pancake muffler

aquanaut · Post by **aquanaut** » Mon Mar 06, 2006 10:54 pm

I'm in dire need of a pancake muffler for the Left (pilot) side of my '48 170. The right side is still in good condition but I've developed blockage in the left. Maybe someone has up graded their system and the old one still has some life left? I don't need the muffs just the muffler. From what I've found out, there really isn't anyone out there who rebuilds these and I'm not real crazy about throwing down the money for the upgrade right now. Any and all help would be appreciated.
Thanks,
Dave

starkw1 · Post by **starkw1** » Tue Mar 07, 2006 3:12 am

I have a pair of pancake mufflers I removed about 5 yrs ago when I replaced them with the round Hanlon Wilson type. They need some (or a lot) of repair. If interested write to me off-line.

Warren Starkebaum
'48 C-170
Seat re-upholstery in process
starkew04@aol.com

KAP54 · Post by **KAP54** » Tue Mar 07, 2006 5:36 pm

I was considering converting from the pancake to the round mufflers as I again have a crack in one, but have been told that there is no STC for this conversion. Haven't seen one listed in the MX site. Obviously this has been done before so what is the proceedure to get it approved?

Post by **Bruce Fenstermacher** » Tue Mar 07, 2006 7:02 pm

It is approved on the type certificate.

Post by **GAHorn** » Wed Mar 08, 2006 6:57 am

KAP54 wrote:I was considering converting from the pancake to the round mufflers as I again have a crack in one, but have been told that there is no STC for this conversion. Haven't seen one listed in the MX site. Obviously this has been done before so what is the proceedure to get it approved?

As Bruce correctly pointed out...it's already approved via the Type Certificate. The conversion costs about $1600 in parts.

Aircraft exhaust systems are some of the most overlooked, and neglected systems on light aircraft, and they are just as important as flight controls, engines, and wing attachments. An exhaust can have hidden, insidious failures, yet give little or no indication until it's too late. A failing exhaust can KILL you. Yet many pilots and mechanics even, will "gloss-over" a detailed inspection, and when defects are found, owners will defer making repairs until threatened by their inspectors. Hot Tip: Avoid paying for fuel, oil, tires, brakes, and radios.... but fix that exhaust! It's more important in many ways to your safety!

There are several folks who offer Hanlon-Wilson types for our aircraft. There's a couple of cautionary things to consider.
1. Aviation Exhaust/Muffler shops should be very knowlegeable about this upgrade...but they are not. I have members call me all the time who have been sold the wrong items. (BUY and READ your IPC for your model aircraft.)

2. If you have an A-model or earlier (or a 52 B model), you basically need two left-side mufflers and heater shrouds, and a left/right tailpipe. Of course, you'll also need all six risers, and clamps, and the crossover support bracket unless you intend to modify the existing bracket.
3. If you have a 53 or later B model, the right side muffler and heater shroud is different and necessary, but of course, since your airplane was already so equipped, you'll simply be replacing an existing Hanlon-Wilson with like parts, so this is not a big deal. Don't forget the adaptor for the cabin heater. (If you have a 52 or prior airplane disregard this comment #3. You'll be using two left systems.)
4. Later 172 systems will NOT fit! Their mufflers are larger and will contact the cowlings.
I will be addressing this conversion at the Kelowna Convention MX Seminar.

KAP54 · Post by **KAP54** » Wed Mar 08, 2006 2:51 pm

Dave
I appologize for changing the direction of this discussion from your original inquiry. I meant to mention that I would possibly have available a pancake stack that was rebuilt by Wag Aero in 2002 and has about 60 hours in service. It appears to be in very good shape, but is still install on my plane at the present time.

Bruce , George,
Thanks for the information. I, like Dave have a '48. You mention what is needed for the A and B models, but what about the '48 170? Would it be the same as an A or is there a difference that makes the coversion impossible?

Thanks,

Keith Plendl

Post by **Bruce Fenstermacher** » Wed Mar 08, 2006 3:46 pm

You would use the A model set up for a '48. The reason for the different muffler/heater shroud in the later B model is the change in the cabin heat setup.

KAP54 · Post by **KAP54** » Thu Mar 09, 2006 11:02 pm

George,
In your post concerning parts needed for various models you mention the need to modify or get the correct crossover support bracket. My initial reaction to that was WHAT BRACKET?? Evidently someone in the past decided this was just extra weight and threw it in the corner as there is no bracket installed on my plane. Could be why I have problems with cracking. In checking the IPC for the '48, it appears that this is a U shaped tube that attaches to the underside of the engine or engine mount some how and is clamped to the tailpipes. Is this correct? I have the part # for the '48 but as this would have to be modified anyway, I would appreciate it if you could give me the correct # for the Hanlon Wilson installation and explain how it is attached under the engine. Many thanks

Keith Plendl

Post by **GAHorn** » Thu Mar 09, 2006 11:35 pm

PN 0550159 (SN's up to 25763) adn PN 0550159-5 (subsequent serials).
It's a 1/4" or 5/16" steel tube which is flattened at each end, where it attaches to the tailpipe clamps, and with a tab near the middle (adel clamp might work) holding it to the left, fwd, carb-mount bolt.

See B-model IPC, Fig 50, item 13.

cessna170bdriver · Post by **cessna170bdriver** » Thu Mar 09, 2006 11:40 pm

gahorn wrote:PN 0550159 (SN's up to 25763) adn PN 0550159-5 (subsequent serials).
It's a 1/4" or 5/16" steel tube which is flattened at each end, where it attaches to the tailpipe clamps, and with a tab near the middle (adel clamp might work) holding it to the left, fwd, carb-mount bolt.

See B-model IPC, Fig 50, item 13.

Keith,

If you don't have a B-model IPC and you DO have high-speed internet access, it is available at http://www.micro-tools.com/pdf/Cessna/170b_pm.pdf . It's a scanned version, so it's quite large, 12+ megabytes.

Miles

KAP54 · Post by **KAP54** » Sat Mar 18, 2006 4:18 pm

Thanks again for all the helpful information. Ordered a new system from AWI and am in the process of installing it. I do have one pancake style stack that is in good shape if anyone is still looking for one.

Please heed George's warning about keeping the exhaust system in good shape. I decided to check mine after coming away from my last two flights with a headache. Didn't think much of it the first time, but when I started getting one an hour into my last flight, I shut the heat off, opened the vents and decided to check the exhaust before anymore flights. Found a crack in one muffler that had been repaired only 60 hours before.

Keith

aquanaut · Post by **aquanaut** » Sat Mar 18, 2006 10:44 pm

Kieth, e-mail me off line if you would, aquanaut@indy.rr.com I'd like to ask you about the muffler you have.
Dave

The International Cessna 170 Association

pancake muffler

pancake muffler

Pancake Muffler for '48 C-170