Best Engines: GM Builds an Awesome V12 with Detroit Diesel's 12V71 "Buzzin' Dozen"

Learn more about this sweet 12-cylinder engine from Detroit Diesel, the 12V71.

[@tonyelliott7734]

Twin 12 V 71s at max rpms in an offshore yacht is a mechanical symphony that everyone should experience at least once before they die.

[@chrisadkins6830]

Sorry friend but what you said is both true and wrong at the same time. Symphony vs sympathy. Hahahaha.

[@tonyelliott7734]

@@chrisadkins6830 Damn. A combination of spell check and not proof reading before posting strikes again...lol 😆

[@chrisadkins6830]

@@tonyelliott7734 hey, made it even better. The vids of the destruction runs on these screaming Jimmys are awesome. Very few things sound as beautiful as one about to blow

[@tonyelliott7734]

@@chrisadkins6830 DeBoss garage...lol

[@bradchll]

I still see the odd DD 12V71 around, but always in old logging and mining equipment. Forgetting for a moment how visceral these things sound, the 71 series, I believe , were frankly one of the toughest diesels, especially in the worst of conditions . They happily ran continuously at higher rpm . They were a joy to shift in a truck and you had to be fully “on deck” to operate, to be rewarded with quick shifts. Again , hauling off-road in mud a new four stroke would be stuck in one gear until you hit a downhill.

[@92nbush]

Theres an old trucker saying if you're driving a 2 stroke, there's only one way to drive them. First you gotta take your hand and slam in the door jam first thing in the morning, then spill about a half a pot of coffee in your lap so you know you are good and pissed off and keep the petal to the metal for the rest of the day. The reason is that the detroit 2 strokes hate being lugged down and often will cause premature mechanical wear and failure if you drive to gently.

[@philstarsick82]

Amen brother!

[@keithwood4297]

That’s the way we were taught! Let it scream, they love it

[@AlanRoehrich9651]

You don't have to do that with a 12V71T. It has plenty of power. That saying was created by guys who drove naturally aspirated 6V71 engines in fleet trucks.

[@wildcoyote34]

@@AlanRoehrich9651 i remember a guy i used to work with at the rock quarry near where i live ,,guy was used to driving a dumptruck that had an old 1693 caterpillar , the truck i ran every day was a 359 pete that had a 12V71 ,and i remember having that poor guy about shit in his pants when he rode with me cause he swore iwas gonna blow up the engine ,,causei drove it with my right foot on the floorboard ,, that stupid CAT you were looking for the next gear at 1700 RPM ,, that ol Detroit wasn't even getting warm yet at 1700 ,,,dude's eyes about rolled up watching the tachometer getting up towards 2300 before i shifted gears ,,and that old pete had a 6+4 spicer twin stick ,climbing up out of the quarry was a 23 percent grade meaning LOW gear , let er sing ,,the truck he drove would get hot and boil over if you tried what i did all the time with the detroit ,,best thing that ever happened was the day jimmy tried to drive that CAT like my Detroit ,, idon't remember what the boss said but i do remember how mad he was ,,,something about cats not being driven like that ,,and then there was the 1693 that suddenly had several observation windows in the engine block after an incident involving a missed gear going down the 23 percent grade into the pit ,,he tried the same shit i did every day with that buzzin dozen

[@paulkimber6028]

Yep, that's what I was told.. Slam your thumb in the door and drive like you're trying to blow the fucking thing up.

[@kimmer6]

I was a Field Engineer for General Electric Company in the 1970's and 1980's. We saw lots of these twin turbo Detroit V12-71's on gas turbine generator sets. These were mounted in the Accessory Cab at the front of the gas turbine and ran through an Accessory Gearbox. The Detroit Diesels were STARTER MOTORS for frame 5 and Frame 6 gas turbine generators, 24 megawatt and 34 megawatt units. These units were often ''Peakers'' where the utility company needed another 100 megawatts very soon. Start up 4 GE Frame 5's and within 15 minutes they could go from cold to full load, run for several hours or days, then shut down and be on standby. Some refineries and power stations ran them for months on end. They sure drank fuel oil or burned huge amounts of natural gas. The V12-71's were coupled to a Twin Disk torque converter and had a one way jaw clutch to spin up the gas turbine to 20% speed (about 1000 rpm) where fuel was introduced and the spark plugs were firing. When the turbine combustion system lit off, the Detroit Diesel would scream its guts out and assist the turbine to spin up through its rpm range. The turbine would overpower the jaw clutch at some point, maybe 70% speed, and run up to 5100 rpm running speed. Sensors would idle the Detroit for a few minutes in cool down mode then shut it off. Those Detroits had a harsh life. When the turbine start signal switch was turned, the Detroit fired up and idled for about 15 seconds, then would go wide open governor for the next 5-7 minutes. There was no muffler, just a straight stack out of the roof of the Accessory Cab. After about 10 minutes, the Detroit shut down until the next time the operator called for a turbine start. These things were LOUD! I recall that they were rated 600 horsepower as shown on a tag on the diesel.

[@MUUKOW3]

There is a video on KZbin of one these plants firing up. Just amazing sounds!

[@bradchll]

It’s always amazed me that the 53 series, 71 series were used in the most unforgiving circumstances and gave a long life. 92 series not so much but they were dragging a lot of horsepower out of a smaller engine, compared with both Cat and Cummins. For sheer toughness they were hard to beat. We still have some in use powering HD Hayes and Pacific off road logging and equipment haulers ( all museum pieces now) in BC.

[@kimmer6]

@@bradchll I have a nice 3-53 in my shop. Maybe....this year I will trailer mount it, install a seat and a right angle gearbox, and make it the world's noisiest Margarita Mixer.

[@bradchll]

On your idea of the margarita machine using a screaming lil 53 series, fantastic idea! I want to see and hear it if it gets built. Think of it as a mariachi band for gear heads while you sip. I think Jimmy Buffet would be grinning as he was a gear head also.

[@kimmer6]

@@bradchll I'll be the operator and taste tester. You bring the limes.

[@bobsmith2637]

Detroit was the last of GM's big three diesel divisions, coming after Winton/Cleveland and Electro-Motive. I'm a railroader so I'm most familiar with the three series of EMD engines, the 567, 645 and 710 (those numbers are also displacement per cylinder). The 567 is exactly twice the bore and twice the stroke of a 71, and was designed at the same time by the same GM engineering team. The main differences from Detroits are that EMDs have a fabricated (welded) crankcase and top deck (these two sections are bolted together and constitute the 'engine block'), they have individual heads and single cylinders (power assemblies) can be removed and replaced fairly easily. They are overhead cam engines with no pushrods and turbocharged EMDs do not have roots blowers, instead the turbo has an overrunning or 'Sprague' clutch and is kept spinning by the engine geartrain when idling or at lower speeds. As the engine revs up the 'load' of forcing air into the engine gradually shifts from the geartrain to the exhaust turbine, and the clutch disengages once there is enough exhaust pressure for the turbo to freewheel faster than the gears are turning. EMD has used this turbo design since the late 1950s, and it might be the earliest example of what would now be called twincharging. EMDs are all 45 degree V engines, with power outputs ranging from the 600 HP roots-blown 6-567 all the way up to the 5500 HP turbocharged 20-710. The 567 is a legend in the railroad world, as it more than anything else is what killed the steam locomotive in North America. And they all have that signature 2-stroke scream on steroids, the earlier turbocharged 567s and 645s without exhaust silencers are my favourite, they shriek like a banshee, no diesel rattle at all, they sound like a bass-boosted jet engine on takeoff. EMD is now owned by Caterpillar and the 710 engine is still in new production today. It gained electronic injection and controls in the mid-1990s (the computer in our locomotives is called the EMDEC, their version of DDEC), and can be found in locomotives, ships and generators all over the world. Dual-fuel natural gas versions are available and it even meets the EPA's Tier-IV emissions standards with exhaust aftertreatment, though the railroads are avoiding these systems like the plague and as a result very few new EMD locomotives have been built for North American use since Tier-IV came into effect (rebuilds are grandfathered in, and there are thousands of older EMDs still running in daily service in North America alone).

[@JAMESWUERTELE]

I used to work on 645’s for power generation. 2.5 mw a piece.

[@fitzmorrispr]

Makes me wonder if EMD’s tier IV efforts could be translated to the DD platform, as i recall there’s still new blocks available from the company that bought all of DD’s 2 stroke tooling…

[@FlatBroke612]

Nice. I was engineer on a tug with two 645 mains and a couple 8-71 aux engines. Absolute music at full away! I also saw the aftermath of a 12v149 which ran away, it destroyed the alternator and even threw the pole shoes off, it finally stopped after damaging the valve train enough but surprisingly the rotating assembly stayed together. They’re great engines, I have a few 6v53’s in personal projects. One is likely the only Detroit diesel powered 1924 Fordson F model tractor in existence. That was a fun build.

[@jamescaliendo1030]

Thank you for this. As a truck driver here in NYC, and also a rail fan I found your post extremely informative and interesting

[@skipnick]

i never got to run the FL-9 :( i just missed it by 2 years

[@retireditguy9493]

I was in the Navy on the rivers in Vietnam and the Detroit 71 sound is iconic to me as that of the Huey helicopter. I was assigned to ASPBs (Assault Support Patrol Boats) that had 2 12-71s. PBRs on the rivers had 2 6-71s and some of the troop carrying boats also had 6-71s.

[@MUUKOW3]

Well first thankyou for your service and sharing a local mill had bought one of surplus and used it for a log pusher in the ponds .That thing sounded awesome off in the night.

[@zubrickadvisors6742]

Yes I was aboard and LKA and we carried 8 "Mike" boats, or landing craft. The 4 large Mikes had 2 12V-71's. I was a boat officer and the guys used to get pissed at me for taking over and revving those babies to max rpm. But the engineers loved it.

[@michaelhatcher5264]

Detroit Diesel also made a 6-53 V six cilender the Army 🪖 had these in the M- 113 Battle Taxi.

[@bradchll]

In mountainous conditions, logging, especially to be able to shift quickly off a landing, the V-12 was unmatched. Torque at idle was the highest, even amongst much bigger engines, K model Cummins, 3408 Cat. Clark trucking in British Columbia had a fleet of V-12’s hauling refrigerated goods in those mountains. Horrible fuel mileage and constantly in need of topping up the oil was a down side, but my gawd did it ever sound fantastic pulling hard. Very, very effective jake brake as well.

[@MUUKOW3]

Had a friend that was a mechanic for a logging outfit that ran those. Went on a late night "test drive" bobtail. Windows down foot the floor never forget that sound.

[@mainebigfoothunter7088]

I've operated lots of railroad equipment with 4-53 and 3-53 Detroits. As a kid before the interstate came along, I got to hear Detroit powered trucks travel by Dad's farm

[@gcrauwels941]

The -53s have a distinctive sound thanks to the straight lobed blowers.

[@thundermite1241]

Lets not forget the 8v92ta that was featured in the m1070 tank hauler

[@michaelsullivan2361]

I operated a Euclid TS-24 scraper back in the 80’s. 12V-71 in front and a 6-71 in back. Both with straight pipes! Nice machine and pretty fast, around 35 mph on the haul road. But LOUD!!! First time I ever wore earplugs on a scraper. Prior to that, I’d been running Cat 641’s & 631’s. I did like the sound of those two Detroits singing in harmony, however! Back in the 40’s, 50’s & 60’s GM was at the pinnacle of engineering prowess. Nothing was too big for them to take on and excel at. EMD Detroit Diesel GM Coach Euclid Allison They led the world in design and innovation!

[@donaldreadenour3776]

Back in the early '80s, I was a mechanic in a mechanized infantry unit in the U.S. Army in Bamberg, Germany. I was the operator of a M578 Recovery Vehicle (VTR, or a wrecker on tracks weighing 30 tons) which was powered by an 8V71T Detroit and our battalion consisted mainly of APCs (Armored Personnel Carriers) powered by 6V53 Detroits (318 Detroit) and I still have flashbacks to arctic cold mornings before the sun even came up when we would have training alerts and ALL the equipment must be ready to roll out, the smoky haze over the motor pool, the distinctive smell of 2 stroke diesel exhaust in the air, and the roaring thunder which was comprised of the hum of the dozens of the 318 Detroits idling, warming up, and waiting to defend our way of life. Throw in a few Continental V12 air cooled diesels in the 60 ton recovery vehicles (M80s), the straight 6 multifuel "Deuce-and-a-halves", and the 250 HP "Big Block" Cummins in our 5 ton trucks, GOSH!!! I've been out of the service for decades now, but every time I smell diesel fuel, diesel exhaust, or hear the melodic hum of a Detroit Diesel engine, I am compelled to put my hand over my heart and hum "The Star Spangled Banner" no matter who thinks I am a nut!!! ...and to top it off, I'm a Ford guy, but the ol' 2 stroke diesels have a mighty special place in my heart!!!

[@daledavies2334]

Yup the 6v53 is 318 CID. But the 318 generally referred to the 8V71 truck engines which happened to be 318HP. These were naturally aspirated, no turbocharger. The blowers were there for scavenging, not supercharging.

[@ElvinLeadfoot]

1979 Long Hood Kenworth 12V71 twin turbochargers Ed Davis A treat for everyone to see :)

[@yunoguy2498]

Another cool thing about the 2 stroke Detroit units is they are modular so a 12- 71 is basically two 6-71 heads on a shared block and you can use one 8-71 head on a 4-71, all the pistons and liners are interchangeable between the different configurations of the same series and you can even reverse the direction of the head on the inline motors and the block has provisions to swap the cam to the other side so you can have the exhaust side of the head pointing to the left or right. They are overall very well thought out and straight forward to work on and it's a shame more things can't be designed that way today.

[@gregculverwell]

While a long piston skirt is good for piston stability, in this case it was necessary because the piston acted as a spool valve. It had to keep the ports covered when the piston was at the top of stroke. Otherwise the air from the blower would escape into the crankcase. The long piston did make the block taller (and heavier) than otherwise would be necessary.

[@ricksmith4736]

Ol2stroker has two V12 trucks in his collection... He just pulled one to rebuild... Good show..

[@rf159a]

I think I installed a couple of emergency generators that had this engine. The start-up guy said these were some of the best diesels made at the time. This of course was many moons ago. I was an electrician for over 40 years!

[@joesutherland225]

Yup usually had ge gear on electrical side not always though as you could order any prime mover you wanted on all of them.

[@michaelsullivan2361]

I had a job testing standby generators. At one hospital, they had a bank with 2 Cummins powered and one Detroit. One of my tests was to see how fast they would come on line after interruption of commercial power. The 12V-72 ALWAYS won! The two Cummins would just be firing and the Detroit was screaming away at rated power. It was almost instantaneous!

[@MUUKOW3]

​@@michaelsullivan2361The only one close was the Scania 12

[@Colorado_Native]

One small correction. Noise is unwanted sound. These make joyful music. Enjoyed the video. Thanks.

[@edwardpate6128]

As a teenager in the mid 70's I worked at a service station(Remember those?) in the suburbs of Detroit. A regular customer almost daily was a guy with an early 60's GMC with a 3 yard dump body on it and a 6-71 engine. He would fill up on diesel and buy a gallon of oil and pour into the engine and then would go roaring off, that engine screaming like crazy! I always heard them referred to as screamin demons back then.

[@domenickblancato8600]

I was raised on Detroit engines. And I still love them.

[@1Dougloid]

I worked at McDonnell Douglas in the 80s and on the flight line they had two compressors for pressurization checks on the MD11. One was what they called the huffer truck, had two 8v71s back to back and the other was powered by a 12V71. It sounded glorious running at full tilt.

[@ericwhitehead6451]

When I was in the Air Force in the early 90's, I remember the tugs used to pull C-5's and C-141's around used turbo charged V12's. Great sounding engines.

[@keithbrown3704]

I did my apprenticeship with International Harvesters so as a result came into contact with a significant number of Detroit's of various ages from 53 series then much later 92. They struck me as being a well designed and thought out engine finely built components compared to some of the others at that time. There were continuous improvements over the years, including the introduction of the cross head piston, or more commonly called the articulated pistons. I don't recall any other manufacturer employing this system until years later, also above port cooling. These engines have a small rectangular air box cover rather than the big single oval one, aluminum rocker covers bigger injectors etc to name just a few. The oldest Detroit I rebuilt was, I think from memory was called Grey Marine, I may be wrong here but it was x military 6-71 low block, it was powering a small tug boat and reportedly came out of a US landing craft. Obviously a lot of the manufacturing techniques used in this particular engine were of the period, of note was the use of a one piece conventional head gasket rather than the later compression seal ring configuration. I have no idea how many hours the engine had done over all, and there was no indication it had any significant prior work but after the rebuild. liner kits, valves, injectors, bearings, seal and blower bearings, oil pump clean and inspection etc all the normal things, no crank regrinding or anything of that nature it went back into service. Ten year later when I left the area it was still going strong up to 15 hrs a day dragging all types of barges around. My thoughts on the Detroit. I think it was one of the most outstanding engines of its time, yeah it leaked oil and had its flaws, what engine is perfect. but it was honest, worked hard. Because or standardization of parts across a series it was cheep to rebuild and relatively simple in the process. the only service tools required were the injector timing gauges, you could do the rest with a basic tool kit I remember reading in the early 90s that something in the order of 85% or more of Detroit's built were still operating in a multitude of applications. If that's not testament to a good engine design, what is?

[@keithkauffmann5815]

Adam, great videos on the Detroit Diesel motors. My dad worked at DD for 26 years. As a kid, the engine that blew my mind was the 16V149. Basically 2 V8s bolted together with 149 cubic inches per cylinder. If I remember correctly, I think the engine weighed about 10,000 lbs! What an absolute powerhouse.

[@leonardhirtle3645]

I rebuilt several 16v149’s in my marine career. They were an amazing engine. They produced about 1000 hp naturally aspirated. As you said they were 2 v8s bolted together an we had to separate the two blocks to replace seals . This was accomplished by standing them on end in the engine room using large chain falls.

[@danflemmer1999]

Buzzin' duzzen ferever!!!! Love that sound. A pair of 4-71's in a terex scraper ain't too shabby either.

[@alangarton4313]

I drove and worked on the 6-71 in school buses for a dozen years in the 1980's. They not only were a great, long lasting, and powerful engine for a school bus, but they were a lot more forgiving to inexperienced drivers then, say, a 743 or 855 Cummins. We had a couple of the turbocharged engines in the buses, making 250hp, and with a 10 speed trans, it would move right along in the Sierra-Nevada mountains.

[@williamtoy3704]

855NT. One of my favorites.

[@LBrawn]

how are they more forgiving?

[@michaelsullivan2361]

Crown?

[@L-Taraval]

A few years ago, I had the opportunity to purchase a few Crown school buses that operated in the Sierra Nevadas. I forget what district, but I went to inspect them and was just amazed that they had 6-71 turbos with Jake's, 10-speed roadrangers, and Traction sanders, among other things. All started and ran beautifully, but I didn't bid. I'm still kicking myself for not purchasing one of those gems

[@paulkirkland1535]

I grew up around Detroit diesels in the '70's. Oh yeah I remember the "buzzing dozen" in GM heavy duty trucks with 15 speed gearboxes. Certainly brings back memories, I'll never forget the good old days. Great video.

[@chrisberti3794]

I sailed on a ship that was built in the 60's. Used Detroits for everything besides propulsion. Two 12V149s for back up generators when we had no steam. They were so loud that when they were running you could hear them across town from the harbour. If they were both running and you were down checking them out standing on the cat walk between them would make your eyes vibrate and your teeth chatter. We also had two 12V92TAs as back up fire pumps in case we had no electricity. I and about 240 others owe our lives to those engines as they ran in a smoke filled space for days as we fought an incredibly large engine room fire. And lastly we had "the green leakers" two 6-71s in our landing craft. Made a lot of noise to barely get the landing craft moving, and were more likely to overheat than actually land anything anywhere. I loved working on those engines, reliable right until the day the ship went to the big razor factory in the sky.

[@buick1955]

A Screaming Jimmy. One of the best videos on KZbin , The Big Blue Guck - Driving to Work. 1963 GMC Crackerbox, running a Detroit Diesel 6-71 2 cycle engine.

[@DS75921]

Never drove a truck with a buzzing dozen but drove a 8-V71 and it was pure music to the ears.

[@gcrauwels941]

These are the engines that powered many of the yachts and work boats I worked on. The JT6-71TAB (Johnson and Towers marine) produced 485 hp and was pretty much the limit for the 6. We had car ferrys with a pair in 12V71Ns (one at each end) that we could inframe overhaul in a weekend. I did get to work on a pair of 24V71Ns (rare) in a research vessel. Setting the racks took patience. They have a sound I miss tremendously. Really heavy components. Hiking a 6-71 cylinder head up the spiral staircase of a Hatteras motoryacht was not easy, even with two guys.

[@ericgilhart5951]

Those old two strokes Detroit diesel engines are what made america through so many applications

[@JWZelch]

The buzzin’ dozen!

[@76629online]

Most people could never even conceive of how much freight these engines have hauled throughout history. It's mind-boggling.

[@chrisridgeway9790]

The two stroke Detroit ! The most efficient means mankind has ever found for turning fuel into beautiful music !

[@anthonyjackson280]

Harley Shovelhead enters conversation......

[@buckberthod5007]

You're half right. It's the best way to turn money, into fuel, into screaming harmony and smiles

[@halfmil6467]

Author describes it as "turns diesel into noise" Amen 😅

[@kagome122885]

2 stroke Detroit diesels are the best sounding diesel engines

[@user-rn2bi6wx2b]

I remember in 1976 the old Greyhound bus they have Detroit diesel they sound good to 🤠...

[@michaelnault5905]

I rode many Greyhounds as a kid and spent several miles piloting 8V71's as an adult. I'm glad I don't do it anymore, but yes the sound is the music of my youth.

[@robmikell7444]

Hello there friend. I'm a retired heavy equipment mechanic. I've rebuilt a lot of Detroits. When I was a novice I saw a fresh 4-53 run away on startup. I was always extremely cautious around these noisy beasts. To the uninitiated, a Detroit sounds like it's going to blow up. Being 2 cycle, it revs twice as fast. And that smell. Like following a Greyhound bus ( also Detroit). I had a healthy respect for them. We had a 1 foot square board with a mop handle. The blower shutdown ALWAYS comes off on rebuild.. They were there for a reason. Runaways.

[@DeweyBlanton-ku7db]

Thinking about buying a greyhound with a Detroit. Any thoughts on what to modify first?

[@RandThompson-dd3sk]

Yup. When they runaway everybody runs away too. Once I was running a Gradall that ran away. Gritting my teeth hoping it didn't granade in my face as I was weaving thru hydraulic hoses and cylinders getting to the flapper. It's a sound and experience one never forgets.

[@ShadowOppsRC]

Got to love that 2 stroke diesel scream! Thanks for sharing!

[@hughjass1044]

I commend you wholeheartedly for your accurate description of how these engines work and for NOT calling those blowers superchargers which they are not when they are used on these applications. This is one of the most common mistakes that car guys make because they are used to seeing them only on hot rods, hemis, top fuel dragsters and the like where they are in fact, superchargers in those cases. You really need to have had exposure to trucking, diesel mechanics or some related field to understand the difference. Bravo!

[@jdcole333]

I could be wrong but I think the first roots type super chargers were scavenged from DD's. Early on they were all classified as either 6-71 or 8-71 blowers.

[@WhiteTrashMotorsports]

Thank you, I cringe when some dolt calls a turbo. Detroit twin charged because of the blower.

[@johneckert1365]

​@@WhiteTrashMotorsports#ME TOO

[@hughjass1044]

You are in fact, absolutely correct. That's exactly where they came from and it was down to nothing more than availability. The 71 and later 53 series Detroit Diesels were in widespread use in those days and the blowers off of them were plentiful as a result and relatively cheap. Another common misconception is that the 6-71 blower gained such wide favorability for use on Mopar hemi engines because it was engineered to work on a 426 CI engine which the 6-71 Detroit is. This is wrong however as those engines had been around since the late 30s and the 426 Hemi never arrived until the early 60s. It was simply a coincidence and a case of those being very common engines in those days; I myself operated several of them in my early days, and availability was high. @@jdcole333

[@I-Libertine]

Thank you for your channel. It is very interesting and calming, too. Much appreciated.

[@ferragus00]

My father repaired those engines all his life. I grew up with those wonderful sounds. I believe they were generated by the blower with its elecoidal rotors made of aluminum. Wonderful engine. Special mention to the direct cylinder injection system.

[@bw6378]

The tall pistons and bottom rings are required to keep blower air from getting into the crankcase. No fuel is in the air charge, that comes from the unit injectors in the head. Also you might mention that the intake air coming in the ports is what pushes the exhaust out through the valves. Also noteworthy is that the connecting rod is always experiencing compression loading unlike a 4 stroke.

GM has always been good at producing solid power with multiple cylinder options

[@joeo5738]

I went to diesel mechanic school in 1980 and my first rebuild was a v8 Detroit diesel. I loved that motor. Sorry that the 2 stroke had to go away.

[@AJISFREAKENAWESOME]

Never been this early to one of these videos. Love this series so much! My generation just doesn’t get presented this information very regularly so it’s really cool to see some of the engines no one talks about!

[@Blazefork]

You'd love the 53 series, they have about 400 more governed rpm....it's beautiful!

[@johneckert1365]

6v53 sounds AMAZING

[@geraldo7325]

The skirts are long because the ports are covered when the piston is at TDC, this is to prevent air getting into the crankcase. They also have a set of rings at the bottom of the skirt.

[@Johnnycdrums]

Interesting.

[@johngalt97]

As a gasoline 2-stroke enthusiast, I suspected the skirt as closed-valve, and noticed the bottom ring grooves.

[@stevebyrne4235]

One of fleets I maintained had late '70s GMC Sleepercab Astros with 12-71s, 13 speed, and straight pipes; beautiful exhaust note. 4 MPG; completing a topset (injector height/valve lash/governor and rack) was brutal. We had V12 GMC gas tractors as well, single drive axle with a tag axle for the weight, what fun. Still have my first 60 Series Certificate, framed, a relic, like myself.

[@coburnlowman]

I absolutely loved driving up Mount Eagle at night with the windows down. That sound bouncing off the rock back into the cab. Awesome music. Tho I was sitting behind a 6-71. Those things shifted so smoothly. Or the way they dereved and accelerated, made them shift like stirring a pot of gravy.

[@myronfrobisher]

Excellent Adam , well done !!!

[@robertrishel3685]

The very first inland/rivers towboat I ever worked on was powered by three turbo charged 12v71’s. They were real screamers! We had 6 71’s powering our generators, affectionately known to our crew as the “hammers of hell”. I’m pretty sure there were also a lot of 16cyl Detroit two strokes powering some of the other, larger boats.

[@evanswinford7165]

We had 8V71s in our WW2 era scout boat. It was an Aviation Vessel Rescue boat used for pickup up downed air crew in the Pacific. During the war era it had the gas Allison V12s which worked good at sea level. Those were removed and we got the 671 inline engine. Those wore out and were replaced by the 8s. They ran flawlessly for many years in the boat and we had to wipe them down after each cruise looking for oil leaks. The engines had been put all the aft after the war era mid engine set up. The boat sat down in the stern and out could see it when we tied up next to other AVRs. Great engines.

[@DanT271]

Love those old Detroit's nothing compares with the sound! I always rode transit busses as a kid and the drivers were always brutal on the throttle and I loved the sound and black smoke I am also subbed to Scott over at BGM and Ol two stroker

[@michiganmotorsports]

I've worked on large stationary generators with 12V71' s. Such an awesome sounding and performing machine.

[@jimkillen1065]

There is a company and i dont remember there name that has some of those engines , they were also turbo charged that powered pumps used to power wash boilers . I believe they were from New Mexico..They came to the power plant i worked at and hydrblasted the boiler .. I dont remember the engines giving any problems while they were there . I remember they were huge. Like a engine you see on a generator set

[@mikebel74]

A mechanical symphony, someone said. Totally agree. Such good memories listening to the ‘buzzin dozen. A sound like no other. Great post!

[@61rampy65]

My dad drove a bus (the old GM coaches that date back to the 40's) back around 1960, and I sometimes rode a bus to school in 1970, and I loved the sounds of the 6-71! Still do. As much as I liked your sound effects in the last few videos, thank you for putting in a clip of a real V-12 Detroit Diesel! And yes, it did sound like it was turning about 6000 rpm (even tho it wasn't). Cool video, Adam!

[@warmstrong5612]

Makes a semi-truck sound like a race car. Loved seeing and hearing these things on the road as a kid.

[@davidswanson5436]

You surprise me with this knowledge. Thought you were just a car guy. Bravo sir. Gentleman and scholar.

[@DanEBoyd]

Ol2Stroker is another great Detroit Diesel channel.

[@jimmckinney6715]

Great video that brought back a lot of memories. I've rebuilt everything shown in this video and then some. I used to work in the engine rebuild department at Covington Diesel in Greensboro NC, which was a DD distributor. I'm not sure if they still exist. The 71 series were great engines. It was pretty typical to see them with 300,000+ miles on them.

[@David-yy7lb]

My uncle had a long nose 83 Freightliner truck with those 4 round headlights, that truck had a 6v71 Detroit and I love to hear that motor scream when I was a kid going with him over the road👍🏿

[@tombrown1898]

For a number of years, I sold pumps and was consequently in many "mechanical rooms.". I saw many of these magnificent engines that were there to drive generators and water pumps in case of power failure. They were beasts!

[@pcno2832]

Thanks for posting this. I didn't even know that 2 stroke diesels existed in more than theory until your last 2 videos. PS: If you haven't already, you might consider doing a "worst transmissions" video on the Chrysler Ultradrive 4-speed automatic. I had one rebuilt at 30,000 miles, just after the first fluid change, about 25 years ago, and had friends who went through the same thing all through the 1990s. Then, just recently, I read that it was not really the transmissions themselves that caused most of the trouble, it was dealers putting Dexron in them, and that some of the "failed" ones would magically come back to life after Chrysler's fluid was installed. It's a bizarre story considering the fact that Chrysler was rebuilding these things while both the owner's manuals and dipsticks encouraged the use of Dexron to top off the fluid when Chrysler's fluid was unavailable. If you know anyone who worked for Chrysler on the problem, it would make for an interesting interview.

[@stevejarred6484]

May goodness! All this information lately on Detroit Diesel engines from a channel about classic cars and automobiles! Please continue this thread and keep up the good work! I use to work for Lucas Varity Diesel (Later Delphi Diesel) in the Detroit area that re-manufactured Series 60 injectors and fuel pumps and grew to love the sound of their clatter on the test stands ("It was the sound of a hearty paycheck!" you might say... LOL!). It would be an interesting project to adapt one of these types of Detroit Diesel engines to a kit car chassis - It might weigh a ton and slow as a sloth but the sound and torque once you got it going!

[@rockymountainjazzfan1822]

A family friend years ago ran a heavy construction and trucking business. All of his big trucks and heavy equipment were 2-cycle Detroit Diesel-powered. The Detroits' only weakness besides noise were those oil leaks--giving them the nickname "Driptroit". He always said that leaving a Detroit idling for any length of time at regular idle was a big factor in causing the engine oil sealing problems. If he was leaving the Detroits idling for any length of time, he would bump the RPM up to about 1,000-1,200. It used more fuel but seemed to avoid a lot of the oil leakage issues.

[@russvoight1167]

Very good presentation

[@user-xy1lp8jx2h]

I love the sound that those detroit diesels make. Back in the 1970's a construction company in my area had a fleet of Chevy medium duty dump trucks , C60 or C70 's. They were powered by 6V71 detroits. Loved the way they sounded.

[@iceman45ification1]

I miss the sound of those old Detroit 2 strokes. Best sounding diesels ever made. 👌 The reason the pistons were so big was that they needed to seal off the lower liner ports while the piston was in upward motion and also the reason they had rings on the bottom. Otherwise, the pressure would leak into the crankcase and create all sorts of problems. Nice video, my friend. 💪🔥

[@neilmcfadyen5248]

I used to drive and service a terex r35b off highway dump truck back in the 1980s. We used to advance the timing and as long as you serviced them regularly they just kept roaring. Fantastic engine.

[@frasercrone3838]

Being a little picky here but you said the cylinder ports let fuel and air into the engine but of course it was just air and the injector sprayed the fuel in. The jimmy that made the highest pitched scream was the 53 series and in 6V form it was amazing. It revved higher than the other sized engines which added to the sound but if you put an Allison auto behind it then it stepped up a notch again. I worked for an interstate bus company in Australia during the 1980"s and we had 6V 92T and 8V 92T engines in the fleet with the average distance travelled by each vehicle was 30000 kilometers [18,650 miles] a month. The engines were removed at 1,000,000 Kilometers [620,000 miles] regardless of condition to be rebuilt. in ten years only five engines did not make the mandatory rebuild target. The fleet was around the 150-vehicle mark. What's more is that the rebuilt engines would cover the same distance as the maiden engines.

[@bobhill3941]

This was fantastic Adam, I never knew about this engine. I mostly know the 6-71 nomenclature from the supercharger. Hearing the definition for this reminds me of when Ferrari used to name their cars based on the volume of one cylinder in cubic centimeters. Very cool, keep up the great work❤ I also confirmed a hunch that Chevrolet used the "Astro" name from their cabover trucks for their vans.

[@josephdipalma5989]

Awesome video, I started my career as a Union Carhauler in 1988 driving a 1979 GMC Brigidier. It had a 6-71. Awesome sound, but no power to match. It was still a fun truck to drive. We changed to Volvo/GMC's with series 60's in the 90's. What a difference. It's amazing those early Detroits were relevant for over 50 years. Most buses in the NYC area had them also.

[@wayneknodel3347]

I used to live by the TransCanada highway, and worked at the Husky truck stop pumping diesel (and repairing tires😬)as a kid. An outfit called George Smith Trucking used to run only Detroits, if I recall correctly, in ONLY single cabovers with single axles. I don't know if they equipped them with loud mufflers, or they just COULDN'T be muffled, but I remember I could hear those Detroits screaming for minutes before they would come into sight, especially in the wee hours on night shift! It was a memorable sound! Great information and story!

[@chrisleggett685]

In the late 90's I was fresh out of truck driving school. I had to ride a Greyhound bus from Hudson Wisconsin to Dallas TX. I was excited to hear the 2 stroke Detroit in that grey hound bus. 24 hrs later I couldn't wait to get off that bus with it's obnoxious engine!

[@RareClassicCars]

I understand both sentiments

[@MegaMobass]

Never seen a Detroit in the flesh, but I have ties to them, one of my relatives worked for GM at DD in the early years, I think through the war years and on. I’ve always loved the sound of the 2-stroke. Something else cool of note is the larger stationary power plants, the 20v149 are absolute monsters. AT&T from what I understand used primarily DD for their auxiliary power for their central offices.

[@paulkelly4731]

Got 2 of them in my boat... wonderful engines

[@derweibhai]

I have a 6-71 in my International semi. Love the sound. Also have the Fuel Pincher. No issues with it, but also doesn't get the use of the 2 stroke.

[@pmbair]

My brother in law had a 671 Detroit mounted on a Kenworth Brute “Guzzler” vacuum loader truck when I worked for him. I operated and maintained it back in the ‘70’s. We worked mostly in coal-fired electric generating plants across Pennsylvania and New York.

[@shadymaint1]

Had a 8v71t in a wrecker i used to drive. Not very fast but i sure did pull some heavy loads with it. Have also worked on a 16v71t that was part of a large air compressor.

[@partrickstowman8039]

My father in law made his own 4 wheel tractors with Detroits. Started with 6 71 in line and v, then 8 71, 12v71 and the last a twin turbo 12v92. It was huge in the 80s

[@tomromanski7925]

It's nice to see you're delving into some cool diesel history. I'm a farmer and run trucks as well. Growing up the 2 stroke detroit was the choice of power for most of the irrigation wells, and alot are still currently in use today. I also still have 2 trucks, one with an 8v92 and one with 6v92 still running strong. There's nothing like that sound, and I couldn't imagine a world without it! On a side note, have you ever heard of the International Harvester UD series diesel engines? They were early diesels that started on gasoline and then there was a compression lever you pulled to switch it to run on diesel. We have some of those too. That could be a fun topic to research.

[@iBackshift]

When I was young, many log truck companies in my area had 1271's in Cabover freightliers, hauling treelength or shotgun logs. At night when it was quiet, you could hear those trucks for miles and they always had to drop 2 gears on the hill behind my summer cabin. Your vidya is "12v71 pulling Satus Pass". My fave detroit sound is the 8v92.

[@czechmate6916]

Cool video. I’ve been subscribed to Bus Grease Monkey for a while and I love watching his videos.

[@lonokolotowicz5597]

I have had two in my career while driving, one in a 74 pete hood and a 69 brockway. nice engine lots os pep.

[@LeeLarson-rk6cj]

Hands down, one of the toughest engines ever made 👍🏽

[@user-pu9rd7wl9c]

Screamin Detroit Diesel,right?Work horse of legend.😎👍✌🇨🇦good vid/info,thanks

[@yvindHvaal]

As a kid I lived next to a pulp factory and they had a couple of Terex loaders that handeled the pulp wood. Both loaders were poison green and their Detroit Diesel engines were singing loudly while working. They woke the whole neighbour hood up early every morning, even sundays! My first experience with Detroit Diesel engines.

[@gentjim5007]

Ran American friction cranes at a scrap yard for years with 6-71s in them. Saw one throw a rod and put a hole in the block big enough to put a softball through. Another great feature was that they would start in really cold weather (-20) when newer stuff wouldnt. Ours all had ether starts on them for this reason.

[@guyconnell2250]

Drove the 6-71 a bunch when I was 18. 1972 GMC 9500 ready mix truck with ten yard mixer, 300 gallon water tank, and tag axle. With full water tank, full fuel and ten yards weighed about 72000 lbs on the single frame. Had 13 speed trans. Can still hear it. But I thought I was a super trucker.

[@philstarsick82]

Shout out to Dan R. Most in the dd community know and love him. Great man and I am lucky to met him.

[@markpatterson7070]

Great Video !!!!!!!!!!!! Thanks

[@housechadwick7505]

Everyone loves the way they sound in short bursts, get back to me after 16 hours straight in an old International cabover. The wah wah wah wah of it bouncing off the governor, hour after hour after hour. Its how my dad cured me of wanting to be a trucker 😂 I miss th old man.

[@robbkiker6861]

Drove a 8V71 for my dad as a logging truck in the 1970s. That video brings back memories. Go for it on a truck..... don't worry about the low mileage, just have it delivered to Bus Grease Monkey in TN and let him rebuild it. Y'all could do a series of videos together. It would be a blast and very interesting. I watch both of you so we would get a 2 for 1.

[@Dr_Reason]

Ready for the Monfort lane.

[@martentrudeau6948]

Sounds amazing.

[@AJmx2702001]

Detroit 2 strokes were a decent engine and probably the most adapted to any applications around the world more than any other diesel engine of the time which is why I think GM lost the market for heavy trucks from relying on the two strokes for so long

[@Primus54]

My best memory of the sound of that motor is from riding the GM “New Look” transit buses of my youth. (Also known as the “fish bowl” bus.)

[@davidkimmel4216]

Great sound

[@markchodroff250]

My old boss from the 1970’s had a Bertram Sport Fisherman power boat with two 12V 71 Detroit diesels he had them rebuilt at a factory Detroit engine repair shop , from what I understand the boat was a monster! LOL. I was given the Onan generator to check out ,service and repaint-white !

[@jeanclaude7018]

I have a 6V-71 in a 1960s Freightliner in my barn. Kommunist Kalifornia has made it illegal after I bought it. The "426" of the trucking world. That and the inline 6-71 sound almost the same, and the 12V is like a double-tracked 6V sonically. I rode from Jersey to CA in my father's 1959 GMC with a 6-71 as a boy, and that sound has been stuck in my head for half a century. It used to be heard everywhere, but now is so rare. Eventually the role of the 12V-71 was basically taken over by the 8V-92 T in trucks. I learned to drive on one in my father's Western Star. What a hot rod with a quick shifting 13 speed. With turbo and twin stacks, it was quiet too. It easily kept up with the big cam Cummins of the day. Had to keep an eye on the oil level though. Could burn a gallon a day on really hard days of pulling

[@damianbowyer2018]

An Amazing Engine 4 way back then, Adam😊👏