Power flow exhaust on 170B-360 Lycombing

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Francis Cahoon
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Power flow exhaust on 170B-360 Lycombing

Post by Francis Cahoon »

Does anyone own a Cessna 170b-360 lycombing with constant speed prop. I am interested in buying a power flow exhaust. I really would like to talk to someone that actually owns such a plane, with the power flow system.
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c170b53
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Re: Power flow exhaust on 170B-360 Lycombing

Post by c170b53 »

I know we have one member that has one as they attended our last convention in Bardstown with their plane
Jim McIntosh..
1953 C170B S/N 25656
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ghostflyer
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Re: Power flow exhaust on 170B-360 Lycombing

Post by ghostflyer »

I have a 170A with a O-360 with a fixed pitch prop. I put a power flow exhaust on my aircraft and it showed no difference what so ever. This was a loaner to me and if I liked it ,I could buy it. This exhaust was only 10 hrs old and the original owner removed it as he didnt like it at all for various reasons. I had it on for about 5 hours and tried all sort of flight parameters. Over all I think it was worst but I cant put my finger on all the figures . my exhaust that I recieved from Harry Delicker that was in the kit has proven to be the best .
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blueldr
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Re: Power flow exhaust on 170B-360 Lycombing

Post by blueldr »

A quart or two of MMO will be a damn sight less expensive and smells better. It will probably give you about the same power boost too. Of course, if you're addicted to Donkey Dicks, Power Flow is your thing.
BL
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Francis Cahoon
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Re: Power flow exhaust on 170B-360 Lycombing

Post by Francis Cahoon »

Thank you guys for your input. Who is Harry Delicker, and how do I get ahold of him? Did his system give you noticeable horse power gain? I am looking for something I could do more for short field takeoffs. And as far as donkey what ever power flow has a short stack that appears to look about the same as the Cessna pipe. Please give me any more input that anyone can. Thank you.
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GAHorn
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Re: Power flow exhaust on 170B-360 Lycombing

Post by GAHorn »

Francis, the marketing people of magic-potions make all sorts of claims backed up by "scientific data" that is really just voodoo physics.

In order to produce MORE power with LESS fuel requires a huge improvement in efficiency, and that is the basic claim of the Powerflow exhaust. Trouble is...there IS NO such thing as a "tuned" exhaust in these engines. Their claim that less backpressure exists cannot be substantiated because no one has plumbed a manifold pressure gauge into the exhaust pipe and found a "vacuum" such as they claim. I guarantee that the atmospheric pressures within the exhaust pipe...no matter what it's shape and length...will be more than outside it, and that no "sucking" goes on to accelerate the evacuation of exhaust gasses in these engines. (Simple matter: Look at the short length of exhaust risers and tailpipes which previously exist...and then add another 28" or more to it...and You decide if you need a degree in physics to figure out which system gets rid of exhaust pressures faster...short pipes? or longer ones. :?

Additionally, how is it possible with a fixed pitch prop (such as they claim with the original engine) to increase horsepower without increasing RPM? (Not.) And how is it possible that if an increase in RPM occurs (a physically necessary matter to result in increased horsepower) without an accompanying increase in fuel burn? (Answer: If RPM increases, then piston power strokes will accompany that increased RPM, right? If fuel is burned at a ratio of 7:1 with each stroke of the piston, and if the strokes were increased...then more fuel HAS to be burned to accommodate that increase in RPM, right? And if more fuel is burned then either more BTU's are generated (so how can they claim a reduction in temperatures?)... or more exhaust gasses are generated... or BOTH...in which case exhaust pressures must increase. Not the opposite.

Their sleight-of-hand is generated by their claim of increased efficiency...yet no increase is possible unless LESS fuel, LESS heat, and LESS exhaust pressures can be created while increasing combustion frequencies and pressures...NONE of which is possible in a world where the laws of physics apply.

But D. Hannum ( "There's a sucker born every minute.")...would really admire their marketing efforts.

Addendum: I apologize to any PF owners who may have spent money on the product and feel obligated not to speak ill of it, if I inadvertently insulted. I admit I once married a girl whom I refused to speak poorly of as long as she was still around. She was gone a over a year before I finally felt comfortable in admitting the folly. :wink:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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blueldr
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Re: Power flow exhaust on 170B-360 Lycombing

Post by blueldr »

One tends to wonder how many donkeys have been sacrificed for this idea.
BL
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c170b53
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Re: Power flow exhaust on 170B-360 Lycombing

Post by c170b53 »

It would be interesting to know what the weight savings or what the difference is in weight between a 145 stock, a lycoming stock and the PF exhaust.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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Bruce Fenstermacher
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Re: Power flow exhaust on 170B-360 Lycombing

Post by Bruce Fenstermacher »

BL, as stated before, the newest versions are less of an intrusion on the graceful looks of our 170s or any other plane in fact. Of course it will never compare to the look of a pair of pancakes and original fangs.

I venture to say Power flow would have sold more of their devices if the original design where the same which is why they developed the smaller one.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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lowNslow
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Re: Power flow exhaust on 170B-360 Lycombing

Post by lowNslow »

I'd be happy with an exhaust system that is easier to remove and install then the cluster-hug they have now.
Karl
'53 170B N3158B SN:25400
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ghostflyer
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Re: Power flow exhaust on 170B-360 Lycombing

Post by ghostflyer »

Harry Delicker used to make kits for the cessna 170A/B so that when the o-300 Cont was removed it allowed a Lycoming. O-360 to be fitted . His kit included spinners,engine mounts ,exhaust ,nuts and bolts . It was a very impressive kit. It wasn't that expensive either. Harry was a very informative person and was a pleasure to learn from him . Unfortunately Harry passed away recently , so I do not know if his business will carry on .
PS. The power flow was about 1.7 lbs heavier.
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rupertjl
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Re: Power flow exhaust on 170B-360 Lycombing

Post by rupertjl »

I can say with certainty that any "performance" exhaust system is within the noise of what the dynamometer can measure. On our Thunderbolt series engines, we do port and polish the intake runners and try to match flow values for each cylinder. Save your money...or use it elsewhere on the plane for more effective upgrades or servicing.
1950 170A: N9191A s/n 19366
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Francis Cahoon
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Re: Power flow exhaust on 170B-360 Lycombing

Post by Francis Cahoon »

Thank you guys for replying to my question. A lot of what you guys had to say makes sense. I really am looking for any mod that is out there that would increase my ability to shorten my take off distance. If anybody has tried to acquire this type of mod, I thought it might be somebody from this group. So thanks again, and please continue to share your wealth of knowledge and more important, your experience.
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GAHorn
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Re: Power flow exhaust on 170B-360 Lycombing

Post by GAHorn »

lowNslow wrote:I'd be happy with an exhaust system that is easier to remove and install then the cluster-hug they have now.
If I didn't suspect all you guys might jump on my "originality-nut" reputation.... I'd approach Charlie Field up at AWI to create a system similar to the TCM powered 206/210 series with slip-fit connectors and "Y"-type collector/risers, which would terminate in thru-the-cowl-exit-area tailpipes similar to the Bartone-Benham tailpipes. I think that would be the cat's meow.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
femoskol
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Re: Power flow exhaust on 170B-360 Lycoming

Post by femoskol »

Lots of differing opinions. The Grumman Gang certainly has a different take.
I read it. That guy certainly does not know much about this subject. I'm definitely underwhelmed. Some of his statements "seem" to make sense on the surface but wouldn't stand a chance when argued by a knowledgable engine person. Example is the same rpm argument: if his "reasoning were correct" every engine of the same stroke/bore at the same rpm would have the same hp. They just don't. That's how hp is measured: a resistance(actually a brake) is applied to an extension of the crank - a short driveshaft. The more free flowing the exhaust is, the more the hp. Same with combustion, the more compressed or cleaner the intake air, the stronger the push on the piston is. PFs stance is that appx 25% of the air in most carb'd 0320 & 0360 engines is burned exhaust gasses. With PF that can be reduced to as little as 2%. I simultaneously owned a 73(LC -150hp) and a 74(HC -160hp){refers to AA5}. I flew each with and w/o powerflow. There was a world of difference in performance. The 73 w/o wheel pants/strut covers but w/PF would out climb my 74 w/pants/strut covers and HC w/o PF . With PF, usage of mixture is more critical to getting optimal economy, it appears to me.
That uninformed, opinionated guy(often go together) totally left out force of the stroke between PF and w/o PF. His thinking is simplistic at best.
Call Darrell Tillman at PF, tell him you're interested in a PF on your 170B and/or 78-79 AA-5A; and he WILL tell you the straight scoop. PF has received too much negative press from the uninformed, from some mechanics who didn't enjoy the installation process(I understand this but would do it again in an instant! - might take a little longer than an instant), from those who expected their particular plane to be enhanced as much as the best applications, and those who expect nothing to ever break on it. Incidentally, mine has >1,000 trouble free hrs on it.

One more thought on PF criticism. I think that PF should have qualified many of their early advertising claims. They were misleading. They stated 0.5-1.0(maybe more -can't remember) g/hr fuel savings and up to 24.5 hp gain. The problem is you can't have both the hp gain and fuel savings. If you put PF on a fixed pitch prop plane, and flew the same throttle setting on climb out(full) and the same rpm in flight, likely you'd use a little more fuel/hr. The climb would be radically better, the inflight speed would be the same( of course not, if CS prop). PF allows the usage of a higher pitch prop - that'll get speed, and in my case faster ias climb speed. Even at 1200'/min climb, 115ias mph I normally climb at 2600rpms initially, and certainly when my climb(due to DA) can be only 75-80% pwr at that setting. In cooler temps, I just pull back to 2500 and climb until reaching higher altitudes.
One thing PF users often experience(except short stack PF) is reduced CHTs. Before PF, in my 74AA-5, I battled hi CHTs, after PF none. I must admit, I redid my baffling and installed PF at the same time.
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