Engine/Electric Pre Heat SOP

[N42AH]

Heres the question...

I keep my 9A in my hangar that is heated to 60 degrees. When I have my Reiff pre heat plugged in without an engine cover I get 92 degrees, with the cover it is 114 degrees.

So what is everyone getting for temps when their aircraft is plugged in and is it advisable to keep it plugged in even when I know I am not going to be flying for several days?

Will the 114 degrees keep the oil warm enough to keep the moisture at bay?

Thanks

[10builder]

The folks at Mattituck told me that in an operating engine the sensor location will typically reflect ~180F when the temperature in the sump is at ~212F. Of course, that is the minimum temperature moisture must reach to boil off. If you're not getting that, your essentially turning the inside of the engine into a greenhouse - and that's only going to accelerate corrosion.

[Kyle Boatright]

Originally Posted by N42AH

Heres the question...

I keep my 9A in my hangar that is heated to 60 degrees. When I have my Reiff pre heat plugged in without an engine cover I get 92 degrees, with the cover it is 114 degrees.

So what is everyone getting for temps when their aircraft is plugged in and is it advisable to keep it plugged in even when I know I am not going to be flying for several days?

Will the 114 degrees keep the oil warm enough to keep the moisture at bay?

Thanks

The subject of whether it is advisable to leave it plugged in or not is subject to debate. There are good points on both sides.

That said, why preheat if the hangar is maintained at 60F? Personally, I wouldn't bother unless the airplane was kept in <40F temps..

[Sam Buchanan]

Originally Posted by N42AH

Heres the question...

I keep my 9A in my hangar that is heated to 60 degrees. When I have my Reiff pre heat plugged in without an engine cover I get 92 degrees, with the cover it is 114 degrees.

So what is everyone getting for temps when their aircraft is plugged in and is it advisable to keep it plugged in even when I know I am not going to be flying for several days?

Will the 114 degrees keep the oil warm enough to keep the moisture at bay?

Thanks

No preheating needed in your case. Your airplane thinks it's April all winter.

[Ron Lee]

Build and use an engine dryer system.

In your case, I would not even worry about the engine heater. It may actually promote engine corrosion but consider that unverified.

[frankh]

The moisture that is inside your crankcase is not coming from outside sources (at least if it is its a very small amount). Where its coming from is the fact that you have burnt fuel on your previous flight.

Think about this. When you burn fuel the exhaust gas is mainly CO2 an H2O. Some of that gets pushed past the rings and into your crankcase. Now when you land you have this nice hot crankcase, the air inside of which is almost saturated..I.e it is holding as much water it can at that temperature.

Now the crankcase temp falls to the hot air dewpoint (say 150F) and a LOT of moisture will condense on the inside of your case..And drip all over the cam.

So the moisture is in there no matter what you do..Except the warmer you keep the engine the more corrosive that moisture will be....Not a good combination.

This Theorum (which is an educated guess on my part) is why I don't buy the "fly to drive out the moisture argument" cus all your doing is putting it right back in there. Flying often simply re-coats the cam with oil to prevent rusting. If there is moisture in the oil then its sitting at the bottom of the case where in theory it won't do any extra harm.

As has been previously mentioned the best solution is to build a dessicant dryer and remove the moisture..If it works inside your gun cabinet it will work in your engine.

Frank

[miyu1975]

ok....so someone has to ask, might as well be me...How does build a dessicant dryer?

[Ron Lee]

Originally Posted by miyu1975

ok....so someone has to ask, might as well be me...How does build a dessicant dryer?

http://home.pcisys.net/~ronlee/EngineDryer.pdf

Next time you fly, after getting out of the plane go open the oil filler cap and observe anything that may be coming out. I can almost guarantee that what you see is not fairy dust. Once you see that, the notion that you evaporate water from the oil becomes a laughable concept. UPDATE: I had an "ah ha" moment when I realized that the oil that comes out of the breather tube get there as a vapor. Thus what I see coming out of the oil filler tube after a flight may be oil vapor. I need to find a way to collect, condense and examine that vapor. Even if it turns out to be oil vapor, I will still use the engine dryer system.

I open mine after every flight, use the engine dryer system and have started using Camguard to help protect it.

Harbor Freight has some nice blue dessicant that turns pink with use.

Walmart has the stone filters, tubing and aquarium pump. I started with the 10-30 gallon size then went with a 30-60 gallon. Yesterday I realized how I can return the smaller one to service in parallel with the larger unit for more dry air. (Tim Allen grunt).

[frankh]

I detailed my build on here..pretty easy.

Note Petco have their own brand of pumps which have much more capacity and were much cheaper than the named brand.

As Ron pointed out HF has the cheapest dessicant (I uses two packets in my open loop system) and it maybe recharged by drying out in the oven.

Two long columns were more effective (I use 1.5inch drain pipes two of them each 5 foot long in seies) than a short fat coke bottle.

Also as Ron mentioned..The first time you see the column of steam rising out the oil filler (with motivation from the fish tank pump) after the flight you to will be a believer!

Frank

[miyu1975]

isn't part of a having a pre-heater also intended to be better for cold starts too though?