The Russian M14P radial would give you decent weight and about 360hp plus better scale looks and sounds than a turbo diesel.
If you're stuck on a diesel, the only one I would consider is the V8 EPS one which should be certified this year, unfortunately, I'd guess it will be around $100K.
14 years and 408.2 hours on Subaru Turbo powered RV6A
"The world is changed by your example, not by your opinion" Paul Coelho
I can't speak for the large displacement diesels, but I've been doing my best to keep a close eye on Honda's new(er) i-DTEC 1.6L diesel.
It looks to develop ~118HP @ 4,000 rpm, and ~220lb/ft of torque @2,000 rpm.
I haven't been able to track down a weight figure, only that the engine "weighs 47kg less than their equivalent 2.2L diesel".
Assuming the weight figure is good, I think this engine is something to keep an eye on.
Honda diesel! It wasn't that many years ago that they said they would only make gas engines for cars...
It's figured from this that the 2.2 diesel weighs between 230 to 240 kgs (520lbs) which makes the 1.6 a boat anchor still.
boat anchor? That's a safe!
I tuned in to say I own and drive a 6.9 diesel in my ford and it is a very heavy engine and at times can be a nightmare to keep running. In my opinion the goal for a diesel is to have a engine that runs wide open in the 2300-3300 rpm range to satisfy the prop need's and no PRU is needed. I think if a person can find a 3 cyl diesel producing 70 hp on take off and kept around 195 lb. total weight it would be good for the HBA community. By the way the 6.9 is the same as the 7.3 other then bore and stroke, can't tell the difference by looking at them.
KR-2, Taylor Mono,
Mercedes smart diesel is rated at 54bhp and I've seen weights of 65kg and 80kg for it.
The fw-190s that attacked US bombers were dragging 30mm cannons around. They were the best fighter around when introduced with mere 20mm cannons. The British were not happy.