Lister Engine Forum

Lister Engines => Listeroid Engines => Topic started by: 32 coupe on August 05, 2018, 05:24:52 PM

Title: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on August 05, 2018, 05:24:52 PM
I just can't get this thing to produce power.

I sent the cam to Butch who installed the new weights and see no change.

The engine will pull about 1600 watts but if I load it with another 1000 watts it just won't
do the deed.

With  no load I set the speed to 720 engine rpms. That will give me 1800 at the gen head.
I see 120 volts at 63 HZ. With a 1600 load it does 117 volts @60 HZ.
But another 1000 watts and the voltage will fall to 93 volts @ 54 HZ.

The engine is not "working" at this speed the governor just won't "pick up".

I tried several springs and spring combinations.

I am thinking a larger gen pulley to bring the engine rpms up to about 800 or so.

The engine has always run very close EGT's but I see a slight difference now. I guess this is do
to the new cam lobe on the #1 cylinder. I haven't reset the timing on that side yet but I don't believe
it is enough to cause the problem I am having.

I am open to ideas.

Gary

Title: Re: Ashwamegh 25/2 :the saga continues
Post by: BruceM on August 05, 2018, 06:34:03 PM
Have you checked for wrong governor weights (light high speed types) or binding in governor?

Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on August 05, 2018, 07:15:56 PM
Bruce,
Yes, the cam went to Butch for new weights....they are just a little heavier than "stock".

No binding in linkage.  The engine starts and runs great.  It just won't  pull a load.

Gary



Title: Re: Ashwamegh 25/2 :the saga continues
Post by: BruceM on August 05, 2018, 07:31:35 PM
What happens when you manually move the rack?  Is there plenty of authority and power there?  If so, it still comes back to governor.  Is exhaust looking OK? (Wondering about injection, valve timing.)  If valve timing is off a tooth , from a misplaced idler gear, power can suffer but it will otherwise run just fine and exhaust looks fine (until heavily loaded).  I'm assuming the same problem could happen on a twin. Don't ask how I know. ;0


Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on August 05, 2018, 08:35:22 PM
The linkage works with no binding or problems.

The engine starts right up and runs to speed with no smoke and a nice clear exhaust.

I can easily run the throttle up with a slight touch of a finger on the linkage with no change in
the exhaust

I am 100% convinced it is the govenor that is why it went to Butch for the weight change and "check out".

I am thinking pulley change for more engine rpms (720 to 800) or one of those "screen door" return springs.

At this point my 6-1 will put out more HP !

Title: Re: Ashwamegh 25/2 :the saga continues
Post by: BruceM on August 05, 2018, 09:28:29 PM
Yep, my older 6/1 at 5600 feet elevation will pull out more watts, too.
Seems like something might be off in the governor assembly inside the case, since your linkage checks out OK.  A softer spring would help with diagnosis...too soft should hunt.  I hope Butch will pop in here and help get you sorted. 


Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 2Ton46 on August 05, 2018, 10:59:13 PM
If I'm reading correctly, when you have the larger load on that is pulling down to an unacceptable speed, you are able to touch the rack with your finger and bring it up to speed with that load still applied.  If so, this condition is similar to what I have had going on with my 12/2. 

I've been working at the problem some recently and have gotten a much better response by adding an additional spring in series with the one it came with. In my case, the short spring when adjusted to give my desired rpm, would rapidly loose tension as the rack opened. In fact, it would be pretty much not doing any tension as the rack got to the full open position. This led to the rack not opening as the spring tension would drop off and stop overcoming even the now slowing weights, and would result in a large speed loss when my compressor cycled on that sometimes wouldn't even recover to set point by the time it cycled off again.

By adding in a longer spring I was able to greatly reduce the force dropping off as the rack opened. For experimental purposes I used a piece of wire around the bottom of the oil pump as a temporary and adjustable anchor. As an initial setting I tied the spring in series with the other one, after unhooking it from the peg on the block.  I then pulled the pair tight with the wire until the end of the original spring lined up with the peg again. This gave approximately the same tension on the arm as before, but the force no longer drops off as rapidly (or increases as rapidly) as the arm moves.  This gives a nice steady pull to work against the weights over the whole travel of the rack. The downside is speed adjustment now requires more change in length than before.

Boy what a difference! I've gone from badly over damped to a slightly under damped control situation. Upon startup it will slightly overshoot the speed set point and then settle in as it slows to speed. With no load, it seems to be slightly hunting as the rack is moving around a little, but it doesn't by sound or show up in my cheap tach. With a load, it maintains set point beautifully. Now when the compressor cycles on, the speed drops slightly but its back to set point within a second or two. It's fun to watch the rack open up and then back off slightly again when the compressor cycles on and it recovers the speed and gets back to maintaining rpm with the new load. The rpm change is is now fairly small and is perceptible by ear when the compressor loads...but recovers quickly and sounds more like its not lost speed and recovered but is just thumping a little harder suddenly.  When the compressor unloads, its even quicker to get back to set point as it speeds up with the loss of load and settles back.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: mikenash on August 06, 2018, 02:09:37 AM
There are anecdotal stories of folks using "fly-screen door" springs for the same reason?
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 38ac on August 06, 2018, 12:14:22 PM
This is one of those deals where being there beside it would allow for it to be quickly fixed but diagnosing from afar gets pretty wordy.
First question which has all ready been asked.. and if you answered it I missed it, sorry. When the engine is loaded to the point of slowing down can you manually push the rack open and bring it back up to speed?  This must first be checked and answered to get you headed the right direction.

That being said and assuming it will indeed speed back up when you run the racks by hand.  Then you next check the linkage adjustment. Here is how you do that https://youtu.be/N4otiDKDiyk (https://youtu.be/N4otiDKDiyk)

The high speed engines have a very stiff spring and it will not control the engine very well when it is slowed down as 2ton46 very well explained.  The next step would be to replace it with a lighter spring. May I suggest the one from your 6/1? save a trip to town and if it shows improvement would mean you are headed the right direction. 
There is no black art to spring selection. the longest spring you care to fit that has enough pull to give the required RPM without the engine hunting (speeding up and slowing down on its own)  is the one that will give the best regulation.


Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on August 06, 2018, 01:45:54 PM

The first spring I tried was so light the engine would hunt.
I then went to several others including one off my 6/1.
No luck.

I stopped this morning and bought a few more springs from a local
supply shop and will give it another go this weekend.

All the linkages, pumps and injectors are fine and working properly so
I am sure the spring is my problem.


Thanks for everyone's input. I will report back next weekend.

Gary



Title: Re: Ashwamegh 25/2 :the saga continues
Post by: BruceM on August 06, 2018, 02:35:24 PM
Gary-   I use two springs in parallel, one that was a hunter, plus a second spring in parallel that was too soft to be useful alone but combined with the hunter works well.  You don't have to find the perfect single spring.



Title: Re: Ashwamegh 25/2 :the saga continues
Post by: mikenash on August 07, 2018, 10:44:34 AM
Small stationary engine such as those in Lawnmowers or the Chinese 3kVA generators tend to have two springs - one that is attached to the governor and against which the governor works, and another, much much lighter one, attached to the linkage as an anti-hunting device.  In my experience with small petrol gensets, if the small, light spring is lost damaged or worn - the engine will hunt ferociously, no matter what you do with the big spring & its attachments.

All of which maybe just tells us that CS spring is probably tring to do two jobs - and also, maybe, that we're trying to get a level of performance out if it which is challenging its 70-years-old design

Just my $0.02
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 38ac on August 07, 2018, 12:47:22 PM
and also, maybe, that we're trying to get a level of performance out if it which is challenging its 70-years-old design

Just my $0.02

Not maybe but exactly the problem. Back in the day engine governing in England  was required to meet certain "classes"  I dont have the class of the CS committed to memory but  it was very lazy.  Most people DO expect a lot more out of the CS governor that it was designed for and it is to the credit of tinkerers that it works as as it does when tweaked.   In this case 32coupe does have an issue, they work better than he is experiencing even when not messed with.

One thing that vastly improves the engine governing is a larger element in the fuel pump. What this does is give more fuel for less movement of the rack. I think that Eddie has also played with that if I am not mistaken? My 8/1 gen set has a fuel pump from a 25/2 on it and the difference in governing is marked. The exact element diameters are not committed to my memory but I can get the information for anyone thinking about going that route. . The 6/1 8/1 pumps are marked 032 and the larger element pump for a 25/2 or 14/1 will be marked 034.  There are even larger elements available through MICO up to about 10MM I think? Depending on how large a person goes and how he  loads the engine it is wise to install a rack limiter such as Lister put on the engines originally.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: EdDee on August 08, 2018, 11:46:25 AM
Indeed I have played with various pump element sizes - And found that the best all round for performance and speed governing tended towards the largest element I could get...

Smaller elements had a tendency to be lazy on the governor, as well as cause a greater amount of carbon build up in the cylinder when running crappy fuels... There was marginally more "ignition knock" with the larger element when timed correctly for the RPM desired....

Further, I experimented with everything I could lay my hands on spring wise for determining best governor responses...

I ended up with a basic formula of spring length un- tensioned, at rest, being 3x the length of the lower end of the bellcranks total travel as its shortest, to 6x the travel length at its longest.... The spring wire diameter does make a substantial difference, but that being said, the average best wire diameter I found was between .8 and 1.2mm and the nominal coil diameter was around 10 to 12 mm... Wide variances I know, but with not all springs having the same wire hardness (thus changing the forces they can exert over a given pull distance), there is a fair bit of leeway for playing around....

The easiest thing I found was to get 2 identical springs, set one up and start trimming until the response is satisfactory, or best with that particular grade of spring... If you overcook it and trim too much, slap the other one in and don't tighten it till it breaks....Lol.... Trimming off one or two coils at a time was a tedious, but rewarding job ultimately.... Also, I swopped the mounting/adjustment points round for better running too... (as well as getting a nice long adjustable area to work with)...

Some crappy pics below ..... (Not the ideal spring, but what I had on hand at the time.... It holds to around 51Hz unloaded through to about 50.5 when loaded to 3Kw or so...)

Cheers
Ed

PS, the silver tank is an auto oil top up I made and installed..... Keeps the oil up to max level, unattended while running long and extended periods.... It can be filled up during running too, by closing the tap, opening the top plug which has a dipstick attached to it, topping up the the tank, closing the top plug then re-opening the tap....Think its worth a patent application?

....Naah...

If you like it, use it!!

Edit... Oops, forgot to mention.... the crappy pic of the IP rack shows a weak spring I installed to take the slack out of the linkages and further improve governing tremendously... It also provides the peace of mind that should a link fail, the rack closes automatically... Additionally, there is a nut that allows the opening limit to be set to prevent "dirty black specs" on clean washing.... Nuff said!
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: Willw on August 10, 2018, 09:47:44 PM
Re: your auto-fill oil tank; it appears that the feed line from the tank enters the engine through what was originally the dipstick hole.

On my 6/1 clone the correct oil level in the top sump is several inches below this hole, how does the oil tank know when the oil level is correct?

To me your oil tank could be too high, depending on the answer to the above question.

Could your engine be overfull with oil?
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: ajaffa1 on August 10, 2018, 11:12:48 PM
Brand new one for sale here with some good pics: https://www.gumtree.com.au/s-ad/violet-town/miscellaneous-goods/diesel-generator/1191994009

1000 rpm, hope the balance and flywheel castings are OK

Bob
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: EdDee on August 11, 2018, 10:41:21 PM
Hi Willw,

The oil line enters the top weir dipstick hole and stops just at the upper oil level, by adjusting the stop collar on the pipe I can set the depth that the pipe reaches to. The oil tank is sealed and only allows oil out when air can enter the pipe from below, ie as the oil level falls... As a bubble of air enters the tank, it lets a few drops of oil out, the oil level rises, and no more air enters the pipe, oil stops flowing out the tank....

The height of the tank itself has no bearing on the oil level in the sump whatsoever... But the depth that the pipe reaches into the sump does!

Cheers
Ed
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: Willw on August 12, 2018, 05:50:34 AM
Hi EdDee, thank you for the explanation of the oil tank. Ingenious system. :D
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: LowGear on August 12, 2018, 11:11:32 PM
I first saw this at Aunt Gladys's in about 1950.  We'd fill the jug with water and flip it upside down in a pan for the chickens.  Once the vacuum got established the water slowed to a "as used/needed" flow.  I just built something very much like it for plants I leave for weeks at a time inside the house  My neighbor stops by every couple of weeks and fills the used gallon juice jug.  The oil sump is a great application.  Bravo.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: Matt12 on October 26, 2018, 09:07:52 PM
I just can't get this thing to produce power.

I sent the cam to Butch who installed the new weights and see no change.

The engine will pull about 1600 watts but if I load it with another 1000 watts it just won't
do the deed.

With  no load I set the speed to 720 engine rpms. That will give me 1800 at the gen head.
I see 120 volts at 63 HZ. With a 1600 load it does 117 volts @60 HZ.
But another 1000 watts and the voltage will fall to 93 volts @ 54 HZ.

The engine is not "working" at this speed the governor just won't "pick up".

I tried several springs and spring combinations.

I am thinking a larger gen pulley to bring the engine rpms up to about 800 or so.

The engine has always run very close EGT's but I see a slight difference now. I guess this is do
to the new cam lobe on the #1 cylinder. I haven't reset the timing on that side yet but I don't believe
it is enough to cause the problem I am having.

I am open to ideas.

Gary

 Hi Garry,

                It sounds like a too short or weak governor spring,  as you know, the spring pulls the rack open until the revs come up and the gov weights throw outward and pull the rack back to the set speed, it has to be the spring.
Matt
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on November 17, 2018, 07:15:06 PM
Update......after thinking about this for a while I dug throught my
junk and came up with a new 2B pulley and center.

The shaft size was larger so I turned a sleeve for it.

The new pulley is about 1" larger in diameter so if my numbers
are correct it should bring the engine up around 830 rpm or so
from the current 720 or there about.

If I gather the strength tomorrow I'll fire it up and see if it will bring the govenor in line where it will pull a load.

Enjoy !




 
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: broncodriver99 on November 17, 2018, 10:09:59 PM
Looks like you need to find a better key. You are going to be depending on the taper lock for most of the strength with that setup.

IIRC you are in the US. Check out https://www.huyett.com/  They carry offset and oddball key stock.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on November 17, 2018, 10:27:11 PM


Thanks for the tip, I somehow totaly missed that !


Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on November 18, 2018, 08:29:06 PM

Today's saga.....

Had some key stock handy so a small task completed.

This engine starts and runs so nice. The temps are so close while running under load.

So here is what we got:

Engine no load is 856 rpms turning the gen at 1850. So my numbers were pretty close.

Engine loaded at 36 amps is 820 rpms engine and 1750 .

Hz is 61.4 no load with 58.3 hz with a 4.3 KW load.


It is better but no where I think it should be. I'm thinking it should pull 7 to 10 kw .....thoughts ??


I will add that startup was one of the easiest so far. I installed the pulley adjusted the slide for the gen
and set belt tension and on start and running I didn't have to touch it ! The usual method is starting and
stepping numerous time to get the belts to track correctly.

I installed.the factory spring and on startup I had to turn the thumb screw a couple of turns to dial it in.

Easiest startup yet  First spin, no problems......

I will begin the process of different springs again and see if I can get the thing to pull a load. It is better but
still no where near to my expectations.....

Enjoy !



Title: Re: Ashwamegh 25/2 :the saga continues
Post by: mikenash on November 19, 2018, 12:51:49 AM
I know you have been through all that, but I can't help thinking it sounds like a governor issue:

Load comes on.  RPMs drop.  Governor weights move.  linkage opens fuel rack.  RPS increase.  Governor weights move back a bit . . .

I'm not thinking of it from a Lister person's POV cos I don't know enough about them - but from an idiot engineer's point of view, I'm asking myself about the relationship between RPMs dropping in response to load and governor weights responding . . . I'm assuming you have played with that process?  Maybe allowing the RPMs to drop quite a bit to see at what point the governor responds and how?

Excuse me covering ground that has already been traversed

Good luck.  Mike
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: ajaffa1 on November 23, 2018, 11:04:12 AM
Hi 32 Coupe, I`ve been watching this thread for a while without commenting because I too believed it was an issue with the governor, governor spring and etc. There are a lot of people on the forum with much more experience of governor problems than me and I thought they would sort you out.

There are a couple of other issues that will cause an engine to under perform, even with a perfect governing setup. The first is exhaust back pressure and the second is inlet flow. How big are the inlet and exhaust valves, are they proportionately bigger than those on a 6/1 or 12 /2? If not it is never going to produce the power you are expecting. Ditto for the inlet and exhaust ports. How large are the air filters and exhaust pipes? I recommend you try running it without an exhaust or inlet manifold, if this produces a significant improvement in output you have your answer and need to make changes to the valves and ports or change the cylinder heads.

Wouldn`t surprise me at all to find you have a minimally modified 6/1 head on a significantly larger cylindered engine.

Bob
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 38ac on November 23, 2018, 12:50:34 PM
I did the calculations on your engine RPM vs hertz numbers and it appears that you have fixed your belt slipping issues.
Now before you tear into anything you need to do as has been advised here. Load it just as youdid previously then push the on the racks while watching hertz or RPM., If it is strictly a governor problem,it should briskly come back to speed. If it does not pickup you have HP issues not governor issues.  If it comes back but is sluggish about it you have HP issues. The engine must run right for the governor to work as designed and the governor must work right to produce the advertised HP. It is two separate issues but they are intertwined.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: BruceM on November 23, 2018, 04:30:04 PM
+1 for 38ac's assessment, though I thought it was already done and confirmed to be governor.


Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on November 23, 2018, 06:35:41 PM

I have been using the stock intake manifold with the stock filter setup with stock exhaust mufflers.

With that said, yes I can gently rest a finger on the rack and the engine will  come up to speed.

I haven't had the chance to try differnt springs yet but that will be on the list for tomorrow.


Again, the engine starts right up, runs with no smoke and the exhaust and head temps are within 5 degrees
of each other. No binding in the linkages anywhere.

I thought by going from 750 rpms to 850 would solve the problem, but still no luck.

Gary


Title: Re: Ashwamegh 25/2 :the saga continues
Post by: BruceM on November 23, 2018, 06:45:24 PM
If it doesn't hunt, you haven't tried a soft enough spring.  Just barely more than hunting is as good as can be done. A way too soft spring can be added in parallel to stop hunting.  I think 38ac reported the Amish regulator spring is a screen door screen, quite long.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 2Ton46 on November 23, 2018, 10:05:55 PM
From my experience BruceM is correct. Also I found that if you can find another spring similar to the one you are using now, and connect it in series with your current spring you will effectively get a longer spring that helps a lot with the issue you have described.  The pulling force of the short springs that many of these come with drops off too rapidly as the length decreases and in my case it was barely stretched to begin with at a proper rpm setting. So that when the speed dropped under load, it would move a little towards open but since the weights were moving slower it would tend to find a new equilibrium at a slower rpm(never opening the rack far enough to get back up to the original set point with the new load). Touching the rack would get you back up to speed and would probably maintain that speed if the load was steady. In other words the supplied spring has a spring rate that is too high, and longer springs of a similar diameter and wire size tend to have a more favorable spring rate for this application.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: BruceM on November 23, 2018, 10:11:58 PM
Nice technical writing, 2Ton46, and a nice explanation why a spring with somewhat more uniform force over the stretch range is better.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on November 24, 2018, 12:15:06 AM

Before the cam went out for a rebuild I tried 8 or 10 springs, combinations of springs, springs with
bailing wire tied to a fixed spot, springs wih springs......you name it. I got it to just begin to hunt then
would adjust, add, subtract, cuss and holler.......I went back to the original spring....no help.

This time around I have only tried the factory spring. I hope I can get some run time in the next couple of days
after all, I still have all those springs in a box just looking for something to do !

The engine starts/runs so nice I'm pretty disappointed it won't pull much of a load. I have never had much
faith in the thing only because it is what it is. Getting it to run as well as it does has been a joy.
It fires right up and is fairly well balance. I was concerned about bringing the rpms up from 750 to 850
but I do believe it is just as well behaved if not better. Seems to be a bit better balanced and it just sounds
alot better.....hard to describe ....the best description I could give be would be like when a wild cam just starts
to settle in at the lower end of its rpm range.....the lope is gone but no where near top end.

Still hope to load up that Stamford clone head to see what it will do ! The thing just laughs at 4kw.

Enjoy !










Title: Re: Ashwamegh 25/2 :the saga continues
Post by: BruceM on November 24, 2018, 12:34:11 AM
Patience and determination will win out!
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: ajaffa1 on November 24, 2018, 08:40:41 AM
Hi 32 Coupe, I`m assuming you are running a pair of Mico injection pumps, these have numbers on them that should identify the size of the elements. I`m thinking you should be running a 10 mm element, as a 6/1 or 12/2 uses a 7 mm element.

The other thing when running a diesel with twice the cubic capacity is the fuel injector nozzles sizes and pressures. If you are not getting enough diesel into the cylinders it will run but never produce the expected output. The injectors should also have numbers on them which should identify if they are correct for this application.

Bob
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 38ac on November 24, 2018, 09:56:42 PM
Bob, is correct in that the pump elements are larger for the high HP Liesteroids. Don't believe they
are 10MM but I am not near my spec sheets. The pumps for a 25/2 should be marked 034, if they are marked 032 they have the elements used in 6 and 8HP or 12/16 twins. The larger elements have a marked effect on governor operation as it takes less rack movement to give the requires fuel delivery for a given HP.  BUT, even with the small pumps you should be able to pull 7-8KW at 850 RPM. I sure wish I was close enough to come take a look at it.
Title: Re: Ashwamegh 25/2 :the saga continues
Post by: 32 coupe on November 24, 2018, 10:30:15 PM

Butch,
When I load it up and am setting outside your shop door will that be close enough ??

I didn't get to it today but you guys have provided a list of.things to look at tomorrow.

I will report back tomorrow evening, thanks for all the pointers.

Gary