It is going to depend a lot on how you fly the airplane and probably on luck
as well. I recently read in Light Plane Maitenance that the alloy used in
cylinders loses about 50% of its strength by 400F, so presumably the
cylinders will last longer if you fly at lower altitudes (where they will
run cooler) and at lower power settings. Of course, what is the point in
having a turbocharged engine if you are going to do that? When I had a Turbo
Lance, I cruised at 75% power and usually cruised in the mid-teens (the
terrain came up to the low teens). I never had an engine or cylinder
problem but I only had the airplane about 360hrs.

Mike
MU-2

"John Doe" wrote in message
news:_s10f.57789$8q.31419@lakeread01...
I'm in the market to purchase a turbo aircraft...(specifically a 1979
Turbo Lance)

Can someone tell me their experience with the engine maintenace in
relation to having to top overhaul the cylinders? I've heard from some
owners that you should only expect about 800 or so hours on the cyliners
before having to get them topped, while others have said if flown properly
they should make it to the engine TBO.

The plane I'm looking to buy has 800 hours SMOH and they haven't touched
the cylinders since the overhaul. Am I looking at a heavty bill to top
the cylinders soon? (I'm thinking about getting a prebuy done this week)
Will a compression check tell me what I need or does the A&P have to tear
the engine apart to really tell?

Thanks.