8v71 govenor

[Geoff]

I'm in Florida and my book is in Michigan so I can't send you the instructions.   The idle adjustment is on the top of the governor.   Setting the max rpm is easy if no one has miss adjusted the insides.   Seeing how everyone just wants to make remarks, I won't post again.   Send me your email and I will get back to you.    Larrydbaker@aim.com.   good by to everyone else, too bad you didn't want to help him.

Sometimes these posts get to the ridiculous stage.  Mr. Larry Baker, YOU are the one who said look at "da book".  Which is what 90% of the posters on this board need to do, including you, who doesn't even know that the idle adjustment IS NOT on the top of the governor.

Adios, mi amigo.

--Geoff

[Dietrichfarms]

Thanks everyone for all the input. What I'm really looking for is recommendations on who are where to take my bus to get the governor set. Like I said I'm in central Texas but can drive the bus to a location for work. Thanks again for any help.

[luvrbus]

If you are ever in the Bullhead Az or Laughlin Nv area stop by and I will check it for you,In Texas try Stewart and Stevenson they still work on 2 strokes.
What makes you think the governor needs resetting ? once set they usually never need to be reset again till you run the rack.
All the LS-DW governor does on your engine is limit the top RPM and the idle it's not a variable speed governor   
   

[Geoff]

Clifford-- you are right, but how do you know the governor, rack, valves and injectors were set right to begin with?

One of the first things I do when I work on a DD is back the idle screw off, put the rack in the full fuel position, and see how far off the rack is and if it is pushing against the governor.  If it passes that test I know it was set right.

--Geoff

[luvrbus]

I don't know what he is after Geoff ,I do the same with backing the idle screw out.If he thinks holding the pedal in 1 position and the engine will keep the same rpm up on a incline he can forget that with the LS governor

[Dietrichfarms]

I have never had this engine come up against the governor. on at least two occasions when I wasn't paying close enough attention I ran rpms up past 2300.Like I said before bus starts and runs great I just don't like that it will over rev if you hold your foot down. I wont let anyone else drive because of this. I had heard of Stewart and Stevenson in Dallas/Denison, I will give them a call. Thanks Everyone

[luvrbus]

It maybe set on 2500 rpm no load you see that see that setting a lot on a 8v71

[Geoff]

I passed a truck the other day and was doing 90mph @ 2900 rpms.  The 6V92TA took it okay, but my speed was not intentional.

--Geoff

[Dietrichfarms]

Yes that was me on I-10 out of Fort Stockton Texas ran my 8v71 up like that, not intentional. That's why I would like to get governor set.

[bevans6]

At the strong risk of being a day late and a dollar short, has anyone posted the actual instructions for setting the governed high idle speed on a MUI engine yet?

http://miscpartsmanuals3.tpub.com/TM-9-2815-224-34-P/TM-9-2815-224-34-P0502.htm

You can ignore the bits about the turbo cover and you can do it if you're not a soldier, this is just the PUB for military engines on-line.  It's for an 8V-92, but 8V-71 is identical except for no turbo.  In the simplest of terms, you take the cover off the adjusting spring stack (what I call it, I don't know it's real name) that is about 3" long and runs along above the valve cover from the back of the governor on a 8V-71.  You loosen off the lock nut (needs a special tool or some ingenuity), you back off the adjuster five turns, you start the engine, you give it full speed ahead on the speed control lever and you screw the adjuster back in until you reach your desired speed.  Helps to have someone to read the tach for you.  Then you lock it down with the lock nut.  The "adjuster" is AKA the "high speed spring retainer".  You are adding preload to the spring that controls the maximum no-load speed of the engine.  By backing it off you set the maximum no-load speed to "not much" and then you add it back in to where you decide you want it (or if you are a trucker, as fast as you dare, or if you are a soldier, where the Sergeant tells you to set it).  There is something called "droop", which is the difference between no-load maximum speed and full load maximum speed.  Typically droop is around 150 RPM, but varies and is (as far as I know) not adjustable.  If you decide you want 2300 rpm maximum speed at full load (which is what I want, personally, on my engine) I would set the no-load to 2450 rpm (which is what it came set at, being an ex-NATO tank engine) and I checked it, but did not adjust it, because it was dead on.  You can then check idle, buffer screw, starting aid, and all the other stuff if you want to.  It's in the PUB.

Again, apologies if I am being redundant in the thread.

Brian

[Geoff]

Governor droop is determined by how much wear and how much slop you have in your governor weights​ and rack linkage. A Detroit engine with no slop and the governor gap set correctly will have as little as a 50 RPM droop, to maybe none. You need a dyno to check the governor droop as it is checked at full load, something you can't do if you are driving.

I set top no load at 2350.  Mine is set at 2900 rpms because my Jakes came off a military engine with oversized governor parts to run at higher speed.  I drive it at normal speeds, but sometimes forget when passing somebody.

--Geoff

[chessie4905]

Just remember how fast those valves are moving... twice a fast as a four cycle.2900=5800.Some valve float and a keeper dislodges.....BANG!! Blam,, blam,blam. Junk.

[bevans6]

Geoff, I got my droop number from the engine manual for a M110 howitzer, which is what my engine was originally used in.  I copied the specifications when I wrote up my engine swap project.  That's all I know about droop!    Actually, reading the spec again it quotes maximum hp at 2300 and max no-load at 2450, and I assumed that was the droop.  Could well be a mis-interpretation on my part.

Here are the spec's:

ENGINE 8V-71T 7083-7395
Manufacturer Detroit Diesel Engine Division, GMC V-8, compression-ignition, liquid cooled
Type Turbocharged, two-cycle diesel
Model (7083-7398) or (7083-7395) 8V71T
Weight, Dry (as installed) 2,442 lb (1,107.7 kg)
Number of Cylinders 8
Displacement 568 cu in. (9,308 cm3)
Bore 4.25 in. (10.8 cm)
Stroke 5.0 in (12.7 cm)
Compression Ratio 17:1
N-80 Injectors
DW-LS governor
Horsepower, Gross Brake (at 2,300 rpm) 405 (302 kW)
Horsepower, Net Brake 345 (257 kW)
Maximum rpm. No Load (governed) 2,450 rpm
Idle Speed 650-700 rpm

[luvrbus]

Droop only accrues under a load,I just got a 525 hp 8v92 off the dyno set @ 2250 rpm it has a rebuilt governor and all new linkage. I get no droop @400 hp, 25 @425hp the short version is I get 125 droop @525 hp with 1580 ft lbs of torque and I cannot get that droop out of the engine I've tried for 2 days any answers ?  

[Geoff]

Droop only accrues under a load,I just got a 525 hp 8v92 off the dyno set @ 2250 rpm it has a rebuilt governor and all new linkage. I get no droop @400 hp, 25 @425hp the short version is I get 125 droop @525 hp with 1580 ft lbs of torque and I cannot get that droop out of the engine I've tried for 2 days any answers ?  

Do you have a yield link or a solid link in the governor linkage?  You want a solid one.

--Geoff