DD 8V-92 DDEC III (760 HP) for long-range cruising

What style boat are they in? In all reality in most situations they're 2000-2500 hour engines between majors. Parts and so forth are available but might not be instantly available at a local dealer. You can run them slow but need to run them at cruise every 6 hours for about 30 minutes to clean them out. They're more efficient at and under 1000 rpms than modern 4 strokes by a good bit. I ran a 75' Hatteras motor yacht with 12v71TIs at 1000 rpms and we did 10 knots at 12 gph (both). I could live with the detroits but would much prefer 4 strokes from that era such as CAT 3406's.

I wouldn't be afraid of 8v92 mechanical engines at all. There are plenty of parts available, I just bought 6 cylinder kits and gaskets and everything was in stock. The DDEC part is a different story. There are quite a few people on here who have had lots of issues with the electronics . I personally wouldn't consider owning a DDEC engine.

They have a supercharger which makes them very efficient at 1000 rpms and under. Yes you could run them that way, but I'd plan on running them at cruise rpm's every 4-6 hours for 30 minutes, probably could get away with every 6 hours with DDECs

Rarely, but yes just like anything. I've had an ECM go bad once.......some engine control stuff such as a shifter solenoid.....but was able to find it. Personally like I said earlier I'd be looking for 4 stroke diesels. Cats in that era and HP were very good, MAN's were also good.

We have 1989 89v2s @735HP in a 60MY, 87,000lbs. Both motors have 4300 original hours on them. We are rebuilding one now. All parts for the major were available. We run 1350rpm to get 10kts which is our hull speed. With either the 20KW or 8KW running I plan 15 gallons/hour. The real burn is around 13 gallons per hour. Every few hours we run it up to 18-1900rpms for 10 mins. Hope this helps.

I had 1993 era 12v92 DDEC in my boat. I did a top end on one and a major on the other. All of the mechanical engine parts were readily available (pistons, heads, bearings, etc.). The DDEC parts are a whole different issue. The parts have not been manufactured by Sturdy (OEM) for a long time. When (not if) you need a part your options are limited. You can send the component to Sturdy and they may be able to repair it. Or you can try to find used parts from places like EBay.
The other challenge is finding someone to work on the DDEC items. There are very few of these folks left. And if you have an issue in Alaska or Mexico you’ll be flying someone in if you can find someone willing to travel.
I don’t recall if the DDEC III version made the switch to 24v components or still have the 12v components. Mine had the 12v components which creates even more hassles. 24v starters and alternators with 12v DDEC components means you have converters and more potential failure points.
I wouldn’t buy a boat with those engines but to each his own.

Pacific Power did my work as well, including major overhaul. The guy that did mine unfortunately passed away. His son is the service manager there now. I'll bet if you specifically ask about parts and service on the DDEC components you will get a different answer. I had intermittent electrical gremlins in my DDECs that PP was never able to diagnose yet alone repair. And that's back when they had a really knowledgeable tech.

Again, to each his own. I'm just trying to give you my real world experience. I babied mine along for 8 years and dumped big money into them. In the end, I lost confidence in the engines so it was either sell the boat or replace the engines. Also keep in mind, I'm in the large commercial marine industry. I have big account relationships with places like PP and lots of resources available. Still couldn't solve my concerns.

If I can help in any way or if you want to discuss further, DM me your # and I'll gladly give you a call.