Citabria Winter Kit?

I recentley purchased a 1969 Citabria 7KCAB and plan on doing some winter flying here in Fairbanks, AK. I bought the plane in March so I was flying in 10 degree weather before with the oil cooler 100% blocked off and the oil temp would only get to about 120. I've been serching for some type of winter baffle kit but can not find any info on one. I read the best way to go is to restrict the air flow from the bootom of the cowling but don't know how I could do that. I could put foil tape on the front but herd that might casue hot/cold spots on the cyclinders. Just curous what you guys do for winter flying? Any pictures of a system would be great. Thanks

tape.

I would tape the cowl scoops in front with vertical strips, starting on the inside by the crank, then a strip or two on the outside to keep the heads warmer. Start small and work in.

On the Champ I would cover most of the oil cooling scoop.

Ask Jon over at Northland aviation.

epeltier said:

I recentley purchased a 1969 Citabria 7KCAB and plan on doing some winter flying here in Fairbanks, AK. I bought the plane in March so I was flying in 10 degree weather before with the oil cooler 100% blocked off and the oil temp would only get to about 120. I've been serching for some type of winter baffle kit but can not find any info on one. I read the best way to go is to restrict the air flow from the bootom of the cowling but don't know how I could do that. I could put foil tape on the front but herd that might casue hot/cold spots on the cyclinders. Just curous what you guys do for winter flying? Any pictures of a system would be great. Thanks

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I have had the same problems. I always feel like I am one step behind the temperatures as I add more tape. Similarly, with the oil cooler totally covered and 3-4 strips of tape on the scoops, I am still <<180.

I think that you need to install some sort of ground or air adjustable cowl flap to close off the giant hole in the bottom of the cowling. I haven't done that yet, but I would like to this winter. Based on other people's experiences with the 7 and 8 series, that really seems to be an essential part of the solution for Fairbanks-type winter temperatures.

I would be very careful putting tape on the cowl inlets. Granted, a lot of folks have done this, and I've not heard of issues that could be tied directly to this practice, but.... By covering part of that inlet, you are changing the flow PATTERN more than the volume of air flowing through the cowling, and thus the engine.

There are several good reasons that aircraft designers choose to regulate air flow through the pressure cowl during some flight regimes, they typically do so by restricting flow at the outlet of the cowling...by the use of cowl flaps.

Besides, how many planes have you seen around with missing paint or semi permanent stickum on the nose cowl, from those applications of 100 mph tape?

Not saying any of this is a disaster necessarily, but duct tape across the cowl inlet is going to create tubulent flow over the cylinders. That may or may not be a bad thing. My airplane had an air inlet scoop sticking up for cabin air, right in front of # 1 cylinder....and that cylinder always ran much hotter than the other three. Only 4 cyl Lyc I ever met that ran # 1 as hottest, consistently.

MTV

Hey GCBC, do you have any information how to attach a cowl flap on the underside? With the lip on the cowling itself you would have to go from the sheetmetal side and go foreward. Also I'm trying to find out if there is an STC to relocate the battery from the rear of the plane. I would love to have it on the firewall but I herd its near imposible these days to get a field approval for anytihng. Under the seat would be nice like the atlee dodge kit does but its not approved for a Citabria.

I do it similar to what aktango says above. Tape is easy and adjustable. It's been used for so long now that I don't think you have to fret engine damage unless you go off the deep end with it. I start near the case and work my way out. I've yet to use more than two strips on the cowling. Duct tape on cowling and aluminum tape on the oil cooler. Watch out for 3M aluminum tape 3340. It will leave a bunch of glue on your cooler to clean up. I use Shuretape AF 975 and tape both the inlet and outlet side of my cooler. The duct tape I use on the cowl is temporary and gets removed within a week or so of putting on the cowl so that it does not get too friendly with my Polytone paint.



Jerry

Sweet photo. Thanks for the Info.

Hi. I have a 75 7GCBC. The cowlings are a little different to your 69 model but I believe the cooler is in the same place, on rear baffle, left side. I have an aluminum plate (with holes drilled in it to restrict flow) that screws onto the back of the cooler (exit). Never used it but it make sense and looks like it it would work. I'll take a picture and post it when I get a chance. Cheers.

Pics of the oil cooler and winter cover (on cooler exit). Not bolted on. Just held up for the picture. Some foam tape on the face to keep it from fretting on the cooler.

I have the same plate on a 96 citabria, however my cooler is not bolted on the firewall it sits of a bit and my plate bolts directly to the "BACK" of the cooler and NO holes in the plate. I usually run about 170deg but we are not as cold here. Winter temps average -5 to +20!! I choose to fly when its a little warmer rather than real cold anyways.

wirenuts said:

I have the same plate on a 96 citabria, however my cooler is not bolted on the firewall it sits of a bit and my plate bolts directly to the "BACK" of the cooler and NO holes in the plate. I usually run about 170deg but we are not as cold here. Winter temps average -5 to +20!! I choose to fly when its a little warmer rather than real cold anyways.

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Were trying to toughen up Dave but it takes time. ;-)

Glenn

Running one strip duct tape on inside of cowling openings and blocking the cooler off compleatly on 1960 GC , would show 180 degrees in Zero degrees ambient , at
2350 rpm and 100mph .