the side scoop to the engine which had a casing, cast ali?, over it to keep the air from spilling away from the fins. I think this was based on the marine version of the engine.
Cannot comment myself, but those I respect who have used both engines with understanding say the Anzani is superior to the Excelsior in many ways.
With these enclosed engines it is important to have the air easy access to the ducting. It then needs an air tight duct of slowly reducing diameter to increase the spead of the air to that which is efficient in removing the heat in a timely manor from the fins. The exhausted hot air needs a low pressure area of exterior bodywork to exit efficiently and not to be sucked back into, or under the car. While air is a gas it can be predicted by fluid dynamics. As the air increases in speed it will pull more in behind it like a syphon. On exiting the hot engine it will have expanded so will need a little more room.
This any new holes, ducting or other mods needs to take these principles into account. It is easy to make a port on the assumption it is introducing more air, when in fact it is upsetting a pre planned system and preventing air flow. A classic few examples from Goggo land.
Example 1 Export Goggo saloons had rear quarter light windows. It was found that with these open the pressure wave formed pushed air away from the side vents in the body and the cars overheated.
Example 2 The Goggo engine is sealed horizontally in its bay. Cold air comes in the top. It goes into the carb and blower. The blower blows it over the cylinders forwards to exit in front of the ducted blower, and away with the hot exhaust. Remove the rubber seals and the car will get a bit hot, reducing performance. Remove the blower duct, as in perhaps a quarter of Goggos I have seen at rallies, and you will have a car living on hot air in its carb, thus a weak mixture, and unable to cool itself as it is breathing its own preheated cooling air. These cars tend to knock out piston 2, as it overheats more. Another dead Goggo.
So you need to know why you have made any new holes in a car for cooling. Watch for any evidence of overheating, either way. Maplin sell thermocouple heat sensors for very little. A great investment. It might be noted that over hot clutches tend to slip, as do low fluid oil bath wet clutchs.
Have you checked your clutch push rod? It is not uncommon for this rod to bell up and thus be incapable of relaxing its position. In effect the clutch is left half on. Many Albion users put a ball bearing in the end to take up the load on a hard bit off metal.
