This is the damage done as reported by my mechanic
After downloading the engine analyzer we found that during the descent and approach phase of flight, when I reduce MP, the EGT increases to above 1500 F. I usually fly around 1480-1490 F. It is most pronounced during the approach though. I'll set my power and then verify all temps are good - usually having to enrich the mixture to keep the EGT below 1500. But this gets me so often...usually after turn to base, I'll make a small adjustment to MP, like from 1300 to 1200 inches, pretty much a tiny adjustment, forgetting to check my EGT. And then it hits me to remember to check the EGT and its around 1540!!!!! All the while the CHT is nice and steady around 340.
Any idea what would cause this? There isn't one particular cylinder that this happens to, across the board the EGT rises.
The valves all look good. I did however come across an issue you need to keep a close eye on. Cylinder #2 (left front from the pilots seat) has undergone some serious heat stress. It looks like preignition/ detonation has occurred. The piston still has its edges but they are rough and distorted. The concern is a fissure has opened up above the intake valve on the aluminum cylinder head. It’s wide and long and there is also a small one above the spark plug.
After downloading the engine analyzer we found that during the descent and approach phase of flight, when I reduce MP, the EGT increases to above 1500 F. I usually fly around 1480-1490 F. It is most pronounced during the approach though. I'll set my power and then verify all temps are good - usually having to enrich the mixture to keep the EGT below 1500. But this gets me so often...usually after turn to base, I'll make a small adjustment to MP, like from 1300 to 1200 inches, pretty much a tiny adjustment, forgetting to check my EGT. And then it hits me to remember to check the EGT and its around 1540!!!!! All the while the CHT is nice and steady around 340.
Any idea what would cause this? There isn't one particular cylinder that this happens to, across the board the EGT rises.
