Either that engine has a miss, or more likely they are using the wrong or a misadjusted governor. These engines normally run smooth as can be, they shouldn’t be hunting like that at idle.
The racks on either bank aren't adjusted correctly, that's why it is hunting. It's probably on purpose. These engines will drop valves and keep purring at a steady idle
The governor needs to be adjusted, it's not supposed to have an idle lope. (But I suppose it won't hurt anything - unless it goes open-loop, in which case the engine speed will increase uncontrollably, though the overspeed cutoff should prevent damage.)
If I translate the description correctly this engine originally had a big DC generator at the end of the crankshaft, driving the traction motors of a locomotive. The rotor of that generator is a massive lump of steel and copper and when it is removed the governor may not even have enough adjustment range to compensate for the all weight removed. Thus it idles loped.
For Pete's sake... take that lope out of the governor.. set the idle up to where it should be, at 350+/-... and how about air filters for the blowers?!!
So impressive! I just love 💕 these old time diesel locomotive engines! I've started engines like these on passenger 🛳️🚢 ferry's including the 2305 horsepower turbocharged units. I'm an all time diesel buff!
Sounds like the idle was set too low, which explains the severe variations to the RPM. Maybe find a generation unit to provide enough resistance to run smoothly. But what a great find!
poorly adjusted governor. Something that their little brothers, the Detroit diesels, also suffered from. Although this is the first big EMD i've ever seen to have that kind of surge. The surge should have gone away after a few seconds, if it had even surged at all at startup.
Brendan Powell.... No, it is a post 1st generation (1938 - 1943), 567C or D model. The earliest 567's 1st came out as the 567U (cast, top deck), then the 567V (fabricated top deck), and both utilized the "rectangular" airbox & crankcase covers. The 567A and B models also had the same covers, then beginning with the "C" & "D" models & all consecutive EMD's had & have the round covers as does this one in the video. The reason this engine is "loping" (hunting") is due (most likely) to, too low oil pressure to the governor.... IF, it still retains the original Woodward hydraulic governor, which I'm sure it does.... this is very first EMD that I've heard with governor "wander".... but it's not unheard of, and is usually caused by.. as I mentioned previously, idle oil pressure to the Governor being insufficient.... which "can be" caused by too low of an idle speed, which "should be" set at 275/300 rpm.
It’s likely because it has been powering the traction motors on a locomotive prior to being removed. The loss of weight and force put on the governor caused by the removal of the generator, and the governor not being adjusted properly past that is likely the cause of the engine hunting for idle (lope).
