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PA-12/18 winterization - new to winter GA flying

akmarty

MEMBER
A few days ago I went flying during one of the colder days this year in ANC (10deg F). I added my second piece of tape to the oil cooler for a complete cover. The previous flight with temps about freezing the oil temp topped out about 145deg during a 2hr duration. The tape helped but still had a hard time getting it to 180deg (topped at 160-165). I’ve noticed condensation in the top of my dipstick if I don’t get the oil up to 180deg during the flight. The other thing I noticed was CHT staying pretty low as well (300-350deg) and rapidly cooling in the pattern as I fly downwind the final. In the pattern the oil temp was as low as 125deg. Not flying a crazy bomber pattern either.

So….I’ve searched the forum and read all that I can find on cub winter ops and I did not see an answer. I am assuming there is not a compression issue(last annual was all in the 70’s).

Has anyone ever added small or partial covers to the cooling intakes on a PA-12/18 with an O-320? I’d love to see pics if you have them. I did hear one guy offhandedly mention he would duct tape his opening.

Thanks
 
https://fadodge.com/winter-front/

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I’m sorry I neglected to mention my bird has rear baffle mounted oil cooler and no chin opening on the cowl. I’m wondering about a cover for this area..IMG_0644.JPG


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You’ll find condensation regardless of oil temp. Personally I don’t pay attention to CHTs. Only oil temp. And if 165° is all there is? Good enough. Parking outside? Any condensation will freeze so corrosion isn’t a factor. Inside a hangar? I’ve become a fan of dehydrators.
 
I would not consider covering any inlet openings unless you have a 4 cylinder EGT/CHT. Contrary to popular opinion the rear cylinders are not always the hot ones. Where did you put the tape for the rear oil cooler? I made a plate of thin aluminum that slides down the front of the cooler and the baffle I had problems with getting tape to stick plate works fine. My normal CHT's are usually 325-325 even in the summer. 165 degrees will still cook of moisture just slower. Are you using Camguard? The stuff in Philips 20-50 Victory oil IS NOT CAMGUARD!! it is a friction additive. What RPM are you running? DENNY
 
I would not consider covering any inlet openings unless you have a 4 cylinder EGT/CHT. Contrary to popular opinion the rear cylinders are not always the hot ones. Where did you put the tape for the rear oil cooler? I made a plate of thin aluminum that slides down the front of the cooler and the baffle I had problems with getting tape to stick plate works fine. My normal CHT's are usually 325-325 even in the summer. 165 degrees will still cook of moisture just slower. Are you using Camguard? The stuff in Philips 20-50 Victory oil IS NOT CAMGUARD!! it is a friction additive. What RPM are you running? DENNY

I don’t have 4 cyl CHT/EGT on this plane.

I use aluminum tape and place it on the back. No space for flow to leak and it hasn’t come off.

I use CamGuard with my oil changes which are Victory 20w50.

I was running 2400 rpm in an attempt to keep it running warmer.


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Yes, keep doing what you’re doing. I would be VERY careful covering a portion of the cowl inlets. Even with four cylinder CHT, disturbing the air flow MAY create turbulence and hot spots that go undetected.

Cover the oil cooler, and go fly it. As Stewart says, if you park inside, think about dehydrator.

Finally, in cold, after flying i unscrew the dipstick to allow some moisture to escape. A big deal? Probably not.

MTV
 
In the old days there used to be snap on insulated covers for the Continental kidney oil sumps. Has anyone made one of these for a Lycoming oil sump? The sides of the sump make a good radiator expelling heat. If you can trap this heat, I suspect your winter oil temperatures would be higher.

Hmm? Sounds like a small business opportunity for someone with a sewing machine.
 
In the old days there used to be snap on insulated covers for the Continental kidney oil sumps. Has anyone made one of these for a Lycoming oil sump? The sides of the sump make a good radiator expelling heat. If you can trap this heat, I suspect your winter oil temperatures would be higher.

Hmm? Sounds like a small business opportunity for someone with a sewing machine.

Might be helpful. Figuring out how to attach the thing would be the trick. The kidney tank covers are still available from Wag.

MTV
 
Cessna used to produce winter fronts for the 200 series. I am guessing Piper never did?

Yes, the brand new C-185 I picked up in 1986 came with winter fronts. Absolutely useless POS, frankly, EXCEPT for the induction block off plate…..that’s important on those engines.

But with the block off plates on the cowl inlets, you had NO cabin heat, and when I climbed out of Fairbanks at -30F and passed through 400-500 feet, air temps would start warming. Anything warmer than -25 the engine would start overheating. So, I wound up down low in the super cold the whole trip.

None of the air taxi folks in central AK used the things. As a new transplant from Kodiak, I thought those plates must be a good idea. Maybe somewhere there are extreme cold but no inversions, but not FAI. Pulled those plates off the cowl openings, left the induction plate on, covered the oil cooler with duct tape, and flew on.

And, no, Piper never made cowl inlet covers for the Super Cub. I never used anything like that on Cubs or Huskys in twenty years of cold winter flying. Occasionally I’d see a Cub whose owner thought he had a better idea, with home made plates on the cowl inlets…..but I never saw anything like that on the airplanes that flew a lot in winter.

Cover the oil cooler and go fly.

MTV
 
Might be helpful. Figuring out how to attach the thing would be the trick. The kidney tank covers are still available from Wag.

MTV
It would require several flaps to go above the intake tubes and around the carb, then snapping or tying together. Tie it to the oil drain tubes. If it went above the parting flange, perhaps just a draw string would hold it in place? Likely would not be a tight as the kidney tank cover.
 
Yes, the brand new C-185 I picked up in 1986 came with winter fronts. Absolutely useless POS, frankly, EXCEPT for the induction block off plate…..that’s important on those engines.


MTV
I had that winter kit for my 185...... only used it once. It overheated the CHTs .... took it off at my first landing and put it back in the attic.
 
If you want to increase engine/oil temperature, maybe consider restricting the airflow out of the cowling cheeks. I’ve seen photos of solid baffles on the cheeks as well as some that were adjustable from the panel, like cowl flaps. Seems like that would be less likely to cause problems than taping the air inlets on the front.

Jim
 
If you want to increase engine/oil temperature, maybe consider restricting the airflow out of the cowling cheeks. I’ve seen photos of solid baffles on the cheeks as well as some that were adjustable from the panel, like cowl flaps. Seems like that would be less likely to cause problems than taping the air inlets on the front.

Jim

Yes, if you’re going to block off anything, consider blocking off exit air. Cessnas used cowl flaps for this purpose. On my Cub in FAI, I fabricated a set of cowl cheek baffles that attached to the firewall with rivnuts, and conformed to the cowl doors, with a rubber seal on the outer edge. Painted black, we’re totally invisible unless cowl door was open. These increased CHTs a few degrees. On a Top Cub, with those huge rear cowl openings in MN, these made a significant difference. Top Cubs have a wide open cowl, and run really cold in winter. Really needed to improve that cowling for cold……..makes me shiver recalling.

An outfit in Fairbanks years ago STCd a cowl flap for cubs, tha blocked off part of bottom cowl outlet. I never flew a Cub with that mod, so no idea how effective.

MTV
 
I don't mess with the intake openings or the (smaller than normal) cowling cheeks. I do, however, have one of those oil cooler shutters from Anti-Splat Aero. I can control the oil temperature from the cockpit. Works well.

I found that taping the oil cooler was too much of a guessing game.

O-320-160 with rear-mounted oil cooler.
 
I have this same “issue”. I upgraded to a vernatherm this last spring which helped some over the stock setup. I made two different sized aluminum sheets that I slide in front of the rear mounted oil cooler and that’s helped some but when it’s 20° and lower, even blocking the majority of the front of the cooler and taping the rear doesn’t get temps up to 180° consistently or for long. I purchased Anti Splat’s oil cooler louver setup and hope that helps and will allow for adjustment from the cockpit as needed.
 
When discussing oil temps you really need to factor in where your oil temp sender is installed. If in the filter adaptor it'll register about 15-20* lower than if in the engine case. At least that's what I found with my engine.
 
I would not consider covering any inlet openings unless you have a 4 cylinder EGT/CHT.

Since you have a 4 cylinder EGT/CHT would you consider testing the effects of a narrowed enclosure? For the past 28 years I have always used a vertical strip of duct tape on each inboard side of the cowl inlets to boost my engine oil temps. My engine has survived just fine. I'm sure one test will not effect your engines longevity.

So much is said about the concerns over disrupting the airflow inlets and at some point I'm sure these concerns become valid. However, is one strip of duct tape on each inlet going to send your gages into red alert or cause concern? It makes a wonderful difference in oil temps when it's cold up there.

The results might be interesting since you can monitor the effects.

Jerry
 
Since you have a 4 cylinder EGT/CHT would you consider testing the effects of a narrowed enclosure? For the past 28 years I have always used a vertical strip of duct tape on each inboard side of the cowl inlets to boost my engine oil temps. My engine has survived just fine. I'm sure one test will not effect your engines longevity.

So much is said about the concerns over disrupting the airflow inlets and at some point I'm sure these concerns become valid. However, is one strip of duct tape on each inlet going to send your gages into red alert or cause concern? It makes a wonderful difference in oil temps when it's cold up there.

The results might be interesting since you can monitor the effects.

Jerry

Jerry,

I ran this past a Lycoming Tech Rep once out of curiosity. His response was.....errrr.....probably won't hurt anything. I explained that I had an engine monitor. He responded "That's fine, but a monitor only tells you what's happening at the probe. There can be hot spots not detected by a probe on a cylinder."

So, he kind of equivocated and suggested that you probably won't do damage, but.....not recommended by Lycoming. He agreed that restricting outflow was a better choice.

That said, I seriously doubt that the cowl inlets on a Cub are very seriously scientifically designed either.....with or without blockage.

MTV
 
Jerry the problem with doing the test is it will only be reproducible on my cub. I spent 1 1/2 years modifying front ramps/getting air tight baffling/other stuff to lower my CHT's. It also has a larger than stock oil cooler mounted on the rear baffle (major pain to work around) I am sure my engine would probably be fine but every engine/plane is different. I have seen cubs with the same cowl/engine/prop that run CHT's 30-40 degrees hotter than mine at the same speed even in colder temps. I have seen too many planes that run just fine with normal oil temps but have major CHT issues on one or more cylinder, the only way we knew it was with the 4/6 cylinder EGT/CHT without it you never know what you don't know.
DENNY
 
On a related note. What do you Alaska guys do to make pushing the plane around in the cold easier? It's about all I can handle even at 25 degrees. I've heard some people pack the wheel bearings with lighter grease? Just went from 850's to 31's. It was pretty difficult before.
 
Jerry the problem with doing the test is it will only be reproducible on my cub.

Sure but I would think that is a given on any test. There should be some sort of indication of its effect regardless of how tight your cowling is or how loose mine might be. I only proposed it since you seemed to be on top of the finer points in CHT observations and was curious if you were curious enough to give it a test. I'm sure any change in that opening would have an effect on CHT's as you explained with your fine tuning efforts of your engine baffles. The question is would it be enough to raise a flag.

Jerry
 
I went flying again yesterday. Temps were just below freezing. With the oil cooler completely taped over is popped right to about 180 and during cruise at 2400rpm got up to 190-195.


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Sure but I would think that is a given on any test. There should be some sort of indication of its effect regardless of how tight your cowling is or how loose mine might be. I only proposed it since you seemed to be on top of the finer points in CHT observations and was curious if you were curious enough to give it a test. I'm sure any change in that opening would have an effect on CHT's as you explained with your fine tuning efforts of your engine baffles. The question is would it be enough to raise a flag.

Jerry

The problem is no matter what the outcome was good or bad you cannot say with any certainty that is how it would effect another cub and the OP has a 12 so that would really be a crapshoot. Doing changes to the oil cooler is fine because you have a gauge to monitor it.
DENNY
 
On a related note. What do you Alaska guys do to make pushing the plane around in the cold easier? It's about all I can handle even at 25 degrees. I've heard some people pack the wheel bearings with lighter grease? Just went from 850's to 31's. It was pretty difficult before.

What pressure in the Bushwheels? They make any airplane much more difficult to reposition on the ground. Then again, too much pressure sorta defeats the purpose of Bushwheels.

MTV
 
On a related note. What do you Alaska guys do to make pushing the plane around in the cold easier? It's about all I can handle even at 25 degrees. I've heard some people pack the wheel bearings with lighter grease? Just went from 850's to 31's. It was pretty difficult before.

Aeroshell 22 grease makes the tailwheel pivot, lock, and unlock better in the cold than some of the thicker stuff. I use it year round for tailwheel and wheel bearings. Your tire pressure will drop the colder it gets. I have AOSS shocks so I now tend the keep my Bushwheels up around 6-8 psi for daily use. Makes pushing the plane around a lot easier.
DENNY
 
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