Detroit 2 Stroke

[@gckshea]

The block/crankcase does not pressurize with incoming intake air. The crankcase is a separate chamber unlike gasoline two-strokes that rely on crankcase pressure to charge incoming fuel/air and effect scavenging when ports in the cylinder are open. the positive pressure from the constant pressure Roots supercharger pressurize the air gallery above the sealed crankcase. If someone understands how a two stroke gasoline engine works, they are mind boggled then how the Detroit works without the same principles, and why an exhaust valve is necessary. What a simple engine! Thank you for your enthusiasm!!!!! Love it!

[@scottcupp8129]

Love your channel. I am a big DD2 stroke fan and always have been. In high school our bus was a Crown tandem axle and it had an 8v71 in it. I love the fact that these videos keep the memories alive. Thanks a million for the narratives.

[@pawfan]

Glad someone is still teaching shop!

[@shanghai011475]

The blower doesn't pressurize the block, it pressurizes the air box portion of the block. You cannot have that air pressure in the crank case portion of the block. It will blow the oil out of the bearings and back up into the head which will cause failure relatively fast. The engine will start and run at idle without the blower working but will not burn fuel fast enough to rev past idle very much and will sputter and fart flames.

[@iceman45ification1]

I loved hearing these engines rev up when they were around. The old metro buses all had the six cylinder versions. And, if I'm not mistaken, the GMC Topkick rigs had the V8's. Wicked sounding engines!! 😮

[@jaratt85]

A lot of the GMC's had the 6V71 while the old Greyhounds and whatnot had the transverse straight six version. The really psycho one is the 24V71 and the 16V92T. Yes they made a 24 cylinder V configuration engine with 71 cu in per cylinder and a turbocharged V16 with 92 cu in per cylinder. That's where they really started to actually make some power. Unfortunately the turbos really killed the sound.

[@theq4602]

Saw this video many moons ago as a teen. Now I have one as an adult. Truly dreams do come true. Thank you Keith.

[@mattberg6785]

Hopefully you're still teaching about these awesome pieces of history. So simple, so durable and sound unlike anything else. The little babies of EMD. Versatile like no other

[@GOLDENHALK37]

I Drive one everyday I still own the same engine in my bus conversion 2015 she still running strong

[@chasevollbrecht8085]

One of the things that should be equipped to the Detroit as a air shut off valve and a co2 tank

[@cb400fhonda6]

Thanks that was a gr8 lesson Took me back to the days I used to rebuild these But they had turbo on them Those suckers Gas guzlers

[@peteprizzi8508]

To anyone- Are these engines outlawed?? Don't think it could pass emissions. But they sure do sound cool!

[@tomreisinger6220]

The information regarding fuel pressure button on the pt system is not the same as the Detroit fuel orrifice, changing the restricted fitting doesn't effect the delivery because the pressure is limited by the regulator in the transfer pump,if you restrict the return on the pt system it will get results some of which are not good like poor deceleration, melting pistons etc.

[@usaisalwaysnumber1]

I would have loved to have been one of his students..great instructor..i love Detroit engines,,,

[@lancedreger6872]

They made a V16 also.

[@raincoatz7562]

Those kids in the back on their phones are really missing out. Yea its school, but come on. This is cool. Pay a little attention.

[@2fast4you25]

FUN STARTS AT 5:30 THANK YOU

[@wa7shf]

We had a tractor on the farm that had a 8-71 in it the inline 4 cylinder in it and when it hit 5000 hours. Well rule of thumb is you split the tractor and pull the head and do a rebuild.Well I talked Dad in to letting me put in the Detroit 8-71 in it I had too have an adapter plate made to fit it to the transmission and build some motor mounts other than that it went in like butter.We still have it today and it will put in a full days work and ask for more...

[@troydodge111]

DD didn't make a 6V71.

[@OtisENGINEuity]

You could put spark plugs in the zoomies to help make it burn cleaner :P Cops show up "what the hell do you think you are doing?" as 4 foot flames are shooting out of it "What? I'm making it more environmentally friendly". Something you could point out is that the Vietnam Era PBD (Patrol Boat Delta) used 2 of these engines backed up with Jacuzzi jet drives per boat.

[@g__wizz]

nah... dont work that way.

[@OtisENGINEuity]

g zimmermann have you never seen flame throwers in cars? not sure if it'd light the diesel in the exhaust or not but theoretically it'd be easier than straight diesel as it'd already be at it's flash point

[@g__wizz]

OtisENGINEuity no... just smoke

[@jlo13800]

These run total loss lubrication as they burn SAE30w low ash oil. The Fairbanks Morse op engines did not sure?

[@invisiblekid7374]

Detroit made from a single cylinder all the way up to a 16 cylinder!!!

[@nojoek152]

This same teacher was in another video. He was more passionate, but his info was hte same...

[@naomisharpe3730]

Sweet music.

[@lawrencewheeler8868]

drove a 6 speed Freightliner cabover/w/ sleeper 1973

[@brandonmurphy4366]

Are you still teaching there? I'm just shortly North of you, would love to get in touch. Building a project truck w/ a 6v92ta.

[@chrisradla]

EPA hates them?

[@chasemiller7974]

They pollute to much because it burns fuel on every stroke, unlike 4 stroke engines where it's once every 4 stroke cycle. Same goes for gasoline 2 strokes.

[@wa7shf]

If you did shut the trap door to shut it down they will always suck the seals out of the supercharger and keep running away until the oil was gone or rods were hanging out of the side of the engine.. I had it happen to me on a 8-71 it was not a good day to be around me.I was always told by the older men in the shop to NEVER pull the runaway knob....The holes on the side of the sleeve are drilled at an angle so that the air coming in to the chamber would swirling around in a circle...

[@firstname6208]

you are absolutely correct. the best way to stop a runaway Detroit is to have a hammer and break off a fuel supply line close to the engine. step away and hope it runs out of fuel b4 the rods hang out. and never ever plug the air box drains.

[@shanghai011475]

@@firstname6208 If it is running away for any length of time it will begin to burn oil vapor and removing the fuel supply will not stop it. I keep a CO2 fire extinguisher handy when working on a non DDEC 2 stroke in case it runs away. Also you need to take the valve covers off and put vise grips on the rack so you can force the injector racks closed. One puff of CO2 and she will get quiet fast.

[@richardmaurer9002]

That is the biggest bunch of bullshit I have ever heard. If enough vacuum is created to pull the seals out of the blower (the second biggest load of bullshit I have ever heard) , how can the engine run away with that kind of negative pressure above the blower? How is air getting into the cylinders?

[@pip12111]

That gGrrrrrrrrowl

[@jeremylavoie8495]

I'm a fan

[@blaydewebb2089]

I got a 12v71 in my boat

[@rajkiranthomas3579]

Why 2 stroke diesel is dead now?

[@chasemiller7974]

Raj Kiran Thomas They pollute too much. It's the same reason you don't see many 2 stroke gasoline engines on the road.

[@pip12111]

Raj Kiran Thomas EPA assholes. Plus they were fuel hogs

[@chasemiller7974]

@Mr Sunshines Well yeah, there just banned for use on roads.

[@rbagel55]

You will still see a few running in some industry and marine, but that is about it.

[@dodgerestoproject]

she's not running right

[@jeroenschuuring6060]

Cilinders 5 and 8 are shot. What I heard in another video.

[@chasemiller7974]

I think I remember in that other video he killed two cylinders for some reason, there was one time in that video that it just purrs at idle all of a sudden, I don't know if he turned them back on or what.