Larry,
Thanks much for the lengthly reply. I know you spent a lot of time at
your key board to produce all of the valuable information that I just
printed out. I am going to try to make an engine pre-heater as per your
instructions because I agree with you, it's better than a dip stick.
Bob Stone
----- Original Message -----
From: "larry flesner" <fles...@midwest.net>
To: "KRnet" <kr...@mylist.net>
Sent: Monday, January 17, 2005 9:54 AM
Subject: KR> engine preheat - long
>. My question is, does anyone know of a method of pre-heating the engine
> prior to start. I have heard of a heated oil dip stick for cars that are
> very popular in the northern states where the temps are below zero in the
> winter, I am wondering if such a device is available for aircraft?????
>>Bob Stone,
>
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
>
> The problem with heated dip sticks or the oil pan heat pad, as I
> see it, is the heat is too concentrated to warm the entire engine
> as you want and the heated pad can actually "cook" the oil if
> the pad is hot enough. A much better solution is to warm the
> entire engine, not just the oil.
>
> I've built several engine heaters that are really inexpensive, easy
> to use, and safe. A friend of mine photographed me building one
> for his C-170 and it was written up in the C-170 Club newsletter.
>
> The advantages are:
> Safe - heat source well away from the engine.
> Easy to use - just slide it under the airplane and back out
> when you are finished. It is self-standing and
> requires no hook-ups.
> CHEAP - materials will cost you about $5 plus the cost of
> a good quality 1500W ceramic heater, the kind that
> is about 8" X 8" or so.
> Easy to build - you can build it in an hour or less.
>
> It is easy enough to build that you should be able to assemble it
> from the following discription.
>
> Go to your local building supplier and get one sheet ( 4' X 8' ) of the
> foam insulation board with the foil cover on both sides. The 1/2"
> or 5/8" thick is sufficent. You will need approx 6' of the 8' length so
> try to buy a damaged piece if they have one for about half price. Even
> an undamaged piece should sell for approx $5. If you don't already
> have one, pick up a good quality ceramic heater with a fan, the small
> square kind that are usually rated for 1500 watts. They should sell for
> about $25. Mine has hi/low heat settings and tip-over shutoff switch.
>
> Measure the distance from the hangar floor to the bottom side of
> the opening at the rear of your cowl and the outside dimention of
> the heater. A slight modification on the top end of the heater
> tube may be in order, depending on the cowl opening.You are now
> ready to start construction.
>
> Basiclly, what you are going to do is construct a square heating
> tube, the outside dimention of your heater, in the form of an L.
> The heater should just slip in one end and the other sets under
> the cowl opening. You construct it from flat panels cut from the
> foam board and tape it together with "duct tape" or the foil tape
> used for duct work. Either one will work.
>
> The horizontal run of the duct should be approx 24" long to keep
> the heat source well away from the engine. The vertical run is
> the distance measured earlier. Draw the two side pieces of the
> L and then the other panels needed to finished the duct on the
> board and cut with a sharpe knife. Instead of a full 90 degee
> corner in the duct, I made mine with a couple of 45 degree bends
> to better help the airflow. Just draw the side pieces the way
> you want the shape to be. When finished, the heater should
> just slip inside the duct.
>
> As for modifing the top end, the C-170 had a gascolator centered
> in the opening of the bottom of the cowl so I built a small deflector
> in the top to keep the hot air from hitting the gascolator directly.
> Modify for your needs depending on the cowl opening size or
> shape.
>
> To use, just slide the duct under the airplane beneath the cowl
> opening and plug in the heater. I usually place a blanket over
> the cowl and cover the air inlet holes in the front to contain
> the heat. There is VERY LITTLE heat loss in the duct so you
> get the full benifit of the 1500W's in the engine compartment.
>
> On one occassion when the temp in the hangar was 30*F, I was
> able to bring the entire engine compartment on the Tripacer up
> to 80*F, as measured by the oil temp guage, in 50 minutes on
> the clock. That ment my cylinders and everything under the
> cowl was ready for a safe start. If your battery is under the cowl,
> even better. If you know you need to add a quart of oil before
> flight and it's been setting in the hangar also, place it under
> the cowl somewhere (top of cylinders) and it will be warmed
> also during the heating process. I've even used the heater to
> preheat the oil for an oil change and had all 6 quarts of the
> replacement oil under the cowl and nice and warm for a
> fast pour.
>
> Refinements: For the health of the engine you don't want to
> cycle the temp in the engine compartment (hot, cold, hot,
> cold, etc.) but I suppose you could leave the heater in place
> on a low setting and keep the engine always warm. Another
> though I had but never bothered with was to plug the heater
> into a thermostat control located under the cowl and let
> the heater cycle and keep the temp constant under the
> cowl. It would be ready to fly when you get to the hangar.
>
>
> If you want or need a picture, e-mail me directly at
>
> fles...@midwest.net
>
> and I see about getting you one.
>
> Try it! You'll never go back to a heating pad or dipstick, at least
> at your home base.
>
> Larry Flesner
>
>
>
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