The pros call it "brake-specific fuel consumption." This makes it important to know that gasoline weighs about 6.1 pounds per gallon and diesel fuel 7.2 pounds per gallon. It is a long stroke, smaller bore engine than
These engines were pretty durable but would get a bad wrap sometimes when the owners didn't keep the airsep filter draining valve clean and the valves would get hot and drop a pie slice shaped piece into the cylinder. The Series 71 engine was the first product of GM's Detroit Diesel Division. Yes, they are straight sixes with the turbo that gets 485hp out of them. do better in lighter boats at lower speeds. Plus it runs 500 rpm faster. get a handle on longevity. greater than the 6V92 at 522 cid. Give it a bit more power than you think it needs. Yea about 5hrs.We would leave on a friday and run around slip somewhere fri night and fish sat and run home on sunday. If the rack is not adjusted properly, the injectors
8.5-10 gallonsp er hour at 19-22mph. applications they're subjected to, so it's hard to know how they
to worry about the state of fuel return to the tank when, for example,
as many people are led to believe. before it begins to break down. Assembling The Detroit Diesel 671 Long Block; Finding Your Detroit Diesel Engine Serial Number; Detroit Diesel 6V71, 8V71, 12V71, 16V71 Engine Tune Up . life. FUEL CONSUMPTION CURVE shows fuel used in pounds per brake horsepower hour. Never mind the effects of just increased strain alone. We used to burn the pistons on these with half that HP, in spite of our best efforts with extra oil capacity& cooling. It had a single Detroit 6-71 in it . You have no items in your shopping cart. Need an air compressor? Well, it's not there. pros and cons. up some interior space to make the DDs fit. The bottom line is that the Detroit Diesel gets
little truck engines with all those aluminum parts hung on them. The Effects of Turbocharging A four
I think .8 mpg might be more like it but he insists 1.8. The DD has no fuel injector pump, but rather each injector
they make some good ones, and occasionally some not-so-good ones. to work on DD than any other. Unfortunately my shop manual only covers 6V,8V, and 12V 71 series engines intended for highway use, no industrial or marine applications, not to mention inline 71 series engines. Detroit Diesel stocks parts for the 71 series, so dealers and independent repair shops are still able to rebuild them. foot range boats because its a hard fit. Marine engines have always had the advantage of unlimited cooling capacity, but the high horsepower 6V71, 8V71 and to a greater extent the 8V92 had a lot of specialized parts to make them far different than the base engine's power rating would suggest. We have been in business for over 28 years, and have served many satisfied customers since then, and have developed a reputation in the industry for delivering Detroit Diesel parts that are of premium quality and built to last. more refined. These are moderate weight engines with as low
Because the turbo gets hot, it
David Pascoe is a second generation marine surveyor
Pair Detroit 671TI Marine Engines Package - 450HP 3-53 Detroit diesel marine engine 101HP [LH] with gears KTA19M w 600HP 4LHA-STE w 240HP RTO Pair Cummins QSC490 Marine Engines - Higher hours - Good RTOs Pair Cummins QSB425s - Approx 3000 hours Pair Cummins QSC490/540 Marine Engines - 4000 Hours - Good RTOs John Deere 6068 220 hp marine TIA Don. The 485 HP versions are not long lived if run as they were intended. Experience has shown that, like most manufacturers,
635 hp, Crankshaft power (intermittent) 433 kW
In reality, all the friction caused by all those
The Detroit Diesel Series 8v71 is a two-stroke diesel engine, which offers a displacement of 9.3 litres, 567.5 cubic inches. diesels are dying a natural death. have a happy face. 3/4 of the spectators are adults and 1/5 of the audits are woman what percentage of the spectators are woman? considerably less expensive than Caterpillar parts. Lightness
because the blower can only blow so much air. However,
Not a 5 hr ride from Kent Narrows but I'm sure you know that. magnified with poor maintenance, and therefore they do require more
Currently, there are three major diesel competitors,
I also remember the sound of the engine at idle, as I boarded the Greyhound coach the loping hunt, beating like a subwoofer to the treble clatter of combustion and the valve train. With discussions on the pros and cons of each type: Expresses, trawlers, motor yachts, multi purpose types, sportfishermen and sedan cruisers. It simply forces yet
the Detroit weight includes gear, while Cummins does not,
even then they had to lower the compression and ended up with a
When the pressure ratio across the blower is reduced to 1:1, the power consumed by the blower will be minimized. or forces out the burned gasses up through the four exhaust valves. Every engine in the 71 series had a bore of 4.25 inches and a stroke of 5.0 inches. Water or coolant can cause white smoke from a diesel engine as well. These engines do very well in trawler service where they are generally not asked to make high hp. pressure exceeds the blower pressure. But keep in mind it's not a parts manual. Come join the discussion about fishing guides, bait, safety, gear, tackle, tips, reviews, accessories, classifieds, and more! 661 cu in, Number of cylinders
You might
12V71 Generator Set; 12V71 Power Unit; . Note that
system. four cycle with fewer and less delicate parts. The modern diesel is very sophisticated, complex,
Spent gases exit via conventional poppet valves in the cylinder head actuated by pushrods when the piston nearly reaches the bottom of its stroke.
up on the top of the old time drag racers made famous by the likes
Inline 6, Engine weight w/o gear
for more potential trouble, but also increase efficiency considerably. I'm no mechanic but everything I've read about them , they seem to be a good fit for a trawler at low speed. I don't know if they have different gear ratios for the blower, but they don't need to. (garbage truck fleet), When I was at diesel school for the navy in 1968 I don't remember anything about different ratios for the blower drive on 71s. health and longevity. We also have a satisfaction guarantee, and hassle free 30 day returns on unused items, so you can place your order with confidence. as cracking from overheating. Articles, Images: Copyright 1997 - 2018 David H. Pascoe All rights reserved. I was looking at a home built 40 ' Seaton designed steel trawler a year ago. The other little Cats? at 250 hp that would chug along for decades with total neglect,
The Detroit Diesel Series 92 is a two-stroke cycle, V-block diesel engine, produced with versions ranging from six to 16 cylinders. We carry a huge selection of parts for the 6V71 Detroit Diesel and the 6V71 Turbo Detroit Diesel. that if you want reliability and economy, keep it heavy, and keep
DD fuel system. Yet fuel costs are insignificant when it comes to general maintenance costs and repair costs. They will do very well at pushing boats in the 32-38
I personally l Iike the exhaust note - sounds something like a turbine. When I was a kid, I loved to sit in the back of the bus and listen to the supercharger whine as the Detroit Diesel 6-71 spun to what seemed like impossibly high rpm. There is a very
engines don't strain as much to give you the speed you want. an engine has design problems, it takes about 15 years before we
Where's the beef? The 6-71 Gray Marine Diesel Engine is a marinized version of the General Motors Detroit Diesel 6-71 engine produced by the Gray Marine Motor Company. Why do people say that forever is not altogether real in love and relationship. WOT is a honest 2500 RPM which is what they are rated for under load.
If you cruise an OA 548 at 14kts you will be working a pair of 671s pretty hard and a complete rebuild at 3000 hours would not surprise me. In 2012, David Pascoe has retired from marine surveying business at age 65. The first and only book of its kind on the subject of investigating pleasure craft casualties and other issues. small engine with 6 or 8 cylinders and pistons that pump and supply
year old 3116 engine yesterday. This creates a lot of drag, but is much better at dissipating heat. Permalink. Marine Engine Rated Horsepower (SHP) with N55 injectors: 100 at 1000 RPM, 121 AT 1200 RPM, 140 at 1400 RPM, 158 at 1600 RPM, 172 at 1800 RPM. cons depending on the application of the engine. Like connecting
exhaust valves, but twice as many of them. Typical 6-71 Fan-to-Flywheel Model an-to- ywheel| models . We all thought that Yanmar was going to lead the way with their
Fuel Consumption with above conditions: 7 gal/hour at 1200 RPM, 9.5 gal/hour at 1800 RPM. Hundreds of thousands of the 71 series engines continue to labor on in stationary applications, earth-moving equipment, buses, trucks, ships and boats. In terms of overall reliability, Id rate them about the same
All were 2 stroke supercharged diesels. A poor choice above that. In the pantheon of marine power, no diesel engine can compare with the two-cycle Detroit Diesel. Read more Quantity: Last One / 1 sold Price: US $13,950.00 Buy It Now Add to cart Best Offer: Make offer Add to Watchlist 37 watchers going to run your boat, and the kind of performance and service
550 psi. The blower is a big help. This is one of the things that has made these engines more
each cylinder to get a large shot of fuel. Articles, Images: Copyright
Marine Power Brochure; Marine Power for Commercial Vessels; 888.687.0539 (U.S.) | 225.706.4858 . As with Mercedes (to
so it results in a temperature increase, even with intercoolers. longer than most 4 stroke engines, creating more rotational mass
2019-2022 Junko A. Pascoe All rights reserved. cylinder temperature. Repowering We get a lot of questions
When money is not the issue, by all means play
The numerals 6 and 71 stand for the number of cylinders in line (6V designates a V-6, which appeared in 1957) and the displacement of one cylinder in cubic inches (actually 70.93 cubic inches). The upper manifold is the "inlet" and the lower is the "return" or "outlet." To prevent confusion, the words in and out are cast in the side of the head. I have a pair of 671 marine diesels 485HP. The smaller
What about the others? The Roots blower allowed the 6-71 to develop maximum torque and horsepower at the same rpm about 2000. (What setup?). Steve Lusardi 2005-10-13 16:49:03 UTC. low profile boats with adequate headroom.. In a boat, the coolant which circulates through the engine is cooled via a heat exchanger, supplied with cool water from outside of the boat, which is mounted on or nearby in a "double loop" configuration. DETROIT DIESEL 6-71TI 485.3HP vs ISUZU UM6RB1TCX 477.4HP. Usually its one injector that sticks and it holds the rack wide open. This one thing that makes DD blocks more complex. Detroit Diesel 71 Series Fuel Pumps. others, for only DD makes two cycle engines. If the builder puts the right size
The key to them is proper maintenance, I run them at 2250 rpm's all day long. around with the German diesels. For a better experience, please enable JavaScript in your browser before proceeding. Listed here are some general maintenance items to check. by roller followers placed in the head with a very short "pushrod." RUN AWAY! The very first of its kind, this book provides the essentials that every novice needs to know, as well as a wealth of esoteric details. This is done by pumping in more fuel and turning
cycle diesel relies upon piston suction to draw air into the cylinder. The most HP I'd want in a 671 is 410, which was made. since the question is posed without any parameters. newer gen. and kick a$$ economy to boot. The Fora platform includes forum software by XenForo. for any diesel, say 0.4 lb of fuel per HP hour So an honest 100 HP costs 40 lb/hr = 7 . All things being equal, engine longevity between the two
Because it was never designed to dissipate those kind of heat
You're
Weight is 32,000 lbs. Coolant capacity is 7.5 gallons. parts. fare in something other than hotrods. Typically, DD engine parts are
And it also greatly reduces the internal
This throws the engine timing off and can result in
The 6-71 makes a unique sound because its a two-stroke diesel. comes up and starts compressing the atomized fuel, it is going to
gone down the drain because you want to go fast. fuel consumption DD 671 N's I have a 80 model 43'FBDC with DD671 N's, I think J&T rated at 310hp. that they are delicate is not an overstatement. Normal oil temperature is between 200 and 235 degrees F. Normal oil pressure (PSI) is between 40-55 at 1200 RPM, and 50-70 at 2100 RPM. gas engine without spark plugs. Except for the
that this new Cummins engine only turns 2300 rpm? valves and a blower, compared with a four cycle with only two valves
because of the interchangeability. You got to get that
I have a 38 Viking with 671TIB'S, 2800 hours and never rebuilt, they run perfect! small Hats, Berties, etc.) One has 5500 hrs but 2100 since overhaul. could see a 3208 and 6V92 sitting together side-by-side on the floor,
Best it can do is 425, and
This is at odds with what my delivery skipper recommends which is 8 gallons per hour @ 8 knots. Mama dont
and DD engines evening out on the overall scorecard except for one
Copyright 2019 Diesel Pro Power, Inc. 760 NW 4th. I do remember one of the instructors telling of being at GM and one of the GM instructors telling of a GM factory ocean racing boat with (I think) 6-71s that ran up to 3500 rpm.
Turbochargers and Blowers Turbochargers
At bottom dead center, the piston uncovers the intake ports, letting in a fresh charge of air, which helps scavenge the spent gases. Very old technology (developed by Alex Winton in the 1920's, the 6-71 was first made in 1938), but very reliable and well proven. We had a 6-71 Naturally Aspirated (NA) engine that ran like a champ in a 42 Uniflite and was still running strong at 4000 hours, never had a hiccup with that engine, my all time favorite Detroit Diesel. With Detroits, you have
had 6-71T's at 425hp and could never get them to run right. Normal coolant temperature is between 160 and 185 degrees F for the 6V71. Why are professional headshots important? this suction and forces air into the cylinder at a much faster rate,
The four cycle engine is aspirated through
dead center. The 1040 hp versions
Yachting may receive financial compensation for products purchased through this site. Even so, there is a major
[4], The Gray Marine 6-71 Marine Diesel was developed from the General Motors 6-71 diesel engine that was in use for on-road applications, farm machinery, and other off-road applications. with Engine and Shaft Alignment, "It's
671 Truck; 671T Generator Engine; V71 Series. few years ago, Caterpillar introduced their 3100 series of new 6
to drive other components such as pumps, air compressors, even alternators
6.8-7.5 gallons per hour at 10-12 mph and. The Detroit Diesel 6V71 has six cylinders, a displacement of 425.6 inches , a bore of 4.25 inches and a stroke of 5 inches, and four main bearings. Yep, more fuel results in even more heat. Can anyone give me a ballpark figure how much fuel a Detroit 6V53 will consume, loaded? 6V71Turbo
inside the cylinder is going to be rather hot. Problem is, on smaller boats, you have to give
The Integrated Detroit Powertrain combines our most fuel efficient engines ever, the GHG17 DD13 and DD15 , with the technologically advanced DT12 transmission and Detroit tandem high speed ratio tandem axles to help you get the most out of every gallon of fuel.. With engine technology calibrated to deliver greater . That figure does not include the engines made for Gray Marine. They
The exhaust valves close, and the piston ascends for another compression stroke. whom they are related), those people aren't shy about pricing. Why? that can make engine selection something that requires very careful
Are they the J&T version? will get either too much or too little fuel and the owner wont
For all performance engines, getting rid of the heat of combustion
Initially intended to be used in GM's trucks and buses, the engine was also designed to take advantage of a variety of manifolds, mountings, generators and transmissions . to depower. Detroit. oooh yes !!! So why cant you get a higher powered Cat? initial cost and repair and maintenance costs, these engines are
10.8 liters
Long story short, it is ridiculous for this vessel to have 735HP engines (as it can't plane). Because
extra moving parts eats up some of the efficiency gain. build ups. Between the two engine types, the injectors are
and no blower. you may want to drive a powerful hydraulic pump for things like
I had 8-71n's and as Ski said, with reasonable care and light duty, they will keep running a very long time. Of late we have been running into
Detroit Diesel / Johnson & Towers 6-71 TIB, Marine Diesel Engine, 485HP Last item available Condition: Used "Running Take-Out marine diesel engine. then you're on your own. Demand Great Fuel Economy The Integrated Detroit Powertrain. Thus: at continuous full power (116 kW @ 2100 rpm) it will use approx 25.0 liters per hour. They have no injector pump (pressure happens within the injector), other than the starter there is no electrical power requirement. The series was introduced in 1974 as a rebored version of its then-popular sister series . [1] The engine's compression ratio is 18.7:1 with a 4.250inch bore and a 5.00inch stroke. Probably the most outstanding feature of the DD
This is at odds with what my delivery skipper recommends which is 8 gallons per hour @ 8 knots. is delivered to the propeller. Last year,
include badly balanced boats which don't trim out properly, resulting
costs. downward, past this row of holes. This engine does best at 375 hp. system to the cylinder head and injector. It's bigger brother, the EMD (Electro Motive Division), had already proven that diesel powered trains, were far superior to steam engines. POWER OUTPUT guaranteed within 5% at But, they didn't smoke, got good fuel economy at slow speeds and would always start and run well. market, which they serve well. I have a '73 43' MYDC with DD 6-71s rated at 216 HP. basically commercial engines, and the drive housing is designed
My question is at what RPM would this boat need to run to be the most efficient under the following circumstances? Stan Grayson in his book Engines Afloat (www.devereuxbooks.com) states that GM built 9,000 6-71s in 1941 and, by 1944, had increased annual production to 62,000 units. The Cat big block engines have
Thanks for jogging my memory. rpm, Bore x stroke
The amount if iron contained in the block makes a difference.