Peter wrote:
When you are at 2000 and on the original cylinders, that would make a great data point.
I will report then, but it can take ten years. 
Peter wrote:
didn’t you at one point have a piston PA46? They have the worst possible reputation for this.
Depends very much which PA46. The original 310 hp version NEEDS to be flown LOP and the engine will break if it’s not flown correctly. Still, it is probably the most attractive one as it has the highest range. Sadly, it proved too much for quite a few pilots so Piper introduced a different engine with 350 hp which must be flown ROP. Cut the range massively and also the efficiency, but it made the plane “safer” for the average pilot. Pity actually, the original Malibu was much superior to the later one in that regard.
Not sure about the top overhaul ratio on both.
I wonder if anyone here as experience with Rajay Turbo Normalizers. They are usually aftermarket (even though some planes had them installed in the factory, e.g. the Turbo TwinComanche) and what they do is to keep the MP at 29 inches by the way of a manual wastegate which is normally open and can be closed via a vernier knob on the panel. IF the turbo is not working, you got the normal NA performance, but if it is, you get to fly a lot higher and faster.
I’ve used those on a Seneca I at some stage in the years back and can’t really remember much about them, apart from the fact that the FI did consider them toys. I used them a few times in climb and it was quite effective as well as in cruise where it got the speed up quite a bit at 15’000 ft.
I know of some Mooneys which have them, even carburetted C’s and wonder if anyone here has experience with this kind of turbos, as it might be something I’d be interested to try. One guy claims 170 kts in a turbo normalized C model at FL210, so that would be rather interesting.
I fly both a NA A36 and my friends TN A36. My cylinders needed replacement at 1100 hours, they looked perfect but were subject to the Superior AD with a 17 year calendar limit. My friends TN A36 has about 1000 hours on the engine (Powermaster IO550), all of them LOP except for take-off and climb. He will have to replace his Superior cylinders for the same reason in a couple years.We both fly LOP most of the time except take-off and climb. No unusual maintenance troubles. His previous Mooney 231 was a nightmare, valve guide problems, badly repaired, expensive and very depressing.
I my total of 5500 hours on my airplane, I had one exhaust valve leaking (discovered during leak test), one blown-out exhaust tube,no other significant engine problems. The first run was factory new (1973) , the second was factory new (1980), the third run was boutique overhaul (1999) and the most smooth/powerful.
dirkdj wrote:
His previous Mooney 231 was a nightmare
Which engine? The original GB was known for this kind of thing. I actually wonder about the 231 myself, as some very attractively priced ones are available. Interestingly, some are with the original GB having been overhauled and still is a GB. I thought they all would be modified to LB standard when overhauled.
Has anyone got hands on experience on the 231 and if so, which engine and what were your experiences?
GB? LB?
The TSIO-360 engine was made in different variants, including two called -GB and -LB
I do have a 231 with the GB engine. I also read about all were being converted which seems to be true only for factory remans. I haven’t had any big troubles with the engine so far. I do believe thst most of the bad readings you find result from a few reasons
1. POH says fly at peak TIT
2. CHT redline is at 460F
3. max. Fuel flow is very critical – set it too low and you will cook the cylinders
4. insufficient engine Instrumentation and engine handling knowledge
While the LB has the better induction system even the GB can be flown nicely LOP with CHTs below 380 and TITs around 1600. If you take care about your temperatures I do see no reasons why it should be exceptionally troublesome.
Mine has about 1400h and I am hoping to get a few hundred more hourd out of it.
I don’t remember which engine he had. I know that the engine shop did FU it during overhaul and subsequent repair. The valve guides were improperly installed. Most of the hours were before he was educated how to manage the engine. Anyway the Powermaster IO550 has been completely trouble free since installation over 1000 hours ago.
Sir_Percy wrote:
engine handling knowledge
dirkdj wrote:
I know that the engine shop did FU it during overhaul and subsequent repair.
Thanks. Both quite enough to give an engine a bad rep due to annecdotical evidence by people who did not know how to handle it. Malibu 310 hp same case…
