The OP (Jeff) simply wanted to know what people would be willing to pay for a viable diesel engine for an RV-10. As usual, this has quickly turned into a "forget about a diesel! Lycoming traditional engine is best!" thread.
Yes, it might be best to move this thread to Alternative Engines, but we're talking about certified aircraft engines, made by well-known aircraft engine manufacturers (especially in the case of Continental), many thousand of flight hours (the SMA), and millions of flight hours (other Continental diesels).
If we all sit around and wait for someone else to fly these engines to TBO or TBR, how are we ever going to enjoy better technology and greater safety and fuel savings? There are those who are willing to take a reasonable, informed risk in order to be pioneers, and there are some (probably most) who are perfectly content to let "the other guys" prove the technology. I believe this thread is aimed at the pioneer group. I don't think we need to hear over and over again how much better a Lycoming is. I think we already know about that.
Kurt Goodfellow
People should know the story, history, good points, bad points before making a decision. It comes down what you the buyer, is willing to pay and whether you are willing to accept the potential further financial and possible reliability risks of a relatively unproven engine package. This engine does not have anywhere near the flight time the Conti 155 diesel does plus it's an entirely different design so no parallels for reliability should be drawn there.
Historically, light diesel aero engines have had a poor reliability/ cost record on introduction, even the certified ones. It took many years to work out a lot of these issues on most of them. The exception has been the Austro AE-300.
As of 2008 (10 years after introduction) SMA had only about 50 engines in service, mostly on STC'd Cessna 182s (engine cost $75K), most in Europe and Africa where avgas was expensive or hard to find. Initially, most users were happy but then reports started to trickle in that there were systemic crankcase fretting issues and engines were often being removed and returned with as little as 400 hours on them. One fellow flying these in Africa for a Missionary Group told me they were nice to fly but the engines didn't last long before leaking oil and making metal. One at our airport was a hangar queen, having had at least 2 engine changes that I know of with hardly any hours on it.
In 2009, an AD was issued on SMA 182s to change the intercooler and more closely inspect clamps and induction hose connections after several failures. (remember this engine runs 90 inches MAP for takeoff). This has been a problem area on other aero diesels as well. High induction temps at the intercooler inlet and high pressures mean things have to be done right here. Lose an induction hose and you lose as much as 75% power.
I think the "E" model was introduced in 2009ish and certified in 2011 to address various problems but it was one of these which suffered a turbocharger failure and a forced landing on a factory 182 test article in 2013. Cessna was on/off /on/off with the 182 diesel project and pulled the plug in 2015. There were other similar occurrences which were not well publicized. SMA was never very transparent with issues. Remember, this basic engine had already been certified for 15 years. The following article covers some of the story and mystery about the lack information:
https://generalaviationnews.com/2015/08/30/tracking-down-answers-at-oshkosh/
The latest engines require a turbocharger replacement at 1200 hours, halfway to TBO last I heard. The turbos are working very hard at these pressure ratios (around 3-3.5) so their longevity may not be so good.
Apparently some propellers are also not so happy with the power pulses of this engine which is another concern with the entire package. I'd hope that Continental has directed a lot of testing at that aspect too.
I am guessing that Continental has devoted considerable time and technical resources to fixing all known issues with this engine in the last few years but considering the very limited number flying, they were still having issues as little as 2 years ago. Maybe all is well now in 2017 but I think we lack enough flight hours so far on the latest iteration to have a good confidence level.
SMA and Continental of late, should have pounded a bunch of these engines at MCP years ago, both in a test cell and development aircraft to uncover these design issues before market introduction. That in itself is worrying and does little to inspire confidence, along with their reluctance to tell the true story. It's ok to stay quiet in the development stage where failures are expected and part of the process to work out the bugs. But staying quiet after the engine is certified and in service does your reputation no favors.
I am happy to see this RV10 flying with the 230E under the guidance of Continental. It's the first step to more widespread release and use of the engine in Experimentals. There is certainly a market for it as we see a lot of interest in aero diesel threads here and on other forums. I wish them success after the hard road they've negotiated.
Of note also is that Soloy will now be doing STC'd SMA installations on 182s this year so the design seems to be gaining some new traction now.
Power to you if you feel comfortable being a pioneer here but as with any alternative engine you should simply go into the decision making process knowing the history and with eyes wide open. It may not be all roses as some of us have found out the hard way...
Here's a photo inside this engine which may interest gearheads (lower right of page):
https://www.smaengines.com/our-product/sr305-230er