Q-talk 109 - Winter Preheating
- Category: Q-Talk Articles
- Published: Wednesday, 23 December 2009 16:24
- Written by Doug Humble
- Hits: 1510
For those of us up North, winter slows us down but doesn't stop us. Here are some ingenious ways to preheat the engine compartment.
This contraption is made from a small electric space heater and some ducting I found at Lowes. I safety wired the ducting to the front of the heater and used duct tape to fasten things together. The wide mouth duct goes into my cowling exit.
Paul Fisher sends in these photos and describes his engine preheating technique.
Here's an easy way to preheat your airplane. I built a simple heater from two standard hair dryers. You start with foam (like you find at any craft store) that is about two inches thick and make cut out's that fit the air inlets on the cowling. It doesn't matter if you cut them oversized since the foam will collapse and form the right size, so it doesn't really make too much difference how accurately you cut! Now you have what appears to be cowl plugs. I then cut holes just big enough to stick a hair dryer in. Again, nothing fancy, just need to get it to work. Cutting these holes a little small is a good idea because you want the foam to hold the hair dryer in place. Use whatever you want to make the cuts, but an electric carving knife worked great for me!
No special brand of hair dryer is necessary. I just used what my wife had discarded. As long as the "heat" setting still works, it's fine! I suppose it would work with a single hair dryer, but I use two. Typically 15-30 minutes, depending on outside air temperature, is all it takes to get all of the CHTs about 60 degrees. Today it took more like 40 minutes, but it was 5 degrees! (-15C)
Like I said, this isn't complicated (KISS principle!). The cowl inlets are designed for air to flow through them to transfer heat away from the engine. If you just direct some warm air through them, the same heat transfer will happen and you'll warm up the engine. I've been doing this for 14 years now and so far it seems to work!
Paul A. Fisher Q-200, N17PF ?1150 hours Taylor Ridge, Illinois
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