[ngb1066]

I have been interested for some time in the possibilty of installing diesel engines in a 337. For a time it appeared that the SMA four stroke 230-235HP engine was the only candidate and it appears to have been successful in the Cessna 182. The "improved" version of the SMA engine has just received EASA certification and this amongst other things raises the service ceiling, which was a problem with the original engine. There are apparently plans for SMA to bring out a 280HP model in due course. Tule River raised the suggestion of developing an STC for fitting SMA engines to the 337 a while back, but I do not believe they have taken the idea any further.

Thielert/Centurion have put on hold their plans for their 300+HP version of their engine and in any event the experience of users in the UK of the Thielert product has not been good.

The Deltahawk engine as a two stroke has always looked interesting, offering a better power to weight ratio than the competition. It can also burn motor diesel, unlike the SMA engine which is limited to Jet A or Jet A1. I have looked at the TF Hawk website setting out their plans for the 337 Goldenhawk with Deltahawk engines, but it is not clear how far they have got with that project. My main reservation about this is that the four cylinder Deltahawk engine will when certified, probably later this year, have a maximum power output of 200HP. I wonder if this is really sufficient to power a 337, particularly the heavier pressurised models. I would be interested to hear views on that. Deltahawk plan in due course to bring out 6 and 8 cylinder versions of their engine, offering power up to 400HP, but that is likely to be some time away.