Which Exhaust System to Use?

[Soaringpilot]

I recently experienced a large hole in the exhaust pipe below the lower cowl of my 1946 BC-12D with a Continental 85.
It makes sense to think about upgrading the exhaust system, but there are a few options and enough people who are passionate about each one.
My choices are the Cessna 150, Luscombe 8E and Hanlon Wilson. There is also one from Classic Aero. I'd like it to be stainless and have adequate heat for Alaska winters (no colder than -20).
I'd like to hear your choices and the pros and cons.

Thanks,
Ed K

[PA1195]

Re: Which Exhaust System to Use?

The C-150 system makes good heat down to -20F from the left muffler, and tapping the right can provide a second source for defrost. But the system takes up space inside the cowl and depending on cowl design most have to install a fiberglass extrusion (available from Crosswinds STOL) to make room for the forward portion of the cans. Mine are folded inside the -4 longer cowl (so no extrusion) and have longer exhaust stacks to clear the bottom of the cowl.

Other systems may work as well and be easier to install. The secret is to provide as much heating surface area and airflow under the shroud. Have a look at them and decide.

Gary

[astjp2]

Re: Which Exhaust System to Use?

Use the cessna 150 exhaust, there is a 337 I put in the tech references section. You will need a blister on your cowling to clear the muffler. Tim

[flyguy]

Re: Which Exhaust System to Use?

I'm using what is probably pretty common as a replacement; the Luscombe dual exhaust. Doesn't have a muffler and is rather loud. Fits nicely only requiring the appropriate holes in the bottom cowling. My engine is an 85.
DC

[N96337]

Re: Which Exhaust System to Use?

I've got Aeronca exhaust (almost identical to the Luscombe) on my 85, but did one for my best friend with the 150 exhaust. His has noticeably more heat output than mine. It does take a blister, but that's not a huge deal in my mind for the extra heat....and like was said, you can shroud the second one for a bit more heat.
John

[Soaringpilot]

Re: Which Exhaust System to Use?

Hi Tim,

Can you help me find your 337 data online. Thanks

[Soaringpilot]

Re: Which Exhaust System to Use?

Hi Tim,

Can you help me find your 337 data online. Thanks

[PA1195]

Re: Which Exhaust System to Use?

http://www.taylorcraft.org/resources.html

It's under 337 and STC data. I have one on mine (N36007) as well from another source.

Gary

[ifdale]

Re: Which Exhaust System to Use?

I have a Hanlin Wilson on mine. I've always wondered how it differs from the Cessna 150. Anyone who knows please chime in. Anyways I have a full wrap heat shroud on each muffler, and pull all the heat off them I can which helps in the winter, as I fly a lot in the cold. I think the problem. I wish I knew how much the setup weighs. No doubt more than the Luscombe but likely more heat...I still have the original (pretty small) 90 degree heat box that goes thru the firewall, I think if I put a larger more free flowing setup I would get more heat inside the cabin.

[ifdale]

Re: Which Exhaust System to Use?

Gary, what kind of heat box setup do you have going through the firewall?

[PA1195]

Re: Which Exhaust System to Use?

In reply to above I have two heat boxes on the firewall. One appears to be similar to a common yet modern Atlee Dodge 2" unit that's typically installed on Pipers (http://www.fadodge.com/ss-universal-cabin-heat-box/). It receives the full flow of the left C-150 muffler and is fed via the forward facing duct adapter in the left front engine baffle. They make a cockpit side defroster adapter that feeds two 1" Aeroducts that can be directed to the upper panel cover below the windshield but that's not been installed in my plane. This box has the typical heated air dump feature when heat isn't required.

The second is a 2" bulkhead valve that's essentially a 2" straight aluminum tube with a flanged portion to rivet to the firewall that incorporates a shutoff valve and is fed from the right heat muff. It extends inside the cockpit where I install a long free ended length of 2" Aeroduct that's used as a moveable window defroster. That valve is placarded "off for carb heat" so all the right muff's heat is made available when carb heat is required. It doesn't have an air dump feature...just off and on. I block off the inlet under the firewall side hose in summer with a metal cap.

Heat output depends on exhaust temperature, air temperature, and rate of flow (airspeed/prop wash) through the exhaust muffs.

Gary

[astjp2]

Re: Which Exhaust System to Use?

Cessna used the Hanlon Wilson exhaust. Aeronca did too. They didn't make their own all the time, sometimes its cheaper to buy from a subcontractor than to tool up and fabricate your own stuff. Tim

I have a Hanlin Wilson on mine. I've always wondered how it differs from the Cessna 150. Anyone who knows please chime in. Anyways I have a full wrap heat shroud on each muffler, and pull all the heat off them I can which helps in the winter, as I fly a lot in the cold. I think the problem. I wish I knew how much the setup weighs. No doubt more than the Luscombe but likely more heat...I still have the original (pretty small) 90 degree heat box that goes thru the firewall, I think if I put a larger more free flowing setup I would get more heat inside the cabin.

[PA1195]

Re: Which Exhaust System to Use?

Another item that helps with cockpit heat is a curtain behind the seat. I hang mine with nylon ties from a fuselage tube at the rear of my skylight and it covers the rear baggage area top to bottom and side to side. It's easy to move aside to load baggage yet will separate the cold baggage area from the warm cockpit in winter. Any proper material that's flexible in the cold will work. It can either be rolled up or removed in summer.

Gary