Temporary pre-heater?

cowman

cowman

Final Approach
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Cowman
So it's gotten cold up here and I've found my Archer to be VERY hard to get started and also found it runs very rough for about 20-30 seconds after finally getting it going.

I will be installing a pre-heater in a week or two at the same time I do the annual. In the meantime I have some flights to make and I'd like to be nice to my engine and make life easier. Any temporary solutions?

I have an un-insulated large divided T-hangar so heating the hanger isn't really an option. Don't yet have a blanket for the cowling or cowl plugs but I suppose I should get those anyway.

I think I remember seeing somewhere that some people use a trouble light under the cowling to provide some heat? Hair drier for a 15-30 minutes before takeoff?
 
Maybe see if you can borrow a red dragon preheater from someone.

I had one when I had my cherokee 140 and it made starting that engine much much easier. I used it anytime the temps were below 45 or so.
 
$19 sleeping bag from Walmart will do. 60 watt incondescent in droplight will give you 20ºF over ambient.
 
So basically I could just put a trouble light down the engine oil door(assuming it will fit) and throw some old blanked out of the closet over the cowling and that will work/be relatively safe?

I assume you'd have to do this the night before or several hours earlier... overnight would be the only practical choice most likely.
 
Warm air rises. It is best to put the light in from some opening in the bottom of the cowl.
 
Someone will probably explain why this is a bad idea but I have found priming more makes a huge difference. My POH states to hit it 3 times with primer.

Took me 30 min to get it started a few weeks back.
I am hitting it 6 times now and it fires up on the first or second rotation.
 
cowman said:
So basically I could just put a trouble light down the engine oil door(assuming it will fit) and throw some old blanked out of the closet over the cowling and that will work/be relatively safe?

I assume you'd have to do this the night before or several hours earlier... overnight would be the only practical choice most likely.
Click to expand...

Not down the oil door...heat rises. So you want to put the trouble light inside the bottom of the cowl at the front strut. I used a 100w bulb for 3 years with a sleeping bag over the top of the cowl on my cherokee (same architecture). Make sure the bulb doesn't come into contact with anything and nothing is dripping on the bulb. You're trying to heat not just the oil but the large mass of the engine.

Another heat sink is the nose and more important, the prop. Get a second blankie and throw over the prop/spinner area, that's help too. Yes, many hours in advance, like the night before.

Not to promote anyone's business or product, but after many years of driving out the the airport (30 min each way) in cold winter because I wanted/needed to fly the next day, I got one of Phillip's switchboxes. If you're handy with a soldering iron you can invent your own - the parts & electronic board run about $150-200.

Here are some links for ideas

http://www.csobeech.com/interior-csob.html#CellPhoneModule

Wiring diagram
http://www.gsm-auto.com/applications.html

Video with the GSM Auto switch
http://www.youtube.com/watch?v=6ZTHYXfbvlw

Phillip's Switchbox
http://switchboxcontrol.com/the-switch-box/

Look familiar?
http://www.waferstar.com/en/gsm-auto-ac.html

About $100 each, you provide the SIM and 14 gage cords:
http://wafersensor.en.alibaba.com/p...er_GSM_Switch_box_Type_GSM_AUTO_AC_type_.html
 
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The starter will struggle if the oil is cold as well. My Cessna 172 SP POH recommends pulling the prop through backwards a few compression cycles to loosen up the oil in the cylinders. Turning the beacon light and other electronics off until the engine starts are also options as then you have the maximum amount of available battery power going to the engine.
 
Trouble light and heavy duty blanket the night before. Should work out fine since you are in a hangar. I also like to use a propane heater l,like the red dragon before engine start.
 
SixPapaCharlie said:
Someone will probably explain why this is a bad idea but I have found priming more makes a huge difference. My POH states to hit it 3 times with primer.

Took me 30 min to get it started a few weeks back.
I am hitting it 6 times now and it fires up on the first or second rotation.
Click to expand...

same thing on our Cherokee 235. In the winter we go from 4 to 6 squirts and it makes all the difference.
 
When priming a cold engine it is best to give it one or two shots of prime. Then get the primer full and start cranking and push the primer in at the same time. Keep stroking the primer as you crank and it will start up fairly quickly. Keep the mixture at idle cut off until it starts then push it in as it gets running. Throttle should be cracked open 1/4-1/2". You don't want to give it a bunch of prime before cranking it as raw gas will collect in the airbox and it will wet out the lower plugs. Most people will then start pumping the throttle and if you get a good backfire you now have a nice engine fire. Have watched a 172 and an Apache suffer significant fire damage from over priming. Don
 
In addition to the trouble light, you could also drain the oil when the engine is hot, keep the oil 80F or so in an heated/ insulated box and reinstall prior to engine start.
 
Clip4 said:
In addition to the trouble light, you could also drain the oil when the engine is hot, keep the oil 80F or so in an heated/ insulated box and reinstall prior to engine start.
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You could also dilute the oil with avgas.
 
You have to be careful not to frost the plugs on cold starts,if you Havnt pre heated.
 
Intake cowl plugs, blanket over the cowl, then a hair dryer blown into the lower cowl exit. Far better than a 100W trouble light.
 
Clip4 said:
Except it doesn't circulate warm oil throughout the engine immediately upon starting.
Click to expand...

A couple pounds of 80 degree oil won't warm a couple hundred pounds of cold metal enough to matter either.
 
Another thought, I have one of these:

P11961488.jpg


I wonder if I could grab some kind of duct size adapter and some dryer vent tubing from a home improvement store and duct the hot air from that thing right into the cowling while I preflight?
 
Prior to my current plane, I simply put a heavy packing/moving blanket over the cowl. I made cutout pieces out of heavy foam left over from a TV shipping box to plug the two cowl openings. Then bought a 6' piece of flex 6" metal duct from Lowes. The duct bent for a perfect fit into the bottom of the cowl. I then set up a small ceramic heater to blow into the metal duct. That keeps the heater well away from the plane and everything else in the hangar should it short out or otherwise self combust. Works like a champ.

I've heard of cell phone activated switches that you can use to turn on this contraption remotely.
 
I just followed Ted's advice and installed Tanis heaters. Obviously not temporary, but a much better overall solution.
 
cowman said:
Another thought, I have one of these:

P11961488.jpg


I wonder if I could grab some kind of duct size adapter and some dryer vent tubing from a home improvement store and duct the hot air from that thing right into the cowling while I preflight?
Click to expand...

You should ensure that you don't constrict the airflow and overheat the salamander. The little "prop" fans that salamanders have aren't meant to push air through ductwork.

That said, a salamander is what I use for my pre-heats (but it really doesn't get all that cold here). This is the post (somewhat modified) that I put in Ted's engine thread last year:

I run my Salamander set-up for 30 to 45 minutes anytime the OAT is 40* or less. It provides a reasonably even heat for the entire engine compartment and raises the oil temps 25* to 30* above ambient. This is the temp immediately after starting the engine. My oil temp will read 10* higher than it actually is before starting because the sensor is externally mounted, but the temp drops immediately upon starting as the cooler oil from the pan starts circulating.

I believe my set-up is better than the red dragon for two reasons. First the heat source is farther from the engine so the air entering the cowl isn't so hot and, second, I'm introducing the warm air into the bottom of the cowl and allowing it to naturally rise instead of trying to force it down from the top.

The Achilles heel of my system is the internal engine components...crank and bearings, etc. There's a lot of mass there that I know I'm not warming much if at all. But it doesn't get that cold here, as in seldom below 20*F and, if it is, I'm not going to be flying anyway.

Here's my system, notice the gap that remains between the salamander and the ductwork. This keeps the salamander from overheating and it's really quite a bit larger than the photo would lead you to believe.

attachment.php
 
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That is almost exactly what I used to do other then the heater I used was much lower power, small electric ceramic heater. My setup was more of a crockpot then an oven. It wouldn't work for a on-the-spot "pre-heat" where you came out to the plane at 20F and wanted the engine warmed up in an hour. Rather, I would turn it on the night before and when I showed up in the morning to leave the engine oil would be 70F after a 20F night.
 
I live in Georgia where it doesn't get brutally cold, but there are winter nights in the 20's and 30's. What temp do you recommend preheating? I figured I'm okay in the 40's, but thought I would do the lamp/blanket trick for flights in the 30's or less.
 
rbridges said:
I live in Georgia where it doesn't get brutally cold, but there are winter nights in the 20's and 30's. What temp do you recommend preheating? I figured I'm okay in the 40's, but thought I would do the lamp/blanket trick for flights in the 30's or less.
Click to expand...

Think about it this way, it doesn't hurt to preheat. Even though I could start the cherokee in the 40's without preheat, I still preheated - it can only help the engine.
 
cowman said:
Another thought, I have one of these:

P11961488.jpg


I wonder if I could grab some kind of duct size adapter and some dryer vent tubing from a home improvement store and duct the hot air from that thing right into the cowling while I preflight?
Click to expand...

Exactly what we have. It has one flaw...

Airflow is reduced and these devices have a high temperature shut-off sensor in the external "cowl". The sensor is intended to shut the unit off in case of fire or flame at the exit end. High temps from the back pressure will shut it down.

Ours kicks off about three times during a typical pre-flight heating session. We just let it cool a bit (still way above ambient) and re-light.

Another tip. Get good gloves. The tubing vibrates with the unit and will fall out of the cowl. And you'll be stupid once... And grab it to shove it back in. Damage to your skin will be in direct relation to how good your central reflexes are. ;)

Another tip... if you use a large one, propane bottles in sub-zero weather will freeze their valves during high fuel flow. Also new bottles all have a flow restricting mechanism that will cut off flow if the bottle is rapidly leaking. In extremely cold weather, the flow rate and cold fuel will close it. :)

One really realy cold day I actually fired up a huge diesel/kerosene salamander to put a little heat into the hangar while also pointing it at the propane tank for the little engine preheat salamander to keep it from freezing up and stopping. Heh. Not too close, of course, but it was bitter that day. If you angle it correctly you can get little puffs of warmer air to flow past the airplane and help keep you warm as you preflight that side. Hahaha.

We have the big diesel/kerosene roll around jet thing for cold weather maintenance days. Get engine oil warm, taxi back, push airplane into hangar and point big heater at our butts while we change oil. Heh. Changes the job from miserable, to only annoying. :)
 
taters said:
http://www.amazon.com/Kats-24100-Watt-Universal-Heater/dp/B000I8VL3O
Kats stick on pad heater

Fits the sump of a Lycoming nicely cylinders will be warm to touch....clean the sump with a solvent ..the 3M aluminum tape backing works very well...then just zip toe the cord up the engine mount near the oil door
Click to expand...

To install these properly you have to strip the paint from the area it sticks to. Then you have to run a bead of high temp silicone around the outside edges so it seals down to the sump. If an edge pulls up it will cause a hot spot on the heater and it will burn out. Don
 
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