Brian's engine install declared finished!

[bevans6]

OK, not quite because I still need to find or have made a new throttle cable, adjust the clutch, hook up the drive shaft and take it somewhere.  But the engine part is done!

Last steps were fiddly.  Hook up the air cleaner, which fits sitting upright on the muffler cover.  Install all the water lines, including fixing the one hard line that had a pin-hole leak.  Fill it with coolant, and man does it take a lot of coolant!  Now I can run it long enough to try to tune it up a bit.

Set the idle at around 500 rpm, and adjust the buffer screw to get a feel for it.  It lopes a bit at 500 rpm, but smooths out pretty as you please as soon as the buffer screw is in place.  Back the buffer screw out again and rev it up.  I find that it stalls coming back to idle, so per the book I raise the idle to around 600 rpm, and that goes away.  Grit my teeth, screw up my courage and do the unloaded high speed test.  My little digital tach says 2425, which is a little higher than I was hoping for, I wanted around 2300.  I don't have the wrench to undo the lock nut so I just leave it for now, that will give me some headroom in third gear climbing hills anyway and I don't think it's that much too fast.

Now I readjust the buffer screw, and figure out the skinner valves for the engine stop and fast idle.  I, and the diagram in the book, have them backwards.  One is normally on, the other is normally off, so everything works backwards.  Fix that, the engine stop cylinder is sticky so take that apart and clean it.  Install the accessory plate on top of the governor, hook up the air lines and test the engine off cylinder - works.  Now the big one - fast idle.  I have actually figured out how the fast idle works and what it does, I know the buffer switch is working at the right place, so now I have to actually test it.  Engine on, me up front with the switch, flick it up, engine picks up and settles at a healthy, non-overspeed panic attack making fast idle.  I run to the back and get the tachometer on it, 1200 rpm.  Again a little fast but set for operating the factory AC.  I could try to adjust it but not today.

Final job for the day was setting the cut out on the new air governor.  It was cutting out at around 135 PSI, which I feel is too high, so I got the cap off, loosened the lock nut and adjusted it down, couple of tries and it's cutting out right around 120, which is where it's supposed to.  Cuts in around 95 psi, just like it's supposed to..

One question - it still wants to stall coming off high idle or any high speed running.  Idle is set around 585 now after it's warmed  up.  Is the cure simply adding some idle speed?  Where do manual trans buses like to be set for idle, and is there some other adjustment (little more buffer screw maybe) that will settle it down faster coming off a high speed?

thanks, Brian

[Melbo]

Congratulations

Gotta feel good to be that far along

Melbo

[luvrbus]

 Brian is that a std timed or A timed engine with Jakes

good luck

[lostagain]

Sounds great!

2425 rpm is a little fast for a 8V71. I guess it is OK if you don't drive it on the governor all day, and don't let it rev over 2200 going down hill.

A in line 71 is more stout and can take that speed. My 4-71 is set at 2500 rpm.

Turning the buffer screw in a little should prevent it from stalling, IIRC.

I hope you realize that without a video of your bus to post on this board, you are obligated to drive around the continent to show your bus off to all us bus nuts, LOL.

JC

[robertglines1]

Guess I never figured out why the old Chilton's I have from the 70"s says to set no load on a 8V71 at 2450. That's what I went by when I had that engine.   Bob

[luvrbus]

That is not his problem JC you don't have a choice with adjusting the buffer with a Jake switch his problem is the starting aid he will need to pull the left valve cover and use the gauge to match his injectors and set it from the 2nd cylinder,then he will have to redo the rack again,try backing the starting aid all the way out and see if that stops it 

good luck

[bevans6]

Clifford, it's standard timed turbo with jakes.  I have a starting aid screw on the front of the governor, but I have not adjusted it, I left it  set where it was.  Reading the book, I think that I have to check the starting aid adjustment, I have N80 injectors so I need to make a .385" gauge to measure the injector to clevis setting and correct it, then I need to measure the running gap, since I believe that changing the starting aid will affect the gap.  If you change the gap, then you have to re-set all the injector fingers, ie. run the rack.  I tried to measure the static gap, but probably did it wrong, it seemed in spec so again I didn't change it.

I am  getting there!

Brian