Winterization Kit

[3958v]

I am having problems keeping my oil temps up in the winter. After looking at the parts catalog I see that Cessna has a winter kit. I have the lower cover but I dont have the 0552101 Cowl Grill Winterization. I was wondering if any one had originals and would send me a tracing in the mail. I am sure they would be easy to make but I would like to know how much of the opening that Cessna covered. Bii K

[Bruce Fenstermacher]

Bill can't help you with the tracing but can help with the amount of cowling I've closed way over here in Quakertown. Although my airplane is newer than yours they both have the early cowl with grill and internal airbox.

First I usually use a round inspection cover from a fabric airplane to completely cover the lower oil pan cooling hole. I put a layer of duct tape on the cover to protect the cowl paint. Duct tape itself will work to cover this hole. You can pretty much leave this closed except in the summer.

Second using duct tape I have completely covered 2 of the 4 openings between the grill on each side of the cowl. I covered the top and third from the top or every other opening. My though here was to even out the airflow which probably isn't necessary. I also tried to keep the grill open in front of the air intake for the heater which barely works as it is.

I flew this when I commuted daily in any temperature here in PA but would uncover at least some of the grill when it was above 30. All this was before I rebuild my engine and found the baffles between my cylinders missing. Now with them installed the engine runs hotter and I think one grill space each side would to it. Haven't tried it because I'm no longer commuting with the plane and my engine temperatures run about 170 with just the lower center hole covered.

[3958v]

Bruce Thanks fo your reply. I actually have the factory cover for in front of the oil pan. I will show it to you next time I see you around. I do have the baffels between the cylinders but even with them I am only getting 145 degrees with an outside temp of 20 degrees. Bill K

[HA]

if you're talking about the intercylinder baffles, then they are supposed to be there to direct the airflow through the cylinder fins instead of bypassing the cylinders - very bad if they're missing (hot spots in your cylinders). shouldn't do much to change oil temp, unless there was some weird venturi effect set up in the cowl somehow. pretty hard to prove or disprove that one.

I have used strategic amounts of duct tape in the past, but I really like the idea of an inspection plate - the parts book shows a little square cover with some tabs behind it to clip into the oil pan opening, I think I'll whip up something like that with a tab behind that tightens up with a screw so I quit ripping up my paint. Should be able to do the same thing for the upper openings too.

[Bruce Fenstermacher]

HA the only reason I mentioned the inner cylinder baffles is because most of my winter flying was without them and I didn't know it. Know that I've installed them my overall engine temperatures are warmer. Maybe because of less total airflow through the engine which might be the reason someone took them out. My engine oil temperature never came close to the limit. Now it does in the summer.

I wouldn't take out the inner cylinder baffles and don't know or care to figure out if it would hurt the cylinders. I do know that my OEM cylinders which had about 650 since new didn't seem to suffer any ill effects at engine over haul.

[HA]

OK, I'm baffled (arg) as to why cylinder baffles would affect oil temp to make it higher - if anything I'd figure it would go the other way because more cooling air hitting the fins means less heat carried away by the oil. that's a poser. nothing else was changed when you fixed the baffling?

oh well, it is what it is. so, make sure that your baffling tunnel around your oil pan is sealed at the front of the cowl ok, that the air can exit at the rear of the engine ok, and that those 2 air blast tubes from the upper rear baffling down to the oil screen area are aimed correctly etc, and that the baffling strips around the top and sides seal effectively to the cowling, and you've done what you can for the baffling. if none of that can help your oil temp, then you look for either a gauge problem (calibrate it) or something internal in the engine - excessive blowby, tight clearances, something that would add heat to the oil.

I guess I beat that to death, huh? hard to stop once you get thinking about something...

[GAHorn]

I've mentioned it before, but I'll do it again: Exhaust flange leaks will send hot exhaust onto the pushrod housing tubes which are a return oil path and result in hot oil temps.

Hans, the baffles direct airflow to the areas needing it. If you remove the baffles the areas needing cooling air will not get it, and the engine will overheat. I'll give you a really odd example: Some engines have a blocking baffle in FRONT of the front cylinders. Removing that baffle will overheat the cylinders aft of that cylinder. Why? Because a loss of cool air volume will result, in that air will flow around and down in front of that front cylinder and will not be forced into the high-pressure area above all the cyls...thereby denying them airflow.
The inter-cylinder baffles absence will also cause overheating because the lower surfaces of those cyls will not receive cooling air. The air will instead continue downward and exit the cowl.

Bottom line: Make certain all baffles are present and accounted for IN ACCORDANCE WITH THE INSTALLATION DRAWINGS contained in the IPC.

[Bruce Fenstermacher]

Ok HA lets start over. This thread is about trying to get your engine oil temperature to run hotter in the winter by installing baffling on the intakes of the cowl which Cessna had a kit to do.

Not having a kit but a hundred or so hours of operation in the exact location and with the same type of cowl and pressure box as Bill K. (the originator of the thread) I thought I'd offer how much of the cowl openings I successfully closed and the result. But in order to do this I had to mention that the time spend with the cowl baffles in place to raise the oil temperatures the inner upper cylinder baffles where also missing.

Since I've replaced the inner upper cylinder baffles because they should be there by design, my engine oil temperatures have risen overall 15 or so degrees. I can't tell you why other than I believe the total amount of air being allowed to pass over the engine to cool it is more restricted yet may be more even which is the presumed purpose of the inner cylinder baffles.

Since my engine now runs hotter with no cowl baffles it would stand that if I closed off the cowlings as first described for winter operations the engine oil may get to hot.

[zero.one.victor]

....................................................
I have used strategic amounts of duct tape in the past, but I really like the idea of an inspection plate - the parts book shows a little square cover with some tabs behind it to clip into the oil pan opening, I think I'll whip up something like that with a tab behind that tightens up with a screw so I quit ripping up my paint. Should be able to do the same thing for the upper openings too.

My "oil cooler" cover (home-made) is held on by 2 screws. I drilled a hole on each side of the opening in the nosebowl, and come winter, I install tinnermans there and attach the cover. Come warm weather, off comes the cover & the tinnermans til next winter.
It doesn't get cold enough around western washington to need the cowl-grill covers. I believe the pics/drawings I've seen of the factory covers show either the outboard 1/2 or 1/3 of the openings are blanked off by the winter covers.

Eric

[3958v]

Eric Look carefully I think the cover is for the inboard side but I am not totally sure. Parts book is not clear. With the cost of engines these days I really dont want to try trial and error and that is why I was hopeing that some one on the board had an original set so that maybe we could see pictures of them. Bill K

[Bruce Fenstermacher]

Bill
I've looked at both the 170 and the 170A IPC and it clearly shows the baffle blocking the inside of the grill.

Based on my experience I wouldn't be afraid to make them cover half of the grill area then fly and reduce the area blocked as needed.

One reason I didn't block the inside of the grill like the IPC is you are also blocking the cabin heat air intake.

[N2830C]

last year I had only the lower (square) cover and my engine would get too cold when I had to descend quicker than I would like to land. I know this as I have an engine analyzer with CHT and EGT. The outside temps were from 0-30deg F.

I had a set of covers for the airflow over the cylcinders made and my mechanic made them to cover 1/2 of the opening. They work great with no overheating. I take them off when it hits 40 deg F.

[N4281V]

I think if you flip around in The 170 Book you will find the templates for engine intake covers. I made a set for mine and use them for our cold Maine winters. However, it's still not warm enough in the cabin for me to fly below 35F! I don't cover the heater intake on the left side (inboard). We used some .025 aluminium (two pieces) and put rivnuts on the inner pieces and just put some screws through the gap of the grill to hold the two pieces tight against the grill. I also have the tinnerman nut setup for the oil pan area. I also have another piece with lots of drilled out holes for the 40-50 degree days. My engine runs real cool....it has the "seaplane" lip.

[zero.one.victor]

Several years ago before my engine overhaul, I had trouble with high oil temps, probably due to blow-by. I fabricated a seaplane lip (about 2" as I recall) which fastened to the standard little 3/4" or so cowl lip with a whole bunch of little stainless machine screws & nylock nuts. I never did see that it made much difference. But now a friend who is really into aerodynamic cleanup tells me that all those #6 or #8-sized holes in the cowl lip add an astounding amount of drag. Whatever....
Definition of a seaplane lip: what you get after you slip on a wet float & smack your mug against the dock........

Eric

[GAHorn]

You could probably disguise them with universal-head rivets in the holes?