What you describe sounds like a vernatherm from the outside... a 1 inch "nut"
that's only about 1/8" thick on the oil filter plate. The vernatherm works opposite a
car thermostat, though. Rather than requiring to operate to cool, it must operate to
*not* cool. It's got a tapered plug on the end that extends when heated. Rather than
me try to describe it poorly, check out:
http://www.sacskyranch.com/eng18.htm


Mike Noel wrote:
: I decided to check the vernatherm on my Archer's engine because it is
: running on the high end of the green during summer flights. I had already
: checked the sending unit and guage and found it to be OK. I then removed a
: 1" hex cap from the top left of the oil filter adapter on the accessory
: case. It is a few inched below the elbow that attaches the crankcase vent
: tube and so was not easy to get off. I had to grind away a bit of metal
: from the outer diameter of a box end wrench to get it to fit between the hex
: plug and the metal of the engine. The hex cap is hollow and inside I
: found...nothing. I couldn't get a really good look because I had left my
: mirror at home, but there was nothing obviously under the plug except a
: threaded passage.

: Is this where the vernatherm is supposed to be located? If it is and one is
: not installed, just what happens to the oil temperature?

: --
: Regards,
: Mike
:
: http://mywebpage.netscape.com/amountainaero/fspic1.html



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************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering Ph.D. Graduate Student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************