Lower Engine Baffle A65

[Scott]

Good day all

-33C here this morning so I've been working on parts in my basement including the engine baffles. Needless to say they're in rough shape. One part I was never aware of back in 1985 is the lower baffle that runs on top of the intake. I believe it's referred to as the crankcase baffle P/N BC-A6019

It had apparently been removed, with no ill effects, but I need to fabricate a new one and I've been unable to find a reasonable photo or drawing. Can anyone point me in the right direction please.

Otherwise the only other CF-CLR update is that the left aileron is now complete sans fabric.

Thanks
S

[Norm G]

Re: Lower Engine Baffle A65

Scott,
I have one at the airport in my hangar someplace. The next time there I take some pictures for you, or, if your interested, we could agree on a price for the one I have.
Norm G

[barnstmr]

Re: Lower Engine Baffle A65

This photo is from the old Cap'n Jon webpage... the crankcase baffle is the green sheet metal assembly.

[Norm G]

Re: Lower Engine Baffle A65

Scott,
I found the baffle, it was in my guarge. Anyway I took some pictures.
Norm G

[Robert Lees]

Re: Lower Engine Baffle A65

This baffle seems to be particular to the Taylorcraft. I look after a number of Cubs, from A65 to C90, and they don't have this baffle. I wonder if it's because of the side-by-side (wider) fuselage that causes engine cooling issues?

Does the L-2 have this? And is this baffle used on the Aeronca Chief but not the Champ (for the Aeronca aficionados out there)?

Rob

[Mark Julicher]

Re: Lower Engine Baffle A65

I have seen two Aeronca 7AC with the bottom baffle.

[Scott]

Re: Lower Engine Baffle A65

Thanks Norm and Terry
The photos give me enough info to make a new one so much appreciated.

Robert, I had a Chief once but don't recall the baffle configuration, only the tall intakes on the nose cowl.
The Tcraft cooling philosophy was rather unique, the crankcase intake always baffled me (pardon the pun) as it increases air pressure under the engine, which reduces airflow past the cylinder cooling fins and the remainder of the crankcase. And then of course there's the grills which further reduce the delta between above and below the engine. I had Aeronca exhausts which required two holes in the lower cowling and, as is often the case, the holes were bigger than they needed to be and surely increased pressure below the engine even more. Perhaps the cooling airflow was actually the other way! in below and out on top. Maybe this is why the Tcraft is so fast!

Anyway the "secret" to good cooling is maintaining the delta. The crankcase baffle, it seems, is designed to restrict and focus airflow. My guess is it will be important to achieve a good seal with the nose cowl scoop yet I don't see evidence of baffle seal or felt.

[barnstmr]

Re: Lower Engine Baffle A65

Scott... If you are going to make a new one, I think it is made from dead soft aluminum, probably 6061-O x .025 thk. You might also want to search prior threads on here. Someone I recall posted pictures of a nice one they made, incorporating some red silicone rubber baffle seal material to help with the compound shapes.

[barnstmr]

Re: Lower Engine Baffle A65

Here is one of the discussions... there is a pohoto here that I had posted from the super cub forum noting the orange rubber baffle material.


http://vb.taylorcraft.org/showthread...ankcase+baffle

[cvavon]

Re: Lower Engine Baffle A65

Terry that photo was on the thread on my engine install its been 3 years now that i have had the 85 in 26658 and with the front cooling hole covered and no bottom baffle cht are all in the range of 300 to 320 deg summer and winter oil temp stays arond 200 deg all my cooling air goes in the top and out the bottom back.We also built a baffle to run under the crank shaft to close off that gap .