C172 Centurion Diesel, Overview

This airplane is their demonstrator, and the one that I got to fly. It's got upwards of 3500 hours on it with the Centurion engine, and is on its second one. It was originally an ERAU ship (they're less than ten miles down the road in Daytona Beach). When not out on PR trips, it's on the rental line.

The three-bladed prop is a givaway that something's different. Note the ground clearance-I didn't measure it, but it's much more than the original setup.

There are two modifications to the cowl. One is the NACA scoop on the right side for the intercooler.. The other is an oil door on top, dead center because that's where the dipstick winds up.

Here's a better look at the cowl.

The lettering has a purpose...these guys are the importer for this engine for the entire US and north and south America, and even then one of their line guys started to put 100LL in it. So, the big "Jet A Powered" on the side is there for a reason.

You can also see the new oil door in this one. This was an R model. To me it appeared that the new oil door is pretty close to where it is on our N models, but we'll see.

There is no fuel sump cable inside the oil door, although this particular plane retained the factory belly sump. It did not appear to me that they pulled samples from it as a matter of routine.

Here's what the panel winds up looking like. The original tach (out of view to the left) goes away and is replaced by engine and FADEC controls.

The instrument below the VSI shows prop RPM, oil temperature, oil pressure, cylinder head temperature, coolant temperature, and percentage of load (yes, just like a turbine). The one to the right shows fuel temperature, voltage, and fuel flow.

There is no display for engine RPM or manifold pressure, because (1) the FADEC controls all that, and (2) they figure that you don't need to know anyway, since you can't do anything about it.

In general, MP runs between 44 and 50 inches, and the engine runs at around 1.6 x prop speed. This is a little odd for a diesel since most of them are happier at lower speeds. Most industrial diesels never see anything north of 1700 RPM.

Here's a better look. Note also the "Engine Master" switch below and between the instruments. The engine instrumentation comes on with the aircraft master, but you have to engage the engine master to start it.

This is the data connector that lives under the glove box on the right side of the plane. You plug their cable into it, the other end goes into a USB port on a laptop, and the entire history of the engine is before you. This literally took less than 30 seconds.

This is what you get. It's a little tough to see, but virtually every operational parameter since the engine was installed is shown and you can massage the data to ridiculous degrees. It shows the number of starts, hours at each power setting, and then the established limits for each sensor as opposed to what's actually happened.

There are two FADEC units in the plane, and here one is shown on the left side of the screen and the other on the right.

This information gets pulled at the 100 hour and sent to Theilart, and if something happens in the meantime that you don't understand you can ship the file off to them and they'll sort it out.

This particular airplane has more time on it than any other, and they've had to go into this data exactly once for diagnostic purposes. That was when a pilot reported a barely detectable surging-something that would have taken weeks to find under normal circumstances. In this case, it took them ten minutes to isolate the problem (bad sensor) and take care of it.