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Cold weather engine warmer that I can power from my car?

Leopold

Member
Hi, all. New RV8 owner in Seattle, need to keep the plane outside until a hangar opens up close enough to where I live...I've searched the threads and couldn't find the answer to this.

Is there a portable engine warmer that a technically challenged person can get that I can power off my car somehow (no electric available where I'm tied down) that can help me warm the engine a bit before I turn it over on cold days? Ideally, would like it not to be something I need to attach in any permanent way to the plane, and can keep in my car trunk.

Sorry if this is a silly question.

Thanks,

Seth
 
Not a silly question! Take a look at the heater vents in your car. Pick one that has good outflow and make an adapter that fits over it. Park your car close to the nose of the airplane. Then connect the adapter to some to some aluminum dryer hose and run that hose out your car window and into one side of your air inlets. Run your heater at full heat output and maximum blower fan speed. Plug the other inlet, put a bunch of blankets over the cowl, and wait for an hour or so. You can preflight during that time, or wait inside the car. It will still be warm enough for you inside. I used that method for the years that the airplanes I flew were parked outside and there was no power available.
 
If I was in that situation, I'd install the mother of all Reiff or equivalent engine heating systems on the airplane, AND have a small ceramic heater set-up to blow warm air in through the bottom of the cowl. I'd power all of it with a $400 portable generator.

Unless it is extremely cold, that setup should be able to significantly warm an engine within a reasonable amount of time - say 30 minutes.

IMO, the only thing your car could supply would be enough energy to turn the fan on a propane fired heater, and I'm not sure I'd be comfortable going that route.
 
Seth,

What is "cold"? Surely Seattle doesn't get below 10˚ F.

Here is what Lycoming has to say on the subject of pre-heating.

Lycoming said:
For most Lycoming models, preheat should be applied anytime temperatures are at 10˚ F or lower. The exception to this rule is the 76 series models that include the O-320-H, and the O/LO-360-E. These engines should be preheated when temperatures are below 20˚ F.

Here is the full page from Lycoming.

One interesting note in the Lycoming Operator's Manual is that the engine is warm enough to fly when you can advance the throttle and the engine does not stumble. No oil or cylinder head temperatures are give. (However, I wait until all my CHT's are up to 200˚ F before taxiing. Just my personal limitation.)
 
Hi, all. New RV8 owner in Seattle, need to keep the plane outside until a hangar opens up close enough to where I live...I've searched the threads and couldn't find the answer to this.

Is there a portable engine warmer that a technically challenged person can get that I can power off my car somehow (no electric available where I'm tied down) that can help me warm the engine a bit before I turn it over on cold days? Ideally, would like it not to be something I need to attach in any permanent way to the plane, and can keep in my car trunk.

Sorry if this is a silly question.

Thanks,

Seth

Maybe all you need to do for your motor in cold Seattle climates is to use this.... https://www.aircraftspruce.com/catalog/eppages/phillipsxc.php
 
I just looked at your outlook forecast and it isn't going below 40F at night. If you are already past the coldest part of this season, you may opt to delay the acquisition of a pre-heat solution. If, by the time you go for engine start, it's 45F or higher, you will likely have no problem with starting and will just need a bit more time for things to warm up.
 
Lots of good advice but here are some numbers.

350 lbs of metal
.215 btu/lb.F
want 80F engine
have 10F ambient
efficiency of heating - around 60% based on Reiff performance

You will need around 5000 BTU with insulated engine cover and no circulation loss to heat 40F temp delta. The calculation is ballpark equal to my Reiff actuals.

If you do it fast (Reiff takes 5 hrs with basic system) then you need more POWER. Either propane or amps. 5000 BTU is about 1.5 kw-hrs. If all electric, that is about 100 amp hours. Or 100 amps for one hour. A pretty heavy load for a car at idle.

Reiff won't heat it that fast, but is more universal. So a long extension cord w/Reiff or a generator for a few hours is a good bet and usable when the hangar is available.

If you want minimum temps, use the Lycoming recommended oil and starting temps, then just use a fast idle to warm the oil to a desired temp. Gasoline burned internally is pretty effective.

Propane is an option if you want to power a fan and use it in the back country in the future.

An insulated duct, a fan from the interior is looking pretty good, but think about how much flow and time that will take.

So pick your poison . . . path.

IMO Multiweight oil, picking a warmer day and using Lyc recommendations seems like a reasonable way to go. Just use 1000-1200 rpm to warm engine and oil before higher loads and RPM . . . . . like runup and TO. (Unless the extension cord will reach.)
 
So besides cowl blanket and covering the cowl inlet and outlet.... Car heater vent is anemic...

1) Put a sump warmer that is DC powered, plug into your car and wait an hour with blanket.

2) Buy or make one of the many store bought or DYI mini propane heater with flex duct and DC powered fan projects.... Google it. Kit Plane, EAA Sport Pilot have had articles.

With the aforementioned blanket 30 minutes of propane hot air in the cowl should knock the cold cobwebs off.

BTW I lived in Seattle Area for 15 years. It does not get that cold. I flew out of BFI as a CFI-I-ME and Part 135 charter pilot for years. I started airplanes cold all the time with no issues if temps were above freezing no issue. It's not a big deal. Just make sure you get OP after start and allow OT (Min is 165F) to warm up before T/O. Lycoming recommends pre-heat below 20F. Anything 40F and above pre-heat is not needed, wasted of effort and time (but what ever makes you happy, heating the engine or flying). You really don't need heat but your car vents are not going to hack it.

https://www.lycoming.com/content/operating-cold-weather

On my Piper Apache Twin I had at Harvey up in Snohomish. I used heated dipsticks for cars adapted for my O320's. The tip is heated and it sat in the oil. It used 120V AC. My covered parking had AC power available. It did a nice job of heating oil, cheap and portable. I commuted to BFI in the plane so faster warm up was needed. By the time I got to the end of the runway I had sufficient OT. Again Seattle is mild:

Seattle Hi/Lo Rain
December 46° / 39° 14 days
January 47° / 39° 14 days
February 49° / 40° 12 days
 
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Engine warmer

I have thought about this as well, from carrying a 27# generator, extra battery, inverter to power up my crankcase heater, extension cord. Add a couple of inexpensive sleeping bags for a blanket, then there are these 12 volt diesel heaters that put out 27KBtu, hoses, 2 gal diesel or jet a. Here is a link to the heater on amazon takes 3" ductinghttp://https://images-na.ssl-images-amazon.com/images/I/619O9O8CINL._SL1500_.jpg

Then i think if i were to overnight i'd just take an extension cord and get a couple of sleeping bags modify them to make an engine blanket.

Keith Rhea
RV7
2020 contributor
 
...
On my Piper Apache Twin I had at Harvey up in Snohomish. I used heated dipsticks for cars adapted for my O320's. The tip is heated and it sat in the oil. It used 120V AC. My covered parking had AC power available. It did a nice job of heating oil, cheap and portable...

The Lycoming document I referenced above states:
Lycoming said:
... Use of the heated dip stick is not recommended by Lycoming, although most other methods are considered to be satisfactory...
 
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Thanks so much -- great thoughts

Dear VAF friends,

What a great set of responses. Thanks so much.

What I am getting from this is that I'm overthinking it. In my climate, Lycoming (and several in this thread) say that it should be manageable without installing anything too fancy (and thanks to gmcjetman and N941WR for the Lycoming cold weather links). Those who said so are correct: It does not get bitter cold in Seattle (and when it does, I'm not interested in flying). I have no need to be up if it's colder than 20?F. The Lycoming article suggests that the magic is finding the right fuel-air mixture, and varying it (specifically, more fuel) when it's colder.

I do have multi viscosity oil in there, thanks to gasman for that link.

This parallels my recent experience; the couple times I've started it up when it was cold -- defined as high 30's after a colder night, so perhaps the innards are still cold -- I needed to run the fuel pump a second time and give it a few more pumps of throttle. It did not catch the first or second time I turned it over (and I took care not to turn it over more than a few seconds) but it did the third time, particularly when the throttle was open more than a crack.

I will just need to learn how to find the sweet spot for how many pumps and how open to keep the throttle with this engine when it's cold.

I really appreciate the good ideas and the links.

Perhaps most importantly: What a helpful, welcoming community. I feel so fortunate to be a part of it. Steep learning curve, but having so much fun.

Thanks so much,

Seth
 
The Lycoming document I referenced above states:

I don't care what Lycoming says I'm a rebel. :D It works great. The thing is you have get the right length that heats the tip only and is fully in the oil. First you pull regular dip stick and store it. Then put heated one in unpluged. Then you plug in. The danger is melting the tube I suppose. Well mine I made a custom top that screwed into the dip stick tube and held it secure. I had a guide mid way as well that kept it centered, and only very end of the dip stick was heated and totally in oil. Most of the length was not hot. If you got a heated dip stick that heated whole length it's a BAD THING. So when I got ready I unplug them and let it cool while I rolled up extension chords. It is a tad of a pain because you have to wipe oil off and then put regular dip stick in. I had PVC tube to store the dip sticks in. It worked. Now I had them on all night. So it likely is not going to work fast or extreme conditions. So I understand why Lyc does not recommend, it's a bit of a PIA.
 
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If you are priming the engine with the throttle - be very careful. It can dump a lot of raw fuel into the intake.
 
I'm going to ask what might be a very stupid question, but I have to ask. I'm in the south and it's never too cold to crank an engine, but here goes.

I'm an electrical contractor and we use heat boxes to warm PVC conduit on job sites. One cool day on the job we had to do some creative pipe bending and we did not have our PVC heater. I shoved the pipe up the exhaust on my truck, waited 5 minutes, and completed my job with my nicely warmed conduit.

So, why not plumb hot exhaust up into the bottom of the cowl? Any carbon monoxide will surely be gone before you get in the plane to crank it up. What do the masses think??
 
So, why not plumb hot exhaust up into the bottom of the cowl? Any carbon monoxide will surely be gone before you get in the plane to crank it up. What do the masses think??

I think the idea of blowing combustion products into the cowl is a really bad idea for many reasons you can think of I am sure... Keep in mind the airplanes exhaust is routed outside the cowl for a reason.
 
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after you preheat with engine exhaust your airplane engine will be soaking wet.
however.....one day my preheater was broken and the truck exhaust warmed my engine nicely.
 
I also have used pickup exhaust pipe to heat and bend PVC pipe, and seems like a good option for heating engine in a irregular, cold morning type day. I agree that moisture would condense on the cold surfaces. However, I fly thru the rain on occasion and things also get wet. Seems like a viable option to me if trying to fly out on a cold morning with no power out on a ramp some where. Seems like it would NOT be a good idea to preheat inside the hangar this way. I use a remote switched electric stick on type sump heater. Raises indicated temps about 10 degrees after 3-4 hours. Maybe I should look at the dipstick heater described above...
 
This is not to be taken as a suggestion, just an interesting (for me anyway) tidbit of trivia. I had a pilot that I worked with a few years back and his father commercially hunted predators from Cubs in some extremely cold temps in the Dakotas back in the 50s and 60s. It was so cold that the oil would be as thick as molasses in the morning. Their work around was to put quick drains on the aircraft and drain the oil into gas cans at night and take it home with them to be stored near the fireplace/wood stove. In the morning, they had nice warm oil to pour back in their frozen planes, which was about as good of a preheating system as they could devise back then.
 
Vehicle's Alternator?

Would the car's alternator produce enough power to power a dedicated engine pre-warming system? Turn the car on, run the leads off the car battery into an inverter or sorts, and then you could, in theory, have 120v and hopefully enough power to preheat the airplane's engine. 600watts is 50a @ 12v. I'm sure most automotive alternators are capable of well over 50 amps.
 
600 watts will be a pretty slow preheat.just a fyi if left on for 8 hrs. 450 watts to a 200lb jabiru would stabilize with a temp. 60-70 deg. above ambient. i would preheat 3 hrs if i could for oat of 20 deg.these were stick on pads.
seems that a small generator, probably need 2000 watts could do a preheat the fastest. and the little generator would come in handy for a lot of stuff.
you can increase the efficiency of the portable electric heater by .
1. have an intake hose for the heater. by putting this hose in the cowl you are not constantly heating 20 deg. air.
2. i put an inline duct fan in my output hose. probably almost tripled airflow fpm .
 
I lived in AK for 25 years and have a masters degree in preheating and deicing small aircraft.

If I have electricity I use a pan heater and ceramic heater (or hair dryer) for an hour or two.

If I?m in a hurry I use a MSR stove with a duct into the cowl.

Either way, the key is a fitted, insulated cowl cover.

Keep in mind this was on my 170a
 
Would the car's alternator produce enough power to power a dedicated engine pre-warming system? Turn the car on, run the leads off the car battery into an inverter or sorts, and then you could, in theory, have 120v and hopefully enough power to preheat the airplane's engine. 600watts is 50a @ 12v. I'm sure most automotive alternators are capable of well over 50 amps.

I used a cheap 1000 watt inverter when I assembled my 6 on the ramp with no elec source. The problem is that your car's alternator will no likely produce 600 watts of excess current while at idle. The energy draw for an hour might fully drain the battery.

Modern alternators are typically north of 100 amps, but don't produce that current below around 2000 RPM.

Larry
 
You can by an inverting Ryobi gas generator 2000W (2200W surge). Runs about 4 hours on a gal. Love it. Goes for about $500 Home Depot at today prices. I bought my a few years ago on sale for about $400. Home Depot often has coupons for 20% off.

It's equiv to the small Honda Generator with similar quality, and much better than a Harbor Freight Honda clone.

When I lost house power for a few days I put it in the back yard and ran a extension cord to run Frig, TV and a light. I could also run a small window AC unit with Frig disconnected. With Micro wave it had to be the only thing connected. It worked well in a pinch.
 
Perhaps a stupid question (Florida boy!), but can you just run a duct from the car exhaust pipe to the cowl?
Too much moisture?
 
Remember the spud in the t/pipe trick? If you do, you are dating yourself, like me.
I'd consider the exhaust of an idling car as warm, not hot, and would take forever to take the chill of an a/c engine. And yes it would be extremely moist.

Per post#19 - I heard stories from old time bush pilots about overnighting on some remote ice lake in -40+ temps, they would remove the battery and drain the oil and keep them near the camp fire, or they would be there for the duration...
 
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As already mentioned...

Post 9 references something very similar to this, but the link didn't work for me.

In my opinion, one of these diesel "parking heaters" is great option. Entire systems cost about $200, puts out CLEAN hot air (with exhaust all going out the other end) and does so on about 1/8th of a gallon per hour at full bore. They only use about 10A to start, but once they're running pull only around 2 amps. You could easily run one off of an old Odyssey for the hour or two you needed to to pre heat.

I have one in my camper (plumbed to the main fuel tank, with the exhaust routed outside obviously), and it is an absolute winner. I spend most of my weekend nights camping in the snow, and I run the thing on low to keep the camper at "t shirt weather".

I would say this is much cheaper, easier, and more efficient than using a generator to power an electric heater.

https://www.amazon.com/Diesel-Heate...s=diesel+parking+heater&qid=1582843689&sr=8-6
 
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A friend of mine made a preheater very similiar to this one and used it to preheat the APU on a Gulfstream in northern Greenland, outdoors, in the middle of winter.

https://www.youtube.com/watch?v=apetDu4o9e4

That appears to be based /built using an MSR dragonfly camp stove.
https://youtu.be/-7McMiGX9SY?t=46

They are a great camp stove and pre heater heat source. In my experience the white fuel/ kerosene/ jet A is worth carrying in a fuel bottle. Using LL100 ruins the pump cup seals in a single use. (even though the literature says you can use gasoline.)
 
You could check truck stops for 12V space heaters or blow driers. I think some canard home-builts used these for feet heaters.
 
A friend of mine made a preheater very similiar to this one and used it to preheat the APU on a Gulfstream in northern Greenland, outdoors, in the middle of winter.

https://www.youtube.com/watch?v=apetDu4o9e4
This cost $1000.
https://www.aircraftspruce.com/catalog/eppages/ncpreheater.php

I could make something with a small propane heater and some dryer flex duct for $100 - $200 that would work better.... Also not a fan of open flames under the plane. I went to Youtube and searched PRE-HEATER airplane. There are lots of ideas... some good some guaranteed burn your airplane and hanger to the ground. :eek:

You could check truck stops for 12V space heaters or blow driers. I think some canard home-builts used these for feet heaters.
I think these would be anemic, not enough heat to do much. However try it and let us know how it works.


Passive method is insulated cover https://www.aircraftspruce.com/catalog/pspages/bruces-cust-cvr-49.php?clickkey=40518 (commercial product is expensive).
An oil pan heater takes about 2-3 hours to work. It needs AC you can run on an extension cord to a friendly outdoor outlet or a small gas generator. It is safe and easy. No open flames near plane. With an insulated cover it should get the engine warmer than ambient.
 
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fwiw the 12 volt hair dryers are about 800 watts. 120 volt space heaters that can work well are 1500 watts.
not sure the wiring on all car cig. lighters can do it.
 
What about getting a Turkey fryer and rigging up a heater? I think that would really put out the heat.
 
My good buddy buys and sells these. Very convenient. Years ago they were available from major aviation retailers. Then they were discontinued for unknown reason.

 
just sold mine last year to a piper cub owner. he flies into wilderness a lot and his unit took a diver. they work! as i remember up to 40000 btu if you crank it up. you need 12 volts and a propane source. a one pound bottle doesn't allow the propane to boil fast enough. maybe a 5 would work. 10 lb for sure.
mine was a red dragon.
 
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