reliability

which diesel in the 150 hp range naturally aspirated is the most reliable?

older is ok

 

Detroit Diesel 671 non turbo.... But can you take the weight. After that consider Cummings, Deere, Catepillar. All made of Iron... Aluminum engines or lightweight ngines less so. Checkout http://www.yachtsurvey.com/comparing_diesel_types.htm

 

There is a lot of good engines in this category.

My experience gives me the Yanmar four cylinders among the best; rather light, very reliable, easy to maintain. Older, heavier and slower RPM do not mean automatically more reliable, but surely higher consumption and emissions. Reliability depends on the technology employed inside the engine.

Aluminum engines can go perfectly in a boat if you make the proper installation and do not mix metals. A lot of european boats use aluminum engines with no problems as most of the small diesel engines used in Europe descend from automotive or industrial engines, generally made in aluminum, which is the traditional metal for engines in european motor engineering. With the price of gas in Europe nobody uses gas engines except outboards.

The Yacht survey site has questionable affirmations on some issues (specially on sandwich boats). Any method when improperly built with poor craftsmanship will be a failure. This site is not the ultimate bible.

As you're in the States, the Cummins are good and have engines in your category. Most important is the rating you're asking to the engine, ie if it's for a yacht, a patrol boat, or a commercial boat. For a yacht is almost always better to get the lighter engine in for example the category Intermittent with a reasonable RPM (a 4400 RPM diesel is not a reliable engine...) . Less weight means less consumption, smaller tanks etc.

A very important factor of choice is the specific consumption at the cruise speed. That can make make many gallons of difference in the year.

 

For my buck$ the question would be what type engine is available NEW , SURPLUS .

Since I prefer dry stack exhaust and keel cooling , almost an industrial engine is a candidate to operate a vessel

IF you are doing a new build its EZ, replacing an existing engine reduces the available choices if wet exhaust manifolds are desired.

For POWER , most marine engines are conversions of an industrial block , and all the mfg or converters will rate their engines at 4 levels.

24/7/360 for gen sets and trawlers or passage making vessels.
Some ratings have a 15 min limit at peak power (pleasure boat rating) and very reduced power levels for most of the time.

BE sure you know how much power you will need , and for how long , to assure satisfaction with your engine choice.

FF

 

The answer to that exact question is undoubtedly the Gardner LXB in heavy duty configuration. They are still available but you need the space to fit one and the money to buy it!

This boat on brokerage has two fitted in a 'walk round engine room' and still has room to sleep ten! But then it does displace 80 tonnes.

 

dry exhaust, continuous duty, keel cooling, new build and there would be adequate space.

and easy maintainability is a plus.

 

http://www.gardnermarinediesels.com/index.html

 

Take a look in Boats And Harbors , its cheap subscribe if you must.

An example of adverts is ,

Sam Winer inc 330-628-4881

Daewoo diesel turbo 8-1L 177 cont as used in loaders and backhoe. new $6950

My choice International UT 466 NEW ..no price but a guess $5K. Oldrer DT's are pure mechanical, not as efficient as the electric injection but they will run after an electric storm.

There are dozens of advertisers and choices.A 6-71 Detroit would be a good choice used , not as efficient as a super modern engine , but they Die slowly and will get you home.

Gardner's are fine if you have displacement for about 3-4 tons of iron and $50K to spare.

Parts where you are cruising is a concern, In the USA the International or Detroit is my choice as an almost new DT 466 from a wreck is about $3K to $4K and fits a SAE Twin Disc gear box.

Boats & Harbors , do it.

FF

 

gardner 8L3b

 

gardner 8L3B

 

Engine choice

The International DT 466 is an excellent choice. Very commonly found in school buses across the USA.

 

Darn and I thought my 6-71 was big....

 

hello , are they detroit diesels, i dont know much about them, but they sound reliable, i replaced 2 of them in a 66ft commuter with aifos, only because the owner wanted them

 

YES, DETROIT DIESELS, I think they are the most reliable of all engines. Mine have over 15,000 hours been rebuilt 3 times, and have been on three separate boats. They still are fine. I know a guy with a WWII landing craft with the original Detroit Diesels still running. They are not highest HP per lb, or most efficient on gas, or quite, or clean. But they are above average on all. Also they are 100% mechanical, All I need is diesel, and some compress air, and they start... I don't even have turbos.

 

Without making this into a pissing contest, claiming to be the 'most reliable' is one hell of a boast.

The commuter ferries across the Solent to the Isle of Wight traditionally used Gardner powered generators that ran non stop. That's non stop for twenty years! Eventually it was stripped down for inspection and they found no discernible wear after 175000 hours. It was simply bolted back together and remained inservice on that ferry and then it's replacement.

The Kowloon Motorbus Company in Hong Kong always specified Gardner engines in their buses as each engine would out last the life-cycle of two coach bodies (25 years plus) The engines were then marinised and went to work in the fishing trawlers. Engines from the 1920 and 30's are still giving excellent service.

There's been no new Garners built in ages but demand is still sky high for these units and new parts continue to be made to keep them going. They are not everyone's cup of tea, plenty of new trawlers and ferries are launched these days with reconditioned Gardners in preference to any other marine engine available, despite having to pay more for the 'secondhand' engines.