Topic Seems Appropriate for the Season

MBDiagMan

MBDiagMan

Final Approach
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Doc
I hope this does not descend into an oil war thread. It's not meant to do so.

I live in a mild climate, but sometimes fly in thirty and forty degree Fahrenheit weather. I am considering rigging a poor boy preheater by aiming a torpedo heater at an angled piece of plywood or sheet metal to deflect the warm air flow into the bottom of my engine opening.

The quote below is from writings by Harry Fenton, a notable guru when it comes to the small Continental four cylinder engine family. I look forward to reading your experiences and procedures on the matter of cool weather operation of these little motors:

"Cold Weather Oil Considerations

(December 2002)
While digging through some engine parts at my hangar today I made an interesting observation. It is a balmy 25F today and was down to about 7F last night, so the hangar was still cold as a tomb at lunch. I was messing with a crank from a disassembled engine that still had the rods attached. I almost couldn't move the rods due to the stiffness of the residual 50 weight oil!! Out of curiosity, I grabbed my fish scale and to observe the pull required to over the rods. It required a 12-15lbs pull to displace the rod 90 degrees. Once the rods had been turned a dozen times the pull dropped to about 8lbs, but it was still very high.
I opened a can of 50 weight oil that had been cold soaked and it had a thick, wax-like consistency- definitely not good for lubrication! The 20w50 synthetic was better but still very sluggish to pour.

What an eye opener!! There is no way that I would fly again without preheating if the temps were below 45F. Positively, there is no way I would fly with 50w in the engine below 50 degrees as I just can't see how it can be pumped through the engine.

I'm going to take my crankshaft home and conduct some tests over the next few days with various oils and report back. Basically, my idea is to remove the rods, lube each journal with a different weight and type of oil and record the pull required to complete one revolution of the journal. I'm not sure what it will prove other than reinforcing the need to use the correct weight oil and to preheat.

Harry"
 
Why not just slap an oil heater on the pan for a hundred bucks?
 
Up here 0F isn't unusual weather. We still run 20w50 but most have plug-in preheaters.

Below freezing its gets nearly impossible to start my engine without preheating.
 
If it never gets below 30 or 40 degrees I think a couple of 100 watt light bulbs below the oil tank and a blanket over the cowl would do the trick. Power could be run through a simple timer from Ace Hardware so everything would be suitable by the time you get there.
 
Go for a pan heater,use a timer,why worry.
 
Silvaire said:
...a couple of 100 watt light bulbs below the oil tank and a blanket over the cowl would do the trick.
Click to expand...


Looks like that trick is going to go away soon also. The new bulbs don't put off nearly as much heat as the old ones did.
 
Doc,

Be careful of excessive temps from your torpedo heater. Your heat distribution will have you cooking parts that won't benefit from heat. If you use propane you'll be pushing moisture in there, too. Here's an inexpensive heater option that works great. I had one of these heaters hung on my engine mount for several years using simple straps and adel clamps. There's no tip switch and the entire case is metal. It's a great preheater for you occasional users.

http://www.amazon.com/gp/aw/d/B000NM73ZA/ref=redir_mdp_mobile/190-5455407-4837658
 
Many threads on this in archives, I suspect. I put on a stick on pan heater but was underwhelmed. Next, I got a tiny space heater similar to:
http://www.amazon.com/Optimus-H-132...=sr_1_21?s=home-garden&ie=UTF8&qid=1418598219

To the heater face I riveted a metal heater duct reducing fitting like:
http://www.amazon.com/Single-Wall-G...LO/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1418598405

To the 4 inch duct output I connected a dryer hose like:
http://www.amazon.com/Dundas-Jafine.../B0015UGPWQ/ref=sr_1_1?ie=UTF8&qid=1418598359

I plug the heater into a digital 7 day timer, set heater on low, direct dryer hose into lower cowling and have excellent results.
 
I appreciate the responses very much, especially the propane heater warning.

Since it doesn't get all that cold here, I'm going to get a small electric heater and ducting. It shouldn't take long to raise the oil temp from 38 To 50. I expect that I can set up the heater immediately after unlocking the hangar and by the time I make coffee, check weather, and preflight, it will probably be several degrees warmer.

What was everyone's thoughts about the particular oil temperatures the Harry mentioned?

Thanks again for the comments.
 
One thing about electric heaters and lightbulbs. What if you get a fuel leak? Now you have a source of ignition.
 
TheTraveler said:
...The new bulbs don't put off nearly as much heat as the old ones did.
Click to expand...

Regardless of what type of bulb you use 100 watts is 100 watts, there is nothing altered about that or the amount of heat that is generated from it.

Also, in regards to a fuel leak, a 100 watt light bulb is not an "ignition source" It may vaporize the fuel but something else would be required to ignite it. Electric heaters on the other hand are generally 750 to 1500 watts reflected off of an exposed red hot element.
 
Living in the north where its below 30f now, I'm running 20-50 with cam guard.

For preheat, a electric blanket and a few space blankets will work wonders. Dont forget to get a little space heater for the cabin, cold gyros and LCDs can do interesting things as well.

When you do pull the plane out remember if its snowing and you let the plane sit outside in the snow, you're going to want to make sure you're wings are clear.
 
I asked my current mechanic what he recommends up here in the frozen North. His answer: Aeroshell 15W50. He said it already includes the equivalent of cam guard and he has never had issues with it (premature engine wear etc). He does recommend pre-heating of course.
 
azure said:
I asked my current mechanic what he recommends up here in the frozen North. His answer: Aeroshell 15W50. He said it already includes the equivalent of cam guard and he has never had issues with it (premature engine wear etc). He does recommend pre-heating of course.
Click to expand...

Your mechanic is wrong about the Camguard comment. Aeroshell adds the Lycoming H series anti-scuff additive. That has nothing to do with Camguard and Camguard has nothing to do with anti-scuff. You should expect better from your maintenance staff.
 
MBDiagMan said:
I appreciate the responses very much, especially the propane heater warning.

Since it doesn't get all that cold here, I'm going to get a small electric heater and ducting. It shouldn't take long to raise the oil temp from 38 To 50. I expect that I can set up the heater immediately after unlocking the hangar and by the time I make coffee, check weather, and preflight, it will probably be several degrees warmer.

What was everyone's thoughts about the particular oil temperatures the Harry mentioned?

Thanks again for the comments.
Click to expand...

Lycoming and TCM both have published documents regarding cold soaked engines and preheating. TCM uses 20* and Lycoming says 10*. Of course that assumes you're using the proper oil viscosity for the temperature. Most guys I know use 32* as the heat threshold if given time and opportunity. It makes starting easier and we all like to make our engine's lives easier. If I get my oil and cylinder temps to 40* I figure I'm ahead of the manufacturer's requirements. That's good enough. There's no evidence that more heat is more beneficial.

If I was in N Texas and was looking at an occasional heat option I'd go to my local industrial store and buy a 75w silicone heat pad and would apply it to the sump using hi-temp silicone. That's the most effective way to warm your oil that there is. Cheap and easy, and 75w is plenty for the task. I used one for years but I usually used it in conjunction with the Little Buddy I linked earlier. Until you get into the teens your cylinders don't require much heat to ease starting. Just remember that cold cylinders require lots of prime. Most guys who struggle with occasional cold starts don't give their engines nearly enough fuel to start and then they blame the cold temps.

http://www.lycoming.com/Portals/0/t...I 1505 (07-01-2002)/Cold Weather Starting.pdf

http://www.tcmlink.com/pdf2/sil03-1.pdf
 
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I made a pre heater much like FORANE outlined. I left it in place, and plan to do a little testing tomorrow. I have a handheld IR thermometer that I will use to measure temp of oil on dipstick, turn on the heater then shoot the oil on dipstick again after some time has passed to see how much the temperature has risen over time.
 
MBDiagMan said:
I made a pre heater much like FORANE outlined. I left it in place, and plan to do a little testing tomorrow. I have a handheld IR thermometer that I will use to measure temp of oil on dipstick, turn on the heater then shoot the oil on dipstick again after some time has passed to see how much the temperature has risen over time.
Click to expand...

Would you be willing to do a little test for me involving a drug store medical heating pad(s), space blanket over the heating pad(s) on the TOP of the engine, and a furniture blanket over the whole forward end of the airplane?

If it works, and you can get me some pictures I'll give you credits in the article ... if it works. If it does or it doesn't you get a heating pad, space blanket, and moving blanket for whatever purpose you choose.

I like the heating pad idea because NOWHERE in the hangar do you have a light bulb that can break, a red hot wire that is an ignition source, or flame of any sort.

And it is cheap and plentiful. Heating pads at Walmart are ten bucks or so.

JIm
 
As stated, I did some preliminary testing yesterday and here is the result:

Before turning on the heater, I removed the dipstick and measured the temperature of the oil on the dipstick. The ambient at that time was 46 degrees. Then I closed the cowling and turned on the heater. I then opened the cowl, removed the dipstick to measure the oil temp and made note of time and temperature. I did this two times as seen in the data.

Initial temp. 45.8
27 min. 51.4
59 min. 59.0

I was doing some panel work that I did not complete, so I did not get to a point of starting the engine.

My heater is out from under the cowl and in a position where it would be close to impossible for fuel to drip on it.

Jim, if I can finish my panel work and try this arrangement a few times, if it doesn't work well, I would be willing to guinea pig your warmer setup.
 
I use 2-40 watt bulbs(redundancy) continuously below 40F avg OAT's. I keep a blanket on top of engine cowl. Upon arrival for preflight, I add a 1500 watt heater under cowl outlet to bring oil/cht's up to 50F+ for startup. I use Aeroshell 15W50 year around.
 
weirdjim said:
Would you be willing to do a little test for me involving a drug store medical heating pad(s), space blanket over the heating pad(s) on the TOP of the engine, and a furniture blanket over the whole forward end of the airplane?

If it works, and you can get me some pictures I'll give you credits in the article ... if it works. If it does or it doesn't you get a heating pad, space blanket, and moving blanket for whatever purpose you choose.

I like the heating pad idea because NOWHERE in the hangar do you have a light bulb that can break, a red hot wire that is an ignition source, or flame of any sort.

And it is cheap and plentiful. Heating pads at Walmart are ten bucks or so.

JIm
Click to expand...

I used that method before, worked fine, only problem was getting a good wrap around the engine.
 
James331 said:
I used that method before, worked fine, only problem was getting a good wrap around the engine.
Click to expand...


Thermodynamics 101. You don't wrap the engine, you wrap the cowl. Everything inside a thermal chamber (i.e the cowl blanket) is at the same temperature given enough time for thermal equilibrium.

You just toss the blankets on the top of the engine. Pretty easy if the cowl sides come up OR it is easy to stuff blankets inside.

Jim
 
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