Power Flow Exhuast Systems

[n2099x]

I talked again with the people at Power Flow about the system they are working for O-470 equiped 182's. So far they are going with dual exhaust out each cowl flap like the 205's. I explained that the 260se used the stock system and if they stayed within those dimensions it would clear the canard so maybe with minor modafications if any, it would work. He also said they have reached their target of 30hp increase (wow I need that). One of the problems thay are having is prototype planes in Florida. Their web site is powerflowsystems.com or call 1-877-693-7356 if you are interested give them a call, if their is enough of us I'm sure they will respond.

Glen

[Pete of N978PB]

Interesting, but somewhat in conflict with information received several weeks ago at the Cessna Pilots Association's (CPA) C-182 Systems & Procedures Course held at Sporty's.

An attendee asked John Frank of CPA what he knew about the Power Flow Exhaust Systems developments for Cessna 182s.

John's reply was that he had been told by Power Flow Systems people that they were not experiencing the type of improvements in aircraft performance that they had gotten on the C-172 and Cherokee 140. As I recall, John indicated that there was little if any improvement in the C-182 performance.

Now for the caveat: This is not to say that John Frank got the right story from Power Flow Systems, or that there is no improvement. It is only to say that there seems to be a discrepancy of information here that should be reconciled before anyone sinks some big bucks into a new exhaust system. There may well be a simple explanation for the apparent conflicting information.

Since greater capability is always of interest, perhaps we should attempt to get a clarification from both Power Flow Systems and John Frank.

Pete

[n2099x]

I talked to Power Flow today to clarify the information, they said the current O-470 system should yield about 30hp. This is new information, one of the earlier revisions is what John Frank explained. He also said our gain would not be that high with the IO-470 but that we might get 20-25hp. The price would be in the 6k range.

Glen

[Pete of N978PB]

Good info, Glen. That helps reconcile the comments between two recognized and authoritative sources.

As a former bean counter who has trouble distinguishing one end of a hammer from the other, perhaps one of our engineering, technically oriented, and/or aeronautical science pros can help us know just what having an additional 20 - 25 HP in exchange for $6K will do for us. Off hand, and to this ignorant layman, that seems like a lot of money for not a whole lot of additional HP.

For example, if an owner consistently runs his aircraft at about 65% in cruise (say, 22" MP/24 RPM), will the potential of 20 additiional HP at full power provide an additional 13 HP (65% of 20 HP) at the 65% cruise power setting? If so, roughly how much of a speed benefit will that produce?

Also, if an aircraft is operating at cruise with those 13 more horses cranking away, will that be done at the same fuel flow; more; less?

Said another way, if one is happy slogging the time away at 142 kts burning 12.5 - 13.0 GPH without the Power Flow conversion, will the additional power allow a continued cruise speed of 142 kts at a somewhat lower power setting and therefore more efficient fuel burn?

It would seem that there would be a decided benefit at full power settings, such as during takeoff and go-around operations, but what are the continuing benefits assuming consistent cruise level power settings before and after the Power Flow conversion?

And what effects will there be at varying altitudes, if any?

In another dimension, what does the improved flow of exhaust gases do for the engine itself and the exhaust manifold. It would seem that with its more efficient removal of exhaust gases from the cylinders, there should be (1) less wear and tear over time on the engine components, (2) a cleaner engine via a more complete removal of exhaust gases from the combusition chamber, and (3) perhaps less of a heat buildup thereby allowing the engine to generally run a bit cooler. Is this valid thinking?

If so, does that benefit serve to help increase TBO or otherwise provide for a cleaner mechanical operation of the engine?

I'm clueless on the answers to this kind of stuff. Perhaps one or more of you really smart folks can help out.

Cheers!

Pete

[n2099x]

Pete, I'm not sure how to do that math but @2950 lbs. the hp to weight ratio with 260hp is 11.34 lbs. per hp and at 280hp it would be 10.53 lbs. per hp. So there should be a very noticeable increase in performance.

The engine will run smoother with a good tuned exhaust which is easier on everything including the pilot.

Maybe I can get the Power Flow people to post some answers to our questions.

Glen