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M20F cruise speed


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My 1967 M20F has the Lasar 201 style windshield, flap-gap seals and cowl closure.  I plan 145kts.  At 8,000' WOT & 2500 I usually see 148-152kts TAS. 11gph (EGT around 1360).

 I have however gone higher for a good tailwind. http://www.groundspeedrecords.com/index.php?option=com_content&view=category&id=247&Itemid=2060 

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  • 1 year later...
On 8/22/2016 at 6:30 PM, 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 method works perfectly for me every time

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On 8/22/2016 at 8:37 AM, N803RM said:

My 69F has many speed mods, looks like 148 knots TAS.   1500 hrs on engine, old style prop.

Ron

I'm seeing 147 ktas in the same plane with the scimitar prop (occasionally 148-150 ktas). And the IO-360 hot-starts easily, 1st time every time for me, with the "mixture rich, throttle wide open for 12 seconds, throttle to idle, mixture to cut-off, and crank" technique.

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On 8/9/2018 at 5:25 AM, M20F-1968 said:

Highly Modified 1968 F (essentially a J)

TAS 165, 77% HP, 2400 RPM/23.8 MP, 11.2 GPH, 17000 ft.

Obviously at higher MP it would be faster.  

This was flying back from Oshkosh in July.  

John Breda

IMG_2002.jpg.edd2593d99618bed2210daa85bf423a6.jpgIMG_2019.jpg.a60967c1700de512aa9e80b5d1a9a32c.jpg

How much higher MP can you get at that altitude?  Not turbocharged, right?

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On 8/23/2016 at 9:19 AM, Marauder said:

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.

Sent from my iPad using Tapatalk

More to do with “creativity”...

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On 8/22/2016 at 9:56 AM, MyNameIsNobody said:

I hate these threads because posters rarely discuss their altitude/power settings and fuel burn.  My question is why don't you include this for reference?  It takes the "magic out".

its also nice to include what you are using to reference your speed. are you using airspeed indicator, waas gps, Ipad with gps. because if its an airspeed indicator, im pretty sure they aren't very accurate at altitude.

EDIT: I just realized this comment is from 2016 and I am an idiot.

Edited by Niko182
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One of the side benefits of my panel refit and choice of layout allows me to take this picture anytime I want to record current conditions. Everything I'd want to know is right in the picture.  Here's an example. I've got nearly a hundred of these from lots of different flights. 

IMG_2206.thumb.jpg.f2361ebc3af38dff843ae3d4a7758c97.jpg

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1 minute ago, Smiles201 said:

Differences in gross weight and center of gravity can also account for alot of variability.

Mine pretty much always takes off at gross weight and with the fat kid in the front left seat in other words, forward CG ;-)

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51 minutes ago, gsxrpilot said:

One of the side benefits of my panel refit and choice of layout allows me to take this picture anytime I want to record current conditions. Everything I'd want to know is right in the picture.  Here's an example. I've got nearly a hundred of these from lots of different flights. 

IMG_2206.thumb.jpg.f2361ebc3af38dff843ae3d4a7758c97.jpg

But you don't fly an F (see thread title . . . ).

I don't fly an F either, but I enjoy needling those who do with shots of my C:

20161002_133311.thumb.jpg.c5e72e2a3e397afc8a62c5f1749919d1.jpg

As shown, this was at 9500 msl, where I fly WOT - just enough to make the MP needle wiggle, and 2500.

20150522_170516.thumb.jpg.72d36b9bed06dc6919ee86a83e2908be.jpg

Not bad for feeding 180 screaming horses through a carburetor . . . .

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1 minute ago, Hank said:

But you don't fly an F (see thread title . . . ).

True... I was only meaning to show my way of recording performance parameters.

BTW... I use to fly my C exactly the same way you do... In fact I think I learned it from you. :-)

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At 17,000 he would have to a turbo.  His engine gauge is also showing TIT, if I'm seeing it correctly. 


I think John’s highly modded F and wcb are both turbonormalized planes. Not sure where their critical altitudes are.


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6 hours ago, teejayevans said:


You enter 128 into 430, but lower picture shows 125.
Speed claims are like fish stories.

I didn't notice when i posted the pictures, but the heqdings are different, too. Many photos on the phone, thewe are the onss on my tablet. Theres also 2000' altitude difference.

Edited by Hank
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13 hours ago, Niko182 said:

its also nice to include what you are using to reference your speed. are you using airspeed indicator, waas gps, Ipad with gps. because if its an airspeed indicator, im pretty sure they aren't very accurate at altitude.

EDIT: I just realized this comment is from 2016 and I am an idiot.

My comment was as relevant now as it was then...

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On 8/11/2018 at 4:15 PM, MyNameIsNobody said:

How much higher MP can you get at that altitude?  Not turbocharged, right?

Turbonormalized.  It can be brought up to 29" MP (or 27" to be a bit kinder with temperatures).  At that MP,  %HP will be > 75% where it is not advisable to lean and thus will be burning full fuel.   I try not to run it that way however there are people such as Bob Kromer who said to us (as I recall) at one of the Mooney Summits, that these airplanes and their engines were designed to be flown with "everything forward."  If he is there again this Sept. I will confirm with him.  Run that way it is 168-170 kts at 12000ft.

The plane as been lean of peak, at 17000 ft, burning 8.5 gallons per hour with TAS of about 172.

John Breda

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15 hours ago, Marauder said:

 


I think John’s highly modded F and wcb are both turbonormalized planes. Not sure where their critical altitudes are.


Sent from my iPad using Tapatalk Pro

 

I have not gone out and tested critical altitude but I have had it to 18,000 ft and did not have problems retaining manifold pressure.

The old RayJay Manuals, as I recalled, indicated different critical altitudes, the lowest of which was 20,000 ft.  

I should take it out and do some experimenting now that I know the plane better.

John Breda

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