Supplemental cooling for the Sport Cub

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Pete
Two pics of my plane one is right, one is wrong, because I turned them around cause I was not sure which is right way?
The first picture is how I got it second one is turned around looks a lot nicer?

[Jason Tepool]

It's hard to tell in your pictures, but it looks like you could have the doors on the wrong sides. In the end the doors, when closed, should be flush with the door frames. But they do require some fit trimming to obtain that.

[Pete D]

Which ever way they go in with the least pre-load is how you want them. That is the purpose of installing the left on the right and vice versa on a Sport Cub. They are contoured for a Carbon Cub cowling, which is shaped a little different. By swapping sides with the doors, they tend to fit a little better on the Sport Cub because of the different shape of the cowling. If you have to put one pair of screws in, then bend the door a whole bunch to put the second one in, they are probably "backwards" on the Sport Cub.

Pete D.

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Thanks. They went on pretty easy both ways ,they look better the way I have them , I did have to trim a little so Im good.
They had to change the fitting on my fuel flow transducer in order to install cowl flaps. Now the fuel flow is jumping all over the place @2450 jumps from 5.7-8 gals hr. Showed 15 gals hr climbing out yestardeay .Have run about 60 gal thru still the same. The higher you fly the worse it gets ,showed jumps 7.2-8 gals hr 2400 rpm@ 3500Ft.Filled up three times fuel burn was off 5-6 gals every time. Mechanic said he took (2) 45s off put a 90 on the exit side of transducer.Low rpm low altitude seems to work fine.Any suggestions?
Chuck

[JohnM]

John
Yea I didnt see that much diffence on the way home. I am wondering how do you know if cowl flaps are on right I see some people have them on wrong.Instuctions say put left door on right frame. I didnt install so how can i tell which is right. Here are two pictures which one is right? One way front of door is recessed the other the door is flush.

Chuck,

Pete D probably gave you the best answer in his post.

As for the speed, the SportCub I am flying now which has 8.50x6 tires on it yeilds about 98 mph IAS at 2500 rpm and 95 mph IAS at 2400 rpm with the cowl flaps in the mid position. If there is a difference between before & after cowl flaps it has not been enough for me to pick up on but I only had one flight in the airplane prior to cowl flaps. If your speeds differ significantly from mine, much of the difference will have to be attributed to your tundra tires if your speeds are slower.

I just don't think that the cowl flaps will result in a 5 mph speed loss at our speed range. The addition of tundra tires will cause a 5 mph speed loss because they are all drag. The cowl flaps are faired with airflow behind them so the cowl flaps are diverting the outside air flow with IMO not much drag penalty.

Purely an anecdotal observation which any of a half dozen people in the forum might disagree with. Anyway, I flew this morning and the air was just fabulous. Not a ripple anywhere. Vis was great. My demo guy had a grand time.

John

[Pete D]

Thanks. They went on pretty easy both ways ,they look better the way I have them , I did have to trim a little so Im good.
They had to change the fitting on my fuel flow transducer in order to install cowl flaps. Now the fuel flow is jumping all over the place @2450 jumps from 5.7-8 gals hr. Showed 15 gals hr climbing out yestardeay .Have run about 60 gal thru still the same. The higher you fly the worse it gets ,showed jumps 7.2-8 gals hr 2400 rpm@ 3500Ft.Filled up three times fuel burn was off 5-6 gals every time. Mechanic said he took (2) 45s off put a 90 on the exit side of transducer.Low rpm low altitude seems to work fine.Any suggestions?
Chuck

Changing the fitting angles right before or after the fuel flow transducer can require a small amount of recalibrating. If it is jumping around like you say though, that is probably what is causing the inaccuracy.

I can think of three things that might be causing the jumping.

One, the fuel line may be to close to the engine and getting vibration from contacting the engine as it shakes a little bit. Maybe up against or really close to the oil sump?

Two, they may have gotten some sealant inside the fittings when they changed it, causing the little wheel inside to stick.

Three, that 90 fitting you mentioned may be causing the fuel to be turbulent going through the transducer. The manufactures recommend having straight fittings right before and after the transducer. The 45s seem to work ok, and I have on occasion seen a 90, but basically the straighter the fuel goes through that area of the fuel system the better.

Pete D.

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John
I agree no real speed loss with them open half way( probably just over analyzing on the way Ga.)Yestarday am.@2450 IAS 98. Havent flown with them closed yet hopfully this afternoon.
Pete
Transducer/fuel line is not touching anything.He said the cowl flap flange was touching fitting so he changed it to a 90 he didnt move anything else and it was working perfect.So maybe I will have him put 45 back on it,said I would just need longer hose.
Thanks for the help

[Springloaded]

Changing the fitting angles right before or after the fuel flow transducer can require a small amount of recalibrating. If it is jumping around like you say though, that is probably what is causing the inaccuracy.

I can think of three things that might be causing the jumping.

One, the fuel line may be to close to the engine and getting vibration from contacting the engine as it shakes a little bit. Maybe up against or really close to the oil sump?

Two, they may have gotten some sealant inside the fittings when they changed it, causing the little wheel inside to stick.

Three, that 90 fitting you mentioned may be causing the fuel to be turbulent going through the transducer. The manufactures recommend having straight fittings right before and after the transducer. The 45s seem to work ok, and I have on occasion seen a 90, but basically the straighter the fuel goes through that area of the fuel system the better.

Pete D.

Pete
They just moved my trasducer to connect right to carburator with all staight fitting, is it ok to hook directly to carb?

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Never mind just got off phone with manufactor cant be ridged

[Pete D]

Chuck,

I talked to the shop that works on your plane this morning. We are sending them a short piece of hose and some fittings for the installation and I am emailing them a photo of one we did here to help. Hopefully that will take care of it for you. They should have the parts tomorrow if things go according to plan.

Pete D.