Best Preheater

[Darren Kerns]

Guys,
I am thinking about installing Van's engine preheater on the bottom of my oil pan. Any thoughts or suggestions?

Darren Kerns
RV8 N214TK

 

[KirkGrovesRV8]

Reiff

I have the Reiff hot strip on my oil sump and really like it, it brings my oil up to near 100 even with 20 def temps.

 

[pierre smith]

Auto/aviation dept..

I have the Reiff oil pan heater and it's really great but I saw on here last week that there are automotive sump heaters for around $49-$59. Might want to check.

The big benefit of warm/hot oil is the cam lobes and cylinders rely on splash oil for lubrication and cold oil doesn't "splash" very well.

Regards,

Regards,

 

[N941WR]

Has anyone used NAPA?

Check out this link.
They have hot pads from 25W for $17.39 to 500W for $91.09 and a bunch in between.

They also have a 90 W dipstick type heater for less than $20.

 

[keithschult]

Tanis preheater

I like the Tanis I put on my 6A. It heats the cylinders and the oil. These fall days my oil temp before startup is 108-109F, and the cylinders are very warm. In the cold of winter, especially when traveling, it is so good that I don't even need the insulating blanket they supply with the preheater, just the cowl plugs.

 

[Darren Kerns]

EZ Heat

Guys,
I just ordered one from Spruce. EZ Heat. I think I will like it. At least I hope I do.
Thanks to all,
Darren Kerns
RV8 N214TK

 

[plehrke]

I have the Reiff

Has anyone used NAPA?

Check out this link.
They have hot pads from 25W for $17.39 to 500W for $91.09 and a bunch in between.

They also have a 90 W dipstick type heater for less than $20.

I would recommend against the dipstick heater since the oil fill tubes are now plastic. Also they are not recommended by Lycoming in there Flyer of Key Reprints. Does not say why.

I have the Reiff heater for the sump and like them a lot as mentioned by others.

 

[N941WR]

I would recommend against the dipstick heater since the oil fill tubes are now plastic. Also they are not recommended by Lycoming in there Flyer of Key Reprints. Does not say why.

Only on new engines. In my O-290 the tube it good 'ol metal.

I wonder why Lycoming recommends against the dipstick. Could it be that you leave the tube open to bugs and such?

I'm thinking I might go with one of the pad heaters from NAPA.

 

[Geico266]

Anyone have a NAPA size they have used? 25W.........100W? I would leave it plugged in all the time. I would think 100W would be okay.

 

[Adam]

I was told that the dip stick heaters can "cook" the oil because of its hi tip heat which can be over 400.F

 

[Geico266]

The NAPA heaters do not have thermostats on them like the Reiff. I would rather just plug it in and leave it on all the time in the winter. Going to the airport 3-4 hours before a flight does not work for me.

I use a "milk house" heater with house hold ducting to put heat into the bottom of the cowel.

 

[plehrke]

Timer

The NAPA heaters do not have thermostats on them like the Reiff. I would rather just plug it in and leave it on all the time in the winter. Going to the airport 3-4 hours before a flight does not work for me.

I use a timer to turn on the Reiff heater at 2pm every work day to have it warm if I can get to the airport to fly in the evenings after work. It shut the heater off again at 5pm so if I am not there to go flying it just shuts off. The same is true from Sat and Sun mornings. On at 5am and off at 9am. This way I do not need to have it on all the time but it is read and warm if/when I get there.

 

[frankh]

Or use a smaller heater

The NAPA heaters do not have thermostats on them like the Reiff. I would rather just plug it in and leave it on all the time in the winter. Going to the airport 3-4 hours before a flight does not work for me.

I use a "milk house" heater with house hold ducting to put heat into the bottom of the cowel.

I use 2*50W heaters and leave them plugged in all the time. Hottest oil temp I have ever seen is 110F on a warm spring day.

During the 30F OAT I get about 75F oil temp.

I just use mine during the 4 cold months of the year.

This seems better than waiting for a preheat, i.e just unplug and go fly.

This works for relatively warm western oregon

Frank

 

[frankh]

Yup!

Anyone have a NAPA size they have used? 25W.........100W? I would leave it plugged in all the time. I would think 100W would be okay.

I have 100W total without a 'stat...Works great in Western OR...Might want 150W in say Minnesota.

Frank

 

[N941WR]

I wonder why Lycoming recommends against the dipstick. Could it be that you leave the tube open to bugs and such?

I found out why...

They don't sit down in the oil far enough and the part that sticks out of oil does a nice job of turning red and burning the oil at the surface.

 

[asav8tor]

I use a timer to turn on the Reiff heater at 2pm every work day to have it warm if I can get to the airport to fly in the evenings after work. It shut the heater off again at 5pm so if I am not there to go flying it just shuts off. The same is true from Sat and Sun mornings. On at 5am and off at 9am. This way I do not need to have it on all the time but it is read and warm if/when I get there.

2 schools of thought.

(1) plug it in and leave it on all the time.

(2) plug it in and go fly.

If you have it on a timer and it goes on and off every day, each time it heats up the warm air has the ability to hold more H20. It can come in through the breather, exhaust pipes, or evaporate out of the oil. Then when the cool down happens after the timer goes off the moisture will condense inside the motor on things like...... the cam!

You are setting yourself up for rust by cycling the heat on, off, on, off, etc.

I like heat but when you unplug it is time to go fly that way any air that might have moisture will blow out the breather rather than cooling and condensing on steel parts.

 

[plehrke]

I agree

You are setting yourself up for rust by cycling the heat on, off, on, off, etc.

Thanks for the input. I actually fly just about every day and when there are periods of time when the weather is bad and I can not fly, I unplug the heater. I try to not have many cycles when it just cycles on and off without me starting the engine.

 

[randylervold]

My plan

I use 2*50W heaters and leave them plugged in all the time. Hottest oil temp I have ever seen is 110F on a warm spring day.
During the 30F OAT I get about 75F oil temp.
I just use mine during the 4 cold months of the year.
This seems better than waiting for a preheat, i.e just unplug and go fly.
This works for relatively warm western oregon
Frank

Frank,
I'm in Western Oregon/Wash too, at Pearson in fact. I just ordered one of the 50w versions and will install it when it arrives, thanks for the tip on NAPA.

Just curious, how are you determining oil temp? Your engine's oil temp sensor is up at the top of the accessory case.

I plan to install only one 50w version first and see how it does. Cycling it on/off with a timer sounds like an invitation to condensation to me, I'll just leave it on all the time. From reading the description online it sounds like it is adhesive backed. Is that the case, and is the supplied adhesive working?

Thanks,
Randy

 

[Capflyer]

Frank,
I'm in Western Oregon/Wash too, at Pearson in fact. I just ordered one of the 50w versions and will install it when it arrives, thanks for the tip on NAPA.

Just curious, how are you determining oil temp? Your engine's oil temp sensor is up at the top of the accessory case.

I plan to install only one 50w version first and see how it does. Cycling it on/off with a timer sounds like an invitation to condensation to me, I'll just leave it on all the time. From reading the description online it sounds like it is adhesive backed. Is that the case, and is the supplied adhesive working?

Thanks,
Randy

It's that time of year again and I need to do something. How did this end up working out for you last winter Randy?

Are there any other types of homebrew pre-heaters that anyone has made that work and can you share your designs?

 

[randylervold]

My 3 part system worked great last year, have started repeating it this season. Details on my winter ops regimen here.

 

[AlexPeterson]

I'm a fan of putting a line break thermostat (like those used in home electric heat) on the end of a power cord, and blanketing the cowl. The thermostat fits in through the oil door. Whichever heaters are used, this maintains 70F, for example, on everything under the cowl. I happen to have the Reiff sump and cylinder band heaters as well, in case I get stuck outside somewhere.

Whatever is stuck to the sump, be sure it can't foul the throttle or mixture linkage should it get loose.

 

[Sam Buchanan]

My 3 part system worked great last year, have started repeating it this season. Details on my winter ops regimen here.

Randy,

I just checked out your link and agree that engine heating is a good thing:

http://thervjournal.com/cold.html

I flew this morning (21F) and the oil and CHT was ~50F when I arrived at the hangar.

I did notice, however, your stated concern about aviation sump heaters "coking" the oil. The Reiff heater I use has an internal thermostat that limits heater temp to 150F. Since normal operating temp for our oil is 180F or above, I don't see how 150F would compromise the oil. I would be much more concerned about automotive sump heaters that have either no thermostat or thermostats of unknown value.

The cabin heater you use is a good way to inhibit condensation and more than likely something many pilots have not considered.

 

[randylervold]

Hi Sam,

My concern, probably unfounded, is that as the powerful sump heaters that raise the oil temp to 150? or so are getting the oil quite a bit hotter than that at the case surface. Think of the mass that needs to be heated in order to get the sump oil up to 150?. No doubt I'm over-thinking it and this is probably not a factor.

To those interested, of the three things I use for winter management I think the dehumidifier makes the most difference in keeping rust/corrosion off everything in the hangar, including the plane, and may therefore be the most important of the bunch.

FWIW,

 

[AlexPeterson]

Hi Sam,

My concern, probably unfounded, is that as the powerful sump heaters that raise the oil temp to 150? or so are getting the oil quite a bit hotter than that at the case surface. Think of the mass that needs to be heated in order to get the sump oil up to 150?. No doubt I'm over-thinking it and this is probably not a factor.

To those interested, of the three things I use for winter management I think the dehumidifier makes the most difference in keeping rust/corrosion off everything in the hangar, including the plane, and may therefore be the most important of the bunch.

FWIW,

Wow, dehumidifier. We certainly don't need those in MN in the winter! Most dehumidifiers aren't designed to operate below about 50F. We do need them in the summer however...

I believe the Reiff pads are 50 watts apiece, so around 100 watts on the sump. No way that will cause any noticeable localized high temperatures.

I know the rubberized mats can be a problem if they are not in intimate contact with the sump across the whole area. They will fry in those spots, so be sure to get the entire area stuck down.

 

[rocketbob]

I have one of these, and it works great:

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200339139_200339139

Its the same Kat's heat pad that Napa sells. This morning my oil was at 88 degrees when I pulled the airplane out to go to breakfast.

Amazon.com has them, and if you buy something else with it you'll get free shipping:

http://www.amazon.com/Kats-24150-Wa..._3?ie=UTF8&s=automotive&qid=1227383063&sr=1-3

 

[Kyle Boatright]

I live near Atlanta. My solution (while my hangar had electricity) was one of the Reiff hot strips and a timer. I set it so the heater would come on on Saturday morning about 4 AM and go off by 10 AM. In 25 degree weather, 3-4 hours of preheating gives me 100F oil temps and noticable warmth inside the blanketed and plugged cowl.

Now that I'm without electricity, I have a generator which I use to run 2 blowdriers and the reiff hotstrop for 20-30 minutes. Not as effective as several hours with the hot strip, but after 30 minutes the oil temperature is 30 above ambient. I don't know what impact this has on the cylinders, but it is some...

 

[Sam Buchanan]

Hi Sam,

My concern, probably unfounded, is that as the powerful sump heaters that raise the oil temp to 150° or so are getting the oil quite a bit hotter than that at the case surface. Think of the mass that needs to be heated in order to get the sump oil up to 150°. No doubt I'm over-thinking it and this is probably not a factor.

I understand your thinking, Randy, and I think this would likely be the case with some of the heavy-duty unregulated auto heaters. But, it is my understanding the aviation heaters are regulated to 150F at the heater. The oil sump on my engine never gets painfully hot to the touch. After eight winters, I haven't seen any evidence of harm caused by the sump heater.

Someone mentioned the pad-type heater failing if not bonded completely to the sump. My first heater failed after one year and the manufacturer claimed it was due to a very small area of the heater not being completely bonded. I have reason to be less than convinced that was the case, but this is why the aviation heaters now on the market are usually rigid in construction so they will be more tolerant of less than perfect installation.

 

[rocketbob]

I understand your thinking, Randy, and I think this would likely be the case with some of the heavy-duty unregulated auto heaters. But, it is my understanding the aviation heaters are regulated to 150F at the heater. The oil sump on my engine never gets painfully hot to the touch. After eight winters, I haven't seen any evidence of harm caused by the sump heater.

I think your fears are unfounded. Why don't deep fryers burn vegetable oil when the burner's turned all the way up?

In this case the pad heater is at a temperature much lower than a flame on a stove.

I'm inclined to think a pad heater with a thermostat is doing nothing more than slowing down the heating process.

 

[IowaRV9Dreamer]

Reiff works great for me

I just installed the Reiff standard system on my Skipper. There are no thermostats involved. The sump heater is rigid (steel) and is attached with JB Weld to the case. The thermal transfer is very good - on a cold engine you can plug the heat in and the outside of the pad is very quick to get super hot. If you unplug it, the heat goes into the engine oil within like 30 seconds.

So far it's not been that cold (down to about 10) and the engine is comfy warm. Between the sump and cylinder band heaters, the whole engine compartment gets toasty (I'd say 70 degrees). The engine starts on the first blade and the oil temperature goes up as soon as the pump pushes it up to the sender. The oil is kept warm, but below normal operating temperature.

For the record, I'm leaving it plugged in all the time. We had a 172 back East (kept outside) that ran a Reiff heater 24/7 all winter and the engine went to TBO+300. I'll be installing the same system on my RV.

Whatever system you use, it is critical to insulate the entire engine compartment, with nose plugs and a thick blanket on top.

Stay warm!

 

[grantcarruthers]

I'm about to install the Reiff heater and as Sam points out, installation of the other types can lead to failure. Several reasons to go with the Reiff: internal thermostat so no cooked/coked oil, cheaper than brand Y, will honor the warantee even if installation wasn't perfect (they redesigned theirs to allow for imperfect contact although you still want to try real hard to get complete contact).

Reiff has a great website that I read through while deciding what to do about this winter. I think for any hangered, blanketed, and plugged RV that a sump heater like theirs is all you'd need. If it's just stupid cold where you're at you can add the cylinder warmers they've got after trying a sump heater by itsself.

And they're pretty clear that just leaving it on is the best way to go. They even did some tests or link to a test where an engine was left on a heater for a week and the relative humidity went down inside the engine so one could hope that less vapor means less rusting potential. So leave it on all winter or just a few hours before flight. I wouldn't cycle by timer but I'm just parroting their info.

 

[grantcarruthers]

Looks like I was typing at the same time as Iowa, sorry for the apparent duplicate info.

One thing to add/correct, according to the website the Reiff has an integral thermostat that limits temps to 150 degrees at the pad/sump to decrease the chance for burning the oil at the sump interface.

Anyway, looked at the Amazon heating pad, and it's cheaper for sure. Not so sure I'd be happy with the adhesive attachment. One concern with any heater is if it falls off the sump into the cowl. Not sure this would cause a fire or do damage at 150 watts but the JB weld on the REIFF sounds more secure than the adhesive on the Cheapo??

Anyone had a heater fall off, any damage from the heat going to the cowl?? What temp would these pads generate and what would the cowl do at those temps??

 

[IowaRV9Dreamer]

One thing to add/correct, according to the website the Reiff has an integral thermostat that limits temps to 150 degrees at the pad/sump to decrease the chance for burning the oil at the sump interface.

Hi Grant - I'm not sure that's true for the standard system. Their "Turbo" system (which has 2 sump pads) has an external thermostat, but I'm 99% sure my HotStrip doesn't.

I do recall calling and asking, because I was concerned about it. The answer I got was that it doesn't need one, since it can't heat up enough to do any damage. I think that is true - once the strip is bonded onto the sump, you can really feel how the heat transfers right in. The only place that is really hot is the outer (non-sump) side of the HotStrip. That's pretty much true for the cylinder band heaters as well.

 

[Kyle Boatright]

Hi Grant - I'm not sure that's true for the standard system. Their "Turbo" system (which has 2 sump pads) has an external thermostat, but I'm 99% sure my HotStrip doesn't.

I do recall calling and asking, because I was concerned about it. The answer I got was that it doesn't need one, since it can't heat up enough to do any damage. I think that is true - once the strip is bonded onto the sump, you can really feel how the heat transfers right in. The only place that is really hot is the outer (non-sump) side of the HotStrip. That's pretty much true for the cylinder band heaters as well.

My hotstrip has a thermostat. It is glued to the sump several inches away from the hotstrip.

 

[hevansrv7a]

Primitive but Effective

I threw a large tarp over the engine area from prop to aft of firewall, clamped it around the prop and in front and to a large sheet of cardboard that fits from ground to belly aft of the pipes. Three spring clamps. The tarp is folded once, so it traps some dead air, but an insulating blanket would improve this setup somewhat.

Now in the cave thus created, on the ground, I put a small ceramic heater, 1500W, with its own thermostat. The entire engine is kept reasonable warm at all times in our miserable Michigan winter. The heater was "surplus" so my total outlay was about $20.

Although this would keep the engine free of condensation, I continue to keep my engine dryer on, too.

The only drawback to this is it does nothing for travel.

 

[Reiff Preheat Systems]

One thing to add/correct, according to the website the Reiff has an integral thermostat that limits temps to 150 degrees at the pad/sump to decrease the chance for burning the oil at the sump interface.

Anyway, looked at the Amazon heating pad, and it's cheaper for sure. Not so sure I'd be happy with the adhesive attachment. One concern with any heater is if it falls off the sump into the cowl. Not sure this would cause a fire or do damage at 150 watts but the JB weld on the REIFF sounds more secure than the adhesive on the Cheapo??

Just want to clarify... our thermostat is bonded to the sump several inches from the heating elements specifically so that it will measure the oil temp and NOT the temp of the heating element. It will keep the oil from exceeding 150F.

Localized overheating at the spot where the heating element is installed is avoided by properly sizing the element, i.e. watt density. And we had to prove it will not burn the oil to get FAA-PMA approval.

Our FAQ #18 addresses this in more detail ( http://www.reiffpreheat.com/FAQ.htm#QA18 :

Will the oil sump heater overheat the oil?
No. As stated in the performance tables, the maximum oil temperature rise produced by our highest wattage system (Turbo XP) is about 130oF above ambient. A thermostat further limits the oil temp to about 150oF. The temperature of the oil while the engine is running should be 180-200oF, so you can see we are keeping it well below that. The temperature that damages oil is 300oF, and with a 130oF rise there is no physical way our heater will be able to get the oil that high even if the thermostat fails. Even the localized temp of the oil at the point where the heating element is bonded will not be excessive. At an ambient 70oF the temp on the inside surface of an empty sump, at the point where the heater is bonded, is 160-180oF max.​

Regarding the PSA (pressure sensitive adhesive) on silicone pads, it can work well but it is critical to install it correctly. Surface prep is very important as well as curing. Typically the bond strength right after sticking the pad on will be around 20%, and after proper curing 100%.

 

[Reiff Preheat Systems]

I found out why...

They don't sit down in the oil far enough and the part that sticks out of oil does a nice job of turning red and burning the oil at the surface.

Lycoming recommends against dipstick heaters because some dipstick tubes are plastic and might be damaged by the hot dipstick. Also the watt density (watts per sq inch of heater surface area) of some units is high and can scorch the oil that comes in contact with the heater. Chunks of burned oil floating around in your engine is bad, e.g. plugged oil passages, oil starved bearings, etc.

 

[Reiff Preheat Systems]

2 schools of thought.

(1) plug it in and leave it on all the time.

(2) plug it in and go fly.

If you have it on a timer and it goes on and off every day, each time it heats up the warm air has the ability to hold more H20. It can come in through the breather, exhaust pipes, or evaporate out of the oil. Then when the cool down happens after the timer goes off the moisture will condense inside the motor on things like...... the cam!

You are setting yourself up for rust by cycling the heat on, off, on, off, etc.

I like heat but when you unplug it is time to go fly that way any air that might have moisture will blow out the breather rather than cooling and condensing on steel parts.

I agree. Timers are good if you know in advance when you will fly and set the timer to turn the heater on the night before. But I wouldn't cycle it on and off every day "just in case" you might want to fly.

 

[Reiff Preheat Systems]

And they're pretty clear that just leaving it on is the best way to go. They even did some tests or link to a test where an engine was left on a heater for a week and the relative humidity went down inside the engine so one could hope that less vapor means less rusting potential. So leave it on all winter or just a few hours before flight. I wouldn't cycle by timer but I'm just parroting their info.

That test was done by Aviation Consumer using our Standard System (50w/cyl and 100w on the sump). It's referenced in our FAQ #3.