N7645F Engine Preheater

Ace Flying Club of Endicott, Inc.
N7645F Engine Preheater

Summary

Our airplane is equipped with a Reiff Preheating Systems engine preheat system.

The preheat system consists of an electric oil pan heater, electric cylinder heaters, an extension cord, and a cowl blanket.

We use the preheat system in cold weather to heat the engine before starting it.

Highlights of Use

When should I preheat?	Preheat the engine according to these guidelines: If the engine contains W80 oil, preheat at hangar 30 F or colder. If the engine contains W65 oil, preheat at hangar 20 F or colder. There is a thermometer on the wall inside the hangar. Generally, it is 5 F to 10 F warmer inside the hangar than it is outdoors at the airport. The tachometer log sheet always tells what kind of oil is installed in the engine. It is OK to preheat if the hangar temperature is warmer than these numbers. You won't hurt anything.
How much time does it take?	Our preheater works very slowly. Start preheating several hours before you need the engine to be preheated. Six hours is optimal. Plug in the airplane the night before if you like.
How do I use the preheater?	To use the system, Unscrew the dipstick and set it ajar on the dipstick tube. Connect the orange extension cord to the preheater plug, which is wire-tied onto the dipstick tube. Plug the orange extension cord into the wall outlet. Throw the cowl blanket over the cowling. Wait several hours to overnight. Remove the blanket and cord. Tighten the dipstick. Start the engine. Go fly.
Any other concerns?	Incomplete preheating will hurt the engine. Allow plenty of time to heat the engine thoroughly before you start it. Letting the engine cool off will hurt it. Once you have begun to heat the engine, keep heating it until right before you start it. Preheating but not flying will hurt the engine. Once you have heated the engine, go fly the airplane until the whole engine warms to operating temperature. After you start the engine, check it for signs that parts of it might not yet be warm enough for flying. Refer to this Lycoming instruction for more information.

Frequently Asked Questions

Find below some commonly asked questions and their answers.

Why do we preheat the engine?
It dramatically decreases engine wear during starts. It makes sure oil circulates immediately. It makes sure there are no cold spots in the engine where oil can congeal. It makes the engine start much more easily.
Does Lycoming offer any guidance on preheating?
Guidance from Lycoming:
- Lycoming Service Instruction 1505 requires that our engine be preheated if the temperature of the engine would have been 10 F or lower at engine start time. The SI also describes that preheating is about heating the whole engine, not just about warming the oil.
- The Lycoming O-360 Operator's Manual says, "During extreme cold weather, it may be necessary to preheat the engine and oil before starting."
- Lycoming advises not to leave the heater on all the time. Rather, if it is cold enough to need to preheat, heat the engine and oil thoroughly, start the engine, and go fly.
What happens to oil as it gets cold?
Oil gets more viscous as it gets colder. According to Shell Oil,
- Our spring and autumn oil, AeroShell W80, is three times more viscous at 30 F than it is at 50 F.
- Our winter oil, AeroShell W65, is three times more viscous at 10 F than it is at 30 F.
- AeroShell W65 at 30 F has the same viscosity as AeroShell W80 at 50 F.
Do we leave the airplane plugged in all the time?
Not anymore! We have experienced engine damage doing this. Plug it in if you need to heat it. Else leave it unplugged.
May I take the cord and blanket with me, so I can preheat at my destination before my return?
Absolutely! And if you are going to be at your destination for just a couple of hours, installing the blanket while the airplane is parked will help keep the engine warm, even without plugging in the heater.
Do I really need to put the blanket onto the cowl?
Using the blanket dramatically improves the heater's performance.
Why do we leave the dipstick ajar?
Heating sometimes produces water vapor inside the crankcase. Leaving the dipstick ajar leaves the dipstick tube open, which lets the water vapor escape.
Where can I learn more about engine preheating?
Read the Lycoming SI or visit Reiff Preheating Systems' web site for more information. Their frequently asked questions page is particularly good.

Revised December 13, 2011

Ace Flying Club of Endicott, Inc. N7645F Engine Preheater

Summary

Highlights of Use

Frequently Asked Questions

Ace Flying Club of Endicott, Inc.
N7645F Engine Preheater