I recently bought a metalized Stinson 108-3 and am on a waitlist for a hangar, so it is parked on the line. I'm in Virginia Beach, so it doesn't get Minnesotta cold, but it does get down into the 20's-30's. There's no power reasonably close without an extension cord having to cross a taxi way, so I am looking into ideas for a battery powered preheater. It's got an electric oil pan heater, which the website states pulls 300 watts.

I have an inverter (2000watt), and am thinking about using a deep cycle battery and the inverter and putting in a timer switch so that it will turn on at a certain time. This setup would require me to go there the night before and set it all up, but I wanted to check that A) this would work, B) It's safe. Battery and inverter would be under the cowl. I wouldn't do it if rain was in the forecast. And C) Is there a better option? I really don't want to use a fuel source since I won't be there. The other thing I was thinking was finding a big battery power station that I could use and recharge, but those run about $500 for anything over 300 watts. I can get a deep cycle battery for about $100.

Thanks for the ideas/insight!

Heat requires HUGE amounts of current. I seriously doubt you’ll find a “practical” battery system that’ll do the job, let alone safely.

I’d buy a small gas powered generator. If a morning is too cool for safe start, go to airport an hour early, fire up gen set, plug in, go have breakfast/coffee, or ?? Then go fly.

For that strategy to work, you MAY need more heat capacity on the engine. Depends how cold, wattage, etc.

Give it time to warm whole engine in any case.

MTV

I agree, you NEED a generator. I have 6 reiff cylinder band heaters and two pads on the oil pan I run with a 1000 watt suitcase honda. I have the gas cap replacement fitting that allows you to connect to a small outboard motor fuel tank so it can run for a long time. Setup the genset the night before, chain it to your landing gear.

300 watts draws about 3 amps at 110v, but at 12v that would be more like 25 amps. Inverters are anywhere from 50-85% efficient so now we are at probably 40 amps. A deep cycle 12v has a nominal capacity of 75 AH. I doubt it would actually supply 40 amp for 15 mins.

But I assume that a heater of that low wattage is only meant to maintain rather than heat it up fast, so I am guessing that you would need to plug it in for a long while to actually warm a cold block.

A generator and more heat or a Red dragon would work.

As shown above, a battery-powered system isn't realistic. When I was tied out I had a cheap generator I left chained to the tiedown ring. When I wanted to go flying I'd start it up a few hours before I wanted to go flying. A Reiff system combined with a generator is the best combination IMO. Depending on the generator and your situation you could start the generator the night before; some will run almost all night and an engine blanket will keep the engine warm for a couple of hours after the generator runs out of gas.

But, do you really need pre-heat? A quick look at Virginia Beech averages and I don't think I'd sweat it. Change to a multi-viscosity oil for the cold months would probably be sufficient.

So this is kind of what I was thinking I was going to have to resort to (generator), just didn't want to bite the bullet. But I guess it's a good excuse to get something that will likely be useful for many years for not only this but camping and tons of other stuff. Thanks!

If you’re going to keep this plane for a long time, I’d highly recommend installing a Reiff or Tanis system. They are lots better than just an oil pan heater, which won’t really get the whole engine heated up. I like to preheat any time the temps are below freezing, and preferably below about 40. The engine will be a lot happier as cold starts are about the worst thing you can do to an aircraft engine. Get a good engine cover too.

The generator is your best bet if you don’t have access to a power outlet. Chain it down like Mark says and I really like his suggestion of the outboard motor gas tank. I really believe in several hours with the Reiff, which is easier done all night.

I don't have to worry too much about a heater down here, even though I have installed the Reiff system on the Maule, but listening to y'all discuss brought up a question.

Would a tarp over the engine blanket to include covering the generator allow the exhaust of the generator to help provide some more heat, or would the fumes be too hard to dissipate when you got ready to fly? We have used a stainless corrugated hose loosely attached to a vehicle exhaust to thaw equipment in the past.

The trouble with the generator exhaust won’t be the carbon monoxide or dioxide. It will be the water vapour. Everything under the blanket will be wet.

Having lived in Virginia Beach, I would tend to agree that there are very few days a year that you would actually need pre-heat. Normally just waiting a few hours will bring the temps up above the threshold, especially if the sun is shining. If not, the weather is probably nasty enough that you wouldn’t want to fly anyway.

12 VDC Red dragon heaters work great with a good cowl blanket. Small 12 aerovolts lithium battery...under three pounds and has enough juice to warm up a cold soaked engine.... so cold the crank had zero clearance... O-290D Willow Alaska....30 below zero... through the bottom of the cowl...hot air directed towards the oil pan....now have a Tanis system with their PMA’d cabin heater.


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m_moyle wrote:12 VDC Red dragon heaters work great with a good cowl blanket. Small 12 aerovolts lithium battery...under three pounds and has enough juice to warm up a cold soaked engine.... so cold the crank had zero clearance... O-290D Willow Alaska....30 below zero... through the bottom of the cowl...hot air directed towards the oil pan....now have a Tanis system with their PMA’d cabin heater.


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I'm not sure what you're describing as a Red Dragon Engine heater. Here's what I think of when I hear Red Dragon engine heater: http://www.2040-parts.com/red-dragon-en ... --i494695/

And, they sure weigh a LOT more than three pounds. Like a propane bottle, battery to run the fan, and the unit itself......

So, what are you describing?

MTV

The trouble with the generator exhaust won’t be the carbon monoxide or dioxide. It will be the water vapour. Everything under the blanket will be wet.

I park outside but have electrical, so I do a SwitchBox connected to a Reiff system. When it works, it works great (the SwitchBox is finicky). However, I think I’m going to lose that electrical when the airport reconfigures the hangars in the next couple of years. I’ve been thinking that the perfect solution is a remote-start generator. Is anyone aware of such a thing? The only ones I have found have required WiFi, which isn’t workable if you don’t have power in the first place... anyone?

If you really need to preheat then I would suggest a forced air heater. Ryobi makes an all in one battery powered propane torpedo heater. Give it a look.

https://www.ryobitools.com/power-tools/ ... ane-heater

Install a Reiff system. Buy a small generator (one kw, Honda or Yamaha). Done.

The generator is useful for other things. Mine runs the boiler in the house if the power fails.

If you fly to a remote location without power, in winter conditions, the Reiff and generator combination is hands-down the safest and most convenient option.

Ryobi heater doing battle in "hard wired" mode but alternately it can be powered by a lithium ion battery with a smaller camping style propane bottle. Some might wonder why the duct is stretched out so long but if collapsed much shorter the overheat sensor is prone to activating and shutting the heater down

I'm looking for a battery-based heater for winter trips where I can't plug in where I land. I think a battery-based preheat is more practical than is implied throughout this thread. I am planning to try it, so I would appreciate folks poking holes at my thinking here if you see any.

A Tanis/Reiff cylinder + pan system draws 250W in a 4-cylinder engine. It takes about 6 hours to hit peak temperature (35C rise starting from -10C), but gets a 22C rise (to +12C) after 90 minutes. That is admittedly an indoor test, so add 30 minutes (also add cowl plugs and an engine blanket). Thus, you need 500Wh, after any losses, to make this work.

I see two options here:

1. 700Wh+ Power Station or Deep Cycle battery + inverter (assuming 70%+ efficiency of DC/AC conversion). Probably 20-25 lbs all in - slightly lighter than a Honda 1000i generator, and twice as light as the 2200i.

2. Custom 30s Li-Ion Battery (90-126V operating voltage), run directly to the engine heater. Yes, Tanis/Reiff are specced for AC, but it's just a resistance heater, no reason you can't give it straight DC. This lets you skip the inverter, saving weight and increasing efficiency. ~15 lbs all in, including a small extension cord.

In either case, for less than one additional pound, you could add a timer and relay to turn the whole system on 2 hours before your scheduled departure time, so you wouldn't have to make a separate trip to turn it on.

I think both of these options are more compelling than a generator or modified camping stove, if a convenient preheat is what you're after.

Try it out and see how it works, then report back. Heating sucks the life out of batteries. It’s not the instantaneous load, it’s a high load for a long time.

Might work in relatively warm temps.

On a different note:

If you’re using a generator to preheat, and it’s COLD, that generator may not starttill you warm IT. Also,I’ve seen a Honda 2000 destroyed because it didnt have the “cold weather kit”.

As I noted in another thread, there’s cold, and then there’s no shit cold. Lots of stuff refuses to work in no shit cold.

MTV

mtv wrote:Try it out and see how it works, then report back. Heating sucks the life out of batteries. It’s not the instantaneous load, it’s a high load for a long time.

Might work in relatively warm temps.

On a different note:

If you’re using a generator to preheat, and it’s COLD, that generator may not starttill you warm IT. Also,I’ve seen a Honda 2000 destroyed because it didnt have the “cold weather kit”.

As I noted in another thread, there’s cold, and then there’s no shit cold. Lots of stuff refuses to work in no shit cold.

MTV

Is there a thread for preheating generators to preheat planes? j/k

I agree about your phases of cold. Part of what makes this project appealing is it gives me a way to warm my engine even on those late fall/early spring days where I could start it no problem at 30-40 F, but would much rather not. I don't anticipate getting into a cold-soaked plane at -15 F but it would be reassuring to know I could if I were otherwise stranded.

I'll report back when I get around to trying this.