M20F cruise speed

[Marauder]

3 minutes ago, Jerry 5TJ said:

Ok, I understand.

But my E was a beast to start hot. If I still had it Ivwould let you guys try your hand.

 

Bring her on big guy. I love a challenge. Too bad you don't still own it.

[M20F]

I posted here once I think my 3-way speed runs with atmosphere conditions but if not will dig out and post next week. I get 130-170kts (Rayjay).   As others have made the point it is highly dependent upon a lot of factors. 

[Hank]

1 hour ago, bluehighwayflyer said:

You have posted this many times, Hank, and I have been meaning to ask you about it.  What has it been about your experience with IO-360s to leads you to believe that they are universally hard to start hot?  Just curious.

Jim

I've only hot-started an F model once, less than 10 minutes after shutdown. It was a bear. Other times after thirty minutes, it wasn't hard.

But search here and on the MAPA lists, hot starting the IO engines is a frequent topic, with many versions of the secret sauce to make it run again. It has been overtaken here by LOP discussion, and I don't spend a lot of time on the MAPA lists anymore so mom not sure how they are going anymore.

 

[merrja]

Hot starts in my F are no problem at all if I use the following procedure 1) boot pump on 2) full rich for about 3 seconds (just enough to push the vapor out of the fuel lines 3) Mixture to full lean 4) throttle half open 5) Start slowing advancing mixture

[Andy95W]

3 hours ago, Jerry 5TJ said:

My C would do about 152 KTAS at 8000' WOT and 2400 rpm.  That is the speed I computed reading the indicated air speed and correcting for temperature & altitude.  

I swear my C does 185 knots on 7.5 gph. 

I flight plan for 145 knots and 10gph, though, just to be on the safe side.

[jetdriven]

2 hours ago, Hank said:

I've only hot-started an F model once, less than 10 minutes after shutdown. It was a bear. Other times after thirty minutes, it wasn't hard.

But search here and on the MAPA lists, hot starting the IO engines is a frequent topic, with many versions of the secret sauce to make it run again. It has been overtaken here by LOP discussion, and I don't spend a lot of time on the MAPA lists anymore so mom not sure how they are going anymore.

 

I've hot started the IO engine ~400 times and it takes 6-10 blades to light off, it's not harder than any other engine.   Takes longer but not any more difficult. 

[Pictreed]

This thread is derailed but I'll take an IO over a O any day.  

My transition trainer was dreading when we shut it down for a stop at an FBO...he has a C but it started right up.  But I was shown how to do it properly.  

[Andy95W]

2 hours ago, Pictreed said:

This thread is derailed but I'll take an IO over a O any day.  

It ain't officially derailed 'til Marauder's fat lady sings.

[LevelWing]

8 hours ago, Hank said:

I have that, too. My 201 windshield is offset by the Hartzell 3-blade.

Reading all of this makes me rethink the F as just a C with extra backseat legroom, hauled around by the hard-to-hot-start IO engine . . .

I don't have the 201 windshield and it's probably not worth the cost to install given the small speed gain. I figure if I ever upgrade the Mooney it'll be to at least a J but probably a K. Then I'll let you know how the hot starts go.

Edited August 23, 2016 by LevelWing

[Yetti]

Not hard to start hot

Shut down at 1100 RPM

Don't touch anything.

Crank till pops.

Slowly move mixture forward.

Flooded procedure.    What they don't tell you is how do you know it is flooded.  It is flooded when you move the mixture forward after popping and it dies.

Then open throttle all the way. mixture close. crank

 

I do alot of 2500 foot under the clouds and under the high winds and GPS speeds are 135 to 140 at 23.5 2350. Bone stock.

Edited August 23, 2016 by Yetti

[Bob_Belville]

Isn't a J just an F with induction and aerodynamic tweaks?

An F with retrofitted 201 goodies should be able to do 160+ ktas @ 75% and best power, ~ 10.7-11.0 gph.

Stock it might be a 140 ktas plane.

I suppose many Fs now have a 201 windshield but few have a full 201 cowl. These birds would be expected to do more than 140 and less than 160. 

So, if your F won't do something close to what you'd expect there are too many possible factors to list. A 40-50 year old plane probably has more drag than a new one. The engine may not be fresh. The old girl may have accumulated a few pounds around the hips.     

 

[M20F]

10 hours ago, merrja said:

Hot starts in my F are no problem at all if I use the following procedure 1) boot pump on 2) full rich for about 3 seconds (just enough to push the vapor out of the fuel lines 3) Mixture to full lean 4) throttle half open 5) Start slowing advancing mixture

This is what I do, if I boost a bit too much it just takes more blades.  When it starts to fire I add the mixture in slowly.  I find that just cranking with no boost (shutdown at 1000 and just crank) doesn't work.  

[jetdriven]

32 minutes ago, M20F said:

This is what I do, if I boost a bit too much it just takes more blades.  When it starts to fire I add the mixture in slowly.  I find that just cranking with no boost (shutdown at 1000 and just crank) doesn't work.  

I have noticed that sometimes it will start and run a couple seconds then die. If you notice, the fuel pressure will be very low.  That's vapor lock and its dying lean. To fix this, run the boost pump, either while cranking or as soon as it starts.  After all the hot air blows from th cowl, turn the pump off. 

[sailon]

Wow, I am amazed at all of the different techniques for hot starts.  I too have lots of experience with hot starts with IO engines, first the Arrow, and now my F.  The best procedure by far was found on this site.  When i shut down expecting to start hot, open the oil access in the cowl.  This lets alot of the heat vent off, and helps with the vapor locking issue.  Second, when I climb in, I push the throttle and mixture (and check prop)  to the wall while I get sorted out.  Then throttle back to 1/4 inch from idle, mixture to cutoff and it usually kicks after 6 to 10 blades.  If it doesn't, I give it a 1 second hit from the boost pump.  No more,  That does the trick. 

One piece windshield (not the 201), no other mods, 150 kts at 75% power, 2500 RPM at 4000 ft.  155 kts at 7000 feet at full throttle ( around 70%)  Sweet spot seems to be between 7 to 10000 ft.

[Marauder]

Isn't a J just an F with induction and aerodynamic tweaks?

An F with retrofitted 201 goodies should be able to do 160+ ktas @ 75% and best power, ~ 10.7-11.0 gph.

Stock it might be a 140 ktas plane.

I suppose many Fs now have a 201 windshield but few have a full 201 cowl. These birds would be expected to do more than 140 and less than 160. 

So, if your F won't do something close to what you'd expect there are too many possible factors to list. A 40-50 year old plane probably has more drag than a new one. The engine may not be fresh. The old girl may have accumulated a few pounds around the hips.     

 

Judging by the TAS speeds all over the map, I wonder how much is due to inaccurate airspeed indicators, poorly rigged planes and other factors.

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[M20F-1968]

I'm in the same ball park as Bob_Bellville...

My F is essentially a J without the inner gear doors. 

It is a 160 kt airplane at 10,000 ft, 75% power and 10.5-11 gph fuel burn.

At 15,0000-17,0000 feet it is a 170-175 kt airplane at the same settings.

I had the blessing and the curse of having purchased a project airplane without a windshield or cowling installed.  I thus could, and had to made it into

what I wanted it to be - thus the J cowling, 201 windshield and all the other J stuff.

John Breda

[Brian Scranton]

At 26/2500, 10,000-12,000 I average 150KTAS. From 12-15K, I see 155KTAS. And from 15K-18K, I see 160KTAS. 

1975 M20F, one piece wind shield (no 201 mods)...with a leaking fuel hose until last week, so my historical GPH are in the 12.5-13.5 range. 

I plan for 140.

I hot start with 1/2 throttle, fully lean mixture. Turn the blade 6-10 times, let her start and hold that mixture at cutoff until she starts to run smooth--then quickly pull the throttle back to 1000rpm and I slowly advance the mixture.

Hope this helps. 

B

 

 

[MARZ]

OK - so today saw 153 TAS - 4500 feet 26 - 2400 @ 11 gph, barometer 30.16 temp 25 top vent door open cowl flaps trailing.

 

Lasar windshield - cowling enclosure

haven't washed and waxed for some time I gotta believe that would be worth a couple kts......

[MyNameIsNobody]

Something is different...Can't put my finger on it.  I now like this thread.  Hmmmmmmm....

[Brandontwalker]

I'm in the same ball park as Bob_Bellville...

My F is essentially a J without the inner gear doors. 

It is a 160 kt airplane at 10,000 ft, 75% power and 10.5-11 gph fuel burn.

At 15,0000-17,0000 feet it is a 170-175 kt airplane at the same settings.

I had the blessing and the curse of having purchased a project airplane without a windshield or cowling installed.  I thus could, and had to made it into

what I wanted it to be - thus the J cowling, 201 windshield and all the other J stuff.

John Breda

Assuming you have a TN on your F. I am closer to 50% power at 15-17k with WOT in my J. Only see around 160 kt.

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[Guitarmaster]

OK - so today saw 153 TAS - 4500 feet 26 - 2400 @ 11 gph, barometer 30.16 temp 25 top vent door open cowl flaps trailing.

 

Lasar windshield - cowling enclosure

haven't washed and waxed for some time I gotta believe that would be worth a couple kts......

LED lights and polished stall strips will give you about 42 extra knots!

Sent from my XT1254 using Tapatalk

[Shadrach]

I've done several speed runs in my box stock 67 F.  It is always different. The fastest 3 way calculated speed was 156kts @6500". It was so cold that the DA was likely closer to 3000'. It will indicate 160kts on the deck with all knobs (excluding the mixture) forward.

The slowest was 141kts at 12,500.

i flight plan for 150 and get it most of the time:

[DaV8or]

To the OP- I gave up on threads like this a long time ago. As you can see, the responses you get are all over the place. There are lots of ways to imagine how fast you're going. People avoid talking about the red knob and lots of ways to image what "75% power" is. ROP, LOP? 

Anyhow, just enjoy your plane the way it is and the way you fly it. Don't go spending tons of money on "rigging" just because you think your plane is slow compared to a bunch of guys on the internet. As for speed mods, well as you can see from the responses here, the stock planes fly faster than the ones with speed mods. So don't waste your money. In this day and age, the cheapest and best speed mod is to trade up to a J.

For what it's worth (not much) my plane has nearly all the speed mods with 201 windshield and SWTA 201 style cowl, and LOP about 8.5-9 gph and 2450 RPM at 6500ft it goes somewhere around 140- 145 kts. I don't try to measure it super accurately so I have no dog in this fight. Like I said, I gave up giving a crap how fast my plane is a long time ago and have nothing to prove to anybody. 

I suspect you'll get there one day too. 

[Bob_Belville]

5 minutes ago, DaV8or said:

To the OP- I gave up on threads like this a long time ago. As you can see, the responses you get are all over the place. There are lots of ways to imagine how fast you're going. People avoid talking about the red knob and lots of ways to image what "75% power" is. ROP, LOP? 

Anyhow, just enjoy your plane the way it is and the way you fly it. Don't go spending tons of money on "rigging" just because you think your plane is slow compared to a bunch of guys on the internet. As for speed mods, well as you can see from the responses here, the stock planes fly faster than the ones with speed mods. So don't waste your money. In this day and age, the cheapest and best speed mod is to trade up to a J.

For what it's worth (not much) my plane has nearly all the speed mods with 201 windshield and SWTA 201 style cowl, and LOP about 8.5-9 gph and 2450 RPM at 6500ft it goes somewhere around 140- 145 kts. I don't try to measure it super accurately so I have no dog in this fight. Like I said, I gave up giving a crap how fast my plane is a long time ago and have nothing to prove to anybody. 

I suspect you'll get there one day too. 

Spoilsport.

Are you sure you're qualified, personality wise, to own a Mooney? Just sayin'... 

[DaV8or]

8 minutes ago, Bob_Belville said:

Spoilsport.

Are you sure you're qualified, personality wise, to own a Mooney? Just sayin'... 

Shhhh... keep it on the down low! I'm a Beech Musketeer guy that's posing as a Mooney guy. Just between you an me, right?