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Cold weather starting

rwarre

Well Known Member
Most times my rv7a (o320 160hp) is plugged in and oil is warm before starting. If I have to leave it outside even at 34 degrees there is not enough juice to turn the prop fast enough to start. (Cold oil). Other than finding a way to plug in, any ideas for starting?
 
Most times my rv7a (o320 160hp) is plugged in and oil is warm before starting. If I have to leave it outside even at 34 degrees there is not enough juice to turn the prop fast enough to start. (Cold oil). Other than finding a way to plug in, any ideas for starting?

34 should not present any issues for a healthy battery and start system. Lycoming guidance:
In extremely low temperatures, oil congeals, battery capacity is lowered, and the starter can be overworked. Improper cold weather starting can result in abnormal engine wear, reduced performance, shortened time between overhauls, or failure for the engine to operate properly.
The use of pre-heat will facilitate starting during cold weather, and is required when the engine has been allowed to drop to temperatures below +10°F/-12°C (+20°F/-6°C for –76 series engine models).
Be sure that the engine oil is in compliance with the recommended grades.
 
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Most times my rv7a (o320 160hp) is plugged in and oil is warm before starting. If I have to leave it outside even at 34 degrees there is not enough juice to turn the prop fast enough to start. (Cold oil). Other than finding a way to plug in, any ideas for starting?

May sound crazy, but why not one of these if you know you'll be outside away from power plugs frequently?

https://www.homedepot.com/p/Sportsm...d-Digital-Inverter-Generator-802085/300792167

https://www.harborfreight.com/gener...powered-portable-generator-epacarb-63025.html

63025_W3.jpg
 
Most times my rv7a (o320 160hp) is plugged in and oil is warm before starting. If I have to leave it outside even at 34 degrees there is not enough juice to turn the prop fast enough to start. (Cold oil). Other than finding a way to plug in, any ideas for starting?

If you can't generate enough RPM, you need more battery or a better starter. If the issue is battery power, you could upgrade to a larger battery. Alternately, you could come up with an easy way to use a tag along booster battery you keep somewhere warm (like your car or home).
 
Using proper weight oil for cold weather would be a thought.

When you get some time, verify your battery is working as it should, having it tested. Can also have your starter checked too.

Also check your starting circuit. Have you checked for voltage drop between battery to solenoid and to starter? Clean connections, etc.

Assume you've also verified your mags are timed correctly
 
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Most times my rv7a (o320 160hp) is plugged in and oil is warm before starting. If I have to leave it outside even at 34 degrees there is not enough juice to turn the prop fast enough to start. (Cold oil). Other than finding a way to plug in, any ideas for starting?

I find pulling the prop through all 4 compression cycles (twice around) before getting in my RV really helps if I need to do cold starts with out preheat.
 
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I find pulling the prop through all 4 compression cycles (twice around) before getting in my RV really helps if I need to do cold starts with out preheat.

I'll have to give this a shot as I had the same issue as OP yesterday with my Skytec lightweight starter.
 
I realize that many have some concerns about the lightweight starters from Skytech but I hate to see them bashed for all situations. I agree with an earlier poster that first step is to check your battery, wiring etc. I have a Lycoming 0320 150 hp (without a primer) with a PC680 battery and Skytech starter. I have zero problems turning over the engine fast enough to start. While like the OP, I normally have it preheated when temps get below freezing, I have started easily at 30 degrees F. My battery in my Tailwind is located behind the PAX seat under the baggage compartment so I also have a fairly long run of #2 welding cable from the battery. Still no problems.

All avionics have a dedicated ground bus but the starter uses the airframe as ground. Other than replacing the starter solenoid (Ford Victoria part), I have not had any problems. I have 700+ hours on my plane.

FWIW

Keith
 
Don’t know if this applies to you but, I have a Lithium Battery and if it’s cold circa 30 degrees I load up the battery by putting on lights. You can watch the voltage increase as the battery internal resistance heats the battery. Then the engine starts instantly.

Kevin
 
Don’t know if this applies to you but, I have a Lithium Battery and if it’s cold circa 30 degrees I load up the battery by putting on lights. You can watch the voltage increase as the battery internal resistance heats the battery. Then the engine starts instantly.

Kevin

That is counter-intuitive and fascinating!

Speaking of preheating, I am in my first winter of airplane ownership, and don't get to fly but once or twice every three or four weeks. Unheated hanger in new jersey. What should i do to keep her warm, or to warm her up before starting?
Titan IO360 188 HP
 
I live in Minnesota, plane lives in an unheated T-hangar…the winters do tend toward the cold side. I can’t heat the uninsulated hangar…if I do, the snow on the roof melts, drips down, and freezes the hangar door shut.

So I don’t worry about keeping the airplane warm, although I do have a little ceramic heater I keep in the cockpit that I can turn on remotely with my phone. The engine has a Reiff Turbo XP sump and cylinder heater, also on the cellphone switch. If I’m flying later, I turn those two heaters on 4 hours or more ahead of time. When it’s time to fly, the cockpit is toasty warm and the engine oil temp is at 70-100 degrees. I’m no A&P, but I’m told that starting a cold airplane engine is very hard on it.

Unrelated, but the first thing I do when putting the plane away after a flight is hook it up to a dehydrator and purge the crankcase of the moisture associated with an IC engine and which will condense as the engine cools back to ambient.
 
Starting update

So I decided to trouble shoot my starting problem using the Skytek procedures on their website. Checked voltage at the starter first. 7 volts, with the battery reading 12 volts. Next I connected the volt meter to the master relay. The side closest to the battery was 12 volts. Ok. Then connected to the other side of that relay. Supposed to be 0 until activating the starter switch. When I hit the switch the plane started immediately. Couldn’t believe it. Talked to Lamar tech support who spectulated that the relay contacts were sticking. I know very little about relays but am replacing the one on my sytem
 
I once forgot to hook up the earth directly to the engine case and then you don't get enough volts through to the starter since it has to draw the volts through engine rubber mounts which is not good. Check to see if the engine case/block is earthed properly...
 
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