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Pireps on firewall forward HP + STC


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The ship was still making her numbers at the time before tare down. 29” and change along with 2700rpm’s. I wouldn’t have said ship was sick. The intake lobes were showing signs of wear so the intake valves weren’t opening as much as they could have... she was pretty matched up with other 201’s I’ve been around on cross country flights. My hanger mate and I had to take the measure of these two aircraft though...I have heard the three blade props are a little slower in cruise, but I doubt it’s more than a kt or two. Horsepower plus only promised 9mph.

Im looking at a powerflow exhaust sitting on my office floor, waiting it’s turn and for my energy level to take on the install. Powerflow says I can expect some 5+kts and some extra takeoff climb for the effort. Is that too, exaggerated?

 

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I have a hard time thinking that 10 HP is worth 10 MPH. A 201 can do 200 MPH at sea level, theoretically, but a 310 HP Ovation can only do 229 MPH.  Thats 29 MPH for an additional 110 HP.   Drag sucks.

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You still stuck at 10hp... where did you arrive at that number? why not 5? Or 0?

At some point, and with the faa involved, they surely must have had the dyno (that I’ve seen in their shop) hard at it to test the hp rating and other things like temps and pressures. Maybe it’s all lip service and the faa is uninterested in what the pitch after stc approval was. Who knows?

I cant say where the hp is measured... at crank shaft, at prop or whatever. I’m sure they have it stripped down without alternator. But I would think there would have to be some kind of prop on the test engine or some way to keep it loaded. I’ll ask the question next time I speak to them. All that is moot though because it is whatever it is. 

If have this right, you are saying there is hp lost from the propeller and alt which makes sense.

actually, I don’t think I’ve seen a stock 201 that can fly 174.x kts true, level, at sea level. I never get to test that notion because usually in the airplane to go somewhere I don’t want to drive. 

 

 

 

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On 7/5/2018 at 3:51 PM, jetdriven said:

I have a hard time thinking that 10 HP is worth 10 MPH. A 201 can do 200 MPH at sea level, theoretically, but a 310 HP Ovation can only do 229 MPH.  Thats 29 MPH for an additional 110 HP.   Drag sucks.

I think all of us that have the 310hp STC would say where the extra hp shines is take off and climb not in cruise. What is the difference in a M20G vs M20F? I think that would be a good comparison of what 20hp does. Both mid bodies, similar aerodynamics with 20hp difference.

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On 7/4/2018 at 5:23 AM, teejayevans said:

HP=Energy, the more kinetic energy you can get, the less energy is available or left  over that becomes heat. Better efficiency, results in less heat, more energy delivered to the prop. We measure HP delivered to the shaft. 

High compression can result in bad combustion, which will result in more heat. Or more fuel will give off more heat. More efficienct should produce less heat .

That must be why Lycoming uses bigger, heavier angle valve cylinder heads with more fins, and oil spray on the bottom of the pistons of the 8.7:1 compression of the 200 hp, with its more efficient fuel injection, while they use lighter, parallel valve heads without the oil spray on the carbureted 180 hp version of the engine. All to get rid of the heat of a mere 20 hp. The amount of heat is determined by how much fuel is burned inside the combustion chamber and converted to thrust. More power equals more heat. It really is that simple unless you are comparing super inefficient to reasonably efficient combustion. Same reason the TLS engine had to be modified to the Bravo engine...to carry away the extra heat with some extra oil cooling of the valve guides. In that case, heating from the extra compression of turbo-charging.

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FWIW when I had  Lycon rebuild an engine in a previous Cessna 182 I had they ported and flow balance the cylinders in it. They Dyno’d the engine afterwords and it surpassed the promised hp increase. They say 3 to 5 hp increase per cylinder and my engine dyno’d at 267hp which was rated at 230hp stock. When I topped my previous 201 I had them do the cylinder work and it was noticeable. It made it a legitimate 201 with takeoff and climb noticeably improved. I have no matrix of the performance increase but with the previous engine they did for me I believe them in regards to hp increase and the difference small hp increase can have in the performance of a 201. I think after 200 hp you have a deminshing return in top speed per hp but climb and takeoff is where it’s realized. 

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59 minutes ago, kmyfm20s said:

FWIW when I had  Lycon rebuild an engine in a previous Cessna 182 I had they ported and flow balance the cylinders in it. They Dyno’d the engine afterwords and it surpassed the promised hp increase. They say 3 to 5 hp increase per cylinder and my engine dyno’d at 267hp which was rated at 230hp stock. When I topped my previous 201 I had them do the cylinder work and it was noticeable. It made it a legitimate 201 with takeoff and climb noticeably improved. I have no matrix of the performance increase but with the previous engine they did for me I believe them in regards to hp increase and the difference small hp increase can have in the performance of a 201. I think after 200 hp you have a deminshing return in top speed per hp but climb and takeoff is where it’s realized. 

Ever consider porting/balancing the 310hp IO550, then get the dyno numbers?

It seems the butt dyno says the 310 is an underestimate of the actual number.... :)

 

I have no idea if or how the FAA accepts the numbers that the engine suppliers provide...

It would be problematic if the engine didn’t provide the stated amount.  The flight testing and number gathering is all done with the same engines  regardless of it’s actually 190 or 210hp...?

PP thoughts only

Best regards,

-a-

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6 minutes ago, carusoam said:

Ever consider porting/balancing the 310hp IO550, then get the dyno numbers?

It seems the butt dyno says the 310 is an underestimate of the actual number.... :)

 

I have no idea if or how the FAA accepts the numbers that the engine suppliers provide...

Best regards,

-a-

It is amazing and hard to believe what a difference the 200rpm makes in the 310 stc. I don’t think I’ll ever need a top end on my Eagle but if I do I will have Lycon work their magic and report back what the Butt Dyno says:)

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  • 4 weeks later...

Made the trip to Oshkosh from VCT... the airplane worked flawlessly and exceeded book numbers by 5 kts about anywhere I checked. Half the trip home was at 8500’ and second half at 12.5. Still running ROP but now have about 45 hrs smoh and ready to transition to LOP. Great gas mileage so far and saw in low 9’s ROP at 12,500. Good trip, lots of fun. Oil consumption was very low imo... used two qts round trip and maybe keeping at or above 7 qts causes some to go out the crankcase vent tube.

The trip up was dicey because weather was crummy once we got past halfway...got my fair share of scud running as we got closer. Flying slow at low power settings to let the weather move east ahead of us...So not much else to know about that.

Was my first time to Oshkosh... everyone said, if you haven’t been, you gotta see! I get it now.

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Sandy,

I chuckled as I walked past the New firewall forward booth, thinking of you and this thread... did you get a chance to talk with them while you were there?

did you go to the Lycoming booth...?  

They were showing individually controlled fuel injectors and individually controlled spark timing...

That would be great to go with the 10:1 CR!  :)

LOP should be wonderful... there are a few places to go to read up on any details...

If you are going to experiment... the ordinary NA engines will be flying above 8k’ for experiments.  This way they stay out of the red box.

The place where engine ping becomes more of a probability.  The higher CR will be more susceptible, so just be aware... See if your red box is different than the others...

If you change your oil before flying a lot of LOP, it will probably stay much cleaner than usual...

PP thoughts only, not a mechanic...

Best regards,

-a-

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Ah shucks, now I’m wishing I could have met some of you there... and put some faces to posts. 

I did buy some LED disco nav lights and pulled the trigger on a HID landing light from Lo Presti. The Lo Presti folks were great and I look forward to the install this weekend. Let there be light!  Already have the fancy Led and it’s just inadequate at my dark country Airport with Black sealer. Boom Beam!!!

Passed by the Gami booth and that fella practically told me what my cht egt readings were to the number...guess it’s part of dialing in, so those are next.

also, along the way, I’ve picked up a spare dual mag for just in case and keep in the hanger. Now Electroair is saying they might have the dual mag solution in first quarter of 2019... believe it when I see it, but I might have a couple good units for sale when they do. The idea for the second spare mag is to get out of a bind in case I’m somewhere and need it pronto to get home or finish going. Beats waiting for 10 days or spending 3k to get one coming.

 

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On 6/15/2018 at 10:43 PM, jetdriven said:

Their website says “up to 25hp” but has anyone ever actually dyno’d one of these engines?  25 Hp is 12% more HP, but it’s 14% more compression and I’m not sure it’s linear. 

In our corporate flight department we've had experience with a few high compression engines built by BPE. They are AEIO540 Lycomings in Extra 300L stunt planes. The bottom line is that we had 2 Extra's, one with a stock engine, the other with 3 different variations of the high compression setup. 

The AEIO540 uses the EXACT same cylinders as the IO360 in the Mooney and the 10 to 1 pistons are the exact same ones used by Firewall Forward. Stock, the angle valve cylinder produces (rated) 50HP on IO360, IO540 and IO720 engines. 

We've dyno tested the engines multiple times. The 10 to 1 pistons add 25HP to the AEIO540, which is to say that the engine goes from a real world dyno of 289.5HP to a real world dyno of 315HP @ 2700RPM. 

I conclude that the 10 to 1 pistons raise the HP from 48.25HP per cylinder to 52.5HP.  On an IO360 the real world HP goes from 193 to 210. 

 

EDIT: the BPE engine is a bunch smoother and more responsive. Pilots clearly prefer it. A few kts faster too. 

Edited by cujet
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I’m running the powerflow gen 2 now with the 10/1 pistons... basically tuned headers with a suppression at the end of the pipe. I’m told by powerflow that it gives back the horses robbed by an untuned stock exhaust system. Now performance exceeds book... it wouldn’t match the book before. 

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For improved airflow...

Look for things like...

  • Modern air intake... some improvements have been made over the years...
  • Modern exhausts... The PF has been gaining popularity...

Some things to keep an eye on...

Swapping exhaust systems can effect the ability to heat the cabin....

Swapping intake systems... keep an eye on how it handles ice ingestion...alt air...

Just some details to make sure of before installing.... as usual...

Sandman, you must have an interesting automobile as well?

PP thoughts only, not a mechanic...

Best regards,

-a-

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On 8/2/2018 at 5:12 PM, Sandman993 said:

Begs another question... exhaust tuning. Don’t know too much about the extra’s setup ... but are your exhaust’s tuned or more like stock airplanes? Interesting.

thanks for your input 

Both Extra 300's have tuned, 6 into 1 headers with tuned megaphone. No muffler, or restrictions/screens for obvious reasons :) (we want it to sound good during shows) 

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Carusoam

dunno how interesting my cars are...

Ram 2500 4x4 diesel enhanced 

GL 550 sport

and a maxima daily driver. None I love better than Scarlet, the over clocked j model. Magic carpet.

btw, I’m installing the Boom Beam as I type. I know everyone says on the other thread that the led’s have caught the hid’s... we can agree to disagree. I’ve seen em side by side... saw spots after for 20min. LoPresti did have an led that was impressive though... makes the Whelen par 46 look pretty docile. 

 

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I don’t know what it is... I’m tossing mine. In the dark environment where I fly, it just doesn’t cut it. My hanger mate just bought a lo presti led at Oshkosh (expensive) and it was a massive difference... you can’t put a price on depth perception on a black runway. Sorry I don’t mean to hijack the thread with light speak.

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On 8/7/2018 at 1:37 PM, Sandman993 said:

Loud n proud!

So all our 200hp 360’s are born 193hp give or take? 

That is correct. There has never been an IO360 that actually made 200HP.  Note also that Lycoming`s initial testing of the IO360 around 1960 showed it delivered 195 HP with a specific tuned exhaust and no airfilter, and a touch less with an airfilter and OEM exhaust... using the rules the FAA then allowed (different now), they could round that up to 200 HP, which was a marketing decision.

Edited by cujet
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1 hour ago, cujet said:

That is correct. There has never been an IO360 that actually made 200HP.  Note also that Lycoming`s initial testing of the IO360 around 1960 showed it delivered 195 HP with a specific tuned exhaust and no airfilter, and a touch less with an airfilter and OEM exhaust... using the rules the FAA then allowed (different now), they could round that up to 200 HP, which was a marketing decision.

I’m in the boat engine biz... the outboard manufacturing world did the round up number thing for many years except mercury... that old German coot would round down an engine so the merc looked superior... they changed the rules sometime around 1990 so everyone had to stop lying. The horsepower race is alive and well today!

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28 minutes ago, bluehighwayflyer said:

I have heard this from many sources and believe it to be true. I have also heard that O-360s produce a legit 180 horsepower. If so, the power delta between them is not that great. Between the IO's angled valves and fuel injection combined with it's ability to run LOP, however, I think the efficiency delta is somewhat more significant.  Just my impression, but also my experience after owning and operating both a C and a J for many years. 

So the huge difference is the nose cowl and the windscreen. I always feared getting a spanking from a c or an e that had sprung for those mods. I’ve heard an e with the 201 mods is not to be trifled with.

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