Willie van der Walt wrote: > I would like to know what effect the spinner will have on my plane, apart > from making it look better. At the moment I fly without a spinner after mine > departed on a ground test run, and destroyed the prop. I did not fly with a > spinner yet and can therefor not make any comparison. I am scared that if > the spinner comes off in flight it will brake the prop and then kill me. I > tried the search and all I found is that the CHT will be higher due to > turbulent air flow. Nothing about speed.
I flew my first year with no spinner, and had relatively cool CHTs, although some of that may be due to my cooling plenums on top of the engine (those have proven to lower CHTs by about 50 degrees F). I added a spinner just before OSH this year. It was a spun aluminum thing from Wag Aero, but it was so badly out of balance that a vibration was immediately noticeable, and was bad enough that I removed it immediately after only one landing. I figured I could do better than that making one out of fiberglass. I used the aluminum one for a mold, duct taping it and laying up four layers of fiberglass on top. With this homebrewed spinner I could feel no vibration at all. I assumed I would see improvements in CHT and top speed, but best I can tell, the CHTs stayed about the same as when I had nothing but the spinner backing plate there, maybe a few degrees cooler. I guess that's a test that's easy enough to repeat, so I'll do that one of these days, but what I remember about it was that it hardly made a difference on my plane. Next time I make one of these I'll vacuum bag it for even better results. I realize my experience is far different from Dan's, but maybe our props are shaped differently inboard near the spinner or something, and it is common knowlege that a missing spinner will raise temps significantly, it just wasn't my experience... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net --------------------------------------------------------------
