• If You Are Having Trouble Logging In with Your Old Username and Password, Please use this Forgot Your Password link to get re-established.
  • Hey! Be sure to login or register!

NAPA Oil Pad Heaters

WSH

Registered User
Hey, what is the preferred size pad oil heaters for an 0320?
Napa has them from 25 to 500 watts, and everything in between. I'm located in the Mid-Atlantic and rarely see anything less than 20 degrees. I'm thinking in the 100-250 watt range, more for speeding up the process then how low the temperature actually gets.

Any thoughts?
 
The last un-regulated oil pad heater I used was 75w and it was on a TCM 6 cylinder. Given how that worked I would hesitate to go with higher output on my own stuff. Honestly I'd pony up and get a thermostatically controlled one and not worry about it. Preheating takes time to do it right. There's no getting around that. Especially if all you're heating is the sump.

Stewart
 
Last edited:
These are pretty simple, thermostatically controlled oil pan heaters: http://www.e-zheat.com/

The problem with a simple oil pan heater is that without thermostat, it MAY cook your oil. Depends on a lot of things, including OAT. The thermostat in the EZ Heat systems is a pretty cheap insurance policy, in my estimation. And, these are really simple to install.

MTV
 
Get a 75 watt one and put it on an on and off timer, always worked for me
 
There is no problem using the napa type silicone pads on the lycoming. I use two 100s on a 0320 sump. You can use them both for quicker heating or one for overnight...The TCM thin oil pan requires that you use the battery silicone type pad. The battery type have the elements spread apart to avoid overheating....
 
There is no problem using the napa type silicone pads on the lycoming. I use two 100s on a 0320 sump. You can use them both for quicker heating or one for overnight...The TCM thin oil pan requires that you use the battery silicone type pad. The battery type have the elements spread apart to avoid overheating....

you are good... :)
you wrote just what I was thinking.. that the thick cast aluminum lycoming case would spread out the heat better than the thin continentals....
 
How many watt would you guys go with for a C90 sump, very thin compared to a Lycoming. This would be for an experimental Cub.

Ryan
 
You would need to use one of the battery type pads mentioned above. The battery type are 50 watts....
 
I've never heard of different types of pad heaters but I never got one at NAPA. Our local bearing supply houses sell the orange silicone pads. The first time I bought one they asked what the capacity of the sump was and handed me the 75 watt size. I've bought a few others since but not for airplanes. My diesel generator has a a sump capacity just under 4 qts and I chose a 50w. In any case the amount of heat needed is variable depending on temperature. My old 75w pad on my TCM sump was borderline too much unless the temps were below 10*. Above that and I wouldn't leave it on overnight. The best heat example I can give is one I reported here a few years ago. At 18* outside temp I plugged my PA-12's Reiff system in for a couple of hours (200w at the sump) and found the oil temp at 90* after that time. To me that demonstrated the capability for overheating if the heater had not been thermostatically controlled and I had left it on for several hours, or if the outside temps had been warmer. I want enough oomph to get the job done quickly but I don't want any overheat potential. A guy needs to consider his conditions and find the size that works best for him. With external thermostats, timers, beeper boxes, etc, you can develop routines to make just about anything work. I prefer the thermostat type because I don't have to be concerned about the heater if I get busy or the weather changes and I return to the plane later than originally planned. In my case I don't have a power outlet so I use a portable generator. That limits my ability to leave it on full time. I know guys who leave theirs plugged in all winter. That's another condition to consider.

SB
 
Last edited:
There are two distinct types of silicone heat pads. The battery type pad is specifically designed to not overheat a battery. You want to use that type on any thin oil pan sump. I usually put two 50 watt Battery pads on the 470-520 TCM type. The normal HOT pad will overheat the TCM pan and "coke" the oil. You will see black hard chunks of Coked oil in your screen. When you pull the pan off you can see where the pad was, by the burnt oil outline. If you use the battery heat pad you will not have this problem. It all is very simple. Ask for the battery type pad. If you are not sure what you got, plug it in and put your hand on it, you will be able to keep your hand on the battery pad, you will not be able to keep your hand on the other type hot pad. We have been doing this for 30 years now in Alaska it is nothing new....
 
Stewart

I've always heard, at least anecdotally, that leaving it continuously on the thermostat was not good for the engine. The theory goes, continual cycling of heating up the oil/moisture/air inside the engine, and then having it cool down, i.e. having the oil/moisture/air condense when cooling, promotes early corrosion.

Of course location would play a large part in the probability, it would obviously seem less likely to occur in AZ than say, SE Alaska for example.

So, leaving it continually on, and above the dew-point, or off until several hours before engine start, seems the best option. I think?

Or, maybe it's just not the problem it has been made out to be?
 
When you made your initial post I went to Reiff's website to see what the output is on my system. I was really surprised to see Reiff now markets a 25w pad heater as an anti-corrosion heater. I was taught long ago that continuous preheat was bad but have seen contradictory articles about it through the years, including in Light Plane maintenance where they said they found no evidence that continuous preheat promoted corrosion. It looks like Reiff agrees with their thinking. I don't know what to believe but since I don't have power available I don't have to worry about it. I use a portable generator and heat for a couple of hours prior to flight. If I had power available I'd probably do the same but may choose a beeper box to turn it on when I wanted. I think any discussion of preheating and preheaters needs to be qualified by climate and operation frequency. Continuous preheat probably makes better sense for airplanes that operate regularly. For occasional use I'm not so sure.

Stewart
 
Plugging it in the night or hours before flight, is the way to go in my opinion. What you do with the engine after you preheat, determines how much moisture stays/forms. If you don't get your operating temps up to that Magic 180F oil temp range all that moisture is forming metal eating acids with the left over combustion by-products that your oil is picking up in the process of cooling/ lubricating your engine...
 
Back
Top