quote:
Originally posted by DEWFPO:
windchill clarification.
Technically, an engine isn't affected by windchill. For example : if the temp is 0 degrees, no matter hard the wind blows, the engine will not get colder than 0 degrees.
But ................. the wind will cause the engine to LOOSE it's heat faster than if there is no wind.
So... if you are putting 750 watts into an engine with a block heater, that block is getting warm and if the wind is blowing at the engine, the block will be looking that heat faster than if the wind were not blowing.
DEWFPO
If you're parked outside, it's colder than -30 F, and there is a HUGE wind, that frost plug heater will make little if any difference.
That's why I like the circulation or "tank" coolant heater. They seem to have way more capacity to deal with things like severe windchill.
True, the block won't get any "colder" as windchill only deals with heat loss. Here in Canada they sometimes mention windchill in so many watts per square metre: if the heat loss is say 1,500 watts per square metre, will the block heater keep up?
No.
That's why around here folks will sometimes throw a huge piece of canvas over the hood of the car and secure it with cinderblocks. The canvas keeps the wind off the motor and really helps the frost plug heater.
Heavy commercial equipment, especially forestry skidders, use "canopy" heaters. They run off propane or diesel fuel and, just like the preheater for an airplane motor (That's where they got the idea from), they heat up the entire engine compartment.
At one time, loggers around here used "slave" coolant systems. You'd see these quick-connect couplers, like hydraulic hose couplers, poking out the winter front of their pickup truck.
They'd drive deep into the bush to the skidder that had been parked overnight or over the weekend at -40. No electricity so no coolant heaters.
You'd use short hoses to hook up the skidder motor cooling system to the pickup cooling system. The hot coolant from the pickup would then circulate through the cold skidder engine block. The temp gauge on the pickup would drop from 185 F to the bottom of the peg.
You'd also hook up booster cables to the skidder to start charging the batteries. After 15-20 minutes, you'd disconnect the coolant lines and boooster cable, and spray ether into the intake plenum for 10 seconds. It would usually fire right up.
This is really rough on the pickup cooling system, and isn't used anymore. Folks figured out that for the price of a generator, you can fire up a small genny for 3-4 hours to heat up the circulation heaters and pan heater. Cheaper than a blown engine - +$10,000.
Winter: it's fun.
Jerry
