Do I need to plug in for a 1-hour stop over?

X

xueuni

Filing Flight Plan
Joined
Mar 28, 2012
Messages
5
Display Name
Display name:
uni
In mid-20 temperature, is it ok to leave a c172 with hot engine unplugged on the ramp for an hour before starting it again? Planning to fly somewhere for a quick brunch..
 
Better if you have cowl plugs or an engine blanket to help keep the heat in while stopped
 
It'll be fine. Your oil temp will be plenty warm at start-up and that'll keep the cylinders warm as well. Any winter plugs or covers you have will help but if you have none you'll get by just fine. I don't usually preheat for mid-20s.
 
For a hour you’ll be fine.

Or just buy a thick sleeping bag from Walmart and use it was a cowl blanket
 
James331 said:
For a hour you’ll be fine.

Or just buy a thick sleeping bag from Walmart and use it was a cowl blanket
Click to expand...

And while you're at Walmart, get a couple rolls of toilet paper to shove in the cowl openings.
 
Bobanna said:
And while you're at Walmart, get a couple rolls of toilet paper to shove in the cowl openings.
Click to expand...

Nah, you toss the rolls out at like 5,000’ and cut them with the wings.
Actually a very fun and skill building thing to do.


But the sleeping bag thing works quite well
 
The oil will still be warmer than if you plugged it in.
 
What you are looking for is for the oil to drip off the dip stick like oil instead of like frozen molasses.
 
Factory preheat recommendations- Continental below 20*F, Lycoming below 10*F. I'd guess the oil temp after an hour will be over 100*.
 
No problem, check the oil before start up and it will feel warm to the touch. Hopefully you are using a semi-synthetic multigrade oil for winter.
 
Stewartb said:
Factory preheat recommendations- Continental below 20*F, Lycoming below 10*F. I'd guess the oil temp after an hour will be over 100*.
Click to expand...

No way I am cranking a 10F cold soaked Lycoming I own. 30F is for a cold soaked engine with multigrade is my limit.
 
Clip4 said:
No way I am cranking a 10F cold soaked Lycoming I own. 30F is for a cold soaked engine with multigrade is my limit.
Click to expand...

If the oil is 100f it’s not cold soaked
 
Cowl blanket and cowl plugs on windy day and after 1 hour oil temps should be at least 50 d F
 
You will be fine. You could cold start in mid 20's. After one hour it will still be somewhat warm and will crank over nice.

Get cowl plugs. Worth it for your case, rain, snow, birds, etc.
 
xueuni said:
In mid-20 temperature, is it ok to leave a c172 with hot engine unplugged on the ramp for an hour before starting it again? Planning to fly somewhere for a quick brunch..
Click to expand...

Minus -20. ???
wouldn't hurt, mid 20 I still would
 
May not be necessary for this trip, but wrapping prop and spinner helps too, otherwise they are just big aluminum heat sinks bleeding out that warmth...
 
We have some old parka sleeves we use on the prop.
 
It's pretty obvious the only way to ensure the engine isn't damaged by a cold start is to make arrangements with the FBO to put it in their heated hangar.
 
@KayDeeW and I flew yesterday and stopped for 2 1/2 hours where the temp was 30*F. With just cowl plugs the engine temp was still warm to the touch when we returned. Adding a cowl blanket/sleeping bag would have probably kept it warm all day.
 
Go ahead and get the 14 man tent and set it up covering the nose of the plane. Stockings for the prop, sleeping bag for the cowl, and don’t forget the smores.
 
tawood said:
Old pillow cases (I use old flannel ones) work good too.
Click to expand...

That’s exactly what I use too on the prop.

Once I decided to buy I did a lot of research on preheating and cold starts and I’m going to be overly anal about it, overhaul is just too much to not put extra effort into this area... I want warm oil, warm cylinder heads, and warm internal engines components...

I would wrap it all up during lunch, costs nothing... wear on cylinders, bearings, etc isn’t cost free, I’d rather error on side of being nice to my lil continental...
 
Pillow cases? Engine cover makers offer insulated blade and spinner covers. I have quilted nylon ones That work okay but my favs are stretchy tight-fitting neoprene. Not so much for retaining heat. I don’t give much merit to that, but I don’t like ice and frost on my prop any more than I do on my wings.
 
Stewartb said:
Pillow cases? Engine cover makers offer insulated blade and spinner covers. I have quilted nylon ones That work okay but my favs are stretchy tight-fitting neoprene. Not so much for retaining heat. I don’t give much merit to that, but I don’t like ice and frost on my prop any more than I do on my wings.
Click to expand...

Yea fleece ones- just temporary until I can sew some. I’ve sewn boat seats before so gunna make custom cowl and prop n spinner cover. Going to use black duck cloth, a liner that incorporates Mylar and polyester and orange fleece on the side in contact with the cowl.

I would say there is a lot of merit to the concept that that big ol chunk of alum out front is a major source of heat loss... I had a friend in the led light building biz for ambulances n such- led lights do produce heat and it’s vital the diodes don’t overheat and to keep energy consumption down they don’t like using fans or whatnot so they use heat sinks- pieces of finned aluminum to wick away the heat.. so I would contend a naked aluminum prop would wick heat away in the same fashion- it’s just a huge heat sink...
 
I've preheated more airplanes than most. Two things I've never seen. A preheated engine melt any prop frost, even in close to the hub, and when using my best prop covers I've never recognized any warmth in the prop blades after any amount of preheat, including overnight.
 
Stewartb said:
I've preheated more airplanes than most. Two things I've never seen. A preheated engine melt any prop frost, even in close to the hub, and when using my best prop covers I've never recognized any warmth in the prop blades after any amount of preheat, including overnight.
Click to expand...

Interesting! All my knowledge is theoretical and from reading at this point, i should grab my buddies infered or laser temp gun and do it both ways to see what that says... im always open to an opinion change especially theory vs real world experience..
 
texasclouds said:
Go ahead and get the 14 man tent and set it up covering the nose of the plane. Stockings for the prop, sleeping bag for the cowl, and don’t forget the smores.
Click to expand...

This reply is much better than mine. It shows more imagination. While my idea of a heated FBO hangar is one of the best responses to the OP, I could have gone bigger by suggesting that the hangar have 400 watt metal halide light fixtures hung on a 6' X 6' grid, and an epoxy coated floor that is so white that sunglasses must be worn when the above mentioned light fixtures are in operation.
 
Huckster79 said:
Interesting! All my knowledge is theoretical and from reading at this point, i should grab my buddies infered or laser temp gun and do it both ways to see what that says... im always open to an opinion change especially theory vs real world experience..
Click to expand...

Modern preheaters put out enough heat to get oil and cylinders heated evenly quite well in a couple of hours. I guess if you live in -40* temps and try to heat with a 60w light bulb you may need to do all you can to keep heat in. In my -30 limit with a Reiff system the prop isn’t a concern for preheating. I do want to keep if frost free, because at -30* the frost is hard and stubborn to scrape off and my Blockbuster card broke a long time ago. :)

When I use my MSR stove in my ammo can for preheating I have to open the front of my insul cover a little to allow air flow. To do that I have to take the spinner cover off. With that the prop covers come off, too.
 
Stewartb said:
Modern preheaters put out enough heat to get oil and cylinders heated evenly quite well in a couple of hours. I guess if you live in -40* temps and try to heat with a 60w light bulb you may need to do all you can to keep heat in. In my -30 limit with a Reiff system the prop isn’t a concern for preheating. I do want to keep if frost free, because at -30* the frost is hard and stubborn to scrape off and my Blockbuster card broke a long time ago. :)

When I use my MSR stove in my ammo can for preheating I have to open the front of my insul cover a little to allow air flow. To do that I have to take the spinner cover off. With that the prop covers come off, too.
Click to expand...

Yea mine seems plenty powerful enough- it’s just a sump heater- but it’s an old philips it looks like jot water heater element not a flat pad. It’s 275 watts. Cowl is warm to touch once I take blanket off. That little laser heat gun could be interesting just to put numbers on it not the pit the hand on it like checking kids fever- though effective checking the numbers difference would be interesting just to see...

I’ve known all I long my “theology” on this may change with practical experiences- built a theology off reading just as a starting point...
 
Free supply of degree symbols for such discussions, for those that cannot generate them. °°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
 
You must log in or register to reply here.
Back
Top