Fletcher500
Guru
Sun, interesting to hear the Industrial side of the story and the fuel burn delta.
There was either a hydraulic or electro mechanical clutch between the two inline engines. Those torpedo recovery boats were built before the 12v was available. Later versions had 12v71s.There was an 80ft torpedo retrieval vessel that I nearly purchased years ago. It had two sets of twin 6-71’s to one tranny, but I recall they were end to end, not side by side. [emoji846]
The US Coast Guard used a variety of 71 series engines, including 471's for generators and hydro pumps and commonly, 671's in their workboats - 40' search and rescue crafts with twin engines. They were extremely reliable and easy to work on - I was a boat engineer and used to work on them routinely in the early 1970's.Hello fellow TFers!
While reading another recent thread about engines I started to search info about Detroit Diesel 71 series engines. I am not owning any but reading history and information I was very interested about it (for my own curiosity/education).
I love old engines and I found really interesting the long history of the series and its architecture etc.
Would you have any story/info about these engines please chime in!
L
Had DD's in a few boats. I would never have them again. They require very knowledgeable mechanics to do simple things like final filter replacements. Blow an injector tip because of a microscopic water molecule or dirt and you a have washed out cylinder in a heartbeat. There goes $10 grand to fix one cylinder. Their gph to nm curve can be beat by other 4 cycle motors. The DD's with turbos make a 220 hp a 450 hp. and they wont last.Hello fellow TFers!
While reading another recent thread about engines I started to search info about Detroit Diesel 71 series engines. I am not owning any but reading history and information I was very interested about it (for my own curiosity/education).
I love old engines and I found really interesting the long history of the series and its architecture etc.
Would you have any story/info about these engines please chime in!
L
During oyster harvesting which accounts for about 80% of the engine hours the engine runs at around 800 rpm. Although I’ve heard so much about how bad low speed operation is on diesels, we never experienced that on the workboats around here with the Detroits.
OK.Would you have any story/info about these engines please chime in!
Hello fellow TFers!
While reading another recent thread about engines I started to search info about Detroit Diesel 71 series engines. I am not owning any but reading history and information I was very interested about it (for my own curiosity/education).
I love old engines and I found really interesting the long history of the series and its architecture etc.
Would you have any story/info about these engines please chime in!
L
And you didn't show us pictures.I just bought a converted fishing trawler in Sydney
And you didn't show us pictures.
Yeah I grew up in Venice on shrimp boats. I just couldn't understand all the hoopla bandied about on boating forums by "knowledgeable" advisors regarding low speed/can't reach rated rpm set-ups are death traps just waiting to swallow the universe. I later deduced that it has to do with having to design pleasure boats for the general public who may wander in to a shop and buy anything their pocketbook can afford with no knowledge of its proper operation or design parameters. There are far more people out there who don't know that a diesel blowing black smoke for longer than acceleration or short bursts of power is BAD than there are who do. Never knew of any commercial fishermen who could afford to run their boats like oilfield skippers did. For them travel time=money. For commercial fishermen, nets in the water time=money. None of them "fish" at "rated" rpms. Since my pleasure boats weren't used commercially I propped them for MY preferred enjoyment (factoring in speed and fuel burn) and always told prospective buyers about this.
Not saying I know everything about marine propulsion, but i do know there is more than one way to "properly" set up a propulsion system. There is a factory recommendation to most safely cover the engine for all applications and operators an engine may encounter, but its not necessarily the best for any one specific use, but they can't tailor installation recommendations to every setting their engine may be used in.
Its kind of like the insanity used in designing the modern US diesel pickups. A large portion are used for nothing more than transporting people, yet they are set-up to be able to deliver massive amounts of power/tq at 70 mph in overdrive because average Joe doesn't know that his vehicle could be set-up to deliver significantly higher MPGs in OD when empty or lightly loaded and that he should drop down a gear or even two when working the vehicle at/near its max payload/tow rating. When Ford/International came out with the Powerstroke ('94~ish) and the aftermarket tuners popped up shortly afterwards I was amazed at all the people blowing engines and burning up transmissions in these big sportstrucks! They thought it was so kewl to be able to roll coal and do burnouts till the tires popped. Problem was the tuner companies didn't know much more about diesel characteristics than the new breed of owners did. By the 2000s most of the tuners had developed programs that were much "safer" but that still offered improved performance for the general public. To get the big power programs you had to call and talk to the tuners and acknowledge the need for further parts/modifications to "safely" use these tunes and that the tuners wouldn't be responsible for damage through their use! Of course Ford, Dodge, and GM wouldn't take responsibility for anything if they found a programmer had been installed. Their thought was "We tried our hardest to idiot proof these things and damned if they didn't make smarter idiots!"
I just bought a converted fishing trawler in Sydney and brought her back round the top of Australia to Perth (home) 600 hours and 4 months of pure pleasure
I read that the last 71 series engine was delivered in the 90s, this is a heck of a longevity for an engine that started to be built in the 30s!
Having worked at a Detroit Diesel (when there was such a thing) Distributor, for the first 13 years of my career before switching to the dark side at the EMD Distributor for the last 10 years, and all in the service department, I can say I have seen a few 71's...also 53's, 92's, 149's, Cleveland Diesels (also two-stroke) and of course the "big" GM diesels (EMD) in 567,645 and 710 displacements. And yes, I have repaired a few 4-strokes along the way...the Series 60 brought DD back from the brink in the truck market!.......
Cheers!