i know a guy in my neck of the woods who buys these DD scrap engines from oil fields and rebuilds them anew... he makes a cool profit on them and they are in quite high demand in the fields. awesome engines. their 2 stroke system is unbreakable. the parts are still available and they are also a hit on medium sized boats. thanks for posting.
@oceantrolls73 You're right there about the boats. My father owned an old 42 foot bridgedecker (1971- 1980) built in1920's originally steam powered. Owner before him refurbished the whole boat and dropped in a new 3-71 about 112 hp. Clean hull he got 10 knots at 1,600 rpm, 2 gallons/hour consumption and nearly 13 knots flat out at, I think about 2,100 rpm. Ran hundreds of hours never missed a beat, real reliable. Noise kept down to OK levels with plenty of sound insulation.
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Detroit Diesels, the most efficient engine ever built for converting fuel into noise!
Also one of the greenest engines ever built, directly recycles lube oil straight back to the ground :) Love em. Hundreds of the 71's and 92's still in service in Australia, mostly as emergency back up power units, the occasional one still found on road in an old Kenworth, but not many left. Pity.
@electricshockproof They are still manufactured new by MTU detroit (6v53t,8v71TA, 8v92TA, all are DDEC I believe) for the military, because emissions and fuel economy doesn't matter (still beats a gas turbine.......), and they need absolute reliability and power in a reasonable sized package. They also re manufacture ANY detroit diesel. I personally think the hummers should get 4-53TA's with DDEC, and if that call was made MTU certainly would bring them into production.
Free inexhaustible energy is real!But Millions are spend in supressing that information,Get a REAL working magnet motor at LT-MAGNET-MOTORdotCOM ,Free yourself!
thats why just about every 2stroke diesel you will ever see has a supercharger on it. the supercharger forces out the exhaust gases when the intake ports are uncovered by the piston through the exhaust valves. its called scavenging if you dont beleive me you can "google" it.
I used to drive a large dump truck with one of these. It was murder on the ears, I couldn't imagine a long haul trucker being saddled with this. The power band is interesting, it comes in at a really high rev, sounds like it is always about to shred. But tough nuts these things are, they run forever.
my buddy has one on his generator to run his ranch its half a mile from the ranch house and u can still hear it it has no muffler just a stack and its a 4cylindar two stroke
Two-cycle engines require considerably higher RPM than four-cycle engines of the same displacement to generate useful torque due to inherent airflow issues with the engine design. The 3L71 doesn't generate much torque below 2500 RPM, as they cannot clear exhaust gas as efficiently as a four-stroke at slow speed.
This comment has received too many negative votesshow
Dude its a small 2 stroke diesel. It could easily have a 4000 to 5000k powerband. Just an example, the toyota supra straight 6 puts out its highest torque at around 4800rpm..
and the rx8 reaches peak torque at 13500.you cant compare a gas to a diesel.max (governed) rpm is 3600.i looked in the book.and if you can get it to turn the rated 6200 rpm right before it blows a rod then i highly encourage it.
@garrett6699 dude, it's a BIG 2 stroke diesel... for 3 cylinders it should be 213ci. The major reason the 'industrial/commercial' diesels can't pull high revs is mostly bottom end weight, but it's also that the vast predominance (except the newest) are mechanically injected. They don't have the shock reduction or really the fuel control to get the fuel in the cylinder in time with any amount of control at higher RPMs.
@garrett6699 ummmmmm, it has a big ass stroke, same stroke as a 12v71 truck motor. bigger strokes cant turn as fast as smaller strokes.....thats why a 327 chevy will spin faster than a 350 chev without throwing a rod, but the 350 has better torque
@Texassince1836 ALL the 71 and 92 series have the same 5" stroke....the only difference is the Bore, between the two. The 71 use a 4.25" bore and the 92 uses a 4.87" bore. The "USABLE" stroke length
is only about 3.9" before the exhaust valves begin to open...then about 1"- for port opening....I forget the exact length of the ports now....."senior moment". lol
no wrong. This engine spins quite slow actually. Most detroits redline around 2600 or so. they just sound like they are spinning twice that speed because they fire every time the piston comes up(2 stroke) unlike a 4 stroke which fires every other time the piston comes up. They do not run at 4,000 rpm.
@iamdave0887 Apparently those Detroits are heavier internally than I estimated. Most of my two-stroke experience has been with single-cylinder motorcycle engines safe to about 10,000 rpm, and Diesels do rev to a fraction of such speeds.
Well, not a 3-71, but a detroit diesel yes. 6v-71's and 8v-71's were more common for busses. 3-71's were common in industrial equipment like tractors, cranes, and, yes, marine. My personal favorite is the 6V-92 turbo, attached to manual transmission, with jake brake, for an over-the-road truck. That is the best DD music! But there's also nothing like a "new look" bus with 6V-71 and Allison tranny... when I was a kid that was the sound of the city.
In Canada we heard this a lot in the 1970s tv show The Beachcombers. The starring boat, Persephone, had a GMC 2 stroke diesel engine and sounded just like this.
No. A 2-stroke Detroit (GMC) diesel has camshaft-operated exhaust valves in the cylinder head just like a 4-stroke engine. The major diference is that the intake air enters through ports in the cylinder wall. This air is pushed in by a roots blower at the bottom of every stroke and actually 'chases' the exhaust out the exhaust valves located at the top of the cylinder. When the piston rises it closes the intake ports and the exhaust valves close simultaneously.
oh and two strokes don't need an expansion chamber to run, but they'll get you a lot more power, that's where the power band on a two stroke motorbike comes from (without going into detail...)
Very Nice. We got a couple Detroits ourselves. A 2-71 On a Generetor, a 3-71 on pump and generator, 3 4-71's runnin pump and generator, a 6-71 running pump and an 8-71 in a semi. Love the sound they make, runnin all night pumpin water. Puts me to sleep.
Just be aware that these engines weigh quite a bit more then a comparable 53 series Detroit, not to mention three or four inches in height difference so suspension modification is almost mandatory.
Thats true and thats why I have been looking for a 1940's or 50's farm truck a tad larger than a 1 ton, I also want to run a dozer stlyle flywheel so when I get to speed the centrifical force of the flywheel will be so great that the engine will work less causing greater milage, by the way I have not decided on the 3 cylinder 53 or 71 yet, I have been thinking the 48 ci more would be benificial and not too much more for fuel usage
the heavier fly wheel will cause the clutch to wear out faster and the engine be harder to start, which on detroit 2 strokes starting them can be a task at times
I just bought one of the railroad surplus 2-71 1200 rpm gensets, but haven't picked it up yet. Hopefully I can post a video of it running into a load.
We had 2 2-71 20kw gen on a barge I worked on. Ran 24/7 for years that's right like 20 years. Needed injectors and such but very reliable, the 1200rpm ones are great, pretty quiet also. Just DO NOT over heat them, you need a head gasket after that.
The engine is filled with water which is circulated by the water pump. It is a sealed system with a thermostat. As it is a marine engine sea water would normally be circulated through the heat exchanger to get rid of the heat. It takes about 10 minutes before the water warms up.
WHAT???
jmac5058 2 months ago
I used to work on a pair of that Detroit's older cousins, the 110. We had two six cylinder 110's matched to a hospital generator. Good engines.
tardis2005 4 months ago
Sorry, couldn't read the remarks 'cause my eyeballs was vibrating in my head from the noise.
Littlebluetruck1995 9 months ago 2
i know a guy in my neck of the woods who buys these DD scrap engines from oil fields and rebuilds them anew... he makes a cool profit on them and they are in quite high demand in the fields. awesome engines. their 2 stroke system is unbreakable. the parts are still available and they are also a hit on medium sized boats. thanks for posting.
oceantrolls73 11 months ago
@oceantrolls73 You're right there about the boats. My father owned an old 42 foot bridgedecker (1971- 1980) built in1920's originally steam powered. Owner before him refurbished the whole boat and dropped in a new 3-71 about 112 hp. Clean hull he got 10 knots at 1,600 rpm, 2 gallons/hour consumption and nearly 13 knots flat out at, I think about 2,100 rpm. Ran hundreds of hours never missed a beat, real reliable. Noise kept down to OK levels with plenty of sound insulation.
SpitfireUploads 8 months ago
u mean whisper quiet!!!! Not!!!!!
randeddy 1 year ago
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RoofMountWindTurbine 1 year ago
Detroit Diesels, the most efficient engine ever built for converting fuel into noise!
Also one of the greenest engines ever built, directly recycles lube oil straight back to the ground :) Love em. Hundreds of the 71's and 92's still in service in Australia, mostly as emergency back up power units, the occasional one still found on road in an old Kenworth, but not many left. Pity.
whorayful 1 year ago
Always remembered learning about these engines. What are these like on emission?
Blunder1248 1 year ago
@Blunder1248 That's one of the reasons why they're no longer in production.
electricshockproof 1 year ago
@electricshockproof They are still manufactured new by MTU detroit (6v53t,8v71TA, 8v92TA, all are DDEC I believe) for the military, because emissions and fuel economy doesn't matter (still beats a gas turbine.......), and they need absolute reliability and power in a reasonable sized package. They also re manufacture ANY detroit diesel. I personally think the hummers should get 4-53TA's with DDEC, and if that call was made MTU certainly would bring them into production.
JtsGreene 1 year ago
@JtsGreene Ah, I didn't know the military was emission expempt, but it makes sense.
electricshockproof 1 year ago
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fittingciobb 1 year ago
That unmistakable Detroit 2-stroke hum.
TDubya5 1 year ago
thats why just about every 2stroke diesel you will ever see has a supercharger on it. the supercharger forces out the exhaust gases when the intake ports are uncovered by the piston through the exhaust valves. its called scavenging if you dont beleive me you can "google" it.
justin15ac 2 years ago
dude what the fuck is your problem? you think you know everything and you dont. i proved you wrong before.
robby844 2 years ago
how much hp and how many gph???
porpoisefathom 2 years ago
I used to drive a large dump truck with one of these. It was murder on the ears, I couldn't imagine a long haul trucker being saddled with this. The power band is interesting, it comes in at a really high rev, sounds like it is always about to shred. But tough nuts these things are, they run forever.
ewmegoolies 2 years ago
always will love them screaming jimmys and sorry to hear about your ears
urbandestruction 2 years ago
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I have on in my boat......BULLETPROOF!
westie70 2 years ago
That two stroke diesel has a sound of it's own. That motor would be fun in a pick-up truck
melaniew77msn 2 years ago 4
my buddy has one on his generator to run his ranch its half a mile from the ranch house and u can still hear it it has no muffler just a stack and its a 4cylindar two stroke
DRNEGOLICIS 2 years ago
I LOVE HOW ITS WHISPER QUITE!!!!
586guest2 2 years ago 47
WHAT?!
BOBKB3NZX 2 years ago 36
@586guest2 *QUIET
nanocoffeebean 5 months ago
@nanocoffeebean lol apparently i couldn't spell 2 years ago.
586guest2 5 months ago
We had one of these beauties on our Frick sawmill years ago...before upgrading to a 6-71. Love that 2 stroke music.
jasonlawn76 2 years ago
Comment removed
DieselsAndDiodes 2 years ago
whats the horse power, tourque, max rpm(from factory and until she blows) and whats the litre/cubic inch
slooter3 2 years ago
Comment removed
bcschmerker 2 years ago
wow ok you think that powerband is 4000?
robby844 2 years ago 2
Two-cycle engines require considerably higher RPM than four-cycle engines of the same displacement to generate useful torque due to inherent airflow issues with the engine design. The 3L71 doesn't generate much torque below 2500 RPM, as they cannot clear exhaust gas as efficiently as a four-stroke at slow speed.
bcschmerker 2 years ago
MAX rpm on a detroit is 3500 and thats pushing it.
robby844 2 years ago
This comment has received too many negative votes show
Dude its a small 2 stroke diesel. It could easily have a 4000 to 5000k powerband. Just an example, the toyota supra straight 6 puts out its highest torque at around 4800rpm..
garrett6699 2 years ago
and the rx8 reaches peak torque at 13500.you cant compare a gas to a diesel.max (governed) rpm is 3600.i looked in the book.and if you can get it to turn the rated 6200 rpm right before it blows a rod then i highly encourage it.
robby844 2 years ago 3
@garrett6699 dude, it's a BIG 2 stroke diesel... for 3 cylinders it should be 213ci. The major reason the 'industrial/commercial' diesels can't pull high revs is mostly bottom end weight, but it's also that the vast predominance (except the newest) are mechanically injected. They don't have the shock reduction or really the fuel control to get the fuel in the cylinder in time with any amount of control at higher RPMs.
mfree80286 1 year ago
@garrett6699 the peak torque for this is about 1800-2000 rpm... its a detroit diesel 2 stroke, not a dirt bike engine
tuned for pulling it might hit 4-5k... but not for extended periods of time, this engine is made to run 24/7
mageac 1 year ago
@garrett6699 ummmmmm, it has a big ass stroke, same stroke as a 12v71 truck motor. bigger strokes cant turn as fast as smaller strokes.....thats why a 327 chevy will spin faster than a 350 chev without throwing a rod, but the 350 has better torque
Texassince1836 1 year ago
@Texassince1836 ALL the 71 and 92 series have the same 5" stroke....the only difference is the Bore, between the two. The 71 use a 4.25" bore and the 92 uses a 4.87" bore. The "USABLE" stroke length
is only about 3.9" before the exhaust valves begin to open...then about 1"- for port opening....I forget the exact length of the ports now....."senior moment". lol
TurbinePower69 5 months ago
Respond to this video... also, a supra is a gas engine with the stroke a weedeater
Texassince1836 1 year ago
no wrong. This engine spins quite slow actually. Most detroits redline around 2600 or so. they just sound like they are spinning twice that speed because they fire every time the piston comes up(2 stroke) unlike a 4 stroke which fires every other time the piston comes up. They do not run at 4,000 rpm.
iamdave0887 2 years ago 3
@iamdave0887 Apparently those Detroits are heavier internally than I estimated. Most of my two-stroke experience has been with single-cylinder motorcycle engines safe to about 10,000 rpm, and Diesels do rev to a fraction of such speeds.
bcschmerker 2 years ago
I've worked on these before. They were set up as high volume water pumps to pump down an overflow reservoir.
Could also be used to power a gen-set.
rondroid 3 years ago
What vehicle would an engine like this power?
pauchen58 3 years ago
a bus like a highway coach or something
Led757 3 years ago
Well, not a 3-71, but a detroit diesel yes. 6v-71's and 8v-71's were more common for busses. 3-71's were common in industrial equipment like tractors, cranes, and, yes, marine. My personal favorite is the 6V-92 turbo, attached to manual transmission, with jake brake, for an over-the-road truck. That is the best DD music! But there's also nothing like a "new look" bus with 6V-71 and Allison tranny... when I was a kid that was the sound of the city.
andyofvermont 3 years ago
In Canada we heard this a lot in the 1970s tv show The Beachcombers. The starring boat, Persephone, had a GMC 2 stroke diesel engine and sounded just like this.
marsgal42 3 years ago
I'm 48 and I remember The Beachcombers. Relic's boat sounded like this.
supertrucker1960 3 years ago
pulling tractors also..they are beastly
kfx450rdude 3 years ago
the used the 3-71's in heavy equipment and farm tractors
Bkrites 3 years ago
Cockinator, old straight cut roots blowers made a diferent sound than nowadays roots blowers do.
exploder69 3 years ago
i have always wondered, because 2 stokes need an expansion chamber to run right, do the deisel 2 strokes have expansion chambers?
1xDAx1 4 years ago
No. A 2-stroke Detroit (GMC) diesel has camshaft-operated exhaust valves in the cylinder head just like a 4-stroke engine. The major diference is that the intake air enters through ports in the cylinder wall. This air is pushed in by a roots blower at the bottom of every stroke and actually 'chases' the exhaust out the exhaust valves located at the top of the cylinder. When the piston rises it closes the intake ports and the exhaust valves close simultaneously.
JGMagoo 4 years ago 2
oh and two strokes don't need an expansion chamber to run, but they'll get you a lot more power, that's where the power band on a two stroke motorbike comes from (without going into detail...)
TtoksMan 4 years ago
I don't know about other manufacturer's, but
the two cycle Detroits, did NOT have or need,
"expansion chambers", also known as "pre-combustion" chambers, or "pre-cups" for short.
TurbinePower69 3 years ago
Very Nice. We got a couple Detroits ourselves. A 2-71 On a Generetor, a 3-71 on pump and generator, 3 4-71's runnin pump and generator, a 6-71 running pump and an 8-71 in a semi. Love the sound they make, runnin all night pumpin water. Puts me to sleep.
Fighterofwars 4 years ago 2
I am going to build a pickup truck with one of these engines in it
bitchslap9 4 years ago
Just be aware that these engines weigh quite a bit more then a comparable 53 series Detroit, not to mention three or four inches in height difference so suspension modification is almost mandatory.
hifiwasabi 4 years ago
Thats true and thats why I have been looking for a 1940's or 50's farm truck a tad larger than a 1 ton, I also want to run a dozer stlyle flywheel so when I get to speed the centrifical force of the flywheel will be so great that the engine will work less causing greater milage, by the way I have not decided on the 3 cylinder 53 or 71 yet, I have been thinking the 48 ci more would be benificial and not too much more for fuel usage
bitchslap9 4 years ago
the heavier fly wheel will cause the clutch to wear out faster and the engine be harder to start, which on detroit 2 strokes starting them can be a task at times
mageac 3 years ago
Comment removed
DieselsAndDiodes 2 years ago
it is blown by a big strait cut roots type blower thats what is the main nois you hear.
exploder69 4 years ago
I miss the old screamers...
qgjjhv 4 years ago
Me to....especially the 12v71's with exhaust
manifold openings directly off the end (rear)
"hole" on both sides, and the engine "built"
to marine specs, with marine cams,springs,
blower drives, and liners.....then set the
govenor for 2850-3000 rpms.....guaranteed to
produce "goose bumps"!!! :)
TurbinePower69 3 years ago
is it blown or does it have a turbo hiding somewhere???
dietcoke3396 4 years ago
Two strokes fire at evry revolution.
Boeing227 4 years ago
I just bought one of the railroad surplus 2-71 1200 rpm gensets, but haven't picked it up yet. Hopefully I can post a video of it running into a load.
ku4fl 4 years ago
We had 2 2-71 20kw gen on a barge I worked on. Ran 24/7 for years that's right like 20 years. Needed injectors and such but very reliable, the 1200rpm ones are great, pretty quiet also. Just DO NOT over heat them, you need a head gasket after that.
dixoncider 4 years ago
Detroit 'head gaskets' are more like rubber bands then anything else
DODGEDAKOTA95 4 years ago
How are you cooling it?
douro20 4 years ago
The engine is filled with water which is circulated by the water pump. It is a sealed system with a thermostat. As it is a marine engine sea water would normally be circulated through the heat exchanger to get rid of the heat. It takes about 10 minutes before the water warms up.
detroitdiesel33 4 years ago
Gotta love them old "screamin' detroits"
louswire 4 years ago
I think my nebors log skidder has that engine, i love detroit 2 stroke engines
Jthumper 4 years ago
is this a generator or a demonstration of the engine running?
ztwntyn8 4 years ago
It was just an engine when they filmed this.
douro20 4 years ago
oh, thanks. That thing sounds like it's at about 3000 rpm or so. How many rpms are those engines good for?
ztwntyn8 4 years ago
I believe up to 2800, but I've seen 4-71s run at 3000.
douro20 4 years ago
right on
ztwntyn8 4 years ago
in the clip shes running at 1500rpm. It's a 2-stroke.
Boeing227 4 years ago
and being a 2-stroke is probably the reason I thought it was at 3000 lol
ztwntyn8 4 years ago