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Cooling system for inline twin cylinder

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Cooling system for inline twin cylinder

Old 11-30-2021, 05:17 PM
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BirdDog1E
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Default Cooling system for inline twin cylinder

Hello to everyone,
I have to make an air conveyor inside the cowling of my model where I have mounted a two-cylinder inline gas engine ZDZ 210cc.
Kindly, can you give me some advice on how to build it?
I was thinking of fixing it to the engine body, because if I need it, in case of problems, anyway I can remove the cowling?
It has a single hole of about 1.57in of diameter just below the propeller hub.
I have already been advised to build a cone type Venturi, starting from the hole and making a box internally around the two engine heads, also closing the space between the cooling fins of the heads as much as possible to send as much air as possible direclty on them.
I thank anyone who gives me some information or advices and maybe any pictures too.

Last edited by BirdDog1E; 11-30-2021 at 05:27 PM.
Old 12-01-2021, 08:43 AM
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the secret to cooling an inline engine is too have the entry air come in one side of the cowl and exit through the two cylinders to the other side of the cowl, The air has to go through the fins, not around them. It was found in the early 30's that any air more than 1/4 inch away from the fins does 0% cooling so baffles are a must. Your outlet should be at least 4 times the area of your inlet to efficiently let the air expand as it heats up.


Old 12-01-2021, 04:42 PM
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BirdDog1E
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You're right Larry.
Now I understand. My cylinders are in vertical and upside down but the rule will be the same. I convoy the air on the opposite side, the exhausts on the heads and let it out on the other side. Basically I have to build a pressure chamber from a side around the heads and push the air through the fins. I have about one inch and half in diameter of opening on the cowl and just inside it, I apply a rubber seal around the hole connecting it to the chamber to keep in pressure the air pushing it to cool toward the heads of the engine, sending out the air from the opposite side.
Old 12-01-2021, 04:42 PM
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BirdDog1E
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You're right Larry.
Now I understand. My cylinders are in vertical and upside down but the rule will be the same. I convoy the air on the opposite side, the exhausts on the heads and let it out on the other side. Basically I have to build a pressure chamber from a side around the heads and push the air through the fins. I have about one inch and half in diameter of opening on the cowl and just inside it, I apply a rubber seal around the hole connecting it to the chamber to keep in pressure the air pushing it to cool toward the heads of the engine, sending out the air from the opposite side.

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