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Posted

I'm beginning to think that I just have an engine that's on the upper end of the spectrum. We're in the same neighborhood in terms of climate and climb rate. I shoot for 105kts on initial climb. If I'm leveling off under 4K I'll climb at around 120kts.

That is my thought as well. Mike aka Stinky Pants and I have discussed how fast my F is relative to his J. I have taken a number of speed checks over the past few years and they all are in the same ballpark both for cruise and climb.

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Posted

Yours is pretty heavily modded, correct? I think it's time to break out my optical tach and make sure the big fan up front isn't turning faster than its supposed to...

Posted

Yours is pretty heavily modded, correct? I think it's time to break out my optical tach and make sure the big fan up front isn't turning faster than its supposed to...

I have the flap & aileron gap seals, lower cowl enclosure, 201 windshield mod and a JATO. ;)

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Posted

They are all "slow" if you are burning 8.5gph...

I see all this "planning"....

Do you SEE 145kts at those settings? If Yes, your plane is NOT SLOW. You are flying it SLOW. Which is A.O.K.

Yes I run deep LOP at altitude and I know if I increased RPM and FF I could get more speed but when you hear others talk about faster or other asking about being slow it makes you wonder.  I have not done any type of calculation other than using whats available in the GPS and that is only as good as the inputs from the pilot.

  • Like 1
Posted

I'll show you my Johnson bar if you don't believe me. ;)

His Johnson bar was the only thing that was evidence he was a dirty old bird at one time. The transformation of John's F is unbelievable.

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Posted

I'll start looking into these suggestions next week as I'm actually working (I hate the thought) too much this week and won't have time.  This F is a 3 blade and I usually run WOT, 2400 RPM, 50 degree ROP at 6,000 to 8,000.  My JPI 900 shows high 60s for %HP.

When I had my F, I could do 144 TAS at 8K, 8.5 LOP. I had a three blade on it for a couple of months until I couldn't take it anymore, and my TAS dropped to 136. This was a 1970 model, not one of the faster 68's. 

Posted

I think it's tall tales, Ross. Mine is dependable at 140, although my cruise ground speed has ranged from 68-183 knots in sustained level flight. Highway speed in a Mooney is just not pleasant!

P.S.-- your photo shows him well above 75% power. WOT/2500 at 6500 msl is harder than I'd push mine.

Posted

I think it's tall tales, Ross. Mine is dependable at 140, although my cruise ground speed has ranged from 68-183 knots in sustained level flight. Highway speed in a Mooney is just not pleasant!

P.S.-- your photo shows him well above 75% power. WOT/2500 at 6500 msl is harder than I'd push mine.

It depends. I fly WOT at 6500 and the big if is fuel flow. You don't have to be at 75%, right?

Posted

It depends. I fly WOT at 6500 and the big if is fuel flow. You don't have to be at 75%, right?

Not so much with a carbed 360. You can set anything between full rich and peak but I'm pretty sure any of those settings is going to be over 75% at a DA OF 6500. I too run full throttle pretty much all of the time unless I'm trying to descend or land.

  • Like 1
Posted

As posted on the previous speed contest threads, I get a consistent 140ktas+ at 65% at higher altitudes with my stock 1967 M20F, no mods, 3 blade hartzell. The sweetspot is around 8000-10000 where I normally get 143 to 145 with 8.5gph (33 litres) leaned at peak/very slightly lop. Not bad and pretty efficient, despite being miles away from the POH (funny enough later POHs post 1970 are more realistic!). I systematically run the E6b app on my GPS to cross check, and over 5 years on the same routes over and over again I get 143-145ktas at 9 or 10k feet. 

 

The thing I am slightly frustrated with is at lower altitudes it is very difficult to get past 135ktas , basically at any altitude I struggle to get the ASI past the 145mph marking. Even if I really go ROP, I probably only gain a couple knots , not worth the fuel flow. 

So at any altitude I just set 47/48 (rpm+map) and lean to peak and usually get 145mph indicated on 8.5gph, which at higher altitudes translates to 145ktas or thereabouts.

  • Like 1
Posted

As posted on the previous speed contest threads, I get a consistent 140ktas+ at 65% at higher altitudes with my stock 1967 M20F, no mods, 3 blade hartzell. The sweetspot is around 8000-10000 where I normally get 143 to 145 with 8.5gph (33 litres) leaned at peak/very slightly lop. Not bad and pretty efficient, despite being miles away from the POH (funny enough later POHs post 1970 are more realistic!). I systematically run the E6b app on my GPS to cross check, and over 5 years on the same routes over and over again I get 143-145ktas at 9 or 10k feet. 

 

The thing I am slightly frustrated with is at lower altitudes it is very difficult to get past 135ktas , basically at any altitude I struggle to get the ASI past the 145mph marking. Even if I really go ROP, I probably only gain a couple knots , not worth the fuel flow. 

So at any altitude I just set 47/48 (rpm+map) and lean to peak and usually get 145mph indicated on 8.5gph, which at higher altitudes translates to 145ktas or thereabouts.

 

145 mph? I've been looking at knots.

Posted

I'll show you my Johnson bar if you don't believe me. ;)

Is this the Mooney porn I have been hearing about, or is that the photo of the round inlet nose cowl. Now THAT will get those Johnson Bars swinging fast and often. MEOW...

Posted

145mph indicated = 126 kt which normally translates to 144/145 knots true sir speed at my typical cruise altitudes, 9-10k feet

Basically I find it pretty tough to push the Asi needle further than the 9 o clock position which is 145 mph on mine! I can eke out a couple more kts with significantly more power and hence fuel but not really worth it.

Posted

sorry my 9 o'clock is 150 MPH indicated, not 145 but usually only gets to 150 on a good day, 145 more typical. So usually this translates to 142-145kts at 9-10k feet with 33 litres set and ram air, peak/slightly LOP. The book says I should be faster and there are slicker M20Fs out there but frankly that's pretty good already for me for a stock 1967 with 3 blader, and close to what Lood and other get. This has worked on the same routes over and over again the last six years, except the day my step failed to retract and I lost 5kt! Going to ROP does not seem to push it much quicker, apart from the fuel flow.

Posted

what's really funny is that the 1967 M20F POH has 10k ft 2500 rpm = 179 mph true (155 kt), while the 1969 one has 168 mph (146kt), much closer to typical performance ! Clearly some in marketing got told to tone it down somewhat!

  • Like 1
Posted

23/23 nice and easy just the way you like it. Here is a pretty typical flight 4500 2450 / 22 Hank it looks like your suction is a bit high. Don't feel bad I have to put a placard on my panel for tach error (if confirmed)post-11990-0-29146000-1427595801_thumb.j

Oh and sorry for the not so nice panel

Posted

I don't want to be a party pooper on the awesome KIAS you guys are showing off, but you should really do a 3 or 4 leg speed check to validate them.

 

Last summer I used my IAS, temp, pressure alt, etc to compute my TAS.  Funny though, when i compared it to my ground speed, I was "always getting a headwind"... when I did the GPS 3 (or 4) way speed checks, I found a 6 knot error in the IAS at cruise speed - it was showing 6 knots fast!  My POH does show a ASI correction chart, but not 6 knots.  Anyway, I'd highly recommend doing the GS check to figure out what you really have... or leave well enough alone and just enjoy it?

 

If you do the speed check, you can figure out your real TAS and then work backward to IAS and see how far your IAS is off which might be nice to know.

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