Cooler weather flying

CraigH · Post by **CraigH** » Sun Dec 04, 2005 2:44 pm

How do you guys flying in outside air temps of 25F-45F get your oil temps up to 180F? Both my TriPacer and 140A had factory suppleied inlet covers that snapped/screwed over one or more of the air inlets. Is there such an animal available for the 170B?

I've used duct tape in a pinch on some of my other planes as a last resort.

trake · Post by **trake** » Sun Dec 04, 2005 4:49 pm

I have one that covers the hole in front of the crankcase. I dont know if its factory or aftermarket. Speaking of cool weather, at what OAT should a C145/O300 be preheated? Im using multigrade.

zero.one.victor · Post by **zero.one.victor** » Sun Dec 04, 2005 5:13 pm

trake wrote:I have one that covers the hole in front of the crankcase. I dont know if its factory or aftermarket. Speaking of cool weather, at what OAT should a C145/O300 be preheated? Im using multigrade.

I run XC20-50. I've been preheating lately, as it's been getting down below freezing at night and not getting out of the mid-to-high 30's in the daytime. Makes it easier to start, plus less warm-up time. Along with any other less-discernable benefits.
I might quit if & when the below-freezing temps go away.

Eric

N2255D · Post by **N2255D** » Sun Dec 04, 2005 5:23 pm

I used to parts manual for the approximate size and then traced the cylinder opening. I cut a piece of metal @ 1/2 inch larger than the drawing that I made to allow for a bend to go behind the edge of the opening. I took a large adel clamp and reshaped it to hold the cover in place and used rivnuts to attach the clamp to the cover. The rubber on the clamp keeps the paint on the bar from getting messed up. I have a later model cowl with just the single center bar in the opening. For the oil pan I used a drawing that came from the Association some years back. I might still have that if you need. Just have to find it.

CraigH · Post by **CraigH** » Sun Dec 04, 2005 8:46 pm

Just got back from a $100 burger run. Temps at 3000ft were 40F, but after duct taping the bottom inlet I was still only able to get my oil temp above 140F.

Post by **Bruce Fenstermacher** » Sun Dec 04, 2005 9:33 pm

Craig

I have the '52 and earlier cowl.

I use a round inspection cover from a fabric airplane to cover the oil sump hole.

I don't care about my paint so I use duct (duck) tape to cover half of each side of the cylinder air intakes when it's about 30 and below. Above 30 blocking about 1/4 of the air intakes seems to work. On the older cowl the intake is divided into 4 slots that are just smaller than the 2" duct tape so this is pretty easy to do.

If you use duct tape and care about your paint be real careful when you take it off to make sure you dont take any paint with it. It tends to get stuck real good after it has been on there for the entire winter season.

Oh yes forgot to say my plane is the color of silver duct tape so you can't tell it's on there

doug8082a · Post by **doug8082a** » Sun Dec 04, 2005 10:13 pm

N9149A wrote:Oh yes forgot to say my plane is the color of silver duct tape so you can't tell it's on there

No wonder so many use silver as a base color instead of polishing...

CraigH · Post by **CraigH** » Mon Dec 05, 2005 1:46 am

For what it's worth, Goo Gone does a fair job of getting the duct tape residue off when Spring rolls around.

Looks like I'm going to have to come up with something to block off part of the upper air inlets as well.

AR Dave · Post by **AR Dave** » Mon Dec 05, 2005 3:50 am

I'd like more discussion on the cause & effect of cooler oil temps in this case. In Alaska, I had my air intakes and cooler, duct taped in the winter. But Texas? I havn't even thought about this, since moving to Arkansas. But there's also people all around me scared silly if they're not preheating at 40F. I'd like to see what they'd do at -20F.

N3243A · Post by **N3243A** » Mon Dec 05, 2005 6:36 am

trake wrote:I have one that covers the hole in front of the crankcase. I dont know if its factory or aftermarket. Speaking of cool weather, at what OAT should a C145/O300 be preheated? Im using multigrade.

The temp widely accepted in Alaska is to preheat when the OAT is 30 degrees F or colder. If the temp is say 34-35 degrees and one has time, it wouldn't hurt but 30-32 degrees is my cutoff. Also, if it is getting down into the 20's at night, your engine will be cold soaked even though the morning sun may make the current temp into the 30's. A digital CHT gauge helps figure this one out.

Bruce

N3243A · Post by **N3243A** » Mon Dec 05, 2005 6:46 am

AR Dave wrote:I'd like more discussion on the cause & effect of cooler oil temps in this case. In Alaska, I had my air intakes and cooler, duct taped in the winter. But Texas? I havn't even thought about this, since moving to Arkansas. But there's also people all around me scared silly if they're not preheating at 40F. I'd like to see what they'd do at -20F.

Hey Dave,

Did a little flying today up the Knik and around Big Lake. Temp was about -5 F. Oil temp never got above about 160 with oil pan inlet blocked and pressure and suction blast tubes both blocked. In fact I fly with those two tubes blocked most of the times except the warmest weeks of summer. My engine is cold blooded. Took off the ice road at Big Lake solo with 2/3 tanks with a sustained 1300 FPM climb. Gotta like those 80-42 props and cold dense air!!

Bruce

alaskan99669 · Post by **alaskan99669** » Mon Dec 05, 2005 12:47 pm

I've got the sump cover on my plane and my oil temp is not even getting close to boiling off any water. I'm going to try and make a cover like the parts manual shows (picture enclosed). I'll have to try blocking the blast tubes also like Bruce suggested.

Post by **Bruce Fenstermacher** » Mon Dec 05, 2005 1:44 pm

alaskan99669 wrote:.... I'll have to try blocking the blast tubes also like Bruce suggested.

I didn't suggest covering the blast tubes if by blast tubes you mean the ones found in the back of the baffle that cool the lower part of the accessory case.

I block about half the cowl opening which is about what's shown but since I have the older cowl with the 4 horizontal slots I block every other one for a total of 2 each side and I run the duct tape horizontally as well.

alaskan99669 · Post by **alaskan99669** » Mon Dec 05, 2005 2:16 pm

I didn't suggest covering the blast tubes...

The other Bruce said he does that (in Eagle River, AK). Probably not necessary in the lower 48, but I bet it works well here where the average temp will be about zero all winter long, and it is a long winter...

cessna170bdriver · Post by **cessna170bdriver** » Mon Dec 05, 2005 4:12 pm

I've never been based north of about 36 degrees latitude, so cold weather operation has rarely been an issue. With the Cessna oil filter installed, and the oil temp probe in the suction screen, my late B-model consistently ran oil temps about 100 F above ambient in cruise. The only time I "had" to preheat (to escape the in-laws) OAT on the ground was +7F. Knowing it would be even colder at altitude, I emulated the Cessna winterization kit with duct tape, closing off the sump opening and the lower half of the cylinder inlets. (I also taped over the wing root inlets; thank goodness for the late B-model's heater.) OAT in cruise was minus 20 F

and the oil temp never got above 125 indicated, or 145 above ambient. If it ever comes up again, blocking off the blast tubes sounds like a good idea.

Miles