"oilsardine" wrote in message
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"GTH" schrieb im Newsbeitrag
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So, unless you look for ultimate performance, you can do as you want.
BTW, where will the exhaust discharge ?

the exhaust will discharge down/aft. This may not pose an problem, because
I will use 114mm diameter air duct routing the pressurized air from
nose-bowl's inlet to the cylinder shroud. So hot and cold air will not be
mixed.

I would not think that that is a large enough diameter tubes for engine
cooling. Someone may have used that size and had it work OK, but I would be
surprised. I would think that you would need double that, or one tube for
each cylinder.

If you had that size intake, and no tubes, but instead an open plenum
pressurizing one side of the cylinders, you would have much less drag, and
more airflow, than the air slowing down going through the tubes.

Also, most "Updraft" cooling engines do not do well on single engine
airplanes, because the windshield is relatively close behind the engine, and
that makes the whole top of the engine cowl an area of positive pressure.
With positive pressure on the outlet, the air will have a very hard time
getting out, and you will have a hot engine. At the very minimum, the
outlets would need to be on the side of the cowl, ala Thorpe T-18. I think
even those have some of the air exiting the bottom, in the area of low
pressure. I'm sure someone will correct that if it is wrong.
--
Jim in NC