Author Topic: Can A 71 Series Blower Air Flap Emergency Engine Stop Shutter  (Read 2489 times)

Online HB of CJ

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Can A 71 Series Blower Air Flap Emergency Engine Stop Shutter
« on: December 15, 2012, 06:16:15 PM »
Assembly be modified and installed onto a 92 series Detroit?  Inquiring minds wonder.  HB of CJ (old coot) :)

Offline TomC

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Re: Can A 71 Series Blower Air Flap Emergency Engine Stop Shutter
« Reply #1 on: December 15, 2012, 10:29:13 PM »
92 Series never had the emergency stop flap-they re designed the injectors so it wasn't needed. When my 8V-71 was turbo'd, Don took off the emergency flap also.  Only needed with non spring return injectors. Good Luck, TomC
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.

Offline wg4t50

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Re: Can A 71 Series Blower Air Flap Emergency Engine Stop Shutter
« Reply #2 on: December 16, 2012, 02:38:03 AM »
Indeed, The break a way rack saved many engines from an injector stuck at full fuel.
Dave M
MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for ever.
Central Virginia

Offline bevans6

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Re: Can A 71 Series Blower Air Flap Emergency Engine Stop Shutter
« Reply #3 on: December 16, 2012, 05:37:04 AM »
When I got my bus, the emergency flap solenoid was disconnected.  When I inquired about it, the local DD dealer tech guy told me that there was a directive low those many years ago to disconnect it.  Apparently it caused more problems by being accidentally activated than it solved.  The injector springs referred to are actually the rack levers, not the injectors.  They are mounted to the rack tube with a spring loaded joint so that if an injector gets stuck open all the other injectors can continue to operate normally, and return to idle or no-fuel.  It's easy to tell - just take a valve cover off and see if you can move one lever without moving them all (engine off).  My engine was updated to have the spring racks.  Obviously, the spring rack solves the injector sticking problem but doesn't solve the run-away on oil problem which can only be shut down by lack of air for combustion, which the flap should do for you.  The thing is, there are other ways to shut that sort of runaway down, like maybe a Halon fire system plumbed into the intake.  The issue with the flap is that it is mechanically activated by a solenoid, and can activate incorrectly.  Mine did it twice, causing a no-start till I figured out the flap was down, but if it happened at speed you would stand a great chance of blowing out the blower oil seals, and then when you fixed the flap and started the engine again getting the run-away from the oil being dumped in by the now-ruined blower seals.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Online HB of CJ

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Re: Can A 71 Series Blower Air Flap Emergency Engine Stop Shutter
« Reply #4 on: December 16, 2012, 07:53:05 PM »
I was thinking along the lines of a blown turbo seal, or a physical condition or breakage where the mill was burning it's own lube oil and running wild like due to busted rings or the mill being tilted.  HB of CJ (old coot)

(long ago and far away, three (3) nice homes were totalled in no small part by accidently tripping that air flap blower thingie on the first due engine.  Nobody knew what happened or how to reset it.  I was not there.  The first bo bo in a cascading events of disaster.  Fire department goof up) That's all I'm sayin'.  HB

 

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