Inexpensive and effective engine preheater pre-heater w/ photos

pboyce · #1 01-14-2009, 03:43 PM

On my RV-7A, I installed an engine oil sump heater pad purchased from NAPA. That heats the oil nicely, however, what about the rest of the engine? I've been reading several posts which say that cylinder pre-heating is also very important. So I built an inexpensive yet effective forced-air heater. The heater has a 750 watt or 1500 watt setting and I've found that the 750 setting is more than enough for a couple of hours. I used 4" duct since my cowl exit is bigger than most, for others 3" duct will work. I fashioned a ring using some scrap 0.063 which I then pop riveted to the heater, as you can see from the photos. I then pop riveted the duct flange to the ring. The Lakewood heater, 4" aluminum duct, and duct flange all came from Ace Hardware, about $45. This thing works great.

MCA · #2 01-14-2009, 03:48 PM

I made one very similar a few years ago and it works great!

Now to find a decent remote turn on switch!

pboyce · #3 01-14-2009, 03:57 PM

I did a search on these forums and found a link to an inexpensive kit which uses a cell phone in your hangar to activate a circuit. So you just call the cell phone and it turns on the equipment. However, for simplicity sake, I ended up putting everything on a timer. Here is the link to the cell phone kit:
http://www.apogeekits.com/remote_con...cell_phone.htm

WyoDave · #4 01-14-2009, 04:00 PM

I made a similar set up. I used a Honeywell Mini Tower heater, $25-$30. The heater itself is a vertical cylinder. With the plastic top pulled out of the heater, a piece of 6" inch duct fits perfectly. Even in a 0 degree hanger it works great and doesn't take long.

AZtailwind · #5 01-14-2009, 04:17 PM

You would be suprised at how that pan heater would heat everything firewall forward if a blanket was covering it all-

pboyce · #6 01-14-2009, 04:21 PM

Brad,

You have made a good comment. I should have added that I use a blanket over the cowl as well as plugging the 2 air inlets. That really helps with keeping the heat inside the cowl!

frankh · #7 01-15-2009, 10:32 AM

and a plenum with cowl plugs I find the top of the engine is warm to the touch even on the coldest days..I have 100W of oil pan heater only.

I leave it plugged in all the time and the oil temp is about +30F compared to OAT...Plenty for around here at least.

Frank

flyboy1963 · #8 01-15-2009, 11:38 AM

Oh, I'm envious, but you guys just kill me! preheat.... in a hangar!!!! Bloody luxury!

Does anyone have a report of how the Tanis or Reiff or x-brand silicone pad heaters work on the oil pan OUTDOORS????.....with cowl & prop cover?
How many watts, and how long, do you need to go from say -10 degrees C to a decent starting temp? (whatever that is!) I was looking froward to some winter clear air flying, but not without preheat!

looking for some good advice, thanks guys!

RScott · #9 01-15-2009, 08:15 PM

Friend of mine just ordered a heater kit from Alaska, comes in it's own carrying case, has a propane heater, a battery operated blower and has it's own battery, so you can use it even if you don't have AC power. I'll ask what make it is.

David Clifford · #10 01-16-2009, 08:19 AM

I installed the Reiff 200 Watt Hot Strip to the sump of my C-152 and love it. I got tired of fooling around with the blowers, tubes, and long waits for pre-heat. Even after 1/2 hour or more pre-heat with a blower, you are going to have a slug of ice cold molasses thick oil trying to move through the tiny oil passages in the engine. With the Reiff, after putting the plane in the hanger after flying I plug the cowl openings, blanket the cowl to hold in the heat, plug it in and forget about it. The Reiff has a thermostate switch that turns off/on at aprox 150* so you are not cooking the oil. Even in the below -0* we are experiencing here in Michigan, when I remove the cowl plugs during pre-flight and reach in to feel the cylinders, they are at about 100*,,,,nice and warm for an EZ start and less wear and tear on the engine. I also hook up and plug in my home made closed loop engine dehydrator when I put the plane away and run that 24/7. Uses the equivelent of burning two 100-Watt light bulbs part time. Costs me pennies per day to operate 24/7. I have no affiliation with Reiff but love their product and service. I originally leaned towards the Reiff system with the cylinder bands but the owner suggested that the hot strips alone would work fine in keeping the cylinders warm by plugging and blanketing the cowling. Looking outside right now the sky is blue and its -8*,,,,,i'm heading to the airport to enjoy some cold weather flying!