Mooney 231 flying

MNFlyboy

MNFlyboy

Well-Known Member
Ok Mooney pilots, bit of a flying question for ya here. I've put about 250hrs into a 79 turbo 231 (K Model) Mooney for my job. We've just opened up the case to rebuild and found a cracked head. My boss was not real happy about this and now we've acquired another Mooney, same model but with TKS for winter flying.

I've never had any formal training on the aircraft, just reading the POH and the perf charts and procedures, but I'm looking for tips and hints from Mooney drivers on how to best operate the aircraft and especially avoid harm to the engine (i.e. shock cooling) in the future.

Cheers
 
Not a Mooney pilot but might be able to help, but I would like to get a little more info. Where are you running the plane as far as power setting? How many hours on the engine before you started flying it? What are the typical flight profiles (O2 needed or non-O2)? What are the CHT and EGT temps in climb/cruise/descent?
 
:yeahthat:

Yes, tell us more! You can't automatically attribute a cracked jug to shock cooling! Sometimes that stuff just happens. (I'm also an A&P)
 
Reduce 2'' every 2 minutes. That is what our operation does, but there are many different methods / techniques.
 
I assume by "rebuild" you mean major overhaul. IF that is the case, then why is your boss upset about a cracked jug? Cylinders are rather inexpensive in comparison to engine overhauls. I'm also assuming that your Mooney's engine made it to the manufacturer's Recommended TBO?

More info is needed! Hours on engine? Has the engine ever been top overhauled? Is it in for a Major Overhaul? Power settings that you run the engine? Altitudes you typically cruise? ETC

The M20K I flew had a TSIO-360 Connie. Is yours the same motor?
 
Does it have ECI cylinders? Those crack all by themselves.

The TSIO-360 is a fickle beast but not a bad one. It needs to be operated properly. The 231 was Mooney's first foray into turbocharging and they didn't get it all right. The cowl flaps aren't very effective and high CHTs are a problem in the summer. The best remedy against high CHTs is to cruise lean of peak (that's a whole other debate) and climb at 120 knots. If the airplane has an intercooler installed (most do) you have to get in to the STC's conversion chart to avoid overboosting. That's probably the most common problem I see - nobody knows about the conversion for the charge air being 50 degrees or 60 degrees cooler than what the stock, non-intercooled engine is looking for the effective MP is higher. Redline is 2" below what's on the MP gauge on most days in the K model I'm most familiar with.

Since it's a turbo motor, throttle changes must be made deliberately and slowly. The throttle does not have a vernier and makes it easy to over control the throttle. It's much easier to handle a turbo engine with a vernier (M20M, M20TN). Same goes for mixture. If you don't have GAMIs and the engine won't run lean of peak, don't lean past 1550TIT. Also, make sure the takeoff and idle fuel flow are set properly. If the mixture controller is set too lean the temps will get out of control on climb. I also don't fly the 231 higher than 16,000. The cooling systems are inadequate to be operating higher than that where the cooling air efficiency starts to drop.

There's good info on Mooneyspace. The 231 is a maligned airplane but not a bad one. Feel free to ask me more specific questions, I've got a lot of turbo Mooney time.
 
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