zeitgeist57 Posted July 22, 2012 Report Share Posted July 22, 2012 30+ years idle...couple of shots of WD-40 as a starting fluid... http://www.youtube.com/watch?v=8M1o2rpO_JY&feature=g-vrec DETROIT DIESEL DON'T CARE Quote Link to comment Share on other sites More sharing options...
Murse Posted July 22, 2012 Report Share Posted July 22, 2012 I love how gramps nonchalantly walks around it and slowly places the 2x4 on the intake, all while the boys are runnin like they're gonna die!!! Quote Link to comment Share on other sites More sharing options...
Nickey4271647545519 Posted July 22, 2012 Report Share Posted July 22, 2012 Came in here expecting to see a 2-stroke.... and that's what I found. Quote Link to comment Share on other sites More sharing options...
PRD2BDF Posted July 22, 2012 Report Share Posted July 22, 2012 What happened and don't say "didn't you hear the video?" Quote Link to comment Share on other sites More sharing options...
Draco-REX Posted July 22, 2012 Report Share Posted July 22, 2012 Runaway diesels are fun to watch. Quote Link to comment Share on other sites More sharing options...
spankis Posted July 22, 2012 Report Share Posted July 22, 2012 What happened and don't say "didn't you hear the video?" Oldass diesel engine idled up to about infinity rpms on it's own (called runaway), sounded like it was about to explode. Kids ran away, old man came in and fixed it by blocking the intake. Quote Link to comment Share on other sites More sharing options...
Nickey4271647545519 Posted July 22, 2012 Report Share Posted July 22, 2012 One of my favorite run away videos And what a proper 2 stroke diesel sounds like. :megusta: Quote Link to comment Share on other sites More sharing options...
MattKatz Posted July 22, 2012 Report Share Posted July 22, 2012 Why do they do this? Quote Link to comment Share on other sites More sharing options...
zeitgeist57 Posted July 22, 2012 Author Report Share Posted July 22, 2012 Why do they do this? The reasons vary by engine, but since diesels are compression ignition (no spark plugs), once you get them going they pretty much keep running as long as you give them air and fuel. Most "runaway" situations come from the injector pump failing to meter incoming fuel. Some leaks can cause this too... Quickest way to stop it is block off all air supply. As you can see, it's tough to do with a turbo boosting a ton of air into some monster engine screaming at 5k rpms... Also, you can see that your initial reaction to a runaway diesel is to RUN AWAY BEFORE IT BLOWS SKY HIGH. Scary diesels are scary! :fuckyeah: Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted July 22, 2012 Report Share Posted July 22, 2012 And what a proper 2 stroke diesel sounds like. :megusta: I love that. After all these years of watching car/truck/racing videos, I have never heard anything like that. That is pretty badass. Quote Link to comment Share on other sites More sharing options...
MattKatz Posted July 22, 2012 Report Share Posted July 22, 2012 Thats too complicated to Drive...What kind of setup is that....and hes flipping switches to come down to a stop....WTH? Quote Link to comment Share on other sites More sharing options...
appn88 Posted July 22, 2012 Report Share Posted July 22, 2012 Thats too complicated to Drive...What kind of setup is that....and hes flipping switches to come down to a stop....WTH? im guessing he is flipping the second lever to go through another series of gears Quote Link to comment Share on other sites More sharing options...
Aaron Posted July 22, 2012 Report Share Posted July 22, 2012 im guessing he is flipping the second lever to go through another series of gears Well, of course. Its the switches he was toggling at the end... Quote Link to comment Share on other sites More sharing options...
Nickey4271647545519 Posted July 22, 2012 Report Share Posted July 22, 2012 Thats too complicated to Drive...What kind of setup is that....and hes flipping switches to come down to a stop....WTH? IIRC that's a 5speed with a 4 speed behind it. Hence the twin sticks. Almost all old big trucks use that set up. Still haven't figured out the switches though. Quote Link to comment Share on other sites More sharing options...
Fubar231 Posted July 22, 2012 Report Share Posted July 22, 2012 IIRC that's a 5speed with a 4 speed behind it. Hence the twin sticks. Almost all old big trucks use that set up. Still haven't figured out the switches though. So what does the rear 4 speed control? I get the first 5, but how does the second 4 speed effect the gears? Quote Link to comment Share on other sites More sharing options...
Nickey4271647545519 Posted July 22, 2012 Report Share Posted July 22, 2012 So what does the rear 4 speed control? I get the first 5, but how does the second 4 speed effect the gears? Splits your gears up even more so you can have more tq multiplication. Instead of only having 5 gears, you now 20 different gear selections to keep the engine around peak tq. Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted July 22, 2012 Report Share Posted July 22, 2012 Yup. Diesels have much narrower power bands than gasoline, hence more gears needed to keep them in their band. Quote Link to comment Share on other sites More sharing options...
MattKatz Posted July 22, 2012 Report Share Posted July 22, 2012 Id Need to see a break down of how this operates and the proper sequence of shifting to understand. Quote Link to comment Share on other sites More sharing options...
trix-storm Posted July 22, 2012 Report Share Posted July 22, 2012 Yup. Diesels have much narrower power bands than gasoline, hence more gears needed to keep them in their band. Exactly, same reason big rigs have 10 speeds with a splitter for low/high range. Quote Link to comment Share on other sites More sharing options...
Steve R. Posted July 22, 2012 Report Share Posted July 22, 2012 Switch to the left is an engine brake. I have no idea whether that would have been on that truck when it was built or not. Funny this thread should show up, I was watching a whole bunch of diesel runaway/pulling/carnage vids this morning. This impressed me because of how fast they were shifting, no where near stock obviously. The amount of torque you can get out of diesels still amazes me... With the dual gearboxes, I believe you could shift the whole way thru the primary and then change the second box and work back thru them again and so on. You end up with a lot of really short gears but they really help get you moving. Obviously like the guy in the video you can shift systematically skipping gears when they are not needed. Quote Link to comment Share on other sites More sharing options...
Fubar231 Posted July 22, 2012 Report Share Posted July 22, 2012 Splits your gears up even more so you can have more tq multiplication. Instead of only having 5 gears, you now 20 different gear selections to keep the engine around peak tq. Ive known that. I mean say your in 4th and you move the 2nd stick, would it be like "8th" gear and be longer than 5th/6th etc. or does it just, not change the rear end ratio, but just adjust the ratio of the gear from the first trans? Does that make sense? Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted July 22, 2012 Report Share Posted July 22, 2012 the only truck I've seen setup with anything like that had a 2 speed rear axle, it was on a dump truck with a sbc gas motor. Quote Link to comment Share on other sites More sharing options...
Tractor Posted July 22, 2012 Report Share Posted July 22, 2012 chevy c40 dump trucks had the two speed rear end. Not sure which other ones. My duece and a half can be split shifted using the transfer case when you have a heavy load. The sequence is; Transfer case - Low range transmission 1st gear 2nd gear 3rd gear transfer case to high range transmission 2nd gear 3rd gear 4th gear 5th gear Doing this on the street would be very annoying and you'd have shifted 5 times before you even got through an intersection. Its slow enough empty and using only high range you can easily use up a green arrow making a left turn. Quote Link to comment Share on other sites More sharing options...
Avenger1647545502 Posted July 23, 2012 Report Share Posted July 23, 2012 Diesels run away because they don't use a throttle to control airflow, there is no equivalent to the throttle blade in the intake of a gas engine. RPM and idle are controlled solely by the amount of fuel metered into the engine, so if the injectors stick open there is NOTHING to keep RPMs from increasing until the engine either fails or reaches the peak RPM for that amount of fuel. The only way to shut off a runaway is to either kill the fuel supply (good luck shutting off a mechanical fuel pump quickly) or blocking the airflow. Most diesel shops keep a pie tin or pizza sheet around to slap over the intake if necessary. An OHP officer I know told me the reason they only carry CO2 extinguishers instead of other types...when a truck crashes, frequently the cab will be destroyed but the motor is still running. Just discharge the extinguisher into the intake and it'll stop the motor when you can't get to the key. Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted July 23, 2012 Report Share Posted July 23, 2012 chevy c40 dump trucks had the two speed rear end. Not sure which other ones. My duece and a half can be split shifted using the transfer case when you have a heavy load. The sequence is; Transfer case - Low range transmission 1st gear 2nd gear 3rd gear transfer case to high range transmission 2nd gear 3rd gear 4th gear 5th gear Doing this on the street would be very annoying and you'd have shifted 5 times before you even got through an intersection. Its slow enough empty and using only high range you can easily use up a green arrow making a left turn. the one I've seen was a 6 ton dump (c60 maybe??), he never used the 2 speeds in the axle though. Quote Link to comment Share on other sites More sharing options...
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