whee wrote:That Aerotherm heater kinda cool, though I can't figure out what makes it cost 1 AMU. To the engine an Aerotherm would be equivalent to having a heater hanger so leaving it on all the time would be fine.

My biggest annoyance with engine heating discussions is when someone (in this case it is Aerotherm's website) says they can heat their engine in 30min and be good to go
It takes TIME, like a couple hours minimum, to get the internal engine parts heated and that is what we are really after with an engine preheat. Sure you can blow hot air on your intake system for 30min which will get it warm enough to easily start the engine but will do zero in preventing cold start engine damage.

I plan to install a Reiff preheat on my engine but in the mean time I have a 250W ceramic heater I stick under the cowl and run overnight. I also toss a moving blanket over the cowl. With single digit overnight temps my EGT, CHT and oil temp indications are all in the upper seventies when I arrive at the hangar in the morning.

Sorta related comment: I had a buddy with a big bore snowmobile (1200cc); crazy fun to ride. When left outside overnight in cold temperatures it would take two guy pulling on the rope to get it started. One guy couldn't turn the engine over. Once it was warmed up you could start it with one hand.

On The Fly wrote: Furthermore, the crankshaft is sitting in thin bearings in an aluminum crankcase which actually constricts in the cold, causing extremely close tolerances around the crankshaft. These extra close tolerances allow very little room for lubrication in very cold temps.

Hman442 wrote:

On The Fly wrote: Furthermore, the crankshaft is sitting in thin bearings in an aluminum crankcase which actually constricts in the cold, causing extremely close tolerances around the crankshaft. These extra close tolerances allow very little room for lubrication in very cold temps.

One of the engine guru book writer guys, Mike Busch IIRC, wrote that on a new/fresh engine that the crank clearance is .0018... that's 1.8 thousandths. At something like 20 below, the dissimilar metal thing has the clearance reduced by 2 thousandths, so essentially the engine is "stuck", but only by .2 thousandths, so it still turns over if you hang off the prop, etc. Point being that just heating the oil isn't enough, and has been stated above, heating for a "little while" isn't enough to get the case warmed up through and through. Of course, the counterpoint is, lots of our cars & pickups have aluminum blocks with steel cranks, the same oil clearances on the crankshaft, does everyone up in Akaska preheat their car ? I'm curious, having not lived up there. I've started my own vehicles at those temps, but it's only been a time or two every 10 years or so.

Hman442 wrote:

On The Fly wrote: Furthermore, the crankshaft is sitting in thin bearings in an aluminum crankcase which actually constricts in the cold, causing extremely close tolerances around the crankshaft. These extra close tolerances allow very little room for lubrication in very cold temps.

One of the engine guru book writer guys, Mike Busch IIRC, wrote that on a new/fresh engine that the crank clearance is .0018... that's 1.8 thousandths. At something like 20 below, the dissimilar metal thing has the clearance reduced by 2 thousandths, so essentially the engine is "stuck", but only by .2 thousandths, so it still turns over if you hang off the prop, etc. Point being that just heating the oil isn't enough, and has been stated above, heating for a "little while" isn't enough to get the case warmed up through and through. Of course, the counterpoint is, lots of our cars & pickups have aluminum blocks with steel cranks, the same oil clearances on the crankshaft, does everyone up in Akaska preheat their car ? I'm curious, having not lived up there. I've started my own vehicles at those temps, but it's only been a time or two every 10 years or so.

NineThreeKilo wrote:From continental

“If a heated hangar is not available and the aircraft and engine have been exposed to temperatures below 20 degrees Fahrenheit / -7 degrees Centigrade and has an engine mounted preheating system the following procedure may be used.

Engine mounted preheating systems should include individual cylinder head heater thermocouples, oil sump heater pad and crankcase heater pad. The use of a nacelle blanket will increase the effectiveness of engine preheating.

1. Follow the specific instruction provided by the manufacturer of the preheating system for its operation.

2. Begin preheating of the engine at least 5 hours prior to expected departure. However, do not leave the engine preheating system in operation for more than 24 hours.

NOTE: The use of an approved thermal blanket or cover will help to reduce the effects of wind and cold air circulation when the aircraft is not hangered. Normally the manufacturer of the preheating system has thermal blankets available for purchase.
3. Start the engine immediately after completion of the preheating process. Since the engine will be warm, use the normal start procedure.”

http://reiffpreheat.com/Continental%20S ... %20Ops.pdf


If you’re not local to the airport you could leave it plugged in but OFF and trigger it on with one of those cell switches or a WiFi switch if you are in range of WiFi.

NineThreeKilo wrote:That’s why I said to use a WiFi or cell switch, just send it the signal to turn on 5hrs before you’re thinking you’re going to fire the engine up.

A1Skinner wrote:

NineThreeKilo wrote:That’s why I said to use a WiFi or cell switch, just send it the signal to turn on 5hrs before you’re thinking you’re going to fire the engine up.

Sorry, missed that part. Up here in the north we have terrible cell service, but if it works that's a great way to do it.

mtv wrote:Yes, and for Gods sake, don’t park your plane in a heated hangar all winter.....

MTV

NineThreeKilo wrote:

mtv wrote:Yes, and for Gods sake, don’t park your plane in a heated hangar all winter.....

MTV

Not trying to be argumentative, I only was reposting what continental said in a bulletin about leaving engine heaters on.

Comparing a engine heater vs a heated hangar, wouldn’t the fact that in a heated hangar the air around the engine, and the plane as a whole for that matter, is at about the same temp, vs the engine heater where the inside of the engine was warm, but the air around the engine was cold, the outside “skin” on the engine was at the cold ambient temp, as would be the engine mounts, prop, etc?

Kinda like having a cup of room temp water in a 70f room vs having a cup of 70f water in a room that’s 15f.

I’m not a scientist, nor did I stay at a holiday in or anything, just as a owner/operator of a 520 powered plane I err on the side of the OEMs bulletin shy of seeing something very clear that goes against said bulletin.

Cary wrote:

NineThreeKilo wrote:

mtv wrote:Yes, and for Gods sake, don’t park your plane in a heated hangar all winter.....

MTV

Not trying to be argumentative, I only was reposting what continental said in a bulletin about leaving engine heaters on.

Comparing a engine heater vs a heated hangar, wouldn’t the fact that in a heated hangar the air around the engine, and the plane as a whole for that matter, is at about the same temp, vs the engine heater where the inside of the engine was warm, but the air around the engine was cold, the outside “skin” on the engine was at the cold ambient temp, as would be the engine mounts, prop, etc?

Kinda like having a cup of room temp water in a 70f room vs having a cup of 70f water in a room that’s 15f.

I’m not a scientist, nor did I stay at a holiday in or anything, just as a owner/operator of a 520 powered plane I err on the side of the OEMs bulletin shy of seeing something very clear that goes against said bulletin.

With my Reiff system running constantly these days, and with the cowl cover and prop/spinner covers on, if I reach into touch the engine, it's warm to the touch. If I touch the spinner, it's warm to the touch. If I pull off one of the prop blade covers, it's warm to the touch out to about mid way and gradually is less warm by the tip. My point is that the engine is fully warm, inside and outside, because the entire engine compartment is warm.

I haven't flown for about 10 days now, due to either weather or life getting in the way. We're due for snow and a real cold snap this weekend, which may make that even longer. Meanwhile, though, my engine is really nice and cozy, just as it would be if I parked the airplane on a nice 70-80 degree day.

Cary