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Show us a picture of your Home made pre Heater

Redbud40

Well Known Member
Finally winter in Texas. Anyone care to show off their pre heat units they made. I tried using a cheap floor heater with some tubing to stick in inlets and exhaust area but it doesn’t quite work like I thought. Looking for ideas.
Thanks.
Red
 
Scrounged stuff...

Easy to use, timer turns it on a few hours before start.
 

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Cowl Plugs in

Timer setup night before or get to hangar before flight and turn on. I live in GA, plane in insulated hangar, never 40 degrees or below in hangar. Shove end of flex pipe over Left exhaust pipe.
 

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Timer setup night before or get to hangar before flight and turn on. I live in GA, plane in insulated hangar, never 40 degrees or below in hangar. Shove end of flex pipe over Left exhaust pipe.

I've seen all varieties of that kind of milkhouse-heater modification, and I'm sure its value as an engine preheater will substantially depend on where and how the plane is hangared. In this climate, it seems to be more applicable to cockpit heating and that's what I use mine for. It was -30F over the weekend here, so adequate pre-heating of the engine means 8+ hours means a substantially more robust effort with an all-out Rieff preheater.
 
Pic not practical

https://www.aircraftspruce.com/catalog/eppages/sumpheaters.php

Attach to a solenoid driven by a cheap cell phone switch. H2O wireless will sell you a sim card and service for $3.00/mo. Call it up to switch on or off however long you need before your preflight.

For me it's four hours prior at 15F

Advantage of the adhered heaters over a hangar-based heater is the portability.

Amazon has a switch for $139 (Not my sale, just showing theirs): https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
 
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Cheapest cell phone switch I could find was Switcheon at $249 for two plugs, and free cell service for one year. Subsequent years cost $4.00 per day ($50/year). No sim, just a nice app using IoT G5 or LTE with actual feed back as to whether or not the switch actually turned on. Great device, has never failed me and I use it a lot. I have the cockpit heater on the other circuit so I can turn on both devices separately or together
 
i don't think i would risk an unattended heater with an electric motor and a heating element that glows red unattended, let alone in a hangar that is already 40 deg.
 
i don't think i would risk an unattended heater with an electric motor and a heating element that glows red unattended, let alone in a hangar that is already 40 deg.

I agree. I just bought one of these heaters for the cockpit and plan to plug it into the other outlet on my Switcheon. It looks like I'll be a lot more comfortable than using the milkhouse heater with a bunch of aluminum foil. I'll turn it on as the same time as the Rieff preheater in hopes that my cockpit will be as toasty as the engine when I come out to do a little Minnesota winter flying.

https://www.aircraftspruce.com/catalog/eppages/aircraftheaters_08-12224.php
 

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My hanger mate allows me to borrow his. Way overkill, but it will warm up the engine quickly. I use it on the lowest setting, being careful not to damage the paint. (sure wish I could figure out how to rotate an attachment)
 

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I am not trying to be a smart @$$ or to hijack this thread.

My DIY preheat is shown here. Able to turn heat or AC up or down from an app on my smartphone.

IMG_0370.jpg

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Hair dryers

I use a hair dryer in each cowl inlet inserted into a piece of foam - petty simple. I use a cellular switch to turn them on 15-30 minutes before I want to fly (depending on outside air temperature). I've used this setup here in Iowa for 12 years on my 7A, and over 30 years on my other homebuilt. Every ten years or so I need to replace a hair dryer - slide one out, slide one in.

Be careful with milkhouse heaters if they sit on the floor. We had a local guy develop a fuel leak and it was ignited by his milkhouse preheater. It completely destroyed his plane and ruined two others in adjacent t hangars. My hair dryers are well above where fuel vapors would accumulate - plus the hangar is well "ventilated" (not well sealed!!).

AM-JKLX3DB0sYrvb5IdMyeYckzSDnoKtqkYfC_dwvawEIab-J_uTUTWtgWfF4zx9o63qARu29BuHWhDPmTVNxJqgBZgODF49jh9YqzPVuP3MiPMltuWWwhHTxIWO-7ZxTDzwERqgYPqFjXq0jYH6sjoFVd3c=w1140-h855-no
 
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My hanger mate allows me to borrow his. Way overkill, but it will warm up the engine quickly. I use it on the lowest setting, being careful not to damage the paint. (sure wish I could figure out how to rotate an attachment)

Rotated.

IMG_4465 - rotated.jpg
 
I am not trying to be a smart @$$ or to hijack this thread.

My DIY preheat is shown here. Able to turn heat or AC up or down from an app on my smartphone.

View attachment 20511

View attachment 20512

No question….a great solution. IF one had internet AND insulation AND air conditioning AND a lot of $$$ to pay the utilities and hangar cost. For the rest of us….it’s whatever we can scrounge up out here in Dogpatch.

For awhile last winter, I had a big (for me) avionics project, and to keep warm I brought in a couple of 120,000 BTU bullet heaters. They did a good job of keeping the hangar warm enough to do a few hours work. The downside, in my un-insulated corrugated-sheet metal T-hangar, is that it melted the snow on my roof and it promptly ran down the front, flooded the front of the hangar, and froze the hangar door to the shut. I ultimately was able to persuade a buddy to swap hangars for a few weeks (his is insulated and heated). After I chipped my door open, I moved my plane out and his in and finished the project basking in the luxury of natural gas while the temps outside routinely plunged to -20F. I shed tears when I had to move out and swap back.

Lesson learned. It was fun to see how the other half lived.
 
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i need to take a pic of my $5 electric frying pan from goodwill.put all the tools you are using in the pan. like someone said cold tools are cold.
 
My heater

Here is my heater, I only use it when I’m at the hangar. I install cowl plugs and it doesn’t take long to warm it up.

B9FE50F8-F88E-41DC-A93E-73EA845A321B.jpg

I installed a sump heater that I plug into a timer if I want it to come on before I get to the hangar for the Saturday morning Breakfast flights.

EZ Heat Model 440 from Spruce
 
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I just built a new 3000W version using it on different planes. So the height is adjustable and the heater itself can be swiveled. It works very well and blows into the air outlet heating up the whole engine and battery if installed firewall forward. For the A-models there is probably a different adapter required. My only concern is when the fan fails it could overheat and is then a fire hazard. I might install a second fan just in case.

WpOSTWb.jpg
 
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This is a 900w interior car warmer, metal casing, mounted on an aluminum base. The extra lighter gauge 'flap' clips over the cowl pins to hold the heater in place. Compact size makes it easy to pack, has proven effective in Canadian winter for 10 years.
 

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A ceramic 1500-3000W heater, few cheap ventilation accessories, some soft foam. I just build the composite cone to connect heater and ventilation connection.
 

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Very innovative and ingenious bunch yall are.
But the big question is, does the forced air heaters via a cowl raise the oil temps up?
 
This is a 900w interior car warmer, metal casing, mounted on an aluminum base. The extra lighter gauge 'flap' clips over the cowl pins to hold the heater in place. Compact size makes it easy to pack, has proven effective in Canadian winter for 10 years.

Used the exact same heater in Piper Navajos down to -30*c, one heater per engine. wrapped in engine tents, cowl plugs for extra measure. Even used it in a deHavilland Beaver one fall with an old blanket wrapped over the front. The Beaver was on floats, so not terribly cold.

If it works for the turbocharged angle valve TIO-540 and the R-985, I'm sure it's fine on an RV.
 
Very innovative and ingenious bunch yall are.
But the big question is, does the forced air heaters via a cowl raise the oil temps up?

Gotta remember they take in ambient air, heat it then push. I’ve used outside and it struggles, inside my hangar I can raise temps on oil by10-15 degrees an hour.
 
Cheapest cell phone switch I could find was Switcheon at $249 for two plugs, and free cell service for one year. Subsequent years cost $4.00 per day ($50/year). No sim, just a nice app using IoT G5 or LTE with actual feed back as to whether or not the switch actually turned on. Great device, has never failed me and I use it a lot. I have the cockpit heater on the other circuit so I can turn on both devices separately or together

I use a Ting hotspot that costs $3/month, but ends up being around $9 with taxes and data during the winter months. I have my battery charger and preheater connected via cheap $5 wifi outlets and it works great. I can set it on a timer or just turn the heater and charger on/off with my iphone. Very cheap and works great.

Wifi Plugs here.
https://www.amazon.com/gp/product/B09J2LHXNG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Silicone pad sump heater here. I paid $79 for it, but the price seems to have increased.
https://www.amazon.com/gp/product/B0174AUQI4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

This heater has worked great. I had the overpriced Reiff HotStrip sump heaters and it failed(burned) in the first 25 hours +/-. The folks are Reiff wouldn't honor the warranty since I wasn't the installer, so that was the end of my Reiff experience. No more business. The silicone above works much better and was a fraction of the price.
 
Warming heaters

I have been using 2 heaters to warm my plane up. I keep the front electric heater that is ducted into the plenum inlets on to come on at 40 degrees so it runs most of the time. The propane torpedo heater gets turned on when I get to the hangar to fly and the inlet heater gets turned up to high. It sits under the fuselage blowing 150 degree air at the bottom of the fuselage and into the exhaust area. The cowling has a thick foil on one side, green tarp material on the other side and then a sleeping bag to help keep the heat in. (UTOOL Heavy Duty Emergency Blanket, Waterproof Insulated Tarp) It works great.

I can get my engine and cabin warm and ready to start in about 30 min at 10 degrees. I can get the plane warmed up but I have not been able to make it warm enough in the hangar to do any work. It is a metal, non insulated, air leaking poster child for a crappy winter hangar!!
 

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Although it is more ducting, all the ideas in this thread would be more efficient if the cowling "outlet" air was recirculated to the heater "inlet". Just saying.
 
I was once told by a old timer that if your oil temp is above 40 it’s best not to preheat unless you are going to apply the heat for 4 hours or more minimum depending on hangar temperature. His rationale was that most preheating causes inconsistent heat transfer in the engine and parts are at different temperature points and hence different expansion or contraction levels causing increased wear during startup not anticipate in the design of the engine. He stressed that with oil temps below 20 degrees 8 hours should be a minimum preheat time.
Thoughts?
 
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Very innovative and ingenious bunch yall are.
But the big question is, does the forced air heaters via a cowl raise the oil temps up?

The both :D

But when you pre-heat via the bottom cowl, the heat rises through the cylinders and you have a better oil preheating.
 
Although it is more ducting, all the ideas in this thread would be more efficient if the cowling "outlet" air was recirculated to the heater "inlet". Just saying.

Unless you had well insulated ducting the heat loss would be greater in the return air line to the heater. By the time the air moves through the engine and out the bottom most of the heat has been absorbed by the engine.

For a system to pre heat the engine to an acceptable level, pumping hot air into the inlets through the plenum and having it leak out the bottom has proven a good solution for me. With my plenum, it is using the same air path used to cool my engine to heat it.
 
Unless you had well insulated ducting the heat loss would be greater in the return air line to the heater. ....

Of course the return air forced back into the heater would have heat loss. Otherwise, nothing gained! Come on...it won't be cooler than new (un-recirculated) cold air!
 
Of course the return air forced back into the heater would have heat loss. Otherwise, nothing gained! Come on...it won't be cooler than new (un-recirculated) cold air!

Im not saying it wouldnt be better. I am saying the benefit is not worth the cost or effort to me. It is not easy to seal off the exhaust area and slot cut for the nose wheel. I cant imagine what type and shape of plenum would be needed to seal around the exhaust pipes. I have several scratches on my head now and trying to set up a return air system while crawling on frozen concrete doesnt make sense to me. If you want to deo that on your plane, take some pictures so we can all learn something.
 
Thanks for all the ideas. Decided to go with a combo from the suggestions. Hope you all didn’t have patents working😀
 

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Reiff Heating System

All these look pretty cool and I'm sure they all work well but it seems like a lot of work for something that already exists.

The Reiff system with cylinder bands and oil sump heating plate keeps everything nice and toasty here in Michigan. And of course a remote on/off switch.
 
All these look pretty cool and I'm sure they all work well but it seems like a lot of work for something that already exists.

The Reiff system with cylinder bands and oil sump heating plate keeps everything nice and toasty here in Michigan. And of course a remote on/off switch.

Im interested in your remote on/off switch. I may fly over KOZW tomorrow if the weather is as forecasted.
 
Wife and I needed to make a trip to N Texas a couple weekends ago and I knew the Temps the morning of departure was going to be in the 20's! I needed something to preheat a little for sure! I dug around and came up with an old hairdryer and a 8" piece of thin walled galvanized pipe and brought along an extension cord. We got to the airport it was 27 deg, I pushed the plane over near a 110v outlet and inserted (wedged) the hairdryer in between my 4 pipe exhaust. The end of the 2" pipe was about an inch from the oil sump. I left my cowl plugs in and fired it up and then we went in the FBO and watched 1 episode of Leave it to Beaver, checking on the hairdryer several times to make sure I wasn't burning up the plane. To my surprise and delight, the oil temp came up from 27 deg to 76 in about 35 minutes!
 

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Wife and I needed to make a trip to N Texas a couple weekends ago and I knew the Temps the morning of departure was going to be in the 20's! I needed something to preheat a little for sure! I dug around and came up with an old hairdryer and a 8" piece of thin walled galvanized pipe and brought along an extension cord. We got to the airport it was 27 deg, I pushed the plane over near a 110v outlet and inserted (wedged) the hairdryer in between my 4 pipe exhaust. The end of the 2" pipe was about an inch from the oil sump. I left my cowl plugs in and fired it up and then we went in the FBO and watched 1 episode of Leave it to Beaver, checking on the hairdryer several times to make sure I wasn't burning up the plane. To my surprise and delight, the oil temp came up from 27 deg to 76 in about 35 minutes!

Oh man! My wife has had enough hair dryers die a sparking death over the years that I can't even imagine leaving an unattended hair dryer anywhere near my airplane.


All these look pretty cool and I'm sure they all work well but it seems like a lot of work for something that already exists.

The Reiff system with cylinder bands and oil sump heating plate keeps everything nice and toasty here in Michigan. And of course a remote on/off switch.

Yeah, this. At least something that doesn't use a red-hot glowing element in a volatile environment and has a track record of safety for airplane-warming. I have both my new cockpit heater and my Reiff engine pre-heater on a cell-phone switch and that makes the whole thing very convenient.
 
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All these hair dryer remedies give me the creeps. I would not leave my plane unattended with those setups. To me it is a recipe for disaster.
 
Yup. Same thing for me in Ohio. Just plug it in and leave it on. I do open up my oil cap when I leave it on for lengthy time. Put heavy blankets bungee corded around cowl. Keep a my oil at 75F
I know the debate about moisture and corrosion. But I fly often.
 
This is a fun thread to watch just for some of the crazy-wonderful innovations!

But I'm seeing some people focusing on oil temps and getting heated up in short times (like, an hour or less). According to Mike Busch on Engines,
All the warm oil in the world won’t help if the crank-to-bearing or piston-to-cylinder clearances go to zero. To avoid this, it’s essential for a preheat to warm up the both crankcase and the cylinder barrels.

That takes time and is probably why Reiff shows warming times in hours not fractions of hours. Just sayin'.
 
According to Mike Busch on Engines,
All the warm oil in the world won’t help if the crank-to-bearing or piston-to-cylinder clearances go to zero. .


Does Mike have numbers for when our engines cold seize?

Seems like the aluminum and copper and babbitt would shrink faster than the steel by their coefficients of expansion/temp
 
Does Mike have numbers for when our engines cold seize?

Seems like the aluminum and copper and babbitt would shrink faster than the steel by their coefficients of expansion/temp
I think the book has those numbers but I don't have it handy at the moment. And he mentions that the numbers won't be the same for every engine since engine wear will be a factor. There's good info in this article at AOPA, but I really think it's worth getting the book, and not just for this. Tons of good info on preheating, cooling, oil, repairs, operation, maintenance etc. especially for people like me who are good with a wrench but not necessarily engine experts.
 
I like #26 blanket. If you look at any real cold weather operators, Northern Canada, Alaska parked outside they put insulated covers over cowl.

Never have done this but some use King Sized electric blanket and wrap the cowl and stuff in the cowl inlets and exit. It may not be fast but it seems to work if allowed to run for several hours or overnight. Is it safe? Up to you to decide. I don't see why not.

Biggest wear factor is long periods of disuse. Flying to full operating temps for 30-60 minutes daily daily makes engine last longer. Short run ups are the worst. If it's above freezing and see oil pressure right after start you are good. Min oil temp before take off? Some say 100F. Lyc states no stumble when applying takeoff power. OP in green of course.

Lyc says
Prehead required when 10F or lower (some 320H models 20F).
Don't over prime (I prime and wait 30 secs or more to crank letting fuel vaporize)
OP indication right after start shortly after normal delay as during warm temps.
Do not low idle (1000 RPM min) to avoid lead fowling of plugs.
When flying OT 165 to 220F
 
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I like #26 blanket. If you look at any real cold weather operators, Northern Canada, Alaska parked outside they put insulated covers over cowl.

I understand and agree with the value of using a blanket or similar insulated cover if there's a heat source...it makes the heat source, like a Reiff preheater, that much more efficient by limiting convective loss while heating. And I agree that it helps retain engine heat (for a few hours) if applied after shutting down an engine. But after a few hours (depending on the efficiency of that particular blanket) on a cold ramp without any external heat source, the engine will be at ambient air temperature and the blanket accomplishes nothing.
 
Data Points for Reiff

I have two Reiff heater pads adhered to my oil pan.

Overnight temp was 15F. 4 hrs on with cowl plugs in and horse blanket over top of cowl. Prestart oil temp indication was 67F, CHT 52F. Immediately after start oil temp rose to 90F.

Considering where the CHT probes are I think it safe to assume the cylinder barrels were warmer than 52F.
 
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