53 Hat with 6V92"s

[41-Hatteras]

53ED Hat with 6V92"s

Hey guy's I have found a 1985 53ED w 6V92 DD. What information can you share on this 53 also these 6V92's? These have been majored in 1995, they have 1200 hrs on them. Boat has all documentation records on everything. The boat in great condition all most new. I have a 1966 41C that I repowered with Commins 450. Thanks for any information you can provide.
Capt. Ron

 

[SKYCHENEY]

I own a 1985 53, but it is the extended deckhouse model. I also have the 6v92's. I can tell you that we are very happy with the boat. She gets an economical 1nm/gal at 9kts, and can cruise at about 16kts. I bought the boat 2 years ago and she too was like new in many respects. I do have some blisters on the bottom though. Right now I am in the process of replacing the toilets and sewage hoses. The original hoses were really getting cracked and starting to release odor. I also had to replace the original side by side refrigerator since it was constantly leaking condensation water and the temp would not stay constant. Other than that, most of the systems have been just fine.

Sounds like you found a good boat, keep us posted on your progress.

 

[REBrueckner]

I'd sure ask what cruise speed (knots) the prior owner usually ran the boat....then ask what RPM...it's often revealing. 22 knots and 1700 RPM, for example, would make no sense....There are some real cowboy owners: it's best if the engines were run at reasonable RPM since rebuild. Sounds like they were used the normall 100 or so hours annually since "rebuild". As long as the records show engine oil and transmission oil changes sounds like they should be ok.

Be sure the "rebuild" records are detailed and reflect REAL work done....a one line summary bill may not be authentic...Call the engine rebuilder and see what their records reveal. Don't assume anything was touched unless revealed in the detailed "rebuild" record. See all posts here on engine operating characteristics and survey points. An oil sample analysis is cheap insurance.
David Pascoe also discuss 92 series engines. These are often higher HP/cube and hence shorter lived than older 53 and 71 series of more modest HP/cube. Two cycle Detroits are neither the quietest nor cleanest engines, but when taken care of provide good service life especially when run regularly.

When I bought my YF records showed a ten year old rebuild...yet one engine needed new liners, pistons, rings etc....The survey discovered that but in retrospect I did not negotiate enough off the price...but I did not pay top price either.

 

[Paul45c]

As you'll see in that Pascoe article, the longevity of these 92's comes down to what horsepower they're set up at. I've got 500hp 6v92's in my 45c, and my mechanic estimates I'll get about 3000-3500 hours before needing a top overhaul again IF I can run the boat at least 150-200 hrs./yr.

550 hp is a very common rating for 6v92's, and the time between overhaul drops to 1200-1500 hrs.

Be very mindful of what injectors are in those holes, too...with everyone's preoccupation with speed these days, a lot of people will put oversized injectors in to boost hp a little. That'll definitely shorten life. Hosing more fuel in (especially without doing anything more to boost airflow like pumping up turbos to take advantage of the extra fuel flow) just washes oil off the tops of the cylinders. On 6v92's, that starts to happen right over the 500hp mark, my mechanic says. When he rebuilt my motors, he told me that the old owner had oversized injectors in there. For the sake of maybe 15-20hp gained, it dropped life by half. Plus, there was a lot of unburnt fuel that crudded up the transom and left a visible hazy cloud behind the boat on calm days. Honestly, we never saw any decrease in speed; I took maybe an inch of pitch out of my props, and amazingly, the boat's probably faster now than it was before.

Some claim the 2-stroke Detroits are a somewhat dirty motor -- I disagree. There's no question 4-strokes (especially modern ones) will more completely burn at higher cruising rpms, but when these Detroits are set up with the right injectors you don't get any visible emissions. AND, they are absolutely smoke-free at low rpms. Watch boats with MANs, MTUs, Cats, etc. in the idle speed zones, and every one of them will have some visible fuel smoke around the transom. For fishing and slow cruising, I'll take Detroits any day. The reality is we all spend plenty of time at slow speed.