PowerFlow is it worth it

[FlyboyKC]

In the discussion below about swapping out the 180hp for a 200hp, is the Powerflow a reasonable option for the money ~$4k for the 180hp engine? Powerflow states installed in over 400 Mooneys. Are any of those Mooney owners here? I would like to hear some real world feedback.

 

Thanks

Neal
M20G

 

[pirate]

I flew my money 10-15 years with the original exhaust and repaired it many times. I converted to Powerflow around 10 years ago, never a problem with the system since I installed it. I did the challenger air filter and Powerflow exhaust at the same time and I noticed great gains in climb and cruise performance.  Another great benefit is that it helps reduce the risk of Carbon Monoxide. 

i would not hesitate if I had to buy another Powerflow. 

[cnoe]

I flew my money 10-15 years... 

Freudian slip, or typo?

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[Guest]

If a Power Flow is too expensive, you might consider this, I've done a number of these.

http://aircraftexhaust.com/nav.cfm?cat=11&subcat=67&subsub=0&as_id=8&mg_id=74&sys_id=120&display=system

Clarence

[FlyboyKC]

Just now, M20Doc said:

If a Power Flow is too expensive, you might consider this, I've done a number of these.

http://aircraftexhaust.com/nav.cfm?cat=11&subcat=67&subsub=0&as_id=8&mg_id=74&sys_id=120&display=system

Clarence

Is that a tuned exhaust? Does it offer the same advantages of a PowerFlow?

[Bob_Belville]

8 minutes ago, Pirate said:

I flew my money 10-15 years with the original exhaust and repaired it many times. I converted to Powerflow around 10 years ago, never a problem with the system since I installed it. I did the challenger air filter and Powerflow exhaust at the same time and I noticed great gains in climb and cruise performance.  Another great benefit is that it helps reduce the risk of Carbon Monoxide. 

i would not hesitate if I had to buy another Powerflow. 

+1 for the PFS. Mine is 4 years old. I think it adds HP which improves climb and T.O. distance. I pull almost 22" MAP at 10,000 and my old M20E cruises at nearly 160 ktas @ 75%. We spend about 30 minutes at each annual servicing with anti-seize on the slip fittings.   

[Guest]

Just now, FlyboyKC said:

Is that a tuned exhaust? Does it offer the same advantages of a PowerFlow?

No it's not tuned, but it is a very good product and less than half the cost.  The Power Flow is supposed to be removed, cleaned and disassembled each annual, but no one follows the requirement.

Clarence

[Bennett]

I do, or to be accurate, LASAR does this at every annual.

[Bob_Belville]

Just now, M20Doc said:

No it's not tuned, but it is a very good product and less than half the cost.  The Power Flow is supposed to be removed, cleaned and disassembled each annual, but no one follows the requirement.

Clarence

Clarence, we comply with the instructions. As stated above it's about 30 minutes to loosen 2 exhaust headers to be able to slip fittings apart and apply anti- seize. We have a couple of C172s on the field with PFS. The A&P says the maintenance is worth doing. When they seize they tear stuff up.

[FlyboyKC]

Just now, bluehighwayflyer said:

We do.  Every year on our C. It is a bit of a pain but we have never had any problems with our PowerFlow system, possibly as a result.  We have owned the C for 34 years now and the PowerFlow has been installed for almost 10 years, so we have a good basis for comparison.  WOT speed runs went from 143 KTAS to 147 KTAS at 8,000', but fuel flow also went up appreciably. I don't think we would do it again knowing what we know now, but it definitely increases the power output. 

Hmm, interesting on your fuel flow. Its advertised to decrease fuel consumption. How about your climb rate? What do you factor that to have increased by?

[aaronk25]

Nothing is free. If power was reduced back to the previous throttle position that yielded 143kts, fuel burn would be exactly the same. The PFS allows the plane to go faster if desired with more fuel.

I installed it on my J and have 1000hours without it and now 350 with it.

There are other benefits though. Chts are reduced due to more hot exhaust being pulled from the cylinders than what the stock system does. On the power flow there is a vaccum created that help evacuate spent gases so they don't add as much heat to the cylinder.

I too repaired my exhaust several times before purchasing the PFS. The annual maintenance inspection and lube is easy, and if done pretty much eliminates consumable parts.

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[rbridges]

plus it looks damn cool compared to the OEM exhaust.

[macosxuser]

We have had two PF systems on Cardinals in the family. I've flown before/after on these several times. Power is up a little, it's noticeable, but not going to wow you. Engine temps even out, IE, the EGT's are more consistent across all 4. In the winter, this allows us to run leaner, as CHT's remain manageable. In the summer, to keep CHT's down we run rich, so we don't see the fuel burn savings as much. Where it really shines is that last 1,000' of altitude you need to climb to get over a mountain, the extra 3-7HP shows up there quite nicely.

To me, worth it on Carb'd engines, just from the engine health standpoint. Engine is much happier running more balanced pressures.

The big question I have for people, is the E model system worth it? Already can balance the injectors, and have even length intake runners....

[DXB]

For the Powerflow, I've heard it said somewhere on here that there is a preferred carb on the C models  among the 3 that are approved, and the others may not run rich enough. Can anyone confirm? This might be worth exploring before the install.  

On a related note, I have what appears to be the original exhaust on my '68 plane.  No concerns with it have been noted at annual, and I have not died of CO poisoning yet.  Is there a finite lifespan for these exhausts, after which its best to change them? If so I might consider a Powerflow.  Or i might just get the economical alternative Clarence mentions above...

[Bob_Belville]

49 minutes ago, rbridges said:

plus it looks damn cool compared to the OEM exhaust.

And it sounds better. 

[Bob_Belville]

51 minutes ago, macosxuser said:

 

The big question I have for people, is the E model system worth it? Already can balance the injectors, and have even length intake runners....

I have an E model. I don't know how much to credit the PFS but my IO360 is very balanced. I did a Savvy Lean test recently and found that the engine is very well balanced averaging under 0.3 gph gami spread for 7 scans. The engine runs smoothly with all cyls 50+ LOP and a LOP mag check passed easily. I have to credit fine wire plugs and the PFS for some of that. 

[Oscar Avalle]

I had a PFS installed in my PA 28 and now in my M20C. I like the system. I gives you better climb and power (at least after paying the money you pay for it you want and need to believe it...) 

 

 

[carusoam]

Dev,

Visual inspection usually is enough to see if the interior heater muff parts are going to collapse.  Erosion of welds can also be seen.

This is a usual inspection at annual.  There have been updates through the years to improve the construction and function of the heater aspect of the exhaust.

the exhaust system is a pretty harsh environment. Temperature and chemical attack are constant.

My 65C underwent some welding activities to improve some of the wear and tear items...

Heat is hard to come by at 10k' in the winter...  Another consideration for the muffler design, I suppose...

Best regards,

-a-

[cpbloch]

I put a power flow on my 1967 M20F approximately 50 hours ago,  I also have the challenger air filter,  new mags timed right and a 400 smoh engine.   The powerflow is a bit expensive but as others have mentioned in the long run it may be cheaper than fixing an old exhaust.  I also sold my old exhaust for $ 600 on ebay to help get some of the cost back.  I also took the discount for the long lead time, they will give you a nice discount if you can wait a few months for them to get orders together for a larger order build.

The system went in easy, I live in Michigan and ordered the additional heat muff which is could not fit on my plane, but the heat is still fine in the winter.  The performance increase is noticeable in climb and cruise up high.  I gains a real world 4 knots above 7,000 feet and about 150 feet more climb.  The IO360A engine is nicely balance from a fuel flow and I have always been able to run lean of peak.   The power flow improved running lean of peak also I feel it does a better job of balancing the flows in the engine.  I can run lean of peak at 13,000 feet and the engine is super smooth,  which is a great option if you have nice tail winds,  nothing better than 8.5 gallons per hour and 170 knot ground speed when you can get it.   The engine sounds great according to my buddies that are standing around when I taxi by,  and the system looks good.  I did not get the ceramic coating so the pipes are blue but that is a cool look in my mind. 

 

I am very happy with the power flow and would do it again,  my hope is that it lasts a long time, and I get good at the annual ritual of removing two pipes to put the antiseize on the joints. 

have fun , fly safe

 

Chris

[Bob_Belville]

1 minute ago, cpbloch said:

The system went in easy, I live in Michigan and ordered the additional heat muff which is could not fit on my plane, but the heat is still fine in the winter.  The performance increase is noticeable in climb and cruise up high.  I gains a real world 4 knots above 7,000 feet and about 150 feet more climb.  The IO360A engine is nicely balance from a fuel flow and I have always been able to run lean of peak.   The power flow improved running lean of peak also I feel it does a better job of balancing the flows in the engine.  I can run lean of peak at 13,000 feet and the engine is super smooth,  which is a great option if you have nice tail winds,  nothing better than 8.5 gallons per hour and 170 knot ground speed when you can get it.   The engine sounds great according to my buddies that are standing around when I taxi by,  and the system looks good.  I did not get the ceramic coating so the pipes are blue but that is a cool look in my mind. 

Chris . all good points with which I agree.

[pirate]

On June 22, 2016 at 8:32 PM, cnoe said:

Freudian slip, or typo?

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Funny!  Typo sir.

[Tom]

On a tangent: electronic ignitions have been accused of raising CHTs (while being more efficient in certain profiles)

Having a PF exhaust in theory should allow for use of an EIS ignition with less heat concern.  I wish there were more PIREPS on this.

[carusoam]

Tom,

High cost and low reliability are a tuff sell.  Does anyone still have an electronic ignition on a Mooney?

the opportunity to upgrade comes about when the existing system has been worn out. Many people have had good success with the powerflow.  I only know of one electronic ignition and it failed to meet expectation and was removed from service. (I believe)...

The basis of raising or lowering EGTs is when the timing is set further away from TDC.

further from TDC,  CHTs rise, EGTs cool.  Engine is more efficient.  More Hot gasses are being used.

closer to TDC, CHTs are lower,  EGTs rise. Engine is less efficient.  Some Hot gasses are escaping.

the efficiency is a trade for higher CHT.

The Mooney example comes from the M20J that has a history of having two ignition timing settings. 25° and 20° BTDC.

Do the electronic ignitions do anything other than electronically do the same thing that the mechanical timing does?  There isn't a variable timing like automobiles use...

Electronic variable timing would be nice for starting and some other small efficiency gains.  But the existing systems with set timing are pretty good.

Best regards,

-a-

[Tom]

7 minutes ago, carusoam said:

Tom,

High cost and low reliability are a tuff sell.  Does anyone still have an electronic ignition on a Mooney?

Best regards,

-a-

I have three EIS units waiting to instal on aircraft in an unrelated business venture.

My understanding is that:

1) EIS units don't have reliability problems 

2) Because they don't wear out, EIS units pay for themselves after a couple thousand hours of not overhauling/replacing the mags that they replace

3) You can save some fuel burn, at the expense of increased CHTs.  The fuel saved helps the units pay for themselves independent of not having to rebuild the mag it replaces, but CHT concerns and cylinder wear costs may offset.  Thus the supposition that a PF exhaust lowering the CHT may offset the CHT increase from the electronic ignition, and that a PF exhaust and and electronic ignition might be a nice match, especially on a vintage Mooney.  I've paid $2-300 per annual for exhaust welds/repair on my vintage Mooney.

[carusoam]

Do you have a website for the EIS unit that you are referring to?

what type of aircraft are you installing them on?  IO360 or IO550 powered?

I can't remember what unit was involved with the MS user.  Wouldn't be hard to search for.  

Balancing ignition timing, electronic ignition and a low back pressure exhaust would take a tremendous amount of predictive skill.  Probably better to set one up and see what happens.  Following the proper regulatory guidelines, of course...  Do the STCs all work together?

Best regards,

-a-