I have a powerflow on my Lyc O-235 L2C (experimental). Bought the exhaust system used from the A&P who built my engine for me. We did modify it a bit...cut about 2" off each side, where the pipes slide into the exhaust manifold on the engine. Had to do this because the O-235 is narower than an O-320, which it came off of. All I can say is my airplane climbs like hell, sounds great and I have all the power I would ever want. A few years back I stopped at the Powerflow display at Oshkosh and asked them about cutting down the pipes like we did because I had always thought it may be defeating the purpose...they said that small modifcation probably would make zero difference. I have nothing to compare it to but I am very happy with my engine's performance. It is a boxy system that requires a more rectangular cowl...I had to buy the cowl for a Glastar Sportsman to make it fit...the Sportsman BTW, as far as I know, is the only experimental that Powerflow specifically makes a system for, but based on my experience you can modify it.

I have a PowerFlow on my '05 A1-B Husky (Lyc O-360) with MT prop and 26" wheels. Before installing the PF, a friend who also flies a Husky, but with 8.50 wheels, could out climb me (airport elevation 4750') and walk away at top speed at 7000'. After the PF, our climb speeds are the same, and my plane is slightly faster top speed. At low cruise (50% power, around 1950 rpm and 21 inches MP) and flying side-by-side, I'm burning .8 to 1 gph less than he is.

It would take a very long time for the fuel savings to pay for the exhaust - - if ever, but I bought it for the performance increase. And while PF was hoping to gain a bit more with their exhaust in the Husky (they didn't achieve all their goals and were up front about it), the performance increase is worthwhile and noticable IMO - especially at high altitudes where I mostly fly. On the few occassions I get to fly at sea level, the overall performance increase is just so astonishing that I'm too bewildered to be able to quantify anything! You low life flatlanders do have it made, but I'll take the mountains anyway.

side slip wrote:

A1Skinner wrote:Id like to ask about powerflo exhaust as well. Why is it that they can have a system made for an O-320 in a Cessna 172, but not one for the O-320 in my Citabria. Same engine... Is it just the different cowling? Can anyone explain this to me?

They are working on the citabria. They have had it installed for some time, but approval takes time.
I have installed 2 on citabrias, but they were both experimental, they work great.
After installing and testing the powerflow on 6 aircraft, I am confident in their claims.
The engines are whisper quiet, and turbine smooth, and there are noticable gains in thrust. I do pull tests with every plane that I work on, so I have a fair amount of data that backs it up.
It is not uncommon to repitch the prop 2 inches, after putting the powerflow on.

Good to know. Thanks a lot. I will have to give them a call and see if they have anything for me. I have only tried the email route, but find that a phone call usually works a lot better when actually wanting a reply. I am hoping to put powerflo on my 150HP 0-320 and hopeefully get close to the same performance as my buddies 160HP 0-320. Im to cheap to buy a new top end if I can get close to the same results with just exhaust. I have a 52 pitch prop right now, and it climbs like crazy, but I'm hoping with the exhaust I can repitch to 56 or maybe 58, have the same climb, and gain some cruise. I'll keep you posted.

I put a mufflerless crossover system on my 0320 - 160HP (from Vetterman) and picked up about 200RPM, dunno about the fuel flow, but on a 3 hr flight to Kamloops I burned 15 gals. (That's Canuck gals, so would have been about 6 gal/hr 'Merican). Bart (from AeroSport Power) said I'd be running about 50% power, & I now beat the neighbor's 0360 off the water by A full second. I'm a happy camper!

Im averaging 6.3 GPH right now, US Gallons. So you have no muffler at all??

Nope. The neighbors say it barks a bit more on TO, but in cruise there's no noticeable diff. Since it crosses over in front of the sump, it keeps the noise/heat away from the firewall & leaves room for "other stuff" there. The heat muff was a bit skimpy so I bought another one & installed on the other side. One for cabin heat, the other for carb. Minor bending of the lower cowl scoop but nothing major, all fits quite well.

I drilled/bent some holes in the ends of the exhaust pipes (like a muzzle brake?) to soften the pulses @ the end of the pipe, dunno if that helped or not, but seemed like a good idea @ the time.

A1Skinner wrote:...... I am hoping to put powerflo on my 150HP 0-320 and hopefully get close to the same performance as my buddies 160HP 0-320. Im to cheap to buy a new top end if I can get close to the same results with just exhaust. I have a 52 pitch prop right now, and it climbs like crazy, but I'm hoping with the exhaust I can repitch to 56 or maybe 58, have the same climb, and gain some cruise....

Just how much cheaper is the exhaust system? I believe cpnverting an O-320 to 160 horsepower just involves higher-compression pistons, and of course labor costs for honing cylinders plus remove & replace. Depending on engine model, an STC may or may not be required. Even if it does, these aren't much money-- AMR&D (Art Matson) sells one for the 320-E2A for $200.
I own a 150-horse C150TD, it had a 52 pitch prop when I first got it. Too flat, so I replaced it with a factory-new 56 (which turned out to actually be about a 56-3/4) which was a bit coarse for best takeoff performance. I just had it repitched down to about 54-1/2 which is just about perfect for takeoff.

To be honest hotrod, im not sure how much cheaper it is. I thought it was the whole top that needed to be replaced. It is a different head I thought. I will have to do more research. Im not sure what a top is worth, but I had to do one jug and piston on the 0-200 conti in my 150 last spring and that was $1200, so I was figuring around the same times 4 for the Lyc. I will have to speak to my AME and see what he thinks.

Nimpho... I like that setup. Does it come with an STC? What was the cost if I may ask. PM for details if youd prefer. I see what you mean with the muzzle brake design of drilling holes in the end of the pipe. But wondering if that may make more noise inside as it disperses the sound out around instead of straight out the exhaust pipe. Better for the neighbors, but possibly more sound inside?? Not sure...

I spoke with the guys at Power flow this morning, and they tell me that due to there being so many different types of Citabrias, and the relatively low numbers, that I would need to get about 35 to 40 guys together, all willing to put a $500 deposit before they would make an STC for them. That is what they did with the Husky I was told. Kind of to bad. I could buy one for a 172 and bolt it on, but it would require moving my plane to the homeowners maintenance or experimental category, and Im not sure if I want to do that or not...

NimpoCub wrote:I put a mufflerless crossover system on my 0320 - 160HP (from Vetterman) and picked up about 200RPM, dunno about the fuel flow, but on a 3 hr flight to Kamloops I burned 15 gals. (That's Canuck gals, so would have been about 6 gal/hr 'Merican). Bart (from AeroSport Power) said I'd be running about 50% power, & I now beat the neighbor's 0360 off the water by A full second. I'm a happy camper!

By 200 RPM do you mean your red line increased? Or you just gained 200 RPM in climb?

A1Skinner wrote:Nimpho... I like that setup. Does it come with an STC? What was the cost if I may ask. PM for details if youd prefer. I see what you mean with the muzzle brake design of drilling holes in the end of the pipe. But wondering if that may make more noise inside as it disperses the sound out around instead of straight out the exhaust pipe. Better for the neighbors, but possibly more sound inside?? Not sure...

Nope, no STC's for me. I dropped the cert. when I rebuilt, as that is a waaay expensive way to own an airplane.

Cost was around $900, workmanship is A-1, it was built for a Rans, but Bart told me it could be easily modd'd to fit, & it worked fine. I understand Vetterman is making systems for other planes (Cubs+) now as well. Don't have the eddress here, but a Google search would find 'em & answer your ??'s.

I was actually surprised that it was not louder than it is. If it sounded like a Harley, I'd definitely put a muff on!!
Gained 200 static & she climbs like there's a horney Maule on her 6.

I understand that some neerdowell individuals (in other countries I might add) have simply removed the flame tubes form their mufflers. This gains much of the additional performance of the high priced header systems (though not all of course) at little cost - - cut muffler open, remove guts, reweld end. The flame tubes have this nasty habit of sometimes breaking loose and plugging up the exhaust, which at best reduces power and sometimes results in an off field experience.

bumper wrote:I understand that some neerdowell individuals (in other countries I might add) have simply removed the flame tubes form their mufflers. This gains much of the additional performance of the high priced header systems (though not all of course) at little cost - - cut muffler open, remove guts, reweld end. The flame tubes have this nasty habit of sometimes breaking loose and plugging up the exhaust, which at best reduces power and sometimes results in an off field experience.

I'll post the Vetterman site here for those who want to check it out. I didn't know they were doing certified exhaust systems too. The thing about the Vetterman cross over system designed from the beginning to run with no muffler or flame tube is it will have enough area on the straight pipe out to get good length for the cabin heat muff. With removing flame tubes or baffles on the original exhaust I would think there would be less back up heat to the cabin heat muff jacket and might call for more length to be jacketed to do the same job. The Vetterman will be designed to allow for this. Do I need to pay for an ad. I do know the guy.
http://www.vettermanexhaust.com/

A1Skinner wrote: To be honest hotrod, im not sure how much cheaper it is. I thought it was the whole top that needed to be replaced. It is a different head I thought. I will have to do more research....

You might check out the supercub.org site, there's some discussions there about converting from 150 > 160 hp. Depending on the dash number of your engine, it might be just a matter of re-designating the model (for example from a 320-A1A to a B1A?) , so a logbook entry (& maybe dataplate re-stamp) instead of an STC, 337, etc.
Some of your labor costs were removing exhaust, intake, baffles, etc so it would probably not be 4X as much to do all 4 cylinders. A 160 horse is 8.5-1 compression instead of 7:1 in the 150, so 91 octane minimum fuel is required.

Thanks for the info Nimhpo, I checked out the vettermans site and like what I saw. I will have to give them a call. Im thinking of dropping my cert as well. Parts are way cheaper that way...
Hot rod, I am aware of the 91 octane rule on the 160, but I only run 100ll. the price difference really isnt that much if you buy bulk, and its hard to find 87 or 91 without ethanol in it these days...

I have a 1966 182. I will be flying in very humid and hot weather year round. Do any of you have experience with the power flow exhaust on a 182? Would you recommend it? It’s got a O 470

JedBobD wrote:I have a 1966 182. I will be flying in very humid and hot weather year round. Do any of you have experience with the power flow exhaust on a 182? Would you recommend it? It’s got a O 470

Powerflow exhaust for the 6 cylinder engines is new. They bought the tooling/designs from Leading Edge. One of my customers runs one on his 206 and absolutely loves it. They are very well built and last a long time. I will be putting one on my 206 eventually. If you can afford it I'd recommend it for sure.

When I got my C120 (O-290-D) it had an old school Y-type exhaust that had cracked and been re-welded multiple times. About 25-30 hours into my ownership it cracked again. I did a little research and found a shop locally that specializes in aircraft exhausts. Spoke with the owner and he convinced me it wasn't worth trying to salvage the Y-type system. In his option, based on the firing order of the Lycoming the cross over system was much better for engine health and balancing back pressures. He estimates 10-15 hp "reclaimed" on my little 125hp engine. He also recommended against mufflers because they are one more thing to break down and inspect periodically, and it's really not much louder. The cross over design also eliminates a stress point on the peak of the traditional Y system.

I saw 100-200 fpm climb increase, a few knots on top end and actually being able to hit the redline of 2600 RPM at cruise. Is that worth $2000? To me knowing my engine is running smoother and not having to worry about my exhaust cracking anymore was well worth the investment. Every little bit counts on these little birds.

Sounds great IMO:

Edit: Not sure why the embed isn't working, but here's the link: https://www.youtube.com/watch?v=ZZpmbXucMPQ



Old system:

Anyone have a PIREP on these/leading edge for c185 with 520D? Noise, power, looks, quality, cost comparison with stock or other performance exhaust to consider?

hamer wrote:…... I did a little research and found a shop locally that specializes in aircraft exhausts.....

Would that be Custom Aircraft Parts down in El Cajon?
They did some exhaust repair work for me a while back--
did a good job, quick, at a reasonable price.
Usually you only get maybe two out of those three (if you're lucky).

hotrod180 wrote:

hamer wrote:…... I did a little research and found a shop locally that specializes in aircraft exhausts.....

Would that be Custom Aircraft Parts down in El Cajon?
They did some exhaust repair work for me a while back--
did a good job, quick, at a reasonable price.
Usually you only get maybe two out of those three (if you're lucky).

Yep, it was Custom Aircraft Parts in El Cajon. Awesome shop, owner is super helpful/knowledgeable as well.

I agree on the 2/3. They had my system done in under a week after I gave them a few measurements, price didn't break the bank either.