M20J 201 Model Speeds

[EricJ]

2 hours ago, aviatoreb said:

Why wouldn't we all want port and polishing then when we get overhauls?  Other than expense?

I don't know how many places do it any more or have the equipment/talent to do it properly.   You can ruin a head doing this if you're not careful.   It also may be that it just didn't turn out to be worth it for most people, but I don't see it offered that much these days.   The guys with the racing airplanes are probably doing this because they want every bit of power they can get. 

2 hours ago, aviatoreb said:

Also what is porting? I understand what is polishing. Your description as to why was helpful too.

Porting changes the shape of the intake (or exhaust) ports, in the head and/or the intake, to facilitate better airflow.   Sometimes this is as simple as improving the match of the shape of the head port and intake casting with each other.    On our airplanes this isn't as big of a deal since the intake/exhaust tubes are independent pieces rather than large castings, so instead the concentration is on improving the shape of the port inside the head.   If you've ever heard of a "flow bench", that's what's used to test the flow through a head to verify improvement after porting or other modifications.

I found a couple of articles from about fifteen years ago that may help.   Ly-Con, from the second article, is still around but I don't know whether they're still offering this or not, or for certificated airplanes.   As mentioned in the second article, they can't do much beyond smoothing casting flash, etc., on engines for certificated airplanes, so the gains won't be as much.   I suspect for certificated airplanes it just hasn't turned out to be worthwhile for most people.

https://www.aviationconsumer.com/misc/trick-cylinders-porting-and-polishing/

http://www.supercub.org/photopost/data/760/Porting_Air_Power_0409.pdf

[Shadrach]

33 minutes ago, 201er said:

@jetdriven @124% power, you're not pulling the wool over anyone's eyes!

I just assumed that fancy monitor was in LOP Horsepower mode whil the engine was ROP.

[jetdriven]

The JPI percentage of horsepower calculation is pure  bullshit. It has you set it up for 75% cruise which is around 10 gallons an hour, and then you change this calibration factor in the menu until it shows 75% power. And what it does it look at fuel flow it says oh 75% power is 10 gallons an hour so 16 gallons an hour is 120% power or whatever it’s only accurate in a narrow range and only for Near peak EGT it’s really kind of a gimmick really

[201er]

1 minute ago, jetdriven said:

The JPI percentage of horsepower calculation is pure  bullshit. It has you set it up for 75% cruise which is around 10 gallons an hour, and then you change this calibration factor in the menu until it shows 75% power. And what it does it look at fuel flow it says oh 75% power is 10 gallons an hour so 16 gallons an hour is 120% power or whatever it’s only accurate in a narrow range and only for Near peak EGT it’s really kind of a gimmick really

I dunno, always seems to work right for me. Shows ROP power properly until I lean LOP, then it shows LOP based on fuel flow.

[jetdriven]

What  does it show on takeoff? It’s usually 105% or 110%. JPR doesn’t tell you what all it looks at or how it arrives at that value. Here’s the thing though the throttle is always firewalled and the prop is always at 2500 RPM so the percentage of power is always Max available anyway

[201er]

29 minutes ago, jetdriven said:

What  does it show on takeoff? It’s usually 105% or 110%. JPR doesn’t tell you what all it looks at or how it arrives at that value. Here’s the thing though the throttle is always firewalled and the prop is always at 2500 RPM so the percentage of power is always Max available anyway

Like 98%.

Maybe your Mooney isn't faster than everybody else's. Maybe you just rigged the engine to overdrive power

[FlyingDude]

9 minutes ago, 201er said:

Maybe you just rigged the engine to overdrive power

Teach me how it's done.

Asking for a friend.

 

[jetdriven]

It’s easy you just set the prop low pitch stops to a higher value, they take a larger bite out of the air. It’s like overdrive for airplanes. 
Also, climb to 300 feet above your final altitude and then you descend into it it puts the airplane on the step cruises faster that way too 

[Fly Boomer]

14 hours ago, jetdriven said:

Wish we could post pics 

Send in $20 and wait a couple of days.

[aviatoreb]

1 hour ago, EricJ said:

I don't know how many places do it any more or have the equipment/talent to do it properly.   You can ruin a head doing this if you're not careful.   It also may be that it just didn't turn out to be worth it for most people, but I don't see it offered that much these days.   The guys with the racing airplanes are probably doing this because they want every bit of power they can get. 

Porting changes the shape of the intake (or exhaust) ports, in the head and/or the intake, to facilitate better airflow.   Sometimes this is as simple as improving the match of the shape of the head port and intake casting with each other.    On our airplanes this isn't as big of a deal since the intake/exhaust tubes are independent pieces rather than large castings, so instead the concentration is on improving the shape of the port inside the head.   If you've ever heard of a "flow bench", that's what's used to test the flow through a head to verify improvement after porting or other modifications.

I found a couple of articles from about fifteen years ago that may help.   Ly-Con, from the second article, is still around but I don't know whether they're still offering this or not, or for certificated airplanes.   As mentioned in the second article, they can't do much beyond smoothing casting flash, etc., on engines for certificated airplanes, so the gains won't be as much.   I suspect for certificated airplanes it just hasn't turned out to be worthwhile for most people.

https://www.aviationconsumer.com/misc/trick-cylinders-porting-and-polishing/

http://www.supercub.org/photopost/data/760/Porting_Air_Power_0409.pdf

Thanks - those were very interesting articles!

[jetdriven]

2021 was an interesting year.  There were plenty of revenge racers ready to see through the red mist and thrash their planes for glory, us included. Plenty of fast glass, and big motor production machines with some shiny paint.  A couplemof rel fast looking Beechcraft.

Our speed was 188 MPH, which was about 7 MPH off what it really does, this year it was a closed course which had nasty headwinds on the first leg, a direct crosswind on the second leg, and a headwind on the third leg!  But we overhauled every production piston airplane except a 500 Twin Commander.  The previous race, we were not in, and someone stole our race number.  He was friends with our pre-race dinner table mates, and when he found out we were there, said he had alternator trouble and couldnt make it.  When I offered to install his new alternator for free and race him for the number, he declined.  Friendly race and all.  But he never showed,

I wish we would have run them in 2019, we could have kept the number and taken  the other 3 Mooneys in the class by 13-15 MPH. Maybe next year.

http://www.airventurecuprace.com/2021-race-results/

 

http://www.airventurecuprace.com/2019-race-results/

[Ragsf15e]

1 hour ago, 201er said:

Like 98%.

Maybe your Mooney isn't faster than everybody else's. Maybe you just rigged the engine to overdrive power

My edm-930 seems relatively accurate on %power too.  Even on takeoff.  I don’t think it’s exact, but it agrees within a percent or two with the poh when ROP and very close to the ff formula when LOP.

[201er]

1 hour ago, jetdriven said:

When I offered to install his new alternator for free and race him for the number, he declined.  Friendly race and all. 

I'll race you for a free alternator. Actually better make that an RPM increase. With 20 more RPM, I'd make redline and might make same speed as you.

[FlyingDude]

3 hours ago, jetdriven said:

just set the prop low pitch stops to a higher value

Makes perfect sense!  When you want to drive faster, you should start in top gear right away!  Same logic...

[Ragsf15e]

1 hour ago, 201er said:

I'll race you for a free alternator. Actually better make that an RPM increase. With 20 more RPM, I'd make redline and might make same speed as you.

Careful @jetdriven, he didn’t specify the rules… you’re going to end up in a 9.5 hour distance marathon instead of your typical speed/closed course.

[aviatoreb]

6 hours ago, jetdriven said:

2021 was an interesting year.  There were plenty of revenge racers ready to see through the red mist and thrash their planes for glory, us included. Plenty of fast glass, and big motor production machines with some shiny paint.  A couplemof rel fast looking Beechcraft.

Our speed was 188 MPH, which was about 7 MPH off what it really does, this year it was a closed course which had nasty headwinds on the first leg, a direct crosswind on the second leg, and a headwind on the third leg!  But we overhauled every production piston airplane except a 500 Twin Commander.  The previous race, we were not in, and someone stole our race number.  He was friends with our pre-race dinner table mates, and when he found out we were there, said he had alternator trouble and couldnt make it.  When I offered to install his new alternator for free and race him for the number, he declined.  Friendly race and all.  But he never showed,

I wish we would have run them in 2019, we could have kept the number and taken  the other 3 Mooneys in the class by 13-15 MPH. Maybe next year.

http://www.airventurecuprace.com/2021-race-results/

 

http://www.airventurecuprace.com/2019-race-results/

You have an extra special wing thanks to some elbow grease sweat and tears.

[A64Pilot]

7 hours ago, jetdriven said:

2021 was an interesting year.  There were plenty of revenge racers ready to see through the red mist and thrash their planes for glory, us included. Plenty of fast glass, and big motor production machines with some shiny paint.  A couplemof rel fast looking Beechcraft.

Our speed was 188 MPH, which was about 7 MPH off what it really does, this year it was a closed course which had nasty headwinds on the first leg, a direct crosswind on the second leg, and a headwind on the third leg!  But we overhauled every production piston airplane except a 500 Twin Commander.  The previous race, we were not in, and someone stole our race number.  He was friends with our pre-race dinner table mates, and when he found out we were there, said he had alternator trouble and couldnt make it.  When I offered to install his new alternator for free and race him for the number, he declined.  Friendly race and all.  But he never showed,

I wish we would have run them in 2019, we could have kept the number and taken  the other 3 Mooneys in the class by 13-15 MPH. Maybe next year.

http://www.airventurecuprace.com/2021-race-results/

 

http://www.airventurecuprace.com/2019-race-results/

Were there any Meyers 200’s ? I don’t know about now, but they used to be fast and with the IO-550 STC to replace the 520 I doubt they slowed down any.

[carusoam]

Power Opportunities…

1) Port

2) polish

3) Flow match

4) Oversize cylinders with matching rings 

5) 25.000 ignition timing, maxed.

6) Cooling the air intake

7) balanced fuel injectors

8) balanced air cooling

9) Clean out the intake tubes… for balanced air flow…

10) New intake seals… make sure they are working…

11) Have Byron set your engine up….

12) Have Becca do your flight planning….

Or….

13) add 10:1 CR pistons…

14) add a TN…

15) add a spare set of cylinders…

16) add a Merlyn MP controller…

17) add an intercooler…

18) Run 2700.000 rpm, maxed.

19) add extra FF for cooling….

20) Many factory built (Continental) engines have gone to the tuners to get their cylinder heads re-made to factory specs….  For some reason, the factory was unable to make factory spec… for a while…

A short list of power opportunities that have come up around here at times… some are out of context, others are way out of context….   

 

PP thoughts only…

-a-

 

[KSMooniac]

Drag reduction will pay off better than power enhancement, unless you add a turbo and go really high, or replace a bad cam.

I'm slowly following the lead of Byron and Norman on my 77 J. Current project is deleting the pop up roof scoop and forward COM antenna. I would love to get to 160 KTAS while LOP. Norman got to 165 KTAS, but had a LoPresti cowl and power flow exhaust.

Sent from my LM-V405 using Tapatalk

[carusoam]

You guys win the honorary Lopresti award!  (Scott, Byron, and Norman)

Al Mooney was pretty good at selecting the major aerodynamic parts for our Mooneys…

Roy took it to the next level…

Lots of aero clean up and smooth fairings….

Aero works, because fuel is always less affordable…. 

Best regards,

-a-

[201er]

1 hour ago, KSMooniac said:

I'm slowly following the lead of Byron and Norman on my 77 J. Current project is deleting the pop up roof scoop and forward COM antenna. I would love to get to 160 KTAS while LOP.

Forgetting Mike 201er?

163KTAS, 139KIAS, 161GS, 9000ft, 11C OAT, 21.9”MP, 2620RPM, 63%HP, 8.4GPH, 10LOP, 2150lbs GW

[jetdriven]

It’s not good data unless you do the NTPS 3 track method…that’s pretty accurate.  For example, you compute true airspeed off of CAS, the CAS is about 2 mph less at altitude in the normal speed range. And that assumes that the airspeed indicator is accurate, then you got to correct it for temperature and everything else. So I’m not saying you’re full of it, I’m just saying that you need to measure it more precisely and if you’re ASI isn’t calibrated, it’s going to be garbage and garbage out. I just had a Pitot static transponder checked, and the guy noticed that my G5 is reading 2 mph low while they analog airspeed indicator is  exactly right. Which is kind of funny because I bought the G5 to have it more precise reading, and it’s the one that’s off.

[ArtVandelay]

I would assume the G5 can be recalibrated and adjusted, no?

[201er]

4 hours ago, jetdriven said:

So I’m not saying you’re full of it, I’m just saying that you need to measure it more precisely

There’s only one way to find out… race you to Florida today!?

[ArtVandelay]

There’s only one way to find out… race you to Florida today!?

Flight aware is showing 2:24 travel time….you’ll beat an Acclaim if you can do that.

I’d guess your travel time will be 6.5 hours.

Despite his 188mph speed above, he flight plans for 173.