Higher CHT with normal EGT?

[rbp]

This is a flight from Monday, at 29"/2400RPM, 7500MSL.  In order to keep the CHTs no higher than 400, I either have to lower the TIT from 1550 to 1520, or put the cowl flaps in the center (trailing) position.  My son thinks it might be related to either baffles or injectors. He suggested new baffling and GAMIs. Any other insights? 

[PhateX1337]

That does seem like high CHTs relative to your fuel flow, at least compared to my Bravo. For context, in recent warmer weather flying (OAT 75F or so at cruise), at 29"/2400 I was at about 17.5gph, TIT just under 1600 (usually shoot for 1580 or so) and hottest CHT was 347-350. Cowl flaps fully closed.

I spent the time and money to get the GB silicone baffles installed and get turbo GAMIs installed and tuned, and it's made a world of difference. Temps are rarely an issue (other than TIT...which of course always has to be monitored).

[rbp]

9 minutes ago, PhateX1337 said:

That does seem like high CHTs relative to your fuel flow, at least compared to my Bravo. For context, in recent warmer weather flying (OAT 75F or so at cruise), at 29"/2400 I was at about 17.5gph, TIT just under 1600 (usually shoot for 1580 or so) and hottest CHT was 347-350. Cowl flaps fully closed.

I spent the time and money to get the GB silicone baffles installed and get turbo GAMIs installed and tuned, and it's made a world of difference. Temps are rarely an issue (other than TIT...which of course always has to be monitored).

Have you tried to run LOP with the GAMIs?

I'm gonna run the GAMI lean check and maybe have baffles and new injectors installed at the annual in the fall

[PhateX1337]

6 hours ago, rbp said:

Have you tried to run LOP with the GAMIs?

I'm gonna run the GAMI lean check and maybe have baffles and new injectors installed at the annual in the fall

I have tried - I also installed Tempest Fine Wire plugs at the same time. CHT is no issue. I can’t seem to get TIT under about 1615-1620 though while running LOP, even if I drop RPMs down to 2200. I still have a lot more experimenting to do, would love to get LOP working but also recognize it’s hard with the 540. Was debating getting a surefire mag eventually as well…but want to play with the current setup a lot more first.

[LANCECASPER]

10 hours ago, rbp said:

This is a flight from Monday, at 29"/2400RPM, 7500MSL.  In order to keep the CHTs no higher than 400, I either have to lower the TIT from 1550 to 1520, or put the cowl flaps in the center (trailing) position.  My son thinks it might be related to either baffles or injectors. He suggested new baffling and GAMIs. Any other insights? 

Baffle seals for sure.

I tried GAMIs on a couple of the Bravos I owned and never could get it to run lean of peak smoothly.

The baffles helped greatly in the cooling. Fine wire plugs helped it run much more smoothly.

[Rick Junkin]

The 14th post on page three of this thread has the details of my Bravo running LOP. It can be done.

EDIT: Adding relevance to @rbp‘s original post - I had some uneven and higher CHTs and repaired some small tears in my otherwise intact and still flexible baffle seals. You can see in the data above the CHTs are all now within ~10 degrees of each other in cruise and in the low 300s with the cowl flaps fully closed. #5 has a ring thermocouple that reads 40 degrees cooler than the rest on the JPI but is right in line with the others reading from the OEM gauge and OEM bayonet thermocouple.

Cheers,
Rick

Edited May 18, 2023 by Rick Junkin
Added relevance to original post

[rbp]

@Rick Junkin @LANCECASPER @PhateX1337
 

thank you for your valuable responses. I spoke with my A&P last night and he agrees that this is likely a baffle issue, not injectors. However, I am also going to do the Savvy "lean check" procedure.

[LANCECASPER]

Just now, rbp said:

@Rick Junkin @LANCECASPER @PhateX1337
 

thank you for your valuable responses. I spoke with my A&P last night and he agrees that this is likely a baffle issue, not injectors. However, I am also going to do the Savvy "lean check" procedure.

The Gee Bee seals are worth it. If you still have the factory seals, they get "lazy" and flop back allowing the air to escape out the back rather than being forced down over the cooling fins. If you start at the left front and replace it piece by piece it's not a difficult job. My CHTs went down 20 degrees with new seals and mine weren't all that bad.

[rbp]

In searching for the Gee Bee seals, I came upon this: "Information received during a FAA suspected unapproved parts investigation revealed that since 1995, GEE- BEE, 16 Flying F Dr., Palm Springs, CA 92263, had produced silicone baffle seals and landing gear door seal kits for installation on type-certificated aircraft. GEE-BEE does not hold any FAA production approval to produce the seals." https://www.faa.gov/aircraft/safety/programs/sups/upn/media/98-071r.pdf

and "The U.S. Department of Transportation’s Federal Aviation Administration (FAA) proposes a $203,100 civil penalty against GEE-BEE Aeroproducts of Palm Desert, Calif., related to the alleged manufacturing, advertising and installation of unapproved parts" https://www.faa.gov/newsroom/faa-proposes-203100-civil-penalty-against-gee-bee-aeroproducts

[Niko182]

+1 for gee bee. I saw that comment when I looked him up, but at the end of the day my CHT's dropped like 25 to 40 degrees. The only time I've seen anything over 400 in the last couple years except for 1 time taking off out of palm springs with an OAT of 116 degrees.

[LANCECASPER]

21 hours ago, rbp said:

In searching for the Gee Bee seals, I came upon this: "Information received during a FAA suspected unapproved parts investigation revealed that since 1995, GEE- BEE, 16 Flying F Dr., Palm Springs, CA 92263, had produced silicone baffle seals and landing gear door seal kits for installation on type-certificated aircraft. GEE-BEE does not hold any FAA production approval to produce the seals." https://www.faa.gov/aircraft/safety/programs/sups/upn/media/98-071r.pdf

and "The U.S. Department of Transportation’s Federal Aviation Administration (FAA) proposes a $203,100 civil penalty against GEE-BEE Aeroproducts of Palm Desert, Calif., related to the alleged manufacturing, advertising and installation of unapproved parts" https://www.faa.gov/newsroom/faa-proposes-203100-civil-penalty-against-gee-bee-aeroproducts

Old news. That's 28 years ago. If you do a search on here you'll see that was mentioned many moons ago. If you're interested in lowering your CHTs the seals he makes do the best job and since they are die-cut and match perfectly, you'll save a lot of labor.

[Fly Boomer]

2 hours ago, LANCECASPER said:

Old news. That's 28 years ago. If you do a search on here you'll see that was mentioned many moons ago. If you're interested in lowering your CHTs the seals he makes do the best job and since they are die-cut and match perfectly, you'll save a lot of labor.

So, do baffle seals even require any sort of certification or authorization.  Sounds like a standard part.

[rbp]

4 hours ago, LANCECASPER said:

That's 28 years ago

The second article is from Friday, June 7, 2019.

in any event, my A&P suggested them , so if he is OK to install them then so am I 

FWIW, they are $675 + ~$20 shipping, and come in black, red, blue, and with white, and with black or silver rivets to match your ....

[PilotX]

On 5/17/2023 at 8:28 AM, rbp said:

This is a flight from Monday, at 29"/2400RPM, 7500MSL.  In order to keep the CHTs no higher than 400, I either have to lower the TIT from 1550 to 1520, or put the cowl flaps in the center (trailing) position.  My son thinks it might be related to either baffles or injectors. He suggested new baffling and GAMIs. Any other insights? 

 

Going to see if I can extract my engine monitoring data. Haven't done it since the G3X install but the engine module is the same going from GI275 to G3X. Still annoyed by #1 being hotter than the rest by generally 15-20 deg. OATs were between 46-51 at 115-120. I did this same run back, seemingly many years ago in my R182 (5.0 ~50gal) vs Miss Daisy (3.8 ~55gal). There was an Ovation ahead of me that was 20 knots slower so he agreed to speed up and I pulled some power so we could get good spacing. I was running 24"/2200, 14.5gph LOP.

[affricate]

On 5/18/2023 at 7:13 AM, Niko182 said:

+1 for gee bee. I saw that comment when I looked him up, but at the end of the day my CHT's dropped like 25 to 40 degrees. The only time I've seen anything over 400 in the last couple years except for 1 time taking off out of palm springs with an OAT of 116 degrees.

That's my norm right there. I'm in Tucson. I have to climb to altitude slowly to avoid anything over 400.