Piper Cherokee 140 exhaust question

Timbeck2

Timbeck2

Final Approach
Joined
Nov 4, 2015
Messages
9,222
Location
Vail, Arizona
Display Name
Display name:
Timbeck2
Is there any STC'd exhaust out there other than the Power Flow that is a different design than the original? I ask this because when I replace that convoluted, original design POS exhaust system I have now, I plan on the Power Flow NOT because of the hype about more horsepower and better fuel economy but because it is a better design. I've asked a few A&P mechanics and one with IA what they thought about the Power Flow and they said, "don't do it." The IA said it is a PITA to get the cowling on but I want the "short stack" version which doesn't look like too much of a problem to get the cowl on and off.
 
I had a 140 and sold it to an IA. He added the powerflow to the airplane. He never mentioned that he disliked it or had a problem removing/installing the cowling.

otoh - how often do you need to remove the lower cowling?
 
Once a year at least for a "normal" owner. I do so much tweaking, replacing and cleaning on mine I'm probably at at least three times a year for me.

This is what I don't want and I can't find a picture of a Cherokee with a "short stack."

8-large.jpg
 
I have not seen a "short stack" version, but the club does all its oil changes in house, and after the members learn the steps, that system and lower cowl comes off and goes back on easily. We do about 4 oil changes a year, so much experience.

Our plane is a Cessna 172, so the cowl is different from yours.

On the other side of the issue, the HP went up enough we had to repitch the prop to get the full throttle RPM below the red line in level flight. The engine ran smoother further lean of peak, and fuel flow at a given cruise speed is enough less that we concluded we paid for it with fuel savings in the life of one engine overhaul, and the exhaust system lasted well into the next overhaul.

We are debating how soon to replace it with a new one, just like the old one.

The sound of the tuned length headers is unique, and more regular and smooth than the original. My wife recognizes the sound when our plane flies over the house.
 
Timbeck2 said:
I "think" this may be it.

1191259558.jpg
Click to expand...

Yes, that is the"short stack". I agree that the PowerFlow is better designed, better material of construction and, in my mind, a safer system. Never liked the chintzy carb heat muff and the "beer can material" muffler. Not noticed that the lower cowling is all that much more difficult to remove.
 
That is it, Tim. I just put one on mine. It's not difficult, but you do have to modify the nose cone to accept a slightly different intake air flange and make a cutout in the bottom of the cowling, You'll also probably have to reroute or reclamp a few hoses to maintain the required 2" minimum clearance. Haven't flown with the new exhaust, but will HOPEFULLY be buttoning up this insane "annual" (closer to "rebuild") this week. Feel free to give me a call. I can snap pics today if you wish...heading to airport soon.
 
You got it. Leaving now. Will send pics this eve.
 
I have a quick-drain installed on my Cherokee and never remove the bottom cowl when doing an oil change. I only remove it at annual time since it is almost impossible to remove the bolts for the alternate-air shroud without removing it.
 
As a follow up, the pic below isn't from a new exhaust system. They only have the stock system.

P126T170.jpg
 
Just got home from the plane again, and heading back out tomorrow. Anything further you want to see re/ the PowerFlo installation? Big fan so far...much less cluttered than the stock system.
 
Pics of the scat tubing to the heat/defrost on the firewall. Close up of the air inlet tube to the carb, and maybe a pic of the left side to see how the oil cooler tubing gets routed.

Too much? ;)
 
Nope. I have a good left side pic already, I think. The nosecone isn't on the plane yet, but you'll be able to tell what's supposed to happen by front pics and the pic of the nosecone flange. Will follow up tomorrow.
 
Sent pics. Don't know how to resize on phone for posting here,b if they didn't come through, @Timbeck2 ,let me know and I'll get them posted here from home laptop.
 
You must log in or register to reply here.
Back
Top