What are your average CHT/EGTs for your IO-360-A1A

[AerostarDriver]

I am trying to trouble shoot a problem with my E model and I need help fleshing out some data to compare to. I believe my engine is far too rich at the "full rich" mixture setting, so rich that it is flooding the engine when I bring the power back to idle on approach and landing. In order to help me determine if I am chasing down the right thread on this issue I am looking for effectively 3 sets of numbers.

• CHT/EGT in takeoff climb with temp and/or DA
• CHT/EGT in cruise with Power setting an Altitude
• CHT/EGT on approach something like 10-16 inches MP

 

My number are as follows:

In climb, at peak temperature at 500 feet AGL (84 MPH) the reading I took was 325/1290 at 76F OAT with a 2600 DA
Cruise, 24/24, cowl flaps closed at 3500 with an OAT of 74, 335/1360 100 Degrees ROP
Approach, 16MP, 288/1210

I will admit that this may be the completely wrong way to approach my present issue. However, I am finding that after any minor amount of time spent at mixture full rich yields in fowled plugs or the new outcome I discovered today, the engine simply quitting short final. Was able to restart on the taxiway with a flooded engine and fowled plugs.

[takair]

If it’s rich at idle have you checked the idle mixture?  At 1000 rpm, slowly pull the mixture to idle cutoff and note the rpm rise.  0-25 is about right.  50 works, more than 50 and mixture needs to be set.

[AerostarDriver]

1 minute ago, takair said:

If it’s rich at idle have you checked the idle mixture?  At 1000 rpm, slowly pull the mixture to idle cutoff and note the rpm rise.  0-25 is about right.  50 works, more than 50 and mixture needs to be set.

I will test that as I have not done that exact procedure. However, from 1000 RPM I have a 85 RPM increase as I lean to taxi after start.

[takair]

8 minutes ago, AerostarDriver said:

I will test that as I have not done that exact procedure. However, from 1000 RPM I have a 85 RPM increase as I lean to taxi after start.

Ahh, your idle mixture is too rich.  It is the only field adjustment on these injectors, but could correct your problem.

[Guest]

7 hours ago, AerostarDriver said:

I will test that as I have not done that exact procedure. However, from 1000 RPM I have a 85 RPM increase as I lean to taxi after start.

There’s a second adjustment you’ll have to make/check.  Adjusting the idle mixture will change your idle speed, leaning the mixture will increase the idle RPM, which will need to be lowered.

Both adjustments are on the right side of the fuel servo, idle mixture is a spring locked thumb wheel, idle speed is a screw.

Clarence

[Ragsf15e]

Do what the above two guys said.

Your takeoff and cruise cht/egts are pretty close to mine (within about 20 degrees cht and 30-50 degrees egt).

[Guest]

This might help

[carusoam]

18 hours ago, AerostarDriver said:

I am trying to trouble shoot a problem with my E model

• Fowled plugs
• Engine quits under low power

Other things to consider...  or include...

Do you have any FF info to go with that?

Often people will mention their FF they get while taxiing with the throttle closed...  and the weather and altitude at the time...

You will probably get a set of start-up FF and a typical FF once leaned for your home drome...

Did you get any loud pops? From fuel burning in the exhaust pipe..?

Best regards,

-a-

[AerostarDriver]

5 hours ago, carusoam said:

• Fowled plugs
• Engine quits under low power

Other things to consider...  or include...

Do you have any FF info to go with that?

Often people will mention their FF they get while taxiing with the throttle closed...  and the weather and altitude at the time...

You will probably get a set of start-up FF and a typical FF once leaned for your home drome...

Did you get any loud pops? From fuel burning in the exhaust pipe..?

Best regards,

-a-

Still working on my K factor on my JPI 700 but a corrected number I have is 2.7 G/H at 1000RPM. 

No loud pops on approach or at idle. 

 

Pre-mooney, I have a ton of experience flying a number of Arrow IIIs(effectively same firewall forward) which would regularly pop and bang when the power was pulled back on approach.

Edited June 7, 2021 by AerostarDriver

[Shadrach]

9 minutes ago, AerostarDriver said:

Still working on my K factor on my JPI 700 but a corrected number I have is 2.7 G/H at 1000RPM. 

No loud pops on approach or at idle. Pre-mooney, I have a ton of experience flying a number of Arrow IIIs(effectively same firewall forward) which would regularly pop and bang when the power was pulled back on approach.

Pop and bang on approach is often caused by an intake leak. 

[Shadrach]

My CHT’s can vary from cylinder to cylinder by as much as 45° Depending on power setting, indicated airspeed and flight conditions. It appears that you have data for a single cylinder. There is not a lot of information to be had here. Assuming your probe is the bayonet style and tapped into cyl #3, i’d say your CHT looks pretty normal. Especially given that you’re climbing below Vx for max gross for some reason.  Do the idle cut off mixture test on the ground as others have mentioned but do keep in mind that this has nothing to do with full rich fuel flow in climb. Wouldn’t be a bad idea to note your idle rpm on the ground with the throttle closed.

[AerostarDriver]

34 minutes ago, Shadrach said:

My CHT’s can vary from cylinder to cylinder by as much as 45° Depending on power setting, indicated airspeed and flight conditions. It appears that you have data for a single cylinder. There is not a lot of information to be had here. Assuming your probe is the bayonet style and tapped into cyl #3, i’d say your CHT looks pretty normal. Especially given that you’re climbing below Vx for max gross for some reason.  Do the idle cut off mixture test on the ground as others have mentioned but do keep in mind that this has nothing to do with full rich fuel flow in climb. Wouldn’t be a bad idea to note your idle rpm on the ground with the throttle closed.

I have 4 EGTs and CHTs, I am just giving the average temps, my split is normally never more then 30° on the CHTs with no more then a 40° split between the EGTs. 84 is a typo, 94 MPH is my Vx climb out to 500 feet and that normally is not at max gross. I end up seeing better climb rates at Vx then Vy when I am light.

Edited June 7, 2021 by AerostarDriver

[Shadrach]

2 minutes ago, AerostarDriver said:

I have 4 EGTs and CHTs, I am just giving the average temps, my split is normally never more then 30° on the CHTs with no more then a 40° split between the EGTs. 84 is a typo, 94 MPH is my Vx climb out to 500 feet and that normally is not at max gross. I end up seeing better climb rates at Vx then Vy when I am light.

Subtract 1kt from book Vy for every 100lbs under gross. It’s not exact but it’s close enough.

[AerostarDriver]

Just now, Shadrach said:

Subtract 1kt from book Vy for every 100lbs under gross. It’s not exact but it’s close enough.

Good too know! Thank!

[Shadrach]

50 minutes ago, AerostarDriver said:

Good too know! Thank!

I’ll also add that in 15 years of flying my F I have found that 120MIAS offers the best blend of cooling, visibility, climb and surplus airspeed. It works well enough at any weight but the airplane must be cleaned up.

[Vance Harral]

Note: unfortunately you can't compare your EGTs with others' EGTs.  The EGT value "reported" by a thermocouple probe is highly dependent on the exact placement of the probes in the exhaust pipe, and that varies from airplane to airplane.  It depends to a lesser extent on other factors that also vary between individual airplanes, and to an even lesser extent on variations in atmospheric conditions.  Nobody worries about standardizing this, because the only utility of EGT is in understanding relative change from peak EGT.  So while I understand your reason for asking about EGT values, it's just not going to be useful information.  Focus on the other good advice you're getting here.

[M20F]

8 hours ago, Shadrach said:

I’ll also add that in 15 years of flying my F I have found that 120MIAS offers the best blend of cooling, visibility, climb and surplus airspeed. It works well enough at any weight but the airplane must be cleaned up.

Would second this. 

[JamesMooney]

This is really helpful. I’ve been suspicious my idle mixture is too rich. When I lean on the ground I see a 100 RPM increase. 
 

On a recent flight at 85F and DA 3,300 ground, the engine wanted to quit with the mixture anywhere forward of half rich and below 1300 RPM.
 

I’m fairly sure this was sign of an excessively rich idle mixture. 

 

regarding CHTs and EGTs I was running the engine hard (breaking in after an IRAN)… at WOT 24” and 2500 RPM, and 5,000 feet indicated, I was getting around 340 CHT and 1250-1300 EGT (average across all 4 cyl). Sounds consistent with the OP, given I was running closer to 80-82% power. (Note, I think my cowl flaps have a bit of leak when closed… noticed on the ground and by the not-very-hot CHTs…)

[Marauder]

I am trying to trouble shoot a problem with my E model and I need help fleshing out some data to compare to. I believe my engine is far too rich at the "full rich" mixture setting, so rich that it is flooding the engine when I bring the power back to idle on approach and landing. In order to help me determine if I am chasing down the right thread on this issue I am looking for effectively 3 sets of numbers.

• CHT/EGT in takeoff climb with temp and/or DA
• CHT/EGT in cruise with Power setting an Altitude
• CHT/EGT on approach something like 10-16 inches MP

 
My number are as follows:
In climb, at peak temperature at 500 feet AGL (84 MPH) the reading I took was 325/1290 at 76F OAT with a 2600 DA
Cruise, 24/24, cowl flaps closed at 3500 with an OAT of 74, 335/1360 100 Degrees ROP
Approach, 16MP, 288/1210
I will admit that this may be the completely wrong way to approach my present issue. However, I am finding that after any minor amount of time spent at mixture full rich yields in fowled plugs or the new outcome I discovered today, the engine simply quitting short final. Was able to restart on the taxiway with a flooded engine and fowled plugs.

Your temps are in line with what I have seen in the 30 years flying behind my IO-360. As Rob & the good doctor mentioned (and from your observations of RPM increase at idle), I suspect it is rich.

Your CHTs in flight can vary based on the condition of your baffles and other factors.




Sent from my iPad using Tapatalk Pro

[carusoam]

Idle is very sensitive to mixture...

Probably why it has its own mixture setting control...

If you leave the mixture at a cruise setting and don’t use the GUMPS...  the engine will probably croak as you slow in the flare...

PP thoughts only, not a CFI...

Best regards,

-a-

[AerostarDriver]

Thank you all for your help and advice. Finally made it back to my plane with my A&P. We initially could not replicate the failure, however, we did follow the advice of checking the idle mixture which was rich but not excessively rich. Only partially satisficed, we taxied out to the runway, I did my run up and twice the engine quit on runup. Taxied back to the ramp and the engine would not idle below 1200 RPM with out aggressive leaning. We allowed the engine to cool down and we no longer could get the engine quitting on runup until about 8-12 minutes of running.

Has anyone seen or experienced something like this before? We are now leaning towards fuel boiling in the lines some where, with how quickly the engine would quit we are leaning towards an issue with the flow divider or fuel boiling in the flow divider. From what we can see, there are no fuel leaks and no issues at high power settings.

[takair]

26 minutes ago, AerostarDriver said:

Thank you all for your help and advice. Finally made it back to my plane with my A&P. We initially could not replicate the failure, however, we did follow the advice of checking the idle mixture which was rich but not excessively rich. Only partially satisficed, we taxied out to the runway, I did my run up and twice the engine quit on runup. Taxied back to the ramp and the engine would not idle below 1200 RPM with out aggressive leaning. We allowed the engine to cool down and we no longer could get the engine quitting on runup until about 8-12 minutes of running.

Has anyone seen or experienced something like this before? We are now leaning towards fuel boiling in the lines some where, with how quickly the engine would quit we are leaning towards an issue with the flow divider or fuel boiling in the flow divider. From what we can see, there are no fuel leaks and no issues at high power settings.

It sounds like your servo may have an internal problem.  That is not normal.  I had a temperature related issue years ago and a diaphragm had failed.  I now see a slight difference between cold and warm, but mine is slightly rich on start up, but it settles within a minute.

[carusoam]

Fuel boiling in the lines can cause that…

But, fuel boiling in the lines while the engine is running… takes some investigating…

More of a Hot start issue, than a normal running isssue…

Time to hunt down fuel system issues…

PP thoughts only, not a mechanic…

Best regards,

-a-