Antonio wrote:
Even if the extra 3" will not cause damage,they will indeed cause higher temps.
Of course. But it is still better than an overboost over certified limits. If the engine can take 38 inches, then the values at least there are in the ballpark.
BTW, it is placido whose plane we are talking about, not mine, even tough they are parked side by side 
Wow, I am impressed by Paul’s knowledge!
The possibility of incorrect probe reading is a great thing to learn.
I respectfully insist that placido should look at exhaust gas temperature and TIT before and after the overhaul. One easy thing to exclude
Guys, thanks for the valuable input.
The probes have not been changed post overhaul. They are the same as before and drive a G2 engine monitor. My TIT looks good. In cruise once I set power to what I used to before the overhaul and lean to my usual ff I get the same TIT readings as before. In cruise my temps are about 15 degrees hotter than before but I attribute this to the new cylinders. I climb at about 120 kts also and for break in we use normal oil as turbo engines are not broken in with mineral oil.
I have about 35 hrs since overhaul.
What I have noticed also is that the back plate that goes around the engine where the baffles are attached at the top has about half a finger wide space where it contours the engine. Should this have been siliconed?
Turbo Trinis are flown WOT to the desired altitude. I can‘t climb out without all cylinders moving solidly into yellow, which means around 450 degrees. 2 or 3 times I have seen the gauge turn red at 470 degrees just momentarily. To keep temps between 420 and 440 I need to reduce VS to about 500 ft/min.
I can‘t see any exhaust residues anywhere so it should be tight. I just hope I have not already compromised my cylinders.
I will try to get my density controller set correctly and will then check my temps again hoping this will have fixed the issue.
@Urs
Did you spot my pitot cover still being on? In almost 30 years of flying this happened the first time to me? And I was with a flight instructor.
I make all my mistakes with an FI
Normally, with the usual thermocouple sensors, if they all read the ambient when in the hangar, they are unlikely to be over-reading at some higher temp. But it is possible (due to the way thermocouples, and thermocouple instruments, work) so I suggest pulling one of the CHT probes out of the cylinder and putting it in hot water of a known temp.
What tends to happen more often is that CHT probes get located incorrectly. I used to know a pilot of a heavy twin who burnt literally tons of extra avgas (due to flying incorrectly ROP) due to this mistake, discovered after years.
I tend to exclude the probes as they show correctly when in cruise flight where I can set the correct engine operating settings in terms of MP and and FF.
It is at take-öff where I cannot add additional fuel to the excess boost that is being generated. So the suspicion that I am running too lean at high power could be the reason for overheating.
placido wrote:
Turbo Trinis are flown WOT to the desired altitude
Antonio wrote:
If the former, I would definitely adjust the max MP
My mistake: I actually meant the latter. I would adjust MP down to nominal and yes I would RTV the space at the back between engine and baffle too (assuming you are talking the case and not the cylinders!) .
Once you have the correct MP, then you have a good reference for FF. Still your current FF number (apparently higher than nominal, even if the latter is for a lower MP) is obviously not far off. Do you know if your FF is accurate? Do you have onboard a calibrated fuel totaliser (ie one that matches with your fuelling records) that also matches your FF indication? If you use for FF a pressure-based indicator, then a leak in the UDP air line to the FF could erroneously lead you to believe you have a higher FF than actual at high power.
In any case in my experience you will typically get higher CHT with new cyls on Lycos. Not so con Contis. I do not know why.
Baffle seals make a big difference.
placido wrote:
Did you spot my pitot cover still being on? In almost 30 years of flying this happened the first time to me? And I was with a flight instructor.
No, that was my CFI with a new student who saw that and told you. I was in a Meteo Bus passing Sector 3 when you came back to take it off. Won’t happen again for the next 30 years, be sure
I actually stopped when I saw you taxiing to sector 3, thinking you came back from a flight, so I could finally say hello in person….
placido wrote:
It is at take-öff where I cannot add additional fuel to the excess boost that is being generated. So the suspicion that I am running too lean at high power could be the reason for overheating.
That sounds very much like a possibility. What strikes me is that you not only get high temps but also much higher MP, so that is two values out of the ordinary. So the question would be to set take off power manually to the normal MP for climb and see what happens. But instead of experimenting, I’d get the overhauler and your maintenance involved ASAP. I would not be surprised if the wastegate has not been properly regulated.
placido: Let us summarise this:
- your probes are working okay,
- your exhaust temperatures are fine in cruise but this is to be expected because you have control
- you have not told us how the EGT and TIT temperatures are during take off and climb.
Based upon the evolution of this discussion I believe you need to inspect and patiently seal your baffling system, over and above previous advice regarding fuel flow and adjusting MAP.
