M20J 201 Model Speeds

[A64Pilot]

36 minutes ago, bluehighwayflyer said:

Down low, max MP, with a tight induction system and well-balanced injectors flowing 10 GPH? 
 

Oh, and perhaps highly optimized aerodynamics like @jetdriven has.  

More like 19 GPH gave me 168 kts, but the airplane is old and heavy, that’s why I think 175 was possible with a new aircraft with as much weight as possible removed. 

[Ragsf15e]

2 hours ago, A64Pilot said:

Dude, I quoted you word for word, but I do now understand what your saying that your new LOP speed is slightly higher than your previous LOP speed.

I’m trying to figure out why your airplane cruises at 135 kts, where most will cruise at 155 kts. That’s not a little bit, 20 kts is a whole lot. it’s a big number, one that might be at least partially explained by LOP operation.

135 kts is 182 or big motor Maule speed, a J Model ought to blow their doors off.

Well for starters, it’s not a J, but thanks for your concern.  It’s an F.  For an F, it’s right in the middle of normal ROP and LOP speeds at high altitudes.

All I’m saying is you’re great at pontificating and throwing out opinions as fact, but it wouldn’t hurt to read first.

[jetdriven]

2 hours ago, mhrivnak said:

Can you elaborate on how to achieve that? Seems like a lot of Js settle from 145-150 KTAS LOP.

Not sure, it’s Rigged Square, all the doors close, a lot of the antennas have been swapped out for more optimized units, 25° of timing but since we installed the G5 it’s usually 183 to 186 mph true which works out to be around 159 or 160 most of the time. Interestingly, I just had the IFR check done and the G5 reads 2 mph low but the analog air speed is dead ass. Which would put it like 160 or 161 lean of peak but anyway it’s totally possible 

[mhrivnak]

7 minutes ago, jetdriven said:

Not sure, it’s Rigged Square, all the doors close, a lot of the antennas have been swapped out for more optimized units, 25° of timing but since we installed the G5 it’s usually 183 to 186 mph true which works out to be around 159 or 160 most of the time. Interestingly, I just had the IFR check done and the G5 reads 2 mph low but the analog air speed is dead ass. Which would put it like 160 or 161 lean of peak but anyway it’s totally possible 

Nice. What fuel flow do you see?

[jetdriven]

9-10 GPH 

[A64Pilot]

1 hour ago, bluehighwayflyer said:

He either didn’t read or understand my post or the ones I was responding to either.  

I didn’t notice that he wasn’t the original poster that does it seems have a J that only makes 135kts

[ArtVandelay]

I didn’t notice that he wasn’t the original poster that does it seems have a J that only makes 135kts

My J had a worn down intake cam lobe and it did better than that. There’s something (probably a few things) wrong and I would guess the engine not making rated HP is one of them.

[A64Pilot]

5 minutes ago, ArtVandelay said:

My J had a worn down intake cam lobe and it did better than that. There’s something (probably a few things) wrong and I would guess the engine not making rated HP is one of them.

Somethings wrong, hope it’s not an expensive something 

But I still think 175 is achievable in a brand new stripped down J running at sea level, at takeoff power, especially with a “ringer” motor.

At least Pratt & Whitney and GE for a Certification airplane will deliver an engine that’s significantly stronger than average, I assume Lycoming can too

But it’s any airplane, Piper went to a lot of trouble positioning the pitot tube to get the max allowable indicated error.

Edited June 9, 2022 by A64Pilot

[aviatoreb]

48 minutes ago, A64Pilot said:

Somethings wrong, hope it’s not an expensive something 

But I still think 175 is achievable in a brand new stripped down J running at sea level, at takeoff power, especially with a “ringer” motor.

At least Pratt & Whitney and GE for a Certification airplane will deliver an engine that’s significantly stronger than average, I assume Lycoming can too

But it’s any airplane, Piper went to a lot of trouble positioning the pitot tube to get the max allowable indicated error.

That's interesting.  What do they do to make a ringer motor stronger.  How much stronger would you guess?

[Utah20Gflyer]

Next time you are in for annual and doing a gear swing I would verify all the gear doors are rigged correctly, make sure your cowl flaps close properly, etc.  Verify control surfaces are rigged correctly.  Verify you are getting book number on Manifold pressure next time you fly it.   You should be getting more speed from a J, how much I don't know, but currently my G model would pass your J pretty decisively and we can't have that.  The pecking order must me maintained.   

[Shadrach]

3 hours ago, bluehighwayflyer said:

Down low, max MP, with a tight induction system and well-balanced injectors flowing 10 GPH? 
 

Oh, and perhaps highly optimized aerodynamics like @jetdriven has.  

I too can maintain >150KIAS LOP down low. Fuel flow is around ~11gph. Needs to be a cool day and a light plane. Full rich it’s just into the yellow.

[jetdriven]

Wish we could post pics 

[Shadrach]

2 minutes ago, jetdriven said:

Wish we could post pics 

Text or email it to me if you want. I’ll post it for you.

[Shadrach]

26 minutes ago, aviatoreb said:

That's interesting.  What do they do to make a ringer motor stronger.  How much stronger would you guess?

I don’t think there’s a lot to be done. Port and polish. Make sure induction filter and plumbing are perfect.  ignition timing at max spec. The cumulative effects would be small but everything helps…a little.

I don’t have personal knowledge but there’s the story that Continental ran an IO520 without rings and it still made rated horsepower. Supposedly Oil consumption could be measured in GPH.

[aviatoreb]

2 minutes ago, Shadrach said:

I don’t think there’s a lot to be done. Port and polish. Make sure induction filter and plumbing are perfect.  ignition timing at max spec. The cumulative effects would be small but everything helps…a little.

I don’t have personal knowledge but there’s the story that Continental ran an IO520 without rings and it still made rated horsepower. Supposedly Oil consumption could be measured in GPH.

What does port and polishing do to make an engine run better and if so - why isn't it standard?  How much better?

[jetdriven]

I have a client with an IO360 M20F, with a 500 hour factory engine, and it’s been a beautiful piece of equipment, but suddenly out of the blue, the number three oil control ring broke into  three pieces, and it swallowed 6 quarts of oil in 50 minutes. Just the one cylinder

[N201MKTurbo]

4 hours ago, ArtVandelay said:

But your J has turbo, so not apples to apples.

Sure, but down low it doesn’t do much for you. It may even hurt you. Down low it performs just like every other 201 I’ve flown.

[jetdriven]

55 minutes ago, Shadrach said:

Text or email it to me if you want. I’ll post it for you.

Sent! Post away

[EricJ]

48 minutes ago, aviatoreb said:

What does port and polishing do to make an engine run better and if so - why isn't it standard?  How much better?

It just makes the airflow more efficient in the engine by reducing restrictions and encouraging more laminar flow by reducing discontinuities at interfaces.   It is labor/work/tool intensive, so it adds cost.   The benefits are real but usually not enormous, so it's far more cost effective to just make a casting (or whatever) as close as you can and be done with it.

There are a bunch of Nanchang CJ-5s and the similar Yaks at my home field and a friend that owns a machine shop does port-and-polish and some other mods like milling tighter tolerance on the supercharger on those radial engines.   I don't remember the exact numbers, but on those the gains are substantial.    On the cars I used to race where this was done it would typically add around 5%, but it depends on how bad the factory system was and other factors. 

[Shadrach]

1 hour ago, jetdriven said:

Sent! Post away

Impressive numbers Byron!

[aviatoreb]

8 hours ago, EricJ said:

It just makes the airflow more efficient in the engine by reducing restrictions and encouraging more laminar flow by reducing discontinuities at interfaces.   It is labor/work/tool intensive, so it adds cost.   The benefits are real but usually not enormous, so it's far more cost effective to just make a casting (or whatever) as close as you can and be done with it.

There are a bunch of Nanchang CJ-5s and the similar Yaks at my home field and a friend that owns a machine shop does port-and-polish and some other mods like milling tighter tolerance on the supercharger on those radial engines.   I don't remember the exact numbers, but on those the gains are substantial.    On the cars I used to race where this was done it would typically add around 5%, but it depends on how bad the factory system was and other factors. 

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

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

[A64Pilot]

10 hours ago, aviatoreb said:

That's interesting.  What do they do to make a ringer motor stronger.  How much stronger would you guess?

I assume set things to min tolerance for a turbine, a turbines power is compressor limited, flow more air and you can make more power. GE H-80 motor they supplied for Certification carried seal level power to at least 12,000 ft which was as high as we Certified the airplane, average production motor would hit Ng limits at 8,000 ft.

My motor in my Mooney is a Gann “performance” motor, he starts by balancing the engine within 1 gram and I assume ports and polishes the intake ports at least but I don’t know beyond that. Not that I’ve flown many 201’s but it does seem a little stronger than the average Lycoming. That could be Placebo effect too. It came with the airplane so I don’t know what’s different from his standard overhaul and a performance overhaul. If he can increase power and stay within Lycomings TCDS then surely Lycoming can. The reputation he has is good, so he’s either good at convincing people of something that’s not true or there is something there. There are a lot of untruths in marketing.

https://www.gannaviation.com/engine-overhauls

[A64Pilot]

21 minutes ago, aviatoreb said:

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

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

Porting is when you change the shape and or size of the port, for the old Kawasaki 900’s we flattened the floor of the intake, made it sort of like a D shape with the flat part of the D being the bottom, it flowed better, we also cut five angles on the valve seat as opposed to one and ran the part the valve seated to the edge, had the effect of making the valve larger so if flowed better, it’s all about flow, more air you can get in there the more power you can make. The exhaust we essentially just smoothed it out, we built turbo bikes mostly and the ports for a blown motor are different from one that sucks the air in.

You used a flow bench to quantify flow increases if any, but even then a lot of it’s art, a flow bench will tell you how much air is flowing at a given valve lift and pressure differential, but it won’t tell you how much combustion chamber swirl there is, we tried visualizing that with smoke but weren’t successful, this was 1980 before tiny cameras etc.

Its very easy to make an engine power output and band worse by porting, it really is an art. We had two guys come down from North Carolina during the NASCAR off season and help and instruct us on porting, two Brothers.

https://en.wikipedia.org/wiki/Air_flow_bench

I believe you can get a polished and ported motor on overhaul, call Gann Aviation

https://www.gannaviation.com/home.

Never been there myself, never met the man, but know his rep. He does a “performance” overhaul as well as a standard overhaul. I don’t know what all he does though, your very limited as to what you can do with a Certified engine, no high compression pistons etc.

 

Edited June 9, 2022 by A64Pilot

[AH-1 Cobra Pilot]

10 hours ago, Shadrach said:

Impressive numbers Byron!

For such nice avionics, you sure do have ugly switch covers. 

[201er]

10 hours ago, Shadrach said:

Impressive numbers Byron!

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