Cruise/Climb CHTs TSIO360-GB

[Jtabone]

Is there a number or range to keep cht in during cruise and climb? I can typically see 410 on climbout and always limit to 385 in cruise. I only see this on one or two cylinders but sometimes it’s an exercise in cowl flaps open/closed during cruise. I understand the heat issues with the gb so I’m trying to monitor carefully. The POH says 460 but what I have heard is that’s to high. So question is what is a max value on climbout vs Cruise I should be monitoring. Any ideas or suggestions would be great. Thanks

[carusoam]

The metal strength is variable with temperature...

It doesn’t know that the plane is climbing or in cruise...

But, there is only so much a pilot’s wallet can bare...

Deciding on new cylinders vs. FF is a fare discussion...

CHTs kept below 380°F is good guidance.

How low can you keep the CHTs during the climb?

There are a few techniques of producing max power and keeping CHTs cool-ish... Some EGT gauges have a blue box printed on them in the 200°F ROP range...

How far ROP are you climbing?

PP thoughts only, not an engine expert...

Best regards,

-a-

[flyboy0681]

The moment the alarm starts flashing at 390 I get to work cooling them down.

[Jtabone]

I can keep all but one or so under 400 in climb at 36” MP and decrease my pitch angle to cool them under again. So I’m wondering if I need to always keep them under 390 of if a short term climb a little over 400 is ok as a temporary condition? If I keep at 390 the nose is pretty low and I’m not getting a great rate of climb. I am full rich at takeoff. 

[carusoam]

  On 8/18/2019 at 9:37 PM, Jtabone said:

I can keep all but one or so under 400 in climb at 36” MP and decrease my pitch angle to cool them under again. So I’m wondering if I need to always keep them under 390 of if a short term climb a little over 400 is ok as a temporary condition? If I keep at 390 the nose is pretty low and I’m not getting a great rate of climb. I am full rich at takeoff. 

Expand  

When you say ‘need to’ ...

You have entered the area of science based limitations... aka red lines on the instruments...

red lines are ‘have to’ type limitations...

In conversations around here regarding CHTs there are ‘want to(s)’

Now You have bumped into a personal limitation Vertical speed vs CHTs...

Anywhere bellow red line is OK to operate... closer to 380 is best for tribology... closer to red line is worse...

Sooner or later you have to make a choice to fly the plane, and not be paying attention to every wear item the plane has...

Worst case, a set of cylinders wears out at a higher rate... Best case, the set of cylinders lasts to TBO...

The advantage of MS... you can see how other people are operating their plane and form some expectations regarding life time of certain wear items...  yet there are so many variables... there is no guarantee of getting the same results...

Makes sense?

expect two extremes...

1) Pilot tries to baby the plane to keep it from wearing out... flights are scheduled every four days... climb rate never exceed 200fpm... writes a book about climbing LOP in a GA plane...

2) Pilot has a few AMUs extra and wants to fly as fast as possible whenever the desire arises.... Knows what fire breathing dragon mode is.... and enjoys using it...

Both operate within the confines of the POH...

 

PP thoughts only not a mechanic...

Best regards,

-a-

[Jtabone]

Perfect, yes that makes a lot of sense, only had the plane (first plane owned) for a year and 160 hours, but trying to do my best to make sure I’m operating for longevity as much as I can control. 

[gsxrpilot]

A few tips:

• Keep the cowl flaps open
• Full rich
• Lower the RPM to 2550 or 2500
• Lower the nose to increase speed

Back on the ground, in the shop...

• Get the baffles checked for proper function and sealing

[carusoam]

See if you can find the existing threads around here that have been going on for years...

Find another person that shares the same goals you have... compare to the ones that are operating in fire breathing dragon mode...

Take notes... the answers to questions that you haven’t thought of yet will be plentiful... 

 

Have you considered adding details like manifold pressure controller type, or intercooler to your avatar details..?

What TIT limits you are using... how you lean...

Have you been to a MAPA PPP event..?

 

Back when you purchased your plane, did you have some transition training TT, by somebody that really knows your plane?

After a year of getting to know your plane... it might be time to get a refresher...  MAPA PPP is perfect for that.

Or a flight or two with a Mooney specific flight instructor would be greatly helpful...

Or attending a Mooney Fly-in can be enlightening...

Best regards,

-a-