Engine Preheat Systems

[rodsmith]

I will be installing a preheat system on my IO-540. Looks like the choices are limited, either Tanis or Reiff. The Reiff is somewhat cheaper. The main difference between the two is the Reiff uses a band around the base of the cylinder, while the Tanis uses a threaded plug that replaces a rocker cover bolt. The heating philosophy is different, Tanis says can remain plugged in continuously up to 100 deg ambient, Reiff says only use before flying. Would like to hear from builders with experience with either system.

[whee]

Rod, I don’t mean to be “that guy” whom responds while lacking the experience you seek but if I may share my thoughts.

Whether it’s Reiff or Tanis the function of heat transfer is the same. I would choose the Reiff becuase I hate spark plug mounted CHT probes which are required when using the Tanis. I don’t think leaving either system plugged in all the time is a good idea. The daily ambient temperature swings will promote moisture inside the engine. A good insulated engine cover will help dampen the temperature swings so if your situation requires heat all the time then be sure to get a good cover.

[jaredyates]

I will be installing a preheat system on my IO-540. Looks like the choices are limited, either Tanis or Reiff. The Reiff is somewhat cheaper. The main difference between the two is the Reiff uses a band around the base of the cylinder, while the Tanis uses a threaded plug that replaces a rocker cover bolt. The heating philosophy is different, Tanis says can remain plugged in continuously up to 100 deg ambient, Reiff says only use before flying. Would like to hear from builders with experience with either system.

While those two are choices, I wouldn't say that they are the only choices. You can also get a $10 peel and stick pad for the oil pan. But to Jon's concern I think they have fixed the issue of taking up the CHT wells by switching to the rocker cover bolt.

[whee]

While those two are choices, I wouldn't say that they are the only choices. You can also get a $10 peel and stick pad for the oil pan. But to Jon's concern I think they have fixed the issue of taking up the CHT wells by switching to the rocker cover bolt.

That’s right Jared! If forgot about that. Thanks.

I didn’t want to go off an a tangent and mention other systems. I figured Rod had researched and narrowed it down to those two. Of the two I still choose Reiff. I might put one on my plane if I ever get skis installed and do some winter camping. For keeping the engine heated all the time I like the twin hornet from aircraft engine heaters.

[rodsmith]

I hadn't come across the twin hornet. Looks like a viable alternative with an insulated cowling cover.

[AKKen07]

Hey Rod, the guys I’ve spoken to about this around here seem to prefer the Reiff system. Think it heats the whole engine more evenly but, in addition, using a car heater of some sort inside a cowling cover compounds the positive effects. Most Everybody agrees that you are better off not heating the engine 24/7 but just long enough before a flight to heat the engine evenly. But, my thought is that as long as your engine components are not oscillating temperatures frequently, keeping it warm can’t hurt - you’d have to be sure your solution kept everything warm regardless of weather conditions…. That’s speculation.
Most of this is 2nd hand but it’s from talks with good experienced Alaska GA pilots and mechanics. I only heat up a plane before I go flying but I can’t prove the results.

[Bcone1381]

Another Viewpoint:

I'm a Tanis fan. Tanis heats the cylinder head using a threaded element in the valve cover. The Reiff ring around the cylinder base has difficulty getting heat to the head. Here is a shot on Tanis website of an engine with 3 cylinders heated by Reiff's band around the cylinder base, and the bottom three heated by Tanis' element in the valve cover screw. After 36 hours the red shows warm cylinder heads.

Tanis claims there warm cylinders are above the dewpoint so no condensation will form there. So Tanis says it fine to leave it plugged in. A Prop is a big heat sink....metal even bigger... and a constant speed prop will form corrosion in its hub if condesation forms there. I'd be putting my prehearter on a remote switch of some kind that I can control at home.

Tanis FAQ has good data on leaving it on. https://www.tanisaircraft.com/faq/

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[m.mooney]

Very happy with the Reiff system that I have on my Patrol. I also considered Tanis but went with Reiff because of the cylinder bands. I would choose it again, for sure. Nothing against Tanis, I’m sure it’s a very good system. I have an engine blanket from Bruce’s and preheat every time I fly in the winter, regardless of temperature. I use a smart plug/app and hangar Wifi. When away from home, a small propane generator does the trick with one green bottle. The blanket is a critical component, in my opinion. Generally, I’m shocked at the percentage of aircraft owners that don’t preheat.

[jaredyates]

I have a Honda 2000w generator set up to run on propane or gasoline. It was an aftermarket kit.

[m.mooney]

It’s a Baja 700/900. Weighs around 17lbs. Reiff system with sump heater and the cylinder band heaters come in below its capacity so it works great. Engine blanket on, plug in the gen, drink coffee until the gen quits, go fly. I had a Northern Companion in my 180 and thought that was great but I like this much more. Considerably safer and can pull double duty charging electronics. The weight is the penalty but I feel it’s still the best system.

[whee]

Thanks guys. A small Honda with a kit was my plan but I’m going to checkout the Baja.

[Tim213]

Here in Southern California we rarely have to use engine preheat so I don’t have any personal experience with it. However I also have a RV7 I built, and this was recently discussed on the Vans forum. An after market company called AntiSplat Aero that manufacturers items mostly for RVs, has a new engine preheater that threads directly into an oil drain on Lycoming engines. It was tested by numerous pilots for a year before being available to purchase.
the comments on the forum were very positive. They sold out the first batch of units in two days. At a price of $89 I was even going to get one but now have to wait for the next run of units to be made. Just something to consider as it seems to be pretty much hassle free.

https://antisplataero.com/products/no-hassle-engine-pre-heater

[Rollie]

I went an entirely different route. I took a small electric space heater and added a bit of ducting so that I can set it under the plane and it routes the heat up into the cowl exit area. 45-60 minutes and the entire engine is nice and warm, the engine cranks like it does on a warm summer day and the oil temp is already 70-80 degrees F and the pressure is where it belongs. I have never lived close enough to my hangar to make it convenient to plug in a heater 4 hours before I want to fly, but 45-60 minutes? That works great to turn it on, preflight and maybe go over to the FBO and get warm for a few minutes or run to get breakfast while it warms up (if the flight isn't to a breakfast fly-in) I will add that if my wife is going with me 45 minutes is entirely too long to wait.

Another reason I went this route is my last plane was certified so it was more convenient to do this that add an STC for a heater. So I already had this setup when I started flying my Bearhawk.

[Chewie]

A friend of mine did that too. Actually he used an old wall heater from a building supply recycler and fabbed a simple plenum to it for attaching a flex duct. It looks like part of a male elephant but apparently it works great. We have no WiFi at the hangar and it's a bit of a drive to get out there, so this solution has some appeal.

[Bcone1381]

The anti-splat oil pan heater is a good one I think for heating oil in the oil pan two hours before flying. If we Preheat then fly with Reiff or an oil plan heater we generally are doing just fine avoiding metal-metal contact during start. Don't leave it on all week, or all winter to avoid condenstaion. Just a couple hours prior to flying.

Keep an open mind if its real cold. Cylinder scuffing is an issue at some cold temperature CHT. Do some data research of your preheaters ability to raise the CHT. If I can't get 50F then I'd be shopping.

Engines generally don't wear out, they rust out. If the cam, cylinders and prop hub are colder than the dew point, then condensation or frost form. My goal is to make aware that an unhealthy environment can be unknowingly be fabricated by its owner.

I've seen frost inside my hangared C-140's C85 engine through the oil dip stick one Michigan morning in November. Today I'd fix that after a flight by using a hair dryer to blow hot dry air into the oil dipstick out the crankcase breather for 30 seconds then hook up the dehydrator before I shut the hanger lights off. But this is not a rust thread, its a preheat thread....the two dovetail together though as a preheater can produce condensation.

[whee]

The anti-splat oil pan heater is a good one I think for heating oil in the oil pan two hours before flying. If we Preheat then fly with Reiff or an oil plan heater we generally are doing just fine avoiding metal-metal contact during start. Don't leave it on all week, or all winter to avoid condenstaion. Just a couple hours prior to flying.

Keep an open mind if its real cold. Cylinder scuffing is an issue at some cold temperature CHT. Do some data research of your preheaters ability to raise the CHT. If I can't get 50F then I'd be shopping.

Engines generally don't wear out, they rust out. If the cam, cylinders and prop hub are colder than the dew point, then condensation or frost form. My goal is to make aware that an unhealthy environment can be unknowingly be fabricated by its owner.

I've seen frost inside my hangared C-140's C85 engine through the oil dip stick one Michigan morning in November. Today I'd fix that after a flight by using a hair dryer to blow hot dry air into the oil dipstick out the crankcase breather for 30 seconds then hook up the dehydrator before I shut the hanger lights off. But this is not a rust thread, its a preheat thread....the two dovetail together though as a preheater can produce condensation.

Good point Brooks.

Cylinder scuffing, zero clearance at the crank bearings, zero clearance at the cam, etc. Heating the oil doesn’t take long but to get those critical and expensive internal engine parts takes time, several hours.

I too have seen frost inside the dipstick tube of an engine on a cold day. Moisture exists and we just have to decide how we want to deal with it.

[Utah-Jay]

That new Anti-Splat heater for under $100 looks amazing. They sold out (Vans guys bought them up quick) in under a week I believe. A buddy across the hanger taxiway last week was “heating up” his engine with a propane heater and the tubing caught on fire while I was standing there watching. The flames were within 2’ of his engine cowling. I was stepping back and very concerned, as a Vietnam helicopter pilot he seemed unfazed. I gave him the link to the Anti-Splat heater and he ordered one before they sold out. Looks like a very good item. There is a long thread about it with many questions answered by Allen from Anti-Splate over on the Vans forum.

https://vansairforce.net/community/showthread.php?t=212297

[BravoGolf]

I ordered the Anti-Splat heater for my O-360 in my RV-7. I don’t think it would replace a dehumidifier system but for shortening the time I spend waiting for the engine oil to warm up it seems like a good product. I tried a heater pad attached to the sump but it didn’t heat the oil sufficiently.

[500AGL]

The dry-air / dehumidifier systems some of the guys have come up with seem to be quite nice. Threads on SuperCub.org and I’m sure vans as well. Something worth considering for anyone that doesn’t fly often. Biggest issue with moisture is an engine that doesn’t run often, or very long. You have to fly at least an hour at 190* for the oil to burn off contaminants.

For the price and effectiveness the oil probe heater from anti splat seems great. For long term the Reiff is the whole package, we have installed many.

If you’re on a budget, on bush wheels and have a spare plastic barrel here’s an option. Cut out an opening on one side a bit larger than your kerosene salamander heater. Cut the top out and place it under the engine. Fire up the heater a good 2’ away and the barrel sends all the heat up into the engine cowl via the bottom opening. Cowl cover or blanket over the top and In 20 mins oil goes from 10* to 60*, and heats everything.

In the field it’s hard to beat the independence of a propane stove and straight duct up into the engine compartment. Nothing needed but a spark.