Cooling Fan for Model I.C. Engine

[Brian Rupnow]

These two shots show the fan in the shroud, on a dummy shaft from the front and from the rear. The fan does not contact the inside of the shroud when the shaft is rotated. (Big sigh of relief!!)

 

[Brian Rupnow]

This morning was show down time. I had finished the shroud and brackets for the fan yesterday afternoon, and painted the shroud. This morning I got up and added some set-screws to the fan hub, and made up a shaft and pulley for the fan. I was very fortunate in finding a rubber o-ring of the correct length, and the fan was installed on the engine. I am very pleased with the results, and the 2" diameter six bladed fan which is travelling approximately at twice the engine speed puts out a very noticeable breeze over the cylinder cooling fins. The engine exhaust is a bit smoky, because I was running some two cycle oil with the naptha fuel to provide lubrication for the Viton piston ring.--The oil to fuel ratio is 1:20, but I think I can safely cut that back to about 1:35 for future runs. The engine has a wet sump and splash lubrication of the con rod big end.
[ame]https://www.youtube.com/watch?v=XVPX5MXDXrQ[/ame]

 

[johnny1320]

Nice job Brian!