Engine buffling - how does it look? Need for replacement? M20F

[Yannis]

I've been experiencing high cylinders temperatures ever since I got off the plane. I've done quite a bit of reading on how critical it is to keep cylinder temperatures below 400 or 420 degrees Fahrenheit, as many suggest taking steps to remain under this threshold. My Mooney M20F tends to run hot, particularly in the summer or during climb phases. I've been attempting to adjust to improve cylinder longevity but am unsure of the best approach.

 

With plans to travel in the warmer climates of southern Europe, I'm concerned about constantly monitoring the gauges. I have taken some photos of the engine's baffling and wonder if replacing or repairing it could help. It's often recommended to ensure proper baffling for adequate engine cooling. I've noticed that some older models have an updated "doghouse" design for better efficiency.

 

I'm contemplating whether to replace the baffling to improve cylinders temperatures or the currents are sufficient. Additionally, I'm considering upgrading the old gauges to a JPI monitor to better track the engine's temperatures.

 

. What do you think?

 

Thanks

Yannis

London UK

 

 

 

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[67 m20F chump]

I picked up my precut baffle material from Guy Ginby.  Here is the picture.  I run take off to cruise full rich cowl flaps open and climb out 500fpm.  That keeps the temps in line.   If I climb at a slower speed my oil temps get high and cht.  The baffles are tight so I think this is as good as it gets.  I’m using a EI 30 P+c for engine data so I think I’m getting good numbers.

[takair]

2 hours ago, Yannis said:

 

I've been experiencing high cylinders temperatures ever since I got off the plane. I've done quite a bit of reading on how critical it is to keep cylinder temperatures below 400 or 420 degrees Fahrenheit, as many suggest taking steps to remain under this threshold. My Mooney M20F tends to run hot, particularly in the summer or during climb phases. I've been attempting to adjust to improve cylinder longevity but am unsure of the best approach.

 

With plans to travel in the warmer climates of southern Europe, I'm concerned about constantly monitoring the gauges. I have taken some photos of the engine's baffling and wonder if replacing or repairing it could help. It's often recommended to ensure proper baffling for adequate engine cooling. I've noticed that some older models have an updated "doghouse" design for better efficiency.

 

I'm contemplating whether to replace the baffling to improve cylinders temperatures or the currents are sufficient. Additionally, I'm considering upgrading the old gauges to a JPI monitor to better track the engine's temperatures.

 

. What do you think?

 

Thanks

Yannis

London UK

 

 

 

 

Take a look at the cowl itself and see how well the baffles are sealing.  You will see rub marks where there is good contact and you will see some signs of air movement where it leaks.  You seal material looks like it is rather stiff and I see some signs of leaking.  The fuel injected, guppy mouth, dog house Mooneys can easily run in the high 200s to mid 300s.  400 seems very high for these models…even with the standard baffles.

[Yannis]

Take a look at the cowl itself and see how well the baffles are sealing.  You will see rub marks where there is good contact and you will see some signs of air movement where it leaks.  You seal material looks like it is rather stiff and I see some signs of leaking.  The fuel injected, guppy mouth, dog house Mooneys can easily run in the high 200s to mid 300s.  400 seems very high for these models…even with the standard baffles.

I think I’ll have to rebuffle and full the gaps is the cheapest solution. Doghouse would be difficult to find buy and install


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[takair]

30 minutes ago, Yannis said:

I think I’ll have to rebuffle and full the gaps is the cheapest solution. Doghouse would be difficult to find buy and install


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Sorry. Did not mean to imply to add a dog house. Just find the leaks and make them go away. Looking at the cowl is a good way to determine where the baffle is sealing and where it is not. 

[Ragsf15e]

11 hours ago, Yannis said:

 

I've been experiencing high cylinders temperatures ever since I got off the plane. I've done quite a bit of reading on how critical it is to keep cylinder temperatures below 400 or 420 degrees Fahrenheit, as many suggest taking steps to remain under this threshold. My Mooney M20F tends to run hot, particularly in the summer or during climb phases. I've been attempting to adjust to improve cylinder longevity but am unsure of the best approach.

 

With plans to travel in the warmer climates of southern Europe, I'm concerned about constantly monitoring the gauges. I have taken some photos of the engine's baffling and wonder if replacing or repairing it could help. It's often recommended to ensure proper baffling for adequate engine cooling. I've noticed that some older models have an updated "doghouse" design for better efficiency.

 

I'm contemplating whether to replace the baffling to improve cylinders temperatures or the currents are sufficient. Additionally, I'm considering upgrading the old gauges to a JPI monitor to better track the engine's temperatures.

 

. What do you think?

 

Thanks

Yannis

London UK

 

 

 

Sent from my iPhone using Tapatalk

 

Put the cowl on. Put a flashlight in the oil cooler door.  Look into the “guppy mouth”.  Anywhere you see light is a leak.  Your aft baffles look very leaky.  Also look around the alternator in the lower front.

Finally, cruise climb at 120mph for best cooling.

[Shadrach]

Lots of great advice above. The aluminum on the underside of my cowl is polished from the baffle seal material rubbing. My baffle seals are springy enough that they stick up and need to be “dressed” in the proper direction when installing the cowl. Yours don’t look springy they look like they’ve taken a set and are not flexible.  

[Igor_U]

Yannis,

you got some good advice above. I would add a few things...

First, M20F does not have an old style doghouse but baffles with seals similar to M20J. In 19 years of ownership I never had big issues with high cylinder temps. Very rarely would I have CHTs over 400F and that only on very hot days with long climb and slow to escape the turbulence out west. Normally my engine runs very cool and since I replaced with the factory rebuilt, I sometimes don't get 300F on CHT1. I'm talking PNW winters (not to cold) while at standard air temps my CHTs are 300-340F Climbs, <370-380F.

I do have the new baffle seals from GeeBee (Guy) which I believe would help you a lot seeing yours are fairly old and not springy, as Ross put it. The seals I received are not ideal, if you look at the Aft Right corners, where two seals meet, it creates the gap when upper cowl is installed but still i can't complain about the temps. i think the kit would help you specially as your seals are few piece on sides and aft with gaps where the air would escape and not cool the cylinders.  

One more thing I'd point is that on the old engine I had PRC sealant applied at the edge of the baffle to the Cylinder and engine. I think this helped in the past with CHTs but on the new engine I didn't bother as I don't think i need it. Good luck.

 

 

[Bartman]

Your baffle seals look great, just mine that I ordered from Guy, but that wingtip looks precariously close to the wall. 

[Shadrach]

2 hours ago, Igor_U said:

Yannis,

you got some good advice above. I would add a few things...

First, M20F does not have an old style doghouse but baffles with seals similar to M20J. In 19 years of ownership I never had big issues with high cylinder temps. Very rarely would I have CHTs over 400F and that only on very hot days with long climb and slow to escape the turbulence out west. Normally my engine runs very cool and since I replaced with the factory rebuilt, I sometimes don't get 300F on CHT1. I'm talking PNW winters (not to cold) while at standard air temps my CHTs are 300-340F Climbs, <370-380F.

I do have the new baffle seals from GeeBee (Guy) which I believe would help you a lot seeing yours are fairly old and not springy, as Ross put it. The seals I received are not ideal, if you look at the Aft Right corners, where two seals meet, it creates the gap when upper cowl is installed but still i can't complain about the temps. i think the kit would help you specially as your seals are few piece on sides and aft with gaps where the air would escape and not cool the cylinders.  

One more thing I'd point is that on the old engine I had PRC sealant applied at the edge of the baffle to the Cylinder and engine. I think this helped in the past with CHTs but on the new engine I didn't bother as I don't think i need it. Good luck.

 

 

This is how baffle seals should look. My corners are not connected so they overlap but are not fastened together so when they fold down they don’t ribbon but lay flush (more or less) against the top of the cowl. My temps are also a quite cool high 200s to low 300s in cruise and mid to low 300s in climb depending on OAT. What’s up with the extra plumbing to the flow divider? I have a 67F but it does not have a second fuel supply hose coming through the baffle wall. Also, what brand of ignition harness is that?

[Igor_U]

11 hours ago, Shadrach said:

This is how baffle seals should look. My corners are not connected so they overlap but are not fastened together so when they fold down they don’t ribbon but lay flush (more or less) against the top of the cowl. My temps are also a quite cool high 200s to low 300s in cruise and mid to low 300s in climb depending on OAT. What’s up with the extra plumbing to the flow divider? I have a 67F but it does not have a second fuel supply hose coming through the baffle wall. Also, what brand of ignition harness is that?

Ross,

very good catch! This was taken during the engine install 2 years ago and at the time we thought this was the way to plumb it to the Fuel pressure sensor (Lycoming didn't provide the hose for that) as we initially thought the new fuel servo didn't have a port got that. Obviously, we corrected that...

You are right about the corners and that is how I ended up on LHS. Guy's precut seal kit, however has a Aft Right seal too short and doesn't reach to the edge (1.5-2" short) so I have the right side seal attached to it. Not ideal, the best would be to get a roll of the silicone and make a new one, longer... I did mention this to Guy but I don't think he'll make a new die for that seal.

No idea on the harness, it came with factory engine and unfortunately, Champion spark plugs but all is good and still looking new. If someone knows, it would be skip who also recently got the factory engine.

Cheers,

[Igor_U]

12 hours ago, Bartman said:

Your baffle seals look great, just mine that I ordered from Guy, but that wingtip looks precariously close to the wall. 

Well,

it is close but it's really looking closer then it is from the angle. I always position the plane closer to the left wall to allow better access to the RHS of the plane where I have sofa, work surface, old desk and such... And I use an old riding mower to push the plane up the incline and over the door rail.

 

 

[Shadrach]

18 minutes ago, Igor_U said:

Ross,

very good catch! This was taken during the engine install 2 years ago and at the time we thought this was the way to plumb it to the Fuel pressure sensor (Lycoming didn't provide the hose for that) as we initially thought the new fuel servo didn't have a port got that. Obviously, we corrected that...

You are right about the corners and that is how I ended up on LHS. Guy's precut seal kit, however has a Aft Right seal too short and doesn't reach to the edge (1.5-2" short) so I have the right side seal attached to it. Not ideal, the best would be to get a roll of the silicone and make a new one, longer... I did mention this to Guy but I don't think he'll make a new die for that seal.

No idea on the harness, it came with factory engine and unfortunately, Champion spark plugs but all is good and still looking new. If someone knows, it would be skip who also recently got the factory engine.

Cheers,

If you look at it with the cowl on, you will see if it lays flush. If there’s an area where it’s bulging, you can put a notch in it. There are several notches in my rear seal to facilitate a flush fit with the cowl in place.

[Yannis]

Yannis,
you got some good advice above. I would add a few things...
First, M20F does not have an old style doghouse but baffles with seals similar to M20J. In 19 years of ownership I never had big issues with high cylinder temps. Very rarely would I have CHTs over 400F and that only on very hot days with long climb and slow to escape the turbulence out west. Normally my engine runs very cool and since I replaced with the factory rebuilt, I sometimes don't get 300F on CHT1. I'm talking PNW winters (not to cold) while at standard air temps my CHTs are 300-340F Climbs, I do have the new baffle seals from GeeBee (Guy) which I believe would help you a lot seeing yours are fairly old and not springy, as Ross put it. The seals I received are not ideal, if you look at the Aft Right corners, where two seals meet, it creates the gap when upper cowl is installed but still i can't complain about the temps. i think the kit would help you specially as your seals are few piece on sides and aft with gaps where the air would escape and not cool the cylinders.  
One more thing I'd point is that on the old engine I had PRC sealant applied at the edge of the baffle to the Cylinder and engine. I think this helped in the past with CHTs but on the new engine I didn't bother as I don't think i need it. Good luck.
 
 

This definitely looks better in mine. Would it be possible to share how I can contact GeeBee Guy, is there a website? I will buy the same kit as you and I'll share the photos when it's ready. I think new baffle like yours will make a difference.


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[Fly Boomer]

3 hours ago, Yannis said:

This definitely looks better in mine. Would it be possible to share how I can contact GeeBee Guy, is there a website? I will buy the same kit as you and I'll share the photos when it's ready. I think new baffle like yours will make a difference.


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Guy Ginby hangs out on BeechTalk.  Here is the contact info I have -- no guarantees regarding accuracy:

800-556-3160
N77GB@msn.com
https://www.csobeech.com/GeeBee.html
MooneySpace handle is @Gee Bee Aeroproducts

[Yannis]

Thank you!

2 hours ago, Fly Boomer said:

Guy Ginby hangs out on BeechTalk.  Here is the contact info I have -- no guarantees regarding accuracy:

800-556-3160
N77GB@msn.com
https://www.csobeech.com/GeeBee.html
MooneySpace handle is @Gee Bee Aeroproducts

 

[Hector]

I have a 67 F that I purchased just a couple months ago. It has a JPI900 and my temps are in the upper 200’s or low 300’s in flight here in Florida. I’ve actually been worried about CYL temps too low. My previous plane was a C model with a dog house and that plane ran hot on climb, usually over 400 for a bit so I would have to switch to 120mph cruse climb immediately. My F gets to maybe 350 climbing Vy.


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[Yannis]

On 3/3/2024 at 4:10 AM, Hector said:

I have a 67 F that I purchased just a couple months ago. It has a JPI900 and my temps are in the upper 200’s or low 300’s in flight here in Florida. I’ve actually been worried about CYL temps too low. My previous plane was a C model with a dog house and that plane ran hot on climb, usually over 400 for a bit so I would have to switch to 120mph cruse climb immediately. My F gets to maybe 350 climbing Vy.


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I would think that too low for Florida but then again that is a good thing you dont have high temps. I am not sure if I should trust the engine temps readings as I still have the original analog ones. 

[Shadrach]

1 hour ago, Yannis said:

I would think that too low for Florida but then again that is a good thing you dont have high temps. I am not sure if I should trust the engine temps readings as I still have the original analog ones. 

Sounds very plausible to me...Especially if his ignition timing has be retarded from 25° to 20° as have so many of the IO360A1As. 

[StevenL757]

On 2/28/2024 at 6:44 PM, Ragsf15e said:

Put the cowl on. Put a flashlight in the oil cooler door.  Look into the “guppy mouth”.  Anywhere you see light is a leak.  Your aft baffles look very leaky.  Also look around the alternator in the lower front.

This…

[StevenL757]

On 3/1/2024 at 8:42 AM, Yannis said:

Thank you!

Tagging him here…

@Gee Bee Aeroproducts