Maximum hours on Detroit 8V92TI ?

Judging by what you said, it sounds like the previous owner got around 2600 hours between rebuilds if he overhauled them twice. How long 18v92's last all depends, I've seen a set with dead cylinders at 900, others in SF go 1800hrs, some go 4000 hours (rare). I would say typical longevity in a boat like that would be 1800-2800hrs. But 400hrs since rebuild should still give you years and years of enjoyment. Total hours (6000) is kind of meaningless for the most part. I would highly recommend hiring a good engine surveyor to examine them, and report on current condition and what he thinks they will go before purchasing the vessel.

8V92TI Reliability

Hi - I am considering the purchase of a 1984 46 Hatteras Convertible with the 8V92TI engines. They were rebuilt two years ago and have 44 hours on them presently. Are these engines reliable?

Yes they are reliable. Most of the ones overpropped, run hard and wet as described above will go around 2,000 hours between rebuilds. Babied, who knows I've personally seen 4500hrs and they weren't yet rebuilt. Like said above they're as good as any from the era and parts are easy enough to come by and DD has a large dealer network.

Have an Engine Surveyor survey any diesel before buying.

44 hours does seem really light usage for 2 years on the motors.

A bore scope, and a good survey and sea trial should show most things at 44 hrs.


I don't know about that. I had a 12v71 come apart at 150hrs and this was 6 months after major overhaul from a very reputable DD dealer. I think if something wasn't done right in the rebuild it would show up in the first 50 hours. Some issues might take a few hundred hours to show up, like a distorted block with out of round cylinder bores.

She is a dock queen, I'd check them as thorough as if they had extremely hard use, sitting and not running is harder on a diesel than being used.

Just a quick question, if you guys don't mind...

Coming from the perspective of a live-aboard, lets say I move with the weather. Every couple months, cast lines and go a couple hundred miles, enjoy some free time for a week or two, then get a space to tie down for a month or two.

How often should you start your engines to exercise them, even if you're not going anywhere? Once a week, maybe? Let 'em idle for half an hour?

Just curious, if anyone would like to riff on that for a minute, I'd appreciate it.

I start and run the engines and generators on the vessel's I manage every two weeks and let them run 30 minutes or longer. It's best to actually use the boat every 2 weeks and run them with a load, although not always feasible

Thanks.

...X2.