Oil Dipstick Heater

[rangermb]

Has anyone tried one of these. It temporarily replaces the dipstick to put heat into the engine? I use an external heater now, but don't really want to glue a pad heater to the case.

[smccray]

Quote: rangermb

...but don't really want to glue a pad heater to the case.

[scottfromiowa]

Does it have a thermostat?  I had one and didn't care for it.  I have a block heater now with thermostat.  I prefer this in combination with a ceramic heater that I blow with heat duct into the cowl flap opening.

[rangermb]

Quote: smccray

Why?  I respect your decision, but I'd like to understand your concern.

[jetdriven]

I read somewhere they are not good to use.   Oil gets warm but cooks a little, and the engine stays cold.  The real purpose of preheat Is to warm the crank and case so the bearing clearances don't get too tight.  

 

IIRC lyciming does not recommend them either.  

 

[Piloto]

Automobile oil dip stick heaters are very popular in Canada. You see a lot of cars at night at the motels plug in. Besides their simplicity of use warming up the oil directly is more effective than blowing hot air from the outside. Before start you want to make sure the oil is ready to lubricate to avoid bearings wear. Also when you heat from inside the heat is better confined to the engine moving parts (cranckshaft, connecting rod and pistons) than to just cylinder heads when hot air is applied externally.

 

José

[Jeff_S]

As jetdriven has said, these oil dipstick heaters are a definite no-no for aircraft engine preheating. The tolerances in aircraft cylinders are much less than in a car because of the differential metals used, so the goal of engine preheating is not only to warm the oil but also to increase those tolerances back to normal levels and avoid damaging cylinders during a cold start. The oil dipstick method only heats the oil, so you're only solving half the problem (and with modern multi-viscosity oils, not even the most important half).

[animalmover]

A trouble light with a 100w bulb inserted in the cowl and a sleeping bag over the top does a good job. 

[Piloto]

Quote: Jeff_S

As jetdriven has said, these oil dipstick heaters are a definite no-no for aircraft engine preheating. The tolerances in aircraft cylinders are much less than in a car because of the differential metals used, so the goal of engine preheating is not only to warm the oil but also to increase those tolerances back to normal levels and avoid damaging cylinders during a cold start. The oil dipstick method only heats the oil, so you're only solving half the problem (and with modern multi-viscosity oils, not even the most important half).

[Shadrach]

Quote: rangermb

Has anyone tried one of these. It temporarily replaces the dipstick to put heat into the engine? I use an external heater now, but don't really want to glue a pad heater to the case.

[jwilkins]

Quote: rangermb

Has anyone tried one of these. It temporarily replaces the dipstick to put heat into the engine? I use an external heater now, but don't really want to glue a pad heater to the case.

[jetdriven]

From Lycoming SI1505:

 

The use of a heated dipstick is not approved because heat is not distributed throughout the engine, and concentrated heat may damage non-metal engine parts. Proper pre-heat requires a thorough decongealing of all oil.