Engine pre-heating

[40m]

On the factory installed Reiff system what wattage ratings are being used on the bands, sump and cooler? Cold environment
Thanks,
Glenn

[cityrancher]

I have the same set up as Dan L. The cowl cover is a VERY important part of efficient preheating. The wattage is fairly low so you need to trap the heat to work well. It is bulky but I consider it cold weather survival gear as well.

[Dan L]

I don’t remember the wattage now either, but a Honda 1000 generator will run it just fine.

518AD530-509A-4266-87FC-5628EC1C1233.jpg

[cityrancher]

If my memory is any good (???) I believe the wattage is 650 with my setup. I did put the larger silicone heating pad on the oil sump with a Reiff heat band on each cylinder.

[stroutmail]

20181208_143535.jpg

PA is not that cold..I built this for use in the hangar..works well to increase CHT and Oil Temp by 40 deg F in about an hour. Two 900 watt Zerostart (Philips Temro) Little Buddy Cab electric heaters inside repurposed propane heater (using only the fan and housing from the old heater.) The heaters are CSA listed and work very well. I can change CFM and Delta Temp for various conditions. (I added a three speed Vornado fan for more CFM options..you need extra CFM to keep the air temp in the ideal range.) I found 100 deg F outlet air with about 100 CFM to be optimal for 35 deg F ambient.

(This "project" was fun, as I enjoy the process, but in hind-sight, I could have made it simpler and smaller by not using the propane heater "core". The three speed "off the shelf" fan with the Cab heaters inside an 8" HVAC duct would have been just as good. 4" Neoprene (350 def F rated) flex hose would have been easier to use but more expensive and mating/holding the outlet to the rear engine cowling outlet would have been a bit challenging.)

I liked the Aerotherm but found my Sport Cub needed heated air input thru exhaust outlet part of cowling..gets oil temp up and warms the carb and gascolator..starts first crank.

I put heat into front first to raise CHT, then move to the back.20181208_143514.jpg20181208_130615.jpg20181130_183725.jpg

If I traveled to another airport with a layover, I would carry and use the little Hornet heater with an engine cover to maintain the engine heat.

If I wanted just one unit, the I would buy the Aerotherm Deuce with extra long hoses and fab a way to connect to the rear cowling opening.

I think if I had to leave my plane outside in really cold places like Maine, Minnesota or Alaska, the electric resistance heaters are very efficient and convenient. For my flying, I preferred not to add parts to my plane and prefer heating via air convection (more uniform).

[stroutmail]

PreHeatZeroStart.PNGPreHeatMilkhouse.jpgThe 900 watt Zerostart (Philips Temro) Little Buddy Cab electric heater is a very nice compact unit---I think you could take one and use it as a "portable" pre-heater. It blows 35 CFM at 70 degrees F "delta T". (100 degrees F output on a colder 30 degree day) Would need a flexible duct to direct air into the cowl. (6" HVAC steel duct, with 6" to 4" reducer and 3 feet of neoprene flex hose would probably make a light compact setup for less than $125 out of pocket.) Sort of like the "milkhouse" heater with duct attached that I have seen but more compact.

[Dan L]

F5F19E5A-3AD0-4C6F-B285-3969915F1C55.jpg

An alternative heat source for me. Quicker than the Reiff system. It was cold and clear today and I decided to make a last flight for the year.

I'm about to put the skis on too. Not much snow down low yet this winter.

[stroutmail]

Dan, I assume your propane heater is the Red Dragon by Flame Engineering. Looks like a good heater and no doubt faster than electric...especially in places like Montana. I was a bit worried about the flame near the plane.

What air temp do you set for the air entering the cowl??

[Dan L]

Dan, I assume your propane heater is the Red Dragon by Flame Engineering. Looks like a good heater and no doubt faster than electric...especially in places like Montana. I was a bit worried about the flame near the plane.

What air temp do you set for the air entering the cowl??

It is a Scheu Products Co. Inc. heater. The temperature coming out of the unit is 300 degrees. But it cools off by the time it gets to the cowl. It is hot to the touch at the cowl. Too hot to hold on to.

[stroutmail]

Another benefit of preheating..

I flew the plane in temps below 32 F. Then, after sitting in the hangar for two weeks, I took it out again...OAT was 21 F. During the preheat, a "glob" of oil mixed with frozen water melted and fell out of cranckase breather.

If I had just started the cold engine and departed it is possible my breather could have become blocked, leading to oil seal failure from pressure buildup.

Never experienced such issues when flying around Dallas TX years ago.

I was surprised with the moisture, as I had removed oil fill for a time after shutdown thinking that would reduce crankcase humidity. But, it takes a long time for the oil to cool, so putting the oil cap back and leaving with oil still at 100F must still leave quite a bit of humidity.

I will inspect the crankcase breather more carefully in cold weather.