C-85 Exhaust Removal

[DannyDot]

I have a 1941 BL-65 STCed to a BC12D85 with the long engine mounts. The exhaust needs some major work. In my plane there is a single exhaust on the right side. My AP/IA and I have the exhaust loose, but it appears to be impossible to get it out. My AP thinks it was originally in two pieces with a clamp holding the two pieces together. He is recommending we hacksaw the two halves apart and have the assembly rebuilt with a design to be clamped together when put back on the plane.

Any feed back on this course of action? I would prefer not to have a clamp, but I don't see how to get the exhaust assembly off and on in one piece without drastic actions such an detaching the engine mounts.

Danny

[mikerice]

Re: C-85 Exhaust Removal

I am pretty sure that Standard Operating Procedure is to remove the engine and engine mount to get at the exhaust. It is a pain, but the Taylorcraft exhaust was not designed to come off with out removing the engine mount.

I have seen modified exhausts that have a slip joint in the cross over member, but I don't know if that is an approved modification.

[Hank Jarrett]

Re: C-85 Exhaust Removal

It is NOT approved to cut the cross member. The worst thing is, if you do, and there is any leakage (which is hard to check for) you will be pumping Carbon Monoxide into the cockpit through the heater muff.
If someone with any authority who knows how it is supposed to be set up sees it, they will (and SHOULD!) ground your plane. What's really dangerous is you can't see when someone does it. It's a dangerous enough problem that all the heater shrouds I have seen have a placard requiring removal and inspection of the exhaust.
Hank

We would prefer keeping you around. Loosen the mounts with a hoist on the case and fix it right.

[DannyDot]

Re: C-85 Exhaust Removal

Thanks for the feedback. I will do it right and not cut the exhaust.

Is there a source of buying a complete exhaust system ready for installation?

Danny

[Ragwing nut]

Re: C-85 Exhaust Removal

If you have the long mount, why not install a F-19 exhaust?

[M Jones]

Re: C-85 Exhaust Removal

I just had to replace mine before Labor Day. I'm close to Wag Aero, and they had one in stock. My shop picked it up and had it on in the same day so I could make it to the Blakesburg AAA fly-in. It fit perfectly by the way.

aluminized steel exhaust system

Stainless steel is nice if you can order one otherwise.

[DannyDot]

Re: C-85 Exhaust Removal

I just had to replace mine before Labor Day. I'm close to Wag Aero, and they had one in stock. My shop picked it up and had it on in the same day so I could make it to the Blakesburg AAA fly-in. It fit perfectly by the way.

aluminized steel exhaust system

Stainless steel is nice if you can order one otherwise.

Was yours a long mount and did you use the F-19 exhaust?

How much did it cost you?

Danny

[DannyDot]

Re: C-85 Exhaust Removal

If you have the long mount, why not install a F-19 exhaust?

I don't know. Will it fit better than a BC12D exhaust?

Danny

[crispy critter]

Re: C-85 Exhaust Removal

I have a brand new SS exhaust for an F-19. You would never have to worry about rebuilding it again. However,you would have to install it as an owner produced part.

[M Jones]

Re: C-85 Exhaust Removal

Was yours a long mount and did you use the F-19 exhaust?

How much did it cost you?

Danny

Short mount, so it had to be pulled. That was about 2 1/2 hours labor (@ a really reasonable $55 per). The new exhaust was $500 (see the link), so under $700 was the total. Sounds like Keven may have a SS exhaust that you might want to consider.

[Ragwing nut]

Re: C-85 Exhaust Removal

I don't know. Will it fit better than a BC12D exhaust?

Danny

F-19 exhaust does not go behind the motor, so less heat on firewall. Also does not require motor being pulled since it goes in front of the mount. You must have the long mount to install. Do you have a -8 or -12 engine?

[VictorBravo]

Re: C-85 Exhaust Removal

Removing and replacing a stock T-craft exhaust is a real bitch, as mentioned. You have to remove the engine and the engine mount from the firewall. And Hank is 100% correct... do not cut the stock exhaust into two pieces and use a "slip joint". That's a recipe for immediate death.

If your airplane is legal for an F-19 exhaust, or you are willing to get a 337 or STC for a Cessna 150 system, it will be a much more live-able long-term situation.

However, as Rob Lees pointed out a few months ago, the true stainless steel exhausts (304 Stainless, not aluminized steel) have a very long service life and should not fail.

Depending on where you fly, for maximum safety I have to recommend that you simply disable the cabin heat. If you fly in Antarctica this may not be an option, but if you're in anything other than serious cold the cabin heat can be disabled and you simply dress warmer. Disabling the cabin heat system removes a clear potentially life-threatening situation from becoming a possibility. Mine is disabled even though I have a good stainless exhaust. It's just one more thing I can do to stack the odds a little higher in my favor. An additional benefit is that with very little modification you can use the cabin heat side of the shroud to double the available carburetor heat. The stock system is notorious for not making a lot of carb heat. If you live in a moist area (Houston comes to mind), that could also stack the odds in your favor very significantly. Almost every Taylorcraft owner can tell you about getting a mild case of carb ice (or worse) and having the s**t scared out of them.

[Hank Jarrett]

Re: C-85 Exhaust Removal

After reading my last post I need to clarify. The remove and inspect plate on the heater shroud is NOT to look for splices, it is to look for rust holes and leaks in the exhaust. The effect is the same. If Carbon monoxide leaks from a hole or a sleeve, either way, you could die.
Just didn't want to leave an incorrect impression out there.
Hank
On another thread there is someone developing a new SS exhaust for the F-19. How much interest is there is pushing for a new STC exhaust for the 65s? If the crossover were spliced OUTSIDE the heater shroud any leaks would be to the cowl, not the cockpit. Easier to remove, inspect, and could be designed for better extraction, cabin heat and carb heat. We have actually learned a LOT about exhausts since the 40s.

[Ragwing nut]

Re: C-85 Exhaust Removal

After reading my last post I need to clarify. The remove and inspect plate on the heater shroud is NOT to look for splices, it is to look for rust holes and leaks in the exhaust. The effect is the same. If Carbon monoxide leaks from a hole or a sleeve, either way, you could die.
Just didn't want to leave an incorrect impression out there.
Hank
On another thread there is someone developing a new SS exhaust for the F-19. How much interest is there is pushing for a new STC exhaust for the 65s? If the crossover were spliced OUTSIDE the heater shroud any leaks would be to the cowl, not the cockpit. Easier to remove, inspect, and could be designed for better extraction, cabin heat and carb heat. We have actually learned a LOT about exhausts since the 40s.

There is not a location to properly splice a stock rear crossover due to the shroud design. It extends all the way around to the rear stacks on both sides. One of the better mods many have done is use Luscombe exhaust. The right stack comes out in the exact spot the stock exhaust does and just need to cut a second hole for the left side. I believe there is a guy already making SS exaust named Sonny Poach but no paperwork.

[DannyDot]

Re: C-85 Exhaust Removal

Thanks for all of the good advice. I live in Houston and may safety wire my cabin heat shut.

Danny