Tom;
At Bonneville, you could probably even use a small thermosiphon solar panel
to heat the oil or water!
There are two types of heaters that are used on dry sump oil tanks, a pad
type and a cartridge type. The cartridge type is small and convenient; it
even screws into a fitting in the wall of the tank and it's immersed in the
oil. Unfortunately, its small size is a big limitation on its ability to
heat the oil. If a high-wattage cartridge heater is used to heat the oil, it
overheats the oil that is in direct contact with it. Oil doesn't have very
good thermal conductivity, so the oil in contact with the heater gets too
hot and burns while oil further away doesn't absorb much heat. Eventually,
there will be a convection flow established and the whole tank will be
heated but the cartridge heater is still too hot.
The basic problem is the heating element's high "watt-density". A cartridge
heater has such a small surface area, it can't transfer its heat to the oil
efficiently, so it gets very hot for a given amount of electrical power. A
pad type heater is usually a silicone rubber pad with an electrical heating
wire providing heat that is distributed over its entire surface.
This type of heater is usually bonded to the outside of the aluminum oil
tank. The tank wall helps to spread the heat over an even wider surface
area. For the same wattage, the pad heater warms the oil to the same
eventual temperature as a cartridge heater but the oil in contact with the
tank wall next to the heating pad is not overheated.
It's a matter of heat density. Similar to the choice of sitting on a heating
pad or having a match lit under your backside.
Regards, Neil Tucson, AZ
-----Original Message-----
From: Thomas E. Bryant [mailto:saltracer@awwwsome.com]
Sent: Tuesday, April 22, 2003 4:25 PM
To: John Goodman
Cc: land-speed@autox.team.net
Subject: Re: engine oil and coolant temps
John,
Are you using the water from the race engine or from the push truck? I
prefer to preheat without running the race engine.
I have been researching a method of preheating the oil. I have found an
adhesive blanket 6"X12" which is the size of the bottom of the oil tank.
It is 120 volt 180 watt unit. Have you or anyone on the list used one of
these blanket type heaters. If so, how effective are they.
Tom, Redding CA - #216 D/GCC
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