umodelnut Posted June 21, 2012 Share Posted June 21, 2012 Now this is a serious question, no jokes. What makes a Detroit runaway? Is it the rack? Why dont they just pull the fuel shut off like in a normal truck? I was just thinking about that. Examples:::: http://www.youtube.com/watch?v=8M1o2rpO_JY&feature=related Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/ Share on other sites More sharing options...
j hancock Posted June 21, 2012 Share Posted June 21, 2012 One cause that I have heard and thankfully never seen is pulling the seals out of the blower and the engine will run on crankcase oil.Don't know if true but sounds plausible.On a 6-71 thats about 44 qts of oil or 11 gallons of potential run away FUN!!!Jim Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124859 Share on other sites More sharing options...
umodelnut Posted June 21, 2012 Author Share Posted June 21, 2012 One cause that I have heard and thankfully never seen is pulling the seals out of the blower and the engine will run on crankcase oil.Don't know if true but sounds plausible.On a 6-71 thats about 44 qts of oil or 11 gallons of potential run away FUN!!!JimOh, OK. I get it. Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124860 Share on other sites More sharing options...
41chevy Posted June 21, 2012 Share Posted June 21, 2012 A diesels RPMs controlled by the amount of fuel being allowed into it. A worn engine, oil will blow past the piston rings and into the crankcase. The oil from the crankcase gets into the air intake from the breather. A diesel engine will run on this oil. The RPMs increase as the extra oil is taken in. As a result of increased RPMs, more oil is pulled out of the crankcase and into the engine. Now a cycle is created, more RPMs, means more oil, which means more RPMs. A diesel the normally run around 1800 RPM will run up 2 or 3 times that! The engine reaches a point where its now using its own oil as fuel, that shutting off the fuel won't stop it. It will rev up until it blows it self up. The extra oil can come from bad oil seals in a turbo, overfilling the crankcase with oil or even from the out side, like a power steering leak or even a propane or LP gas leak near by. Paul 1 Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124870 Share on other sites More sharing options...
umodelnut Posted June 21, 2012 Author Share Posted June 21, 2012 A diesels RPMs controlled by the amount of fuel being allowed into it. A worn engine, oil will blow past the piston rings and into the crankcase. The oil from the crankcase gets into the air intake from the breather. A diesel engine will run on this oil. The RPMs increase as the extra oil is taken in. As a result of increased RPMs, more oil is pulled out of the crankcase and into the engine. Now a cycle is created, more RPMs, means more oil, which means more RPMs. A diesel the normally run around 1800 RPM will run up 2 or 3 times that! The engine reaches a point where its now using its own oil as fuel, that shutting off the fuel won't stop it. It will rev up until it blows it self up. The extra oil can come from bad oil seals in a turbo, overfilling the crankcase with oil or even from the out side, like a power steering leak or even a propane or LP gas leak near by. PaulWow....I never thought I would understand that but I do. Thanks Paul!!! So my U model coul do that? Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124876 Share on other sites More sharing options...
41chevy Posted June 21, 2012 Share Posted June 21, 2012 Any diesel can run away under the right conditions. From a Diesel VW car to a Mack. Paul Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124880 Share on other sites More sharing options...
Olivetroad Posted June 21, 2012 Share Posted June 21, 2012 We had a detroit in a log skidder run off one time when a hydraulic line going to the front blade broke and it was routed next to the air intake.That is why a detroit has the extra engine kill lever - it shuts a flap in the air intake so hopefully the engine will stop or at least not run off until you can get whatever is feeding the fuel to it shut down. The first diesel engine ran on peanut oil if I remember correctly. We had a RD6 Caterpillar dozer one time that had been used stationary running a belt pulley for several years on waste asphalt oil - yuck! - it is interesting how diesels will run on any fuel if they have enough air coming in at the same time. I always think that if engineers had been working on alternative fuels for the last 80 years instead of only working on diesel as a fuel, we would have been way ahead by now. The same with open pollinated seed corn - if we were to spend 80 years breeding better plants, we would not need hybrids now - I got off track a little there - sorry............... Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124887 Share on other sites More sharing options...
Gus Posted June 21, 2012 Share Posted June 21, 2012 Number one cause of Detroit runaway is due to a stuck injector. Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124904 Share on other sites More sharing options...
Freightrain Posted June 21, 2012 Share Posted June 21, 2012 Any diesel can run away, but a detroit is usually more common only due to the blower, worn seals or stuck rack. Most all leaky ol detriots have an emergency shut off(a control cable hooked to a flapper in the intake tubing) that is used to help shut them down from such an ordeal. Once you shut the air off, they will die away even with all the oil. It takes both to run air and fuel to run. Later versions had a solenoid controlling it from the key. Turn the key off, it closes the flapper automatically. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124906 Share on other sites More sharing options...
randyp Posted June 21, 2012 Share Posted June 21, 2012 Well, there is entirely too much seriousness going on here. I had a nice detroit one time, I spanked her too hard and she RAN AWAY!!! yee hee hee hee hee hee,,,,,randyp Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124915 Share on other sites More sharing options...
Green Dash Posted June 21, 2012 Share Posted June 21, 2012 Geeesh! This bunch is going SOFT!We actually answered Vin's question in a serious intelligent manner.....just like he wanted.WTH????This place is going down......We were supposed to say that Detroits run away because they are SCARED!Those videos raise another question.Why do people run away from Detroits? Quote Jim Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124916 Share on other sites More sharing options...
umodelnut Posted June 21, 2012 Author Share Posted June 21, 2012 Those videos raise another question.Why do people run away from Detroits?I would!!! Holy crap. It would scare the crap outa me!!! I would never look back eather, I'd let her blow. Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124922 Share on other sites More sharing options...
41chevy Posted June 21, 2012 Share Posted June 21, 2012 Geeesh! This bunch is going SOFT!We actually answered Vin's question in a serious intelligent manner.....just like he wanted.WTH????This place is going down......We were supposed to say that Detroits run away because they are SCARED!O.K. here is the answer you expected...Diesels run away for these reasons. 1)Bad home life 2) to much stress at work 3)a bad marriage 4) No marriage, 5) owe too much money 6)did a bad thing and are afraid of being punished 7)just plain nuts 8) afraid of U models. Better Answer??? 1 Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124928 Share on other sites More sharing options...
GreenGiant2 Posted June 22, 2012 Share Posted June 22, 2012 answer #8 1 Quote We the unwilling, Lead by the unqualified, are doing the impossible, for the ungrateful. Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124975 Share on other sites More sharing options...
leversole Posted June 22, 2012 Share Posted June 22, 2012 "... I'd let her blow."I let her blow once...got into trouble with her husband! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-124983 Share on other sites More sharing options...
umodelnut Posted June 22, 2012 Author Share Posted June 22, 2012 I let her blow once...got into trouble with her husband!No, no, no. no!!!! Not that kind leversole!!! Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125021 Share on other sites More sharing options...
Freightrain Posted June 24, 2012 Share Posted June 24, 2012 Once again, I'll bring this up.............http://youtu.be/VG7F0ImuSUQ Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125434 Share on other sites More sharing options...
yarnall Posted June 25, 2012 Share Posted June 25, 2012 My dad has an R685 with a stuck rack. We keep a board handy and the hood up when we start it so we can shut it down. We can move it around on its own power if we are very careful. Mike 1 Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125523 Share on other sites More sharing options...
umodelnut Posted June 25, 2012 Author Share Posted June 25, 2012 My dad has an R685 with a stuck rack. We keep a board handy and the hood up when we start it so we can shut it down. We can move it around on its own power if we are very careful.MikeThats sketchy. Any pictures? Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125539 Share on other sites More sharing options...
slpwlker Posted June 26, 2012 Share Posted June 26, 2012 I always thought it was when they would come to an intersection and there was a Cat,Cummins, Or Mack on the other side it would turn tail and hide. Till it was all clear and not get embarresed. Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125595 Share on other sites More sharing options...
JumperAndSon Posted June 26, 2012 Share Posted June 26, 2012 The REAL Jumper here. Ben and I had a Scania run away on us when we first lit the B model up. Fortunately, Ben is a you-tube addict and had seen those other videos and we were prepared for it (a piece of tile to cover the intake). We recently got a 4-71 from a motor grader with 250 hours on it because it was junked for running away. Upon removal of the valve cover, it was determined that the cotter key vanished from the governor rod at the rack. I paid 20 cents a pound for the engine because of a 5 cent pin! Life is good.Detroits are more prone to run away because of the pump-less injectors sticking from sitting, as well as the 2 stroke design with the air intake at the bottom of the cylinder sleeves dang near in the oil pan.Vinny, nice meeting you at the show. Wasn't a U model something that the Germans had during the second world war? Does yours have a periscope? 2 Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125622 Share on other sites More sharing options...
umodelnut Posted June 26, 2012 Author Share Posted June 26, 2012 The REAL Jumper here. Ben and I had a Scania run away on us when we first lit the B model up. Fortunately, Ben is a you-tube addict and had seen those other videos and we were prepared for it (a piece of tile to cover the intake). We recently got a 4-71 from a motor grader with 250 hours on it because it was junked for running away. Upon removal of the valve cover, it was determined that the cotter key vanished from the governor rod at the rack. I paid 20 cents a pound for the engine because of a 5 cent pin! Life is good.Detroits are more prone to run away because of the pump-less injectors sticking from sitting, as well as the 2 stroke design with the air intake at the bottom of the cylinder sleeves dang near in the oil pan.Vinny, nice meeting you at the show. Wasn't a U model something that the Germans had during the second world war? Does yours have a periscope?I remember Ben telling me the B60 had a stuck rack.It was very nice meeting you too Mr. Jumper. But no, the Germans had a U-Boat submarine, not a U model. Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125643 Share on other sites More sharing options...
JumperAndSon Posted June 26, 2012 Share Posted June 26, 2012 Ha, Ha, Ha! ROTFLOL!! That's funny, Dad.But really, The way they're set up, when a Detroit isn't running, the injectors settle at full throttle. This helps make them very easy to start. Until the flyweights on the governor move out and pull the rack closed, the injectors stay at full throttle. When they sit for a while, the injectors tend to get stuck at full throttle and therefore, the engine runs away. When it's stuck at full throttle, it can start to suck its own oil and in turn, revving even higher. That's why they blow up.Cousin Ben Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125651 Share on other sites More sharing options...
umodelnut Posted June 26, 2012 Author Share Posted June 26, 2012 Ha, Ha, Ha! ROTFLOL!! That's funny, Dad.But really, The way they're set up, when a Detroit isn't running, the injectors settle at full throttle. This helps make them very easy to start. Until the flyweights on the governor move out and pull the rack closed, the injectors stay at full throttle. When they sit for a while, the injectors tend to get stuck at full throttle and therefore, the engine runs away. When it's stuck at full throttle, it can start to suck its own oil and in turn, revving even higher. That's why they blow up.Cousin BenI get it. Thanks Cousin. Quote Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125697 Share on other sites More sharing options...
1958 F.W.D. Posted June 28, 2012 Share Posted June 28, 2012 The best looking Detroit Diesel I ever saw had a huge hole in the side of the block with part of a rod through the hole. 1 Quote TWO STROKES ARE FOR GARDEN TOOLS Link to comment https://www.bigmacktrucks.com/topic/25784-what-makes-detroits-run-away-serious-question/#findComment-125919 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.