Coasting a 6-71 with fuel rack in no fuel?

thomasinnv · December 22, 2015, 02:02:24 AM

Clifford I agree. I should have clarified my post a little better. my bus is an auto, were it a manual I would most certainly have a different point of view.

dcburd · December 23, 2015, 04:33:13 AM

Great information! I am studying up on the 6-71 rack. In summary the rack goes to no fuel during normal deceleration with varying return supplies as little as .1 gpm. The governor holds idle. The statement regarding coasting then slipping out of gear with a rack in no fuel got my attention. I am not into thrillers! Thanks!

luvrbus · December 23, 2015, 04:51:18 AM

Where does the .1 come from,the spill rate on 6L71 you test the pump with is .9 gpm @ any fuel not injected is returned to the tank.

bevans6 · December 23, 2015, 10:43:49 AM

Clifford, I came up with the .1 gpm as what the engine actually burns, if you got 10 mpg at 60 mph. It's probably wrong, I did it in my head and my head ain't all that good any more... 10 mpg at 60 mph is 6 gallons per hour, or 0.1 gallons per minute. OK, having done it again with a calculator it's entirely possible I was right... What I wanted to know was the ratio between what was burned vs what was returned to the fuel tank, because I thought that most of the fuel was actually bypassed back to the tank. Now all I have to do is get 10 mpg, but I felt that a nice little gm might get that.

Brian

bevans6 · December 23, 2015, 10:52:14 AM

So if the .1 gpm burned at 60 mph is right, and you buy fuel for $3.00 per gallon, then you spend 30 cents a minute to drive the bus, which is obvioulsy 30 cents a mile, or $18 an hour. Which is about what I always figured.

Brian

luvrbus · December 23, 2015, 10:56:13 AM

Quote from: dcburd on December 23, 2015, 04:33:13 AM
Great information! I am studying up on the 6-71 rack. In summary the rack goes to no fuel during normal deceleration with varying return supplies as little as .1 gpm. The governor holds idle. The statement regarding coasting then slipping out of gear with a rack in no fuel got my attention. I am not into thrillers! Thanks!

No Brian this is the .1 I was referring to the return

lostagain · December 23, 2015, 11:15:07 AM

Ok, to make it simple, just put it in neutral going down hill and shut it off. No fuel consumption, no fuel return to the tank, and you gain speed. My grand father used to do that, but he had manual steering and manual brakes in his car.

JC

eagle19952 · December 23, 2015, 12:29:13 PM

Quote from: lostagain on December 23, 2015, 11:15:07 AM
Ok, to make it simple, just put it in neutral going down hill and shut it off. No fuel consumption, no fuel return to the tank, and you gain speed. My grand father used to do that, but he had manual steering and manual brakes in his car.

JC

.... was he kicking and screaming ?

bevans6 · December 23, 2015, 12:45:37 PM

Nope, grinnin'!