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Topic: Late Model Foretravel Coaches vs. "The Competition" (Read 2678 times) previous topic - next topic

Re: Late Model Foretravel Coaches vs. "The Competition"

Reply #50 –
Quote from: Pierce & Gaylie Stewart –
That mechanic probably drove a stick 8V-71 and stalled it at an uphill intersection then rolled backwards causing the engine to start but run backwards. They can really make a mess when that happens. The air cleaner turns into the muffler.

Pierce
The 6V92 will run backwards too.  The old style 6V92 were also oil leakers.  We had 14 oil stained spots in the dirt at the terminal I drove out of.  That was where the 15 White Road Bosses were parked.  The spot that was not oil stained had a White Road Boss with a Silver 6v92 parked over it.  That particular engine was much stronger that the old 6V92 engines The old engines were green colored if I remember right, and the new ones silver.  6V92 DD Silver engines began with the serial number F83425 any number after that is a Silver engine.

I actually experienced the engine running backwards as I was leaving the refinery one day.  There was a "speed bump" as you pulled out.  I hit the top of the speed bump with my drive wheels and let up on the fuel at the same time.  She rolled backwards while the clutch was engaged and reversed the engine.  I stepped on the clutch but it was to late.  Black smoke just poured out of the engine compartment.  Pulled the fuel shut off to stop the engine, and then restarted it.  She ran fine then.  Had she continued to run in reverse, she would have pumped the oil right out of the engine.
1994 U225
build #4514

Re: Late Model Foretravel Coaches vs. "The Competition"

Reply #51 –
When the DD is running backwards, quickest, best & simplest is just stall it, no reset air box flapper, and only takes a second to restart and go. yup been there when first started driving em DD 2strokers.
 

Re: Late Model Foretravel Coaches vs. "The Competition"

Reply #52 –
Had forgotten all about the flapper box. I never had to use it. Don't think the DDEC will let the engine run backwards but only a guess. Also, pretty hard to get even a mechanical DD to run backwards with an automatic but if it did, it would be a trick getting it to shut off without waiting. The positive displacement fuel pump would turn the opposite direction so when the fuel in the cylinder heads dropped pressure, it should shut off by itself. Now I remember the flapper box on our fire apparatus was used if we got around a natural or propane gas leak. But any diesel would go crazy around those gasses. Turbo seal failure could also cause any diesel engine to run away.  Even a partial seal failure can cause high temps and burn a hole in pistons. I saw a Cummins in a Mack (South American VW) lose one piston completely and early detonation force the edges of two other pistons down on the compression rings. Think the bore was OK and a bit of surfacing would take the broken ring divots out of the head.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)