Question Using an engine pre-heater on a piston engine

[Neal]

I have the Reiff engine pre-heater for my Lycoming IO-360. I realize it's probably not the best solution as I hear Tanis is the better option but I don't have much experience with this to offer an opinion, just what I heard, and Reiff is the only option offered by CubCrafters at my build time.

Knowing I had a cold morning launch last week, under 30F, I plugged in early in the week as I hoped to fly earlier but had to reschedule. I heard some time back that with Reiff, don't unplug it until ready to fly as there is the possibility of condensation if the engine is not run post heating. I'm curious what temps people use for when to pre-heat, can the Reiff be on too long or can it run continuous until the next flight opportunity? I have to say it worked well, when I got to the runup area there was no waiting for oil temps to rise, it was around 130 when I arrived at the runup. Otherwise it probably would have been 80-90 and had to wait 5-10 minutes for temps to go green for power over 1000 rpm.

I'd love to learn from others on what you use, when to use, how long to use, etc. regards to piston engine pre-heating.

 

[ve6yeq]

I too have the factory-installed Reiff system installed on my EX-3. In my research, this system appeared to be the best plug in system as it gave a more even complete heat to the engine and it has a separate pre-heat for the oil cooler. The only thing lacking appears to be a pre-heat for the constant speed prop as the oil pressure does not settle until I have completed a very slow cycling of the prop during the run-up. (Maybe I just need an insulated cover for the spinner / prop blades?)

Even with the cold weather, I am still running W100 + camguard so I have to make sure to pre-heat everything to the minimum oil temperature for W100 before starting. As the plane is parked on the ramp outside with thinner covers, it seems to need 6+ hours to warm up so I just call the FBO to plug in the extension cord either the night before if I plan to fly early, or when I wake up if I am flying later. If the weather forecast does not work out, I just call the FBO to unplug it. I will add a WiFi switch one of these days as there is WiFi coverage on the ramp.

 

[Neal]

Good point about the CS prop. I've noticed when cycling in the colder weather it does take longer to stabilize back to full forward. I do give it time at RPM to stabilize but does seem to be something affected by the cold weather ops.

I still run 15W-50 (Aeroshell) but that's a good point too, should oil be changed for winter ops? I'm not in the coldest of climates typically in VA but this year has been unusually cold, it's 18F as I type this and I'm launching at 0900 to fly.

 

[Tsquared]

For me I plug in my Tanis when temps start to hover around 40F or lower consistently. I keep it plugged in until temps I might fly in are over 40F. So for MN that's typically mid November until sometime in April. I'm also using an insulated cover when it gets below 25F. I'm in an uninsulated and unheated T hangar.

With the Tanis preheat (cylinder heads and engine oil) my cylinder heads are typically 80F warmer than ambient temp and oil is 35-40F warmer as well before startup. That said I still keep close eye on my oil temp after start and don't taxi or operate above 1000rpm until my oil temp is at least 120F in the winter.

As I understand it, leaving a Reiff system on and then unplugging the system without flying it can allow condensation to build up in the cylinders. If you check out Tanis website they provide a good explanation regarding the advantages of their system. Why Tanis - Tanis Aircraft Products. Doug Evick (Tanis owner before Hartzel purchased the company) used to give presentations with data and thermal images to better articulate what Tanis can do.

RE ve6yeq's comments on the constant speed prop they are spot on. I don't cycle the prop until post run up and even then it's a little slow coming back to full RPM. I looked into getting a prop cover, but was told that with the composite props on the FX3, they didn't suck heat from the engine like a metal prop does and that there weren't any advantages to using a prop cover with a composite prop. But one Canuck to another, Toronto isn't that cold compared to Minneapolis or god forbid Winnipeg, Eh?

Like Neal I run the Aeroshell 5w-50 year round. If I was in Winnipeg, North Dakota or Alaska, I'd change oil types seasonally.

 

[Cubonaut875]

As someone who has experience with both systems you are spot on. The Tannis is a much superior system. When I was specking out my plane I asked about a Tannis system and they said they had not done as many in the full IFR panel. Knowing how the Tannis installs and the proximity to the various sensor leads I opted to go with the Reiff. Cubcrafters functions better with things they do all the time. Problem being, you can't leave the Reiff system plugged in, you have to heat it only a few hours before flying and once you heat it you should fly it. Being a person who likes to fly early in the morning, I am not going to get up at 2:00 am to plug in the heater. I got around it by buying a remote switch SwitcheOn 4G/LTE Remote Power Switch - SwitcheOn SwitchOn power switch, I can set the time for it to start depending on the temp. It is controlled by an app on my phone. It also gives me the temp in the hangar - kinda interesting information. I'm thinking of buying a Tannis Cabin/Avionics preheater to plug into the spare outlet on the power switch, but I'm having trouble justifying the $473.00 for the Cabin heater. The Cabin heater would also keep the battery warm too however. The insulated cover is also a great idea, with the Reiff it allows the whole engine compartment to heat, not just the oil.

 

[Neal]

I'm not sure a few hours is enough for the Reiff based on my recent use. Two weeks ago I did a multi-day preheat attempting to fly waiting on winds. When I finally flew, cranking around 20F outside, the heat level was great, when getting to the runup area I was probably over 130. I typically won't do a runup until over 125. I planned to fly this past Friday so Thursday I went to the hangar to preflight and put the Reiff on at 4 PM. The next morning was in the teens, maybe 20F, and I cranked at around 9 AM. I got to the runup and was still in the yellow and had to run at 1000 rpm a few minutes to get to 125. So in that experience, personally I would want ideally a 24 hour preheat if possible.

Now let me state the obvious so no one beats me to the Darwin award of blowing up their airplane and hangar. When plugging in, or more so disconnecting the plug for the Reiff inside the oil door which is inside the engine compartment, make sure power to your extension cord is OFF. Connect the plug and then apply power. I had a nice arc when disconnecting Friday morning and it's great having an electrical arc in a fuel fumed (assumingly) engine compartment. Yeah, my setup is a little bit of a hassle to disconnect/reconnect that cord but from now on that's my procedure.

 

[Cubonaut875]

Do you have an engine cover? And yes for sure, turn it off before you unplug it. At 12F degrees a couple of weeks ago I had an 85 degree oil temp after only a few hours on the heater, I think I had it turn on at midnight.

 

[Neal]

Do you have an engine cover?

No. Temps here in VA are not normal. Rare do we have winters this cold.

 

[Cubonaut875]

Get a moving blanket from U haul or Harbor freight Moving Blankets - Harbor Freight Tools, it will make the world of difference. The Bruce's custom cover is awesome but it was pricy, it allows the whole engine compartment to heat.

 

[Neal]

Good idea, I have one in the hangar already and will use that going forward. I guess the next question is what temp is desired?