Anti Splat Aero NO HASSLE ENGINE PRE-HEATER

During this year's condition inspection I took the opportunity to put the heater into the front left drain plug hole on our IO-540. We had an early-ish version, with a shorter cord, but had no problem routing the wire up through the baffles, securing the plug with adel clamps right next to the oil dip stick. It is easily accessible via the oil door on the cowl.

For the first flight post inspection, I went to the hangar and plugged in the heater the night prior, with a moving blanket over the cowl, stuffing the intakes with the edge of the blanket. It got down to 14°F overnight, and OAT indicated 25° when I rolled the plane out for the flight. When I fired up the panel, the oil temperature was at 85°F!!! Much better than the typical 60° I would find after using a ducted milk house heater into the bottom of the cowl under similar conditions.

Winner!

While I don't necessarily adhere to the concept, I do note that Lycoming recommends preheating for most of their engines if ambient temps are 10° F or lower.

https://www.lycoming.com/content/operating-cold-weather


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catmandu said:

During this year's condition inspection I took the opportunity to put the heater into the front left drain plug hole on our IO-540. We had an early-ish version, with a shorter cord, but had no problem routing the wire up through the baffles, securing the plug with adel clamps right next to the oil dip stick. It is easily accessible via the oil door on the cowl.

For the first flight post inspection, I went to the hangar and plugged in the heater the night prior, with a moving blanket over the cowl, stuffing the intakes with the edge of the blanket. It got down to 14*F overnight, and OAT indicated 25* when I rolled the plane out for the flight. When I fired up the panel, the oil temperature was at 85*F!!! Much better than the typical 60* I would find after using a ducted milk house heater into the bottom of the cowl under similar conditions.

Winner!

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What were the CHTs before engine start?

RV8JD said:

What were the CHTs before engine start?

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That is far more important than oil temp. If oil is warm but the remainder of the engine is cold then the issues inherent with a cold start won't be completely addressed. But if heating the oil transfers heat to the CHT probes we can assume the crank journals and cylinder bores have been preheated so the start won't put undue stress on the engine.

The ability of a sump heater to warm the entire engine is dependent on interior cowl temp which is influenced by ambient temp, hangar design, climate, and wraps/plugs on the cowl. A sump heater has always provided excellent engine warming in my (mostly) mild climate but could be insufficient in more challenging conditions.

Top and Bottom Heat

We get some pretty cold temps here in Michigan. I was one of the testers of Alans heater and use it every time I want to go fly in the winter. If I have it on for 5-6 hours alone at 15F, my oil will be in the 80+f range.

I also use a 6" square heater ducted into my air intake. I have a thick reflective blanket and sleeping bag I drape over the cowl. My feeling was it is better to warm both the top and bottom of the engine. Probably overkill but only about 500 watts total so I am good with it.

The first picture is of 38f in the hangar and the engine after 4 hours. Oil 78, carb 87, and CHT all around 77f.

The other pictures show what the duct heater looks like and the cowl cover. I am satisfied that I am doing what I can to keep the engine ready to start when I want to fly. I only turn it on either the night before or early in the morning before I want to fly. The big advantage the heater has it is warms the battery too. I took it off so you could see the heater and duct but it all fits nice and tight in the square duct and I have a piece of flex duct insulation that fits over the duct to make sure all the heat goes into the engine.

None of this would be happy without the Switcheon power control. I can not say enough good things about it. Also, thanks to Alan and Antisplat for the heater!!

Now if I could figure out how to get more warm air into the cockpit in flight, I would be happy!

RV8JD said:

What were the CHTs before engine start?

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Twenty year old bar graph monitor is all we have (for now), so not sure. The top of the front two cylinders were warm to the touch in the cold hangar. I'll shoot them with the temperature gun if I think about it next time.

The picture is before start. CHT's at 77f.

catmandu said:

Twenty year old bar graph monitor is all we have (for now), so not sure. The top of the front two cylinders were warm to the touch in the cold hangar. I'll shoot them with the temperature gun if I think about it next time.

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Thanks for the info.

catmandu said:

Twenty year old bar graph monitor is all we have (for now), so not sure. The top of the front two cylinders were warm to the touch in the cold hangar. I'll shoot them with the temperature gun if I think about it next time.

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If the cylinders are warm to the touch, I'd say you have accomplished the goal. For the cylinders to get warm, the rest of the internals must also be.

We’ve got these installed in our RV-6 and RV-8, and I can confirm that they definitely make the front cylinders warm to the touch - much better than the old “shop light stuffed in the exhaust tunnel” method we have used for years.

Is the heat “enough”? Hard to say, but warmer is always going to be better than stone cold….

Paul

Another review

Here is another review of the Antisplat pre-heater, which I installed prior to a trip up to Klamath Falls, OR.

Plane was outside on the ramp, for a couple days.
Morning temp (when plugged in): 15F
Afternoon temp (before engine start): 25F
Heater was plugged in for (4) hours, starting at 8AM.
A packing blanket was placed over the cowl for (3) hours.
Before start: Oil temp 84F & CHT's in the mid to upper 60's.
Engine turned over promptly.
Photo of engine temps attached below.

I decided to go with the Antisplat pre-heater as I did not want to glue on a heating pad and wanted to be able to remove it in the future (non-invasive). I installed it on the left-side drain plug (right side has quick drain). Ran the wire behind the engine and made my own clamp around the plug + adel clamp to engine mount. Overall, very happy.

Following up as intended, I did another overnight heating cycle in the hangar as before. We hit a low of 17°F last night, and the front two cylinders measured mid-60's using the temperature gun this morning. The oil temp was again 85°. So, similar to Poindexter's experience outside.

Looks like a good product, simple and effective! I suggest replacing the two-prong plug with a 3 prong, and connecting the ground to the airframe in case one of the wires chafes and shorts to the airframe.

Another reference point

My last post was regarding results on a ramp, at an FBO, for a short plug-in.
This time, had it in my hangar, with a packing blanket over the cowl. Used a $9 HF digital timer (programmable up to a week) to have it go on well before my trip.
Hangar temps: low 30’s F
Time plugged in: 9 hours
Oil temp (before start-up): 109F
CHT’s (before start-up): 90-93F

Started-up right away

Mine is installed

Another happy user

Last night, I plugged in the EZ heater. Although it wasn’t really cold over the night, this morning, it was 51 degrees, and the oil temp was 90 before start. CHTs were also warmed up some above ambient. Without the heater, the CHTs would have been at or below ambient. We had the standard Vans cowl plugs, but no blanket. (Yes, I realize the oil pressure gauge is hung at 30psi before start, we have a new sender on the way. It does return to zero after shutdown on the first flight)

Looks like Anti Splat hit a home run on this one. I just got my RV-7 last year and I have added quite a few of Alan's up grades.

I live in southern AZ but at a higher elevation nights get below freezing. Cold starts at 40f can still be challenging. This would eliminate the problem. One of my concerns is traveling up north in the winter. I will bet many FBOs could provide a plug in even if the hangers full.

This on my Christmas list for next year since its its spring.

maxmirot said:

One of my concerns is traveling up north in the winter. I will bet many FBOs could provide a plug in even if the hangers full.

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I fly my RV mainly for business so visit a wide variety of FBO’s and non-FBO’s up north and in the mountains. All are very used to and provide an outlet (and blanket) to plug in.

The airport at Boyne Mountain Resort has plugs to plug a heater into BUT you need to bring your own cord! Dont forget the cord!!

Got mine installed!

Just got mine installed. Won’t need it till fall-winter, but I’ll be ready!


Has anyone figured out why, when I post two pictures from my iphone one of them will be turned the wrong way, just like this post? they are both turned correctly on my phone.

Has anyone installed the heater horizontally? I have the superior cold air sump. Quick drain on the left side. The right side drain would put the heater pretty close to the exhaust.
I’m wondering about putting the heater in the plug just above the quick drain.
The second photo shows the plug near the exhaust.

papamike said:

Has anyone installed the heater horizontally? I have the superior cold air sump. Quick drain on the left side. The right side drain would put the heater pretty close to the exhaust.
I’m wondering about putting the heater in the plug just above the quick drain.
The second photo shows the plug near the exhaust.
View attachment 59238View attachment 59239

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Better ask the OEM. Generally speaking, no problem mounting a resistance heater horizontally. Two other potential issues:

Being closer to the top of the oil level versus bottom will increase the heating time though probably not enough to matter or even notice in most duty cycles. Oil has a better specific heat than air, Again probably not an issue but lower is better.

This little heater has a pretty decent watt density, IIRC. It needs to be submerged so the oil can conduct away the heat it generates. If not, the service life will suffer. I'd expect any significant exposure to sump air would kill it pretty quickly.

You'd need to determine your oil quantity vs level to get comfortable here.

Would be interested to hear from ASA if any related testing was done for "off nominal" conditions.