"SabreCowl" Update (part duex)

[Guitarmaster]

It's been a long and sometimes frustrating road, but today success was achieved!

As most of you that have followed this project know, there was an unacceptable increase in CHT to go along with the very acceptable 4-6kt gain in airspeed. 

We tried many things to decrease CHT, most of which was only marginally successful.  The decision was made to open the inlets to add more air and, after today's test flight, there was a solid 20 degree drop and the CHT numbers are what was being targeted!  I personally think the larger inlets look better.

Hard climb (Vx) yielded a high number of 367.  

Cruise numbers leveled out around 357.  This was achieved at 50ROP, WOT; much leaner than I usually run it ROP.  Oil temp was a solid 190.  OAT 22 in the climb and 17 in cruise.  On a really hot day, I am expecting to see no more than 380 on a climb and 365 in cruise.  

I couldn't be happier these numbers!  Some rough calculations don't indicate any loss of airspeed with the larger openings.  I will do a four-way test when I can though.

The next thing to do is removing the third cowl flap and see what kind of difference it makes... if any... in both speed and cooling.

The furry kids went along for the test flight
 

Edited August 20, 2018 by Guitarmaster

[Sabremech]

Can I hit the “Like” button about 6 times? Happy that we finally nailed it and can finish your cowling including paint!! 

David

[wcb]

I would like to see a before cowl, 1st cowl and cowl part duex.  Cowl part duex more pictures, maybe a better angle (I know picky picky)  What is the size difference?

 

David @Sabremech, this is size we talked about??

 

I also have to say it would look really good with the landing light moved to the wing like John Breda's @M20F-1968

Edited August 20, 2018 by wcb

[Oscar Avalle]

19 minutes ago, wcb said:

I would like to see a before cowl, 1st cowl and cowl part duex.  Cowl part duex more pictures, maybe a better angle (I know picky picky)  What is the size difference?

 

David @Sabremech, this is size we talked about??

 

I also have to say it would look really good with the landing light moved to the wing like John Breda's @M20F-1968

Yes, what is the size difference...

[Mcstealth]

Losing the cowl flap would be desirable, correct?

 

[Mcstealth]

1 hour ago, Guitarmaster said:

It's been a long and sometimes frustrating road, but today success was achieved!

As most of you that have followed this project know, there was an unacceptable increase in CHT to go along with the very acceptable 4-6kt gain in airspeed. 

We tried many things to decrease CHT, most of which was only marginally successful.  The decision was made to open the inlets to add more air and, after today's test flight, there was a solid 20 degree drop and the CHT numbers are what was being targeted!  I personally think the larger inlets look better.

Hard climb (Vx) yielded a high number of 367.  

Cruise numbers leveled out around 357.  This was achieved at 50ROP, WOT; much leaner than I usually run it ROP.  Oil temp was a solid 190.  OAT 22 in the climb and 17 in cruise.  On a really hot day, I am expecting to see no more than 380 on a climb and 365 in cruise.  

I couldn't be happier these numbers!  Some rough calculations don't indicate any loss of airspeed with the larger openings.  I will do a four-way test when I can though.

The next thing to do is removing the third cowl flap and see what kind of difference it makes... if any... in both speed and cooling.

The furry kids went along for the test flight
 

The bad guy on the first Jack Reacher movie favors you. Wait uh, you don't know me...…….

[Guitarmaster]

24 minutes ago, wcb said:

I would like to see a before cowl, 1st cowl and cowl part duex.  Cowl part duex more pictures, maybe a better angle (I know picky picky)  What is the size difference?

 

David @Sabremech, this is size we talked about??

 

I also have to say it would look really good with the landing light moved to the wing like John Breda's @M20F-1968

Not the same angle but...
Before:  

 

After:

 

They are slightly less than an inch larger in diameter.

[Bob_Belville]

1 hour ago, Guitarmaster said:

It's been a long and sometimes frustrating road, but today success was achieved!

As most of you that have followed this project know, there was an unacceptable increase in CHT to go along with the very acceptable 4-6kt gain in airspeed. 

We tried many things to decrease CHT, most of which was only marginally successful.  The decision was made to open the inlets to add more air and, after today's test flight, there was a solid 20 degree drop and the CHT numbers are what was being targeted!  I personally think the larger inlets look better.

Hard climb (Vx) yielded a high number of 367.  

Cruise numbers leveled out around 357.  This was achieved at 50ROP, WOT; much leaner than I usually run it ROP.  Oil temp was a solid 190.  OAT 22 in the climb and 17 in cruise.  On a really hot day, I am expecting to see no more than 380 on a climb and 365 in cruise.  

Matt, this is really good news! Is the 190F Oil Temp much of an improvement?

@Sabremech, I think we'll be able to ream out my cowl inlets to fit larger rings, right?

[Guitarmaster]

Yes. Less crap sticking out in the Wind.

Losing the cowl flap would be desirable, correct?
 

Sent from my XT1585 using Tapatalk

[Sabremech]

16 minutes ago, Bob_Belville said:

Matt, this is really good news! Is the 190F Oil Temp much of an improvement?

@Sabremech, I think we'll be able to ream out my cowl inlets to fit larger rings, right?

Hi Bob,

Oil temp didn’t change much if at all with the larger inlet rings. It did make an effect on the CHT’s. We can do larger rings if you’d like to. 

Thanks,

David

[Sabremech]

50 minutes ago, wcb said:

I would like to see a before cowl, 1st cowl and cowl part duex.  Cowl part duex more pictures, maybe a better angle (I know picky picky)  What is the size difference?

 

David @Sabremech, this is size we talked about??

 

I also have to say it would look really good with the landing light moved to the wing like John Breda's @M20F-1968

Yes, same size as the Gen2 cowling will be. 

Thanks,

David

[MyNameIsNobody]

I read my wife the thread and she said: “An inch can really make a nice big difference”...

Glad you got ‘r figured out.  Sell a bunch.  Looks great/faster/cooler.  Trifecta achieved.

Congratulations!

[DXB]

Great news - hope to hear soon whether there's similar cooling benefit for the carb'd birds that have a doghouse currently.  If so, I can't wait to install and have a >150kt bird!!

And I agree the larger inlets look better. 

[Bob_Belville]

43 minutes ago, Sabremech said:

Hi Bob,

Oil temp didn’t change much if at all with the larger inlet rings. It did make an effect on the CHT’s. We can do larger rings if you’d like to. 

Thanks,

David

@190F it's understandable that it might not go down since the vernatherm only closes at 185. Yeah, I think I'd like to mod mine, I removed the rings before KOSH to get a little more air in. 

[Cyril Gibb]

pedantic entry from the great white north: deux, not duex

[Hank]

1 hour ago, Bob_Belville said:

. . . . I removed the rings before KOSH to get a little more air in. 

It OK to remove youryour rings, Bob. Just don't ask Nancy to remove hers!!  

[Aviationinfo]

The cowl is nice and all that, but the inflight group picture (especially the dog’s face closest to you) is terrific!

[MyNameIsNobody]

11 hours ago, Aviationinfo said:

The cowl is nice and all that, but the inflight group picture (especially the dog’s face closest to you) is terrific!

+1 on the expressions from the backseat drivers...Awesome.

[Guitarmaster]

pedantic entry from the great white north: deux, not duex

Never was a goot spelar

Sent from my XT1585 using Tapatalk

[Mooney-Mark]

That's a great looking cowl! I like it with the larger openings as well!

[Raptor05121]

I always thought it would look better with larger openings. Looks fantastic!

[Mcstealth]

So, a 201 modded windscreen, and this Saber mod, will gain what? Total? 

[Sabremech]

1 hour ago, Mcstealth said:

So, a 201 modded windscreen, and this Saber mod, will gain what? Total? 

As I'm learning while doing the cowling mods, it's to hard to give any real speed number because each airplane is unique and performs completely different than any other of the same model. In theory, you'll gain some because of the reduced drag. 

David

[TTaylor]

2 hours ago, Mcstealth said:

So, a 201 modded windscreen, and this Saber mod, will gain what? Total? 

Best guess is about 7 to 9 knots for the two combined.  Throw in all the seals, remove or fair the step if it is fixed, and reverse the brakes or add an inner gear door and you should get close to 10 knots.

My goal has been to get our 75F to 150 knots burning 9 gph at 10,000. 

 

[carusoam]

Matching the spinner, Cowl, and windshield...

Increased everyone’s knowledge regarding the 60’s designed guppy mouth cowl.

Bettered the understanding of improvements found with simple cowl closures.

Reduced drag...

reduced air back-flow out the front of the cowl...

improved manifold air handling...

improved temperature control...

modernized airflow with oil cooler relocation... (for some)

renewed air seals that were leaky...

Streamlined airflow, both inside and out....

• Obvious streamlined exterior airflow around the cowl.
• improved downward air handling into the cylinder fins.
• updated air handling into the engine intake.
• updated air flow through the oil cooler
• added an LED landing light with a more aerodynamic lens cover in front?
• minimizes eddy currents that typically occur in front of the vertical windshield and flat, sunken light...

maximized cool factor...

Increased uniqueness...

Looks pilot perfect in red... 

 

 

These are Some things a pilot may see while reading about this fancy cowl...  

stuff one can compare to in the newer versions of a Mooney...

improvements that are available today, without spending an additional 150amu to get them.... 

 

Way to go Sabremech!

Best regards,

-a-