The 100 watt bulb trick is to merely place a drop cord with a 100 watt
bulb inside the cowl while parked and leave it on 24x7. This was first
suggested as a cheap and easy way to preheat, especially if 2 100 watt
bulbs were used. Simply put plugs or rags or such in the cowl openings,
place a blanket or 2 over the cowl, and while not as good as a good
preheater, did keep the engine at a temp above the desired level.
Aviation Consumer did an article on this in the past. They used the
same trick when they were evaluating the dryers, and found that as with
the preheaters, this trick did not perform as well as the devices
designed for that purpose, but did keep moisture out of the crankcase.
They found that this trick kept the air temp inside the crankcase from
5 to 10 deg above the dew point, so no moisture collected on the engine
internals.

Bud

Charles wrote:
wrote:

Aviation Consumer did an evaluation in the current issue. They liked
them, and recommended them, although they didn't test the brand that
you posted. They said if it pumped dry air as well as the others, it
should work fine. Also, they said the 100 watt bulb in the cowl flap
trick works too.

Bud


Hmm. I already have a heater, what's the bulb trick supposed to do?
There seems to be no concensus on whether heat makes matters better or
worse.

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