Exhaust cracked

[edessa]

Went to check the oil between flights and found this crack. Right rear cylinder.
1976 Piper Cherokee 140/160. 475 SMOH.
Might be time for a Power Flow.

 

[AV8R_87]

Make sure you familiarize yourself with all the periodic inspection requirements for the powerflow exhaust.

 

[edessa]

Make sure you familiarize yourself with all the periodic inspection requirements for the powerflow exhaust.

Thanks for the heads up. Not everyone reads the ICA and follow them.
I installed a Power Flow in my buddies Mooney. I no longer do his annuals and made he knew to let the next guy know to do the inspections.

 

[Gary Ward]

Love my Power Flow exhaust. I now have 1400+ hours on mine. It is on my second engine.
I remove it about every 10-14 months to re anti seize the slip joints.
Well worth it. It performs great on my 0-320. Everyone comments on how good my aircraft sounds. It will climb at close to 1000 ft minute with 2 of us in plane during cool weather. By myself I can climb 1000 ft min all year long. Runs strong for a 160 hp engine.

Only con is carb ice, it happens more with a power flow. You will use carb heat more, no biggie.

 

[Dan Thomas]

A 48-year-old airplane. I bet that exhaust has more than 475 hours on it.

When the engine gets hot, it expands in all directions. The cylinders get farther apart, and so they force that exhaust system to stretch and bend some. Then it cools and the exhaust is compressed. Enough cycles like that and it cracks. The hot exhaust also makes it expand and contract itself even more than the engine does. The metal itself becomes work-hardened and brittle. It's the reason that many systems have expansion slip joints, or they do like Cessna did with the 172: longer, more vertical risers that turn 90° into the muffler. They can rotate in the muffler connections as the engine expands and contracts.

I would bet that the OP might find cracks at the exhaust's cylinder flanges, too. Age and heat.

 

[Magman]

To add to Dan’s comments; the Cherokee 140 does have slip joints.

These are often seized up and it is a task to correct the issue.

If left alone it often results in OP’s condition, which is not too bad.

What is worse is having the cylinder crack.

Cracks can also occur from improper installation when components

are forced out into position or the Tailpipe is hitting the Firewall.

The amount of specialty exhaust shops has shrunk but I can’t say I’m

unhappy with any of them.

 

[edessa]

Power Flow has been ordered. Should have it around December 11 or 12.
In the mean time I will install the dual Garmin G5's I have sitting on the shelf waiting.

 

[Gary Ward]

That seems like a pretty fast delivery?
When I ordered mine I waited something like 6 months for delivery and got a discount for waiting.. My old exhaust was is still good so was not in a hurry for it.

The last time I had the exhaust off I noticed this.

I thought it was a flame arrester, but they call it a silencer. I put a new one in and I swear it seemed like the engine ran better. The sound changed a little also. I looked in my logs and I have closer to 1600 hrs on my exhaust. I installed it in 2018.

 

[edessa]

That seems like a pretty fast delivery?
When I ordered mine I waited something like 6 months for delivery and got a discount for waiting.. My old exhaust was is still good so was not in a hurry for it.

The last time I had the exhaust off I noticed this.

I thought it was a flame arrester, but they call it a silencer. I put a new one in and I swear it seemed like the engine ran better. The sound changed a little also. I looked in my logs and I have closer to 1600 hrs on my exhaust. I installed it in 2018.

I payed for the expedited service.

 

[Htaylor]

Power Flow has been ordered. Should have it around December 11 or 12.
In the mean time I will install the dual Garmin G5's I have sitting on the shelf waiting.

In my experience, the Power Flow really wakes the Cherokee 140 up. Especially coupled with the 160hp STC. You may need to re-pitch the prop. Very much worth the investment.