Note: New 6/1 engine (1/2 hour run time)
Today I gradually took the engine up to 2/3 load (2kw) and the rpm's dropped from 650 to 575 and did not recover.
While loaded, I adjusted the governor back up to 650 and she held, but was obviously working hard (Thumping with a strong exhaust pop).
As I slowly removed the load, the rpm's climbed to 710 and stayed there ??? A huge variation between loaded an unloaded.
Any one else have this issue and how did you resolve it?
Thanks in advance,
veggie
I think that is way too much fluctuation. I would check for proper valve timing first then spill timing and that governor linkage both internal and external has no binds. That slip yoke connecting the bell crank to fuel rack can be the culprit. Picture here of just using an elastic before replacing with a very light metal spring.
Veggie,
I would bet you governor and linkage needs some tinkering. squirt some oil on it and work it.....
Quote from: XYZER on November 13, 2009, 09:12:40 PM
Veggie,
I would bet you governor and linkage needs some tinkering. squirt some oil on it and work it.....
............and clean off all paint that might be hindering operation! ;)
(That probably goes without saying) ;)
That is way too much droop with a load application. Got a couple of questions for you:
How are you measuring RPM?
How are you measuring the load?
How are you applying the load to the generator?
Droop is a fact of life with a pure mechanical generator. Flyweight position is a factor of RPM and spring tension. Since the flyweights have to move to advance the throttle, the RPM must drop to add throttle. I don't have a tach. I use a kill o watt and measure the output frequency of the generator to set RPM. I set mine for 62HZ unloaded. It droops 4HZ to 58HZ at full load around 3+ KW. If my math is correct, that is about 120 generator RPM or about 40 engine RPM.
In a purely resistive load P(watts) = I(current) times E(voltage). 2000 watts divided by 240 volts = 8.33 amps. Are you actually measuring voltage and current to determine load.
Very god points from everyone.
Thanks for the input.
That's the power of this forum. Sharing experience and information. ;)
Cheers,
Veggie
No Jens, I don't think it is to early to worry about this... Your saying that he needs to wait for 100+ hours before he has a generator that will hold proper useable frequency across it's load range? In a backup application, that could be years away... Mine still has only about 83 hours on it... he is saying he has 75 engine RPM drop with 2KW of load. That is around 225 generator RPM drop. If he starts at 1800 generator RPM/60HZ, that is a generator droop to 1575 RPM/52.5HZ... You should easilly be able to make +/- 10 percent frequency(+/-6HZ) across the load range. Mine has always done this with lots of room to spare right from it's first loaded runs... I had perhaps an hour or so of unloaded running before I hooked up the generator and started loading the generator. I did perform the utterpower governor spring mod before I did any loaded running.
I think Veggie is either inadvertently overloading it, or something is binding/not setup right in governor, IP misstimed or valvetrain issues...
None of the components of the speed adjusting system are very smart or can do anything to compensate if another part is misfunctioning, or mismatched. governor weights from a thousand rpm engine cannot be made to work optimally at a greatly lower operating range simply by changing spring tension. By the same token a matched governor and spring cannot give good regulation on an engine that for whatever reason is requiring an exceptional rack movement to render a given percent torque increase. Each of the components goes through its inherent range of motions and if the connected parts dont react it doesnt even shrug.
Jens, could the variation in set point you see be connected to atmospheric variations. A change in output at a given rack position would be the result. The mention of the sharp exhaust note suggested to me the possibility of early valve timing. My engine, which was deliberately ordered unrun at the factory, had timing one tooth early. I dont know how well it would have run but would have been somewhat crippled. Because I am running at a lower operating RPM I had to go to a spring with a lower stack rate to get good response.
I have diddled for hours getting governors balance on welding machines where you just cannot live with hunting (or wont hunt at all,) governors. There is no magic to them but if someone happens to have swapped some components, or the engine is not up to snuff, they can make you pull your hair.
If someone with the identical engine could measure their spring tension accurately at its operating length it would be a good help in eliminating one possibility.
So veggie, have you done the utterpower modification to your governor linkage? If not that might help.
RH
Can anyone tell me how to set the governor linkage that connects the bottom to the top assembly? The rod with adjustable end connectors on both sides. Is there a set procedure for that?
I couldn't find any info when I assembled mine and adjusted it so that the 90deg L-lever at the bottom sits horizontal when the engine is not running. I presume this will influence the amount of pressure the spring has to apply to get RPM right ???
Quote from: 12gauge on November 14, 2009, 08:56:04 PM
So veggie, have you done the utterpower modification to your governor linkage? If not that might help.
RH
Hi 12gauge ,
Not yet, I just learned about the modification from this thread.
It looks like a simple thing to do. I can make the necessary part to enable the swapping of the spring and rod positions.
I figure there's nothing to loose by doing the mod. (Along with all the other things that were suggested by the others.)
Might be a while before I get to it. I have to shift my focus to a permanent cooling system and an exhaust system that takes the gasses outside the garage. Winter is near and I won't be able to run with the garage door open much longer. :(
Veggie
Veggie, I can definitely recommend the mod, it made a bigger difference for me than I suspected and I was quit surprised! I've still got issues with drifting, but its much better.
I hope you get the same results, from what I've read, a lot of people did.
Quote from: dubbleUJay on November 14, 2009, 09:02:35 PM
Can anyone tell me how to set the governor linkage that connects the bottom to the top assembly? The rod with adjustable end connectors on both sides. Is there a set procedure for that?
I couldn't find any info when I assembled mine and adjusted it so that the 90deg L-lever at the bottom sits horizontal when the engine is not running. I presume this will influence the amount of pressure the spring has to apply to get RPM right ???
Generally with a bell crank transfer you should adjust for 90 degree or equal angles of push rods at the operating position, not the parked position. That keeps the motion transfer most lineal. Mobile Bob had a good article on the linearity of flyball governors and why it was critical to have them correctly weighted for the operating range.
Injector pump rack position and engine output are unlikely to have an exactly linear relationship so it can be a useful tool to tweak the linearity relationships of other parts where possible.
As Jens mentioned try to eliminate any sticky wickets caused by paint or rough machining or lost motion from sloppiness. Try to determine by manually moving the rack of the engine against a measured load whether the engines capability is normal. Eliminate the most obvious and experiment with the finer variables should get you there. Sometimes a binding condition will go away by wearing in but other times they get more set in their ways and begin to outright jamb rather than merely be cranky. Excessively high rpms after a suddenly removed load is the most potentially dangerous concern. I would be more for finding the why rather than living with a problem to see if it goes away by itself.
Quote from: Crofter on November 15, 2009, 08:58:52 AM
Generally with a bell crank transfer you should adjust for 90 degree or equal angles of push rods at the operating position, not the parked position. That keeps the motion transfer most lineal. Mobile Bob had a good article on the linearity of flyball governors and why it was critical to have them correctly weighted for the operating range.
Thanks Crofter, I'll try that 2morrow when I have a chance.
The article of Bob, was it on this forum ??? or can you give me a link to it please? That's to say if its not on the LEF which is down. :'(
I think Bobs article was on LEF. I will see if I can link below to some pics I have of the 10-1 on photobucket. There is one shot of the linkage showing the rearrangement of the spring, adjuster rod and added pivot anchor but othe guys have much more specific photos. My present arrangement uses two much lighter springs in tandem to give lower stack rate and narrowed the frequency swings a couple of Cycles per second on the Kill O Watt meter; a definite improvement.
http://s655.photobucket.com/albums/uu276/Tijean_photo/
Veggie
A key spot to look at is where the governor linkage attaches to the sliding fuel rack rod on the Injector Pump. This is done with a little forked rod yolk affair that plugs into a hole on the top of the upper bellcrank. If the rod that plugs into the top of the bellcrank is not loose enough to slide freely, it can bind and limit your travel out to full throttle. I had to do quite a bit of work on mine to get this key part to slide to the full throttle position freely. Unfortunatly this also made it a little sloppy, so the governor response to load changes was not crisp. IE: the engine RPM would change, the linkage would move, but the slop in the yoke component would absorb the movement and not immediatly move the fuel rack to compensate for the RPM change. My fix for this was a VERY lightweight spring across the upper bellcrank. This holds the yoke assembly against the end of it's slop, but still allows it to reach it's full throttle position smoothly. This was my biggest hinderance to smooth governor/throttle response. Even before I fixed it, it was still consideralby more responsive to load increases than you describe.
Here is a pic. Again, the key part is located at the top of the diagonal spring. It needs to be able to pull the fuel rod/rack out to the left to full throttle, without pulling down on the rack and binding. IMO, the rod on that yoke assembly, and it's associated pocket in the upper bellcrank are not long enough to perform this task properly. If I redesign it, I will probably shift the whole upper linkage to a weedeater throttle cable...
(http://i270.photobucket.com/albums/jj85/rmarlett/th_linkage.jpg) (http://s270.photobucket.com/albums/jj85/rmarlett/?action=view¤t=linkage.jpg)
It is possible to achieve quite good RPM regulation on a Lister 8/1 but it takes a bit of work to get it right.
To get the RPM correct you need a revcounter or a HZ meter and a load to put on the generator. I use two 1.5kw electric electric fires and a 1.5kw hot air gun on my 4.5kw Startomatic.
First of all start your set on low load then check what revs your engine is running at 850 for an 8/1 or 650 for the 6/1 or you can use a HZ meter and use 50HZ or 60HZ to set the revs correct. Then put maximum load on the generator and check the revs again it will probably drop. If the revs drop stop the engine and slightly lengthen or shorten the adjustable rod from the governor arm to the pump quadrant. Start the engine again check and adjust low load rev (50HZ or 60HZ) and then fully load up the generator again. It should have made an improvement to the revs. Keep on adjusting and reseting the rod and governor spring and it should be possible to get good revs regulation from min to max load. This takes quite a bit of time but it starts to make sense when you do it. Once you start adjusting the rod it gets better or worse and then you know which way to adjust it.(http://i358.photobucket.com/albums/oo27/listeroil/GOV.jpg)
Mick
Thanks Listeroil,
I think this is probably one of the 1st things to adjust before looking at anything else.
and for the following pics/answers bellow, I thought no one knew as I asked the question so long ago! Sometimes I can kick myself, I should have thought to look in the manual at the parts list!
WJ
I have checked the lister manuals and the lister 3/1 and 6/1 have the same governor weights according to the part numbers.
The 8/1 weights are a bit lighter. Heres some pics.
Mick
(http://i358.photobucket.com/albums/oo27/listeroil/governorweights.jpg)
8/1
(http://i358.photobucket.com/albums/oo27/listeroil/8-1governor.jpg)
6/1
(http://i358.photobucket.com/albums/oo27/listeroil/6-1governor.jpg)
The geometry of the bellcrank to IP rack is rather primitive. No, I'm being kind. It's really primitive. A toothed quadrant and a rack would have been a better way to translate rotary to linear motion.
First thing to do is to remove any paint from the shaft of the fork that goes in the hole in the top of the bellcrank. As Ron mentioned, as the bellcrank rotates, that fork has to slide in and out of the hole in the bellcrank without wobbling, or binding, so the stubby little shaft on the fork has to be free. I had to run a drill bit through mine to get rid of the burrs left over from manufacturing. Then I polished it using carborundum compound. Once the fork slid in and out of the bellcrank freely, I had no problem. Set the speed unloaded to 62 rpm, and when gray smoke starts to appear, you're down to about 58 rpm. That's not bad, considering the vintage of the design, and the crudeness of the final (Indian) product.
You notice that there is no paint on Mick's (Listeroil) linkage. That's probably the best way to keep it.
Quinn
"shaft of the fork that goes in the hole in the top of the bellcrank"
Same piece on my 6/1 was so poorly made that it bound up badly. I drilled out the hole, put in a bronze bushing that gave better support, polished the yoke pin.
It helped a great deal.
The sliding yoke is a bad design, as Quin suggests, the mechanical governor it would perform better with a better linkage.