Thielert 1.7 engine
 

I have aquired an engine comlete with gearbox, editing harness to the Ecu, the Ecu, a radiator, oil cooler, heater core for cabin heat. It is of course 28V system. I want to try to use it on a homebuilt airplane. Problem is I have no wiring schematic to follow to even test run the engine. I have downloaded the Pdf files for the airplane it came off from. But it won't allow me to open the separate chapters. Came from a Diamond DA-42 twin. Any help appreciated,

I would be very surprised if the Thielert 1.7 could be run on 12 volts. I would not expect that data would be provided to enable this, there's no upside for the engine data holder to take a risk by supporting such changes. ECU's can be "precise" in design and operation, so I suggest caution. When an ECU is unhappy, the engine generally stops running with no warning. The diagnostics for that engine requires special software, I've done some maintenance check flying with the diagnostics computer plugged in to find a fault.

For that engine, be certain that you understand the gearbox and propeller limitations before you run it. Only a propeller approved for the engine would be safe to operate on it.

My first thought was to wonder why it was removed ?

This engine has a boat load of life limited parts so it is quite possible it is not airworthy. If it came from a crashed airplane and there was any kind of prop strike the engine is not safe to operate without the hugely expensive factory inspection.

I never planned to change from 24 Volt. The engine was removed due to time-500 hrs. Nothing wrong with it, just by certification this is/was the rule. Replaced with a New 2.0 engine. I have already spoken to MA on the propeller.

Interesting the engine should have a 1200 hr TBR, so if it was replaced at 500 hrs I am guessing it was having problems. The 1.7 has a poor reputation for reliability and maintainablity . There is a reason there is a Thielert 2.0. In particular many 1.7 engines had significant cylinder and piston problems at the 500 to 600 hrs mark. In addition the gearbox only has a 300 hr life.

Personally I don’t see the upside to operating this engine. Yes I get that as a home built you can ignore a lot of the maintenance requirements but these came about as a result of a spate of failures, fortunately mostly in the DA 42 which as a twin meant the airplane still made it home.

Oops, my misinterpretation of what I read. That said, I support what BPF has said, it's a "needy" engine to maintain. When they ran well, I really enjoyed flying them, but I had times when one was not running correctly. Although the fix for those cases seemed fairly simple, the diagnostics weren't always so.

Is that 500 "removal" requirement a DA-42 rule? I have not heard of that one....

Is it one of the very early engines that had a lower TBO/TBR at the time?