M20C/E Alternative

[0TreeLemur]

On 3/9/2020 at 2:42 PM, KLRDMD said:

My C was one of the faster ones I thought and the best I could get was 147 KTAS under perfect conditions.

'03L , she won't go that fast for me...   I plan for 142. What am I doing wrong? 

[KLRDMD]

1 hour ago, 0TreeLemur said:

'03L , she won't go that fast for me...   I plan for 142. What am I doing wrong? 

As I recall that was the first couple of flights after the magnetos were overhauled and, I believe spark plugs replaced. Perfectly smooth air. 142KTAS day in and day out is reasonable.

[0TreeLemur]

Just now, KLRDMD said:

As I recall that was the first couple of flights after the magnetos were overhauled and, I believe spark plugs replaced. Perfectly smooth air. 142KTAS day in and day out is reasonable.

The left mag is approaching 500 h.  Our plan is to install a Surefly.   Maybe that will pep 'er back up.

[Hank]

4 hours ago, 0TreeLemur said:

'03L , she won't go that fast for me...   I plan for 142. What am I doing wrong? 

My 1970 C, with 201 windshield and 3-blade Hartzell trues around 147-148 KTAS at altitude (7500-10,500 msl). I run WOT- [set WOT, then pull back throttle justenough to make the MP needle wiggle], 2500, 50°F ROP.

There was apparently a leak at my carb heat box for several years, because one mountain departure for home I could barely climb and ATL Center asked if I was really a Mooney as Iimped by. Turned out one of the hinges on the carb heat box had broken off and the flappers were wide open [carb heat full on]. Fixed that, replaced the holey muffler and viola! An extra 10mphi! NOW I indicate 140-145 mph in cruise high, and sometimes 155 down at 3000 msl. Cost about an AMU per 2 mph . . . . Used to make book speed or close to it, now I routinely exceed it, 3-blade and all.

Check your rigging. Check your carb heat box and tubing. Check for induction leaks. Fix everything, recheck speed and let us know what you did and the results.

[0TreeLemur]

9 hours ago, Hank said:

My 1970 C, with 201 windshield and 3-blade Hartzell trues around 147-148 KTAS at altitude (7500-10,500 msl). I run WOT- [set WOT, then pull back throttle justenough to make the MP needle wiggle], 2500, 50°F ROP.

There was apparently a leak at my carb heat box for several years, because one mountain departure for home I could barely climb and ATL Center asked if I was really a Mooney as Iimped by. Turned out one of the hinges on the carb heat box had broken off and the flappers were wide open [carb heat full on]. Fixed that, replaced the holey muffler and viola! An extra 10mphi! NOW I indicate 140-145 mph in cruise high, and sometimes 155 down at 3000 msl. Cost about an AMU per 2 mph . . . . Used to make book speed or close to it, now I routinely exceed it, 3-blade and all.

Check your rigging. Check your carb heat box and tubing. Check for induction leaks. Fix everything, recheck speed and let us know what you did and the results.

Since acquiring her in 2017, we've added an engine monitor, upgraded that '60s panel to mid '00's six-pack with a 430W and Accutrak II, resealed the tanks, replaced the engine mounts, new tires, replaced the shock disks, replaced all side windows, epoxy painted the steel tubing with complete 208-B, redid the interior, replaced the governor, installed flap gap seals, removed all remnants of the ADF system, had her legs stripped and painted, removed the belly strobe and put on Orion wing lights/strobes, replaced the door seal, new brake pads, and balanced the prop.   So, we're well along in the "fix everything" dept.   The annual this year was done by Cole Aviation (MSC) and they did a thorough job including inspecting the carb heat box.  That's a lot, but we've done as much of the labor ourselves as allowed.

I cruise at WOT with just enough throttle to delay roughness when doing the lean-find on the engine.   I like to run at 2400 rpm, which is about 73% power at 7000' and 68% at 10,000'.  I'll do a cruising speed test at 2500 rpm and see what difference that makes.

You have that really nice 201 windshield that we don't.  That is worth a few knots for sure. 

Next we have to get our prop IRAN'd 'cause Hartzell is nervous about approving the ECI on 'A' hubs that haven't been internally inspected in over a many(?) years, then install the electronic ignition, it will be time for the next annual.  I can have them check the rigging then.  I am hoping that the electronic ignition helps.  Should get more power out at the same fuel flow, which would translate to more speed, but at higher rpm.

[gsxrpilot]

12 hours ago, 0TreeLemur said:

You have that really nice 201 windshield that we don't.  That is worth a few knots for sure. 

The windshield and cowl probably give you the best speed increase. 

N6XM (RIP) had every speed mod LASAR offered from the windshield to the tie-down rings. Then Don Maxwell went over her to get anything else out of the wind he could, such as reversing the brake calipers. He also did a full re-rig on the control surfaces. 

The result was a legit 152-155 knot C (at the right altitude, and on the last half of the fuel tank) 

[rbridges]

boy, this thread has drifted, and I'm going to add to it.    Does anyone know how much weight affects speed in our mooneys.  Let's say a C or J at full gross vs one that's 200 lbs lighter.  Is there any ballpark idea how much difference that makes in top cruise speed?  

[gsxrpilot]

Lighter is faster

Aft CG is faster

No idea how much...

[Hank]

30 minutes ago, rbridges said:

boy, this thread has drifted, and I'm going to add to it.    Does anyone know how much weight affects speed in our mooneys.  Let's say a C or J at full gross vs one that's 200 lbs lighter.  Is there any ballpark idea how much difference that makes in top cruise speed?  

My Owners Manual has two speed columns, Gross and 2200 lb. You want a copy of my Performance Tables?

[rbridges]

4 minutes ago, Hank said:

My Owners Manual has two speed columns, Gross and 2200 lb. You want a copy of my Performance Tables?

yeah, if you could send me a copy of that table, that would be appreciated.  

[rbridges]

24 minutes ago, gsxrpilot said:

Lighter is faster

Aft CG is faster

No idea how much...

c'mon Paul, you're my statistics guy!

[chriscalandro]

There were people on here a few weeks ago saying to expect 7-10k annuals on their vintage Mooney. 
 

searching a public forum for information like this is less than useful. 

[Hank]

23 minutes ago, chriscalandro said:

There were people on here a few weeks ago saying to expect 7-10k annuals on their vintage Mooney. 

My annuals typically run 20-24 hours labor, plus parts & labor for whatever rlse isndone at that time. Owner-assisted rates are lower, I can see the condition of everything and decide on the spot to replace something or what to watch for if not necessary yet. I prefer knowing . . . .

[Hank]

1 hour ago, rbridges said:

yeah, if you could send me a copy of that table, that would be appreciated.  

My Manual is in the Downloads section. I'll email it to you tonight, too. Performance Tables are at the back.

[gsxrpilot]

36 minutes ago, Hank said:

My annuals typically run 20-24 hours labor, plus parts & labor for whatever rlse isndone at that time. Owner-assisted rates are lower, I can see the condition of everything and decide on the spot to replace something or what to watch for if not necessary yet. I prefer knowing . . . .

It's helps (but not a guarantee) to start with a well maintained Mooney. I've been through 6 annuals on two different Mooneys. One of them a turbo . And never owner assisted. 

I have yet to spend $5K out the door on any annual and that includes whatever upgrades were included that year.

[Tcraft938]

On 3/9/2020 at 3:42 PM, KLRDMD said:

Using comparable airplanes, I fail to see how a $26k Bonanza's insurance would be more than a $50k Mooney. Fair enough if you don't like the yoke. Non-pilot passengers LOVE not having a yoke in front of them and like the fold down rudder pedals on the right side too. Getting in and out for both passengers and pilot is easier without a right side yoke in the way too.

At 12.5GPH in my Bonanza I get 170 KTAS. I'm sorry, but your C model isn't doing 170 KTAS in level flight at any fuel flow, much less 9GPH. My C was one of the faster ones I thought and the best I could get was 147 KTAS under perfect conditions.

No need to be offended. I never said compared a 26k bonanza to a 50k Mooney. Both planes were similar cost. Yes I like the room in the bonanza. For the same money I was able to find updated avionics new engine an scimitar prop. 154kts true on 9.6gph. Since most of my flying is around 200 miles that’s pretty good and the time saved at 170 v 150 kts is negligible. It’s all about the mission and what works for one doesn’t for another. Are there things I wish were different sure. It’s a plane like a woman no such thing as perfect   Lol.   Free plane or gas I will gladly fly either one bonanza or Mooney. 

[DanM20C]

20 hours ago, rbridges said:

boy, this thread has drifted, and I'm going to add to it.    Does anyone know how much weight affects speed in our mooneys.  Let's say a C or J at full gross vs one that's 200 lbs lighter.  Is there any ballpark idea how much difference that makes in top cruise speed?  

I kept a close eye on my speeds in my C over the course of my ownership.  I averaged 141kts in cruise, no speed mods other than a scimitar prop.  The speed difference between the forward and aft CG range at similar weights was 4-5kts.  Not trivial, but normal loading was someplace in the middle, it was hard to load that airplane full forward. I always tried to load as aft as possible for the few extra kts

cheers,

Dan

[DJE22]

On 3/9/2020 at 2:42 PM, KLRDMD said:

Using comparable airplanes, I fail to see how a $26k Bonanza's insurance would be more than a $50k Mooney. Fair enough if you don't like the yoke. Non-pilot passengers LOVE not having a yoke in front of them and like the fold down rudder pedals on the right side too. Getting in and out for both passengers and pilot is easier without a right side yoke in the way too.

At 12.5GPH in my Bonanza I get 170 KTAS. I'm sorry, but your C model isn't doing 170 KTAS in level flight at any fuel flow, much less 9GPH. My C was one of the faster ones I thought and the best I could get was 147 KTAS under perfect conditions.

I’m with KLRMD.

I’ve flown > 1000 hours in an M20F; 400 hours in a J; likely 300 in various other Mooneys and 1500 hours in a bonanza F33. And although I do not recall my typical fuel consumption in the bonanza, it was good all day every day for 170 kts.

Fuel consumption will definitely be higher in the bonanza (regardless which engine it has). And maint. will likely be higher in the bonanza assuming you find a well-maintained Mooney; but there is something about the feel of those 6 cylinders; and sitting up a bit higher; I didn’t mind the big yoke; 

And by the way, 147 kts from the M20C is pretty decent. I have a number of mods on my C and I’m ~149 wot and 2500 at 7/8000’ (10gph)

I’d love a Debonair. But a similar vintage Deb with similar TT and engine time as my C would have cost $30k more up front. (I’d get that back when I sold....just didn’t have the resources at the time to jump that high). 

In the end, they’re all expensive! 

But fun!

[DJE22]

On 3/10/2020 at 10:02 PM, Hank said:

My 1970 C, with 201 windshield and 3-blade Hartzell trues around 147-148 KTAS at altitude (7500-10,500 msl). I run WOT- [set WOT, then pull back throttle justenough to make the MP needle wiggle], 2500, 50°F ROP.

Hello @Hank

i saw your post above and was going to ask what mixture setting, but the I noticed you include 50* ROP. What fuel gph burn do you typically see:

- WOT 

- 50ROP

- 7500’ (or 8500’)

i Have Power Flo so I expect mine to be different (since PF claim is I’m probably using more horsepower) but curious what you’re seeing on yours.

Edited March 20, 2020 by DJE22

[0TreeLemur]

8 hours ago, DJE22 said:

Hello Hank!

i saw your post above and was going to ask what mixture setting, but the I noticed you include 50* ROP. What fuel gph burn do you typically see:

- WOT 

- 50ROP

- 7500’ (or 8500’)

i Have Power Flo so I expect mine to be different (since PF claim is I’m probably using more horsepower) but curious what you’re seeing on yours.

According to Mike Busch in Engines, 50 ROP is the worst place to run our carbureted engines.  Highest internal pressures at that mixture.  He recommends 80-100 ROP.