I have a question for the wise minds here.

I have been looking at a few T206H's with the TIO-540 in them. In the handful of engine log books I've looked at nearly all of them have replaced several cylinders by 500 hours and then had a full replacement of all of the cylinders before 1000 hours. Is this to be expected?

Are the events that necessitate cylinder replacement dangerous?

I have looked at one standard IO-540 and it has a perfect maintenance history past up to about 1000 hours.

Sounds about right. The Navajo has a TIO-540 and we found cylinder cracking to be very much a matter of pilot technique. Pilots who followed a time-tested cooling schedule and who ran the engine rich in climb and cruise tended to avoid cracks. I don’t know the differences between the model in the 206 versus the model in the Navajo, but I’d think they would be similar in terms of what causes cylinders to crack.

Yes, these engines are tough, but they live and work in a tough world. Pilots tend to run them a little lean and these engines need fuel for cooling. Pilots get done flying, they want to shut down and load/unload, and go: Thermal shock.

Take care of that engine, and it will take care of you, give it fuel and avoid thermal shock. I know guys who take them to tbo without changing a cylinder.....

MTV

Pilot technique matters a lot. Specially watching the CHT’s for all cylinders and keeping them below 400°. My plane has an O 470 with a Rajay turbo normalized STC. The engine TBO is 1500 hours and needed to replace my first cylinder at 700 hours, and another two cylinders at 1700 hours.

Surprising how many pilots over in a turbo normalized engine in both climb and cruise. TIT‘s needs to be below 1600°.

At high altitude and closing the wastegate to boost the engine to 23–27 inches of MP, enrichment should be near that of sea level.

I agree with your earlier comment that guys over lean engines when the turbo is engaged.

If you fly a Turbo 206 like a NA 182, you are in for a lot of issues. The TIO-540 is working hard to haul that beast around, and the chop and drop mentality doesn't work in highly stressed turbo applications. The Turbonormalized O-540 in the TR182 is an example of a non-stressed engine, and I have a customer with 2600hrs on his. Very little cylinder work on it. Yes... I am trying to get him to overhaul it.