Austrian manufacturer in talks with car maker after issues with cylinder head corrosion

Diamond Aircraft is calling for an alternative supplier to enter the general aviation diesel-cycle engine market following a rift between it and powerplant supplier Thielert Aircraft Engines (TAE) over cylinder head corrosion in the Diamond DA40 TDI twin-seater.

Diamond says it is in talks with an undisclosed European car manufacturer about replacing the DA40's TAE Centurion 1.7 with an adapted automotive diesel engine. "We want to have a choice of suppliers, just like in the avgas market," says Diamond managing director Michael Feinig.

He claims TAE has stalled development of a long-requested 160hp (120kW) version of the engine as it concentrates on the 4 litre V8 Centurion 4, a commercial decision he says would not have been made if there were a competitor.

Feinig admits relations between the two companies have cooled as the result of a corrosion issue with the Centurion 1.7, but "we are still friends".

TAE research carried out by Montan University in Leoben, Austria showed corrosion to engine cylinder heads was caused by a defective cooler, with soldering flux residue the likely catalyst. TAE says the problem does not occur in its Cessna and Piper retrofit kits and adds: "Because Diamond has chosen another cooler supplier, we now have recommended that Diamond use the same coolers as we do in our retrofit kits."

Feinig says it has had to change the design of the engine mount several times to accommodate over 120 service bulletins from TAE since the engine was certificated in Europe in October 2003. "They changed the software, compression ratio, configuration and other factors so the temperature changed constantly, forcing us to change the cooling system," he says.

Feinig says the problems have now been "100% solved" and Diamond expects to issue a service bulletin regarding the coolers very soon. TAE says it is "glad that it is not an engine-related problem".



Source: Flight International