The International Cessna^® 170 Association

Here in Northern California the temps can get into the 40s and low 50s, seldom into the 30s. The placards for the 1952 B winterization kits state "Remove above 30 degrees". My 170 was based in Phoenix for 30 years and has had the oil tank cowl opening enlarged. On average winter days my oil temp seldom makes it above 160. I have considered buying or manufacturing a winterization kit, however I would be using it in temps above 30 degrees. Should I not worry about the oil temps and just keep up the 25 hrs oil change schedule? What is the reason for the 30 degree limitation?

I have seen discussions about the use of Duct tape and have considered using Duct tape to cover the engine cowl opening in the same way the plate would. Has anyone done this successfully? I suppose however that the 30 degree limitation would also apply to a duct tape closure.

Robert,

The covers are removed above 30 degrees to prevent overheating oil and cylinders. If you know your oil temperature gauge is accurate and your oil is running too cool, I don't see why you couldn't leave the covers on at higher temperatures. I like to see 180 degrees or higher on the oil temp, but I don't expect it to get that high in the Minnesota winters.

I have used duct tape, but I apply it just before a flight and remove it immediately afterwards, cleaning up the adhesive residue with Stits paint cleaner. I'm afraid that if it's left on too long, it might mess up the paint. I may be overcautious, but I'd rather be safe than sorry, as they say. One of these days I need to get myself a set of those covers!

Best Regards,

John

Robert

Like John I like to see 180 degrees and assuming accurate gauges would not be afraid to run some sort of restriction on the inlets to achieve that regardless of the outside temperature.

I've run duct tape almost exclusively covering as much as half the cowl inlets as well as completely covering the oil sump hole.

And I also recommend you remove it at least every few days. I leave mine on the entire season and getting the glue off the paint in the spring is a problem.

Thanks for the responses - I'll give the Duct tape a try.

Its been the experience of many that duct tape corrodes aluminum.

If you use Duct Tape and leave it on bear aluminum for a few years there may be some corrosion.

Won't happen in a few flights.

Remove the duct tape after each flight while the cowling is still warm and there won't be any problem. Any residue can easily be removed while it's warm with WD-40 or gasoline. Leave it on and let it cool down, the adhesive sets up and becomes hard to remove.

The OAT will probably be different on the next flight anyway so re-design the winterization kit to the existing conditions, ie, more or less tape.

I remove the duct tape after each flight, and set aside the square piece (usually 3 strips) - sometimes it is still sticky enough to re use on the next flight.
If you forget and leave that stuff on it is a real mess to remove!

Thomas

Try taping over one or both blast tubes and see what your oil temperature does. I've got the winter kit on AND both blast tubes plugged with rubber stoppers and my oil temp would not get above 160 degrees, but it was 0 degrees outside.

alaskan99669 wrote:Try taping over one or both blast tubes and see what your oil temperature does. I've got the winter kit on AND both blast tubes plugged with rubber stoppers and my oil temp would not get above 160 degrees, but it was 0 degrees outside.

If you got 160 oil temp at zero OAT, you were doing well! I flew last Saturday and didn't get to 150 oil temp at 30 OAT. The coldest OAT I've ever flown was minus 20 at altitude with half of each cooling inlet blocked and the oil sump opening completely blocked, and was only able to get 125 oil temp.

Miles

N9149A wrote: I've run duct tape almost exclusively covering as much as half the cowl inlets as well as completely covering the oil sump hole.

Bruce,
Which half of the cowl inlet do you cover? I've never covered the cowl inlet, only the oil pan hole, but I'm never happy with how cool things run.

Dale

webmaster wrote:

N9149A wrote: I've run duct tape almost exclusively covering as much as half the cowl inlets as well as completely covering the oil sump hole.

Bruce,
Which half of the cowl inlet do you cover? I've never covered the cowl inlet, only the oil pan hole, but I'm never happy with how cool things run.

Dale

Here's a picture from a post a couple of years ago:

I have the early cowl. Duct tape fits neatly between each rib. When I used tape I started at the top slot and covered the entire slot both sides.

I would then fly and see how the oil temperature reacted. For 30 degrees or so this is probably good. I usually wanted more when it got colder so I would skip down a slot and cover the third slot. That was always enough for me here in PA.

Last year I made a set of aluminum plates that go on the inside similar to the stock Cesura plates but I have a cutout for the heat air intake that my plane has on the pilots side. These plates cover the inside half of the cowl opening just like the Cesura plates did.

If I had a late model cowl like the one Miles pictured and I was using duct tape I'd mimic the aluminum one pictured by running the tape up and down covering about half the opening.

BTW I cover my oil sump cooling hole first with an ordinary round aluminum inspection cover from a cloth covered airplane. Works great.

I HAVE A SET OF THE STOPPER-UPPERS FOR THE EARLY COWL. I WILL TAKE SOME PICS IF I CAND FIND THE THINGS. THEY ARE OEM OPTIONS FOR THE RAM AIR OPENINGS. I USED TO STUFF A SHOP TOWEL INTO THE OIL PAN COOLING OPENING FASTEN IT WITH SAFETY WIRE. THESE RAM AIR BAFFLES WOULD AID THE ENGINE TO GET UP TO TEMP QUICKER BUT DURING 20F OR LESS THE OIL TEMP WOULD HARDLY EVER RISE TO 140F

flyguy wrote:I HAVE A SET OF THE STOPPER-UPPERS FOR THE EARLY COWL. I WILL TAKE SOME PICS IF I CAND FIND THE THINGS. THEY ARE OEM OPTIONS FOR THE RAM AIR OPENINGS. I USED TO STUFF A SHOP TOWEL INTO THE OIL PAN COOLING OPENING FASTEN IT WITH SAFETY WIRE. THESE RAM AIR BAFFLES WOULD AID THE ENGINE TO GET UP TO TEMP QUICKER BUT DURING 20F OR LESS THE OIL TEMP WOULD HARDLY EVER RISE TO 140F

In case nobody has figgured him out..... Ol' Gar backwards (which is forwards to HIM) is Ol' RAG!