rbort
Elite Veteran
Location: Franklin, MA - U.S.A.
My Posts This: Topic Forum | Spit testThe point of the spit test if to give you an OK that your engine is not hot, or to tell you that it IS too hot.
Granted yes you don't know if you're running 220 or 260, but its not important. Different days your engine will run hotter or cooler, I flew today and had no idea what temp I was running as I never checked it. In any case all the spit test is doing is showing you that you getting too hot or that you're already too hot.
It goes something like this:
Land, shutoff, lick your finger and rub it on the side of the crankcase where the slant is just in front of the carb:
No sizzle, your good, next observe spit
Spit burns off within a second or two, you're running hot but not too hot.
Spit stays longer you're running fairly cool.
If you can leave your finger on the crankcase for a few seconds, you're running coldish.
Take it as a Go/NoGO test. If you land and your spit sizzles off, then definately that's a NoGo, if it doesnt and doesn't look unusually hot from what you've seen in the past, then fly on.
Knowing exactly what temp it runs at like 223, 237, 252, or 265 doesn't really matter. Sure its nice, but its not the end all of flight if you don't.
Here is another analogy for it, the red temp light in your car, or the temp guage. If you have a light, and the light is not on, you drive on, whether the temp is a, b, or c and it varies with the hotness of the day. If you have a guage, it shows you a temp of a, b, or c, and you will see the temp going up in traffic on a hot day and going down when you go downhill. You don't reach the red line marked on the guage, so you drive on. Same thing as the spit test.
If you hate it, don't use it. When I land and its a hot day and I don't have my temp gun in my hand, I lick my finger and rub it on my crank, and with experience I can tell about where I am based on how the spit reacts and the temp I feel on my finger. Works for me, if you want to, use it, if you don't want to, go buy a temp gun and strap it to your wrist! 
And one last thing, temp checking is most critical for me on the hottest of hot days in the summer. Now that fall/winter is here, I barely pay attention to temperatures unless something is usually wrong. Sometimes too much information takes away from the fun, like having to check your engine with a temp gun every time you land. Even if I did today and it said 200 lets say, would I change mixture to bring it up? Absolutely not, its running just fine I'm not about to start fiddling with needles. If it ain't broke, don't mess with it.
Instead, fly-on and log some more flights 
-=>Raja.
1005 Gasser, G26 3DMax++, 2205+ flights
Spectra-g, G26 3DMax, 870+ flights |
