Author Topic: My old CS Lister, still working at 75....  (Read 42987 times)

starfire

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Re: My old CS Lister, still working at 75....
« Reply #60 on: May 29, 2015, 08:16:36 AM »
Hi Mark, yes you are on to it, its all to do with lead/lag, both torsional and linear vibration. This method can only work with rotational forces, the up down linear  motion is transferred to an offset around a circle . ... ie, any up/down fore/aft movement is vectored around the circle, the moveable weights  then position themselves at a node. The back and forth motion of the weights inside the ring  try to cancel any  torsional "whipping" , they cannot do this completely unless we have a rubber crankshaft, or rubber mounted flywheels,  allowing a relative movement between mover....piston.... and weight.... flywheel, so a small amount of damping  can only  occur by  the balls running back and forth  in the oil causing a frictional loss, much as the usual  harmonic balancer damps via frictional losses in the rubber.  Its easier to explain with maths, but yea, you have the idea.


Mark.... you could possibly try simply tipping a pint or so of water into your experimental wheel/tyre wheel balancer experiment... I cant see why this wouldnt have a similar effect?  Water is also a moveable weight after all.

AdeV

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Re: My old CS Lister, still working at 75....
« Reply #61 on: May 29, 2015, 10:16:46 AM »
This thread has become absolutely fascinating, and some brilliant information. - Parts of it are definitely a contender for the Wall of Knowledge.

Starfire - you wondered about applying the balancing mod to a heavy flywheel engine - there is still a lip available, the outer few inches of flywheel being fatter than the inner cheeks. To secure the tubing, I'd either make some kind of bracket which clipped on using the kidney shaped holes; or, if I had a 'roid, I'd consider drilling/tapping the cheek and fixing the tube in place with tabs & screws. So long as one used reasonably light screws, and took care to ensure the fixings were equally spread around the flywheel, any additional imbalance should be taken up by the ball bearings. I'm lucky, my CS SOM barely moves when its running, even when it's not fixed to the floor.

Cheers!
Ade.
--------------
1x Lister CS Start-o-Matic (complete, runs)
0x Lister JP4 :( - Sold to go in a canal boat.

starfire

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Re: My old CS Lister, still working at 75....
« Reply #62 on: May 29, 2015, 12:34:41 PM »
Thank you for the encouragement, I appreciate it.

The interesting thing here, is no matter how heavy the flywheels are, the exact same dynamic weight will balance that engine, even if you lightened the flywheels, the same weight would be sufficient. The dynamic weight has only to be the same or slightly more than the difference between the effective "weight" of the piston/rod at TDC, and again at BTC. I use parenthesis around the word weight, simply because it varies with RPMs,...... inertia is the PITA word we are looking for here.... the piston gains weight with revs. The dynamic weight required will only work between certain RPM limits, and because its rotating mass, not reciprocating, its effective weight remains the same. Like I said somewhere earlier, its simple but complicated.  Lister and others knew this, cheated,  and just used really heavy flywheels, the unbalanced weight then becoming a smaller  percentage of the total. Its all academic really, but useful knowlege. The other reason for heavy wheels was an attempt to smooth the power strokes in gensets to prevent light flicker.... another cheat when the more elegant solution would have been  multiple cylinders. But money was tight back then too I guess. 

biggkidds

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Re: My old CS Lister, still working at 75....
« Reply #63 on: May 29, 2015, 03:57:20 PM »
Really good info here thanks  ;D
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M61hops

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Re: My old CS Lister, still working at 75....
« Reply #64 on: May 29, 2015, 11:18:56 PM »
Hi starfire, have you actually used this method of balancing an a CS type?  My Metro 'roid was a real extreme hopper and I thought of trying this method because I'd used it successfully on car wheels.  However I was concerned that the power pulses of an engine would move the tubing back and forth and keep the balls from finding the right nodes.  I ended up just trial and error placing some channel iron weights between the flywheel spokes.  This works pretty good but there was a lot of variation in the amount of weight tried as if it wasn't too critical.  I ended up using just the minimum weight to stop the hopping but I see videos of other engines that are overall way more stationary.  Also, I can't help wonder about smoothing the power pulses by adding extra rotating mass.  I got rid of the flicker by adding heavy brake drums to the crankshaft but I wonder if there is an upper limit to flywheel inertia benefits.  It seems like too much could waste power.  I have no idea if you will always get back the power in the combustion event over the rest of the strokes if you had, say, really really massive heavy flywheels.  Does anybody know if there is a point past which you start to lose overall horsepower with too much flywheel mass?  Is the price of cast iron or the bearing size or windage the practical limiter?  I tend to over think sometimes  :P !                  Leland
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starfire

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Re: My old CS Lister, still working at 75....
« Reply #65 on: May 30, 2015, 12:02:47 AM »
Hello Leland.
My very first off grid setup used  a 240 volt alternator  with the 650 rpm Lister, thats when I used this idea to try and cut back the vibes and noise. It worked great, but later decided to use 24 volt truck alternators and a battery bank/inverter setup..... far more user friendly, engine now runs at a non critical 300 rpms, less noise. less fuss, and electricity 24/7, even during engine downtime. So, now I have no need for dynamic balancing rings.... the engine runs slower now.
Flywheels only store energy, they dont use it, so they can be as heavy as you dare make them, and what the bearings will handle. The heavier they are, the smoother the engine will run.... they absorb the power stroke, and then impart back motion during idling strokes.... they resist change.   But, as you suspect, its the law of diminishing returns.  Its a bit like an empty truck, add 5 ton, its heavy, add another 5, its twice as heavy, add another 5, less noticeable, and once we get up to 50 ton, another 5 wont matter. just one thing to be very aware of, is centifugal forces, and rotating mass. With 20 something  inch flywheels  at 650 rpms,  we have a perimeter speed of around 50 mph, and if something flies off...........

millman56

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Re: My old CS Lister, still working at 75....
« Reply #66 on: May 30, 2015, 06:49:35 AM »
Hi Starfire,Leland et al,   
As you know, the CS  pre-combustion chamber engines have a relatively gentle and progressive combustion event, generous bearings and a robust crank, these factors lend themselves to the fitting of  heavy flywheels as the engine is capable of absorbing the twisting action imposed on it as it tries to accelerate half a ton of flywheels.
Do you think that even with the CS engines legendary robustness, that over time, I`m talking tens of thousands of hours here, the crank would fracture prematurely?
One of my pet theories (largely based on ignorance)  is that a single cylinder engine needs to be able to accelerate and decelerate a little over 2 revolutions in order to soften the shock on the crank.   
Having both SOM and spoked type engines I can vouch for the comparative smoothness of the SOM equipped engines,  non are a patch on the square cyl dimensioned alloy piston CD engine for smoothness or robustness though.

Mark.
   

starfire

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Re: My old CS Lister, still working at 75....
« Reply #67 on: May 30, 2015, 08:49:19 AM »
I have never heard of a crank twisting or breaking in a CS ever. The combustion process as you say, is pretty lazy and undramatic in a diesel, as the fuel burns, the chmaber size increases, and more fuel is admitted, sort of making a constant pressure happening. I think the only thing that would kill the engine is over revving and flywheel disintegration  I have read somewhere, possibly on here, that the keys,..... and these are solely responsible for transmitting the torque to the flywheels..... have a sheer strength of 8 tons. So, short of poking a stick through the spokes, I dont think the crank will twist off ever. The only reason I can see not to increase the wheel weight, is bearing loading. I cant comment on those engines using roller bearings, but there is a definite limit with plain bearings.  Any vibration will also increase bearing loading too as the crank and flywheels attempt to shake the engine block up, down and sideways once or twice every revolution.. Id  go for for a more lighter weight dynamic solution, rather than continually adding more dead weight. Yes, some engines do shake more than others, the first one I had slowly destroyed its own engine shed. Thats the one that got the balancing rings. There is also a thing called resonance, where if you close your eyes and grit your teeth, a badly shaking engine can be accelerated into a "smooth" RPM range. If running an AC alternator, this is not an option, the speed sets the AC frequency, and with early unregulated gensets, the voltage. All  engines have resonance because of the dynamic weight variations, and how the manufacturer has approached the problem, and what compromises he has made. Resonance becomes a huge problem with marine engines because of the incredibbly long crankshafts used.
Forgive a slight diversion here ...
One large foreign  ship I was working on sailed to sea even though I was still repairing the secondary Radar....had to catch the tide. While waiting for the heli ride back, wandered down to the engine room and was fascinated with the torque loading indicator  on one prop shaft. Each end of this over 1 metre diameter shaft had a transducer, and the guage indicated the  lead/lag twist at the propellor end  in relation to the engine end. This twist even at 25 percent power, around 15000hp amounted to around 1/4 inch over a 4 metre length of stainless steel shafting. The pulses of the low revving engine could be easily seen, as too the water currents holding back, and then aiding the torque.  Interestingly, these rotating shafts also have nodes of zero, then maximum twisting forces along their length that vary with RPMs....... this is why things can break in very odd places. Nothing is quite as it seems.

dieselgman

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Re: My old CS Lister, still working at 75....
« Reply #68 on: May 30, 2015, 09:55:29 AM »
There have been a few cases of broken crankshafts reported and documented on this forum. I believe that they were all specific to Indian clone products and most likely directly traceable to manufacturing defects or improper engine setups. These cranks do bend as well, seemingly without too much force involved, [being dropped in transit is one such occurrence that we have documented] so I would urge caution in adding too much mass to the assembly - especially if any major imbalance exists.

dieselgman
« Last Edit: May 30, 2015, 09:59:00 AM by dieselgman »
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starfire

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Re: My old CS Lister, still working at 75....
« Reply #69 on: May 30, 2015, 11:59:35 AM »
I would go with what DGman says. Another way to increase flywheel weight of course, is to add it to the generator. Because of the higher RPMs, a smaller rotating mass will have a greater effect, AND, the  "soggy" drive back to the pulsating engine via the rubber Vee belts will further damp out the speed variations. This wont help any engine vibration of course, as the added mass  remains isolated by those same vee belts.

rleonard

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Re: My old CS Lister, still working at 75....
« Reply #70 on: May 30, 2015, 12:04:07 PM »
I have two broken OEM Lister crankshafts in my shop right now.  The latest is a 16-2 twin with the crank in two pieces.  Torsional fatigue, broken at the center bearing.  45 degree crack.

The other one was broken at the end.  Pictures and thread here somewhere.

Bob
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starfire

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Re: My old CS Lister, still working at 75....
« Reply #71 on: May 30, 2015, 12:28:59 PM »
I have no experience with twins. Seems torsional damping would benefit them even more if this is a common occurance?.

M61hops

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Re: My old CS Lister, still working at 75....
« Reply #72 on: May 31, 2015, 01:07:40 AM »
Hi starfire and guys.  Hmmn... I never thought of the possibility of twisting the crankshaft  :-[.  I first tried a heavy pulley on the generator and the belt chirped on each power stroke even though it has a good amount of tension.  That started me dreaming of SOM flywheels.  I think the best way to use a CS type Listeroid would be to run a battery charging alternator like starfire does.  Then the power pulse can go right into the battery, among the other advantages.  For now I'm using an ST gen head and someday might alter the wiring to be able to charge 48v off the windings, or flip switches and use AC 120/240.  I had thought of making a spring loaded belt tensioner that would allow the flywheels to jump ahead on the power stroke and then the spring would let the gen head pulley/flywheel "catch up" over the next 3 strokes.  Decided to cobble together a redneck version of SOM flywheels with easy to get parts instead.  I have to confess that I look at the lug studs on the brake drums and I see some wheels and tires bolted on that reach the ground and then I've got about half a go cart.  Just in my mind... for now  :P !    Leland
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dieselgman

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Re: My old CS Lister, still working at 75....
« Reply #73 on: May 31, 2015, 02:28:22 AM »
I needed a chuckle this evening... and you got it Leland!  :laugh:

Put two of them together and you would have a 4-wheel drive!

dieselgman
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starfire

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Re: My old CS Lister, still working at 75....
« Reply #74 on: May 31, 2015, 05:28:04 AM »
Thought I would add a few of my experiences with reliable off grid power, and the reasoning behind it. Some may find this useful.
Straight 240 volt AC power, engine alternator combo is the most used method.
Pros:
Large power availability for running welders and other workshop tools.
Simple, as it conforms to general accepted practice.
Reliable being proven technology
Simple wiring, compatable with all mains appliances
Cons:
Inefficient. Engines are only at peak efficiency when almost fully loaded.   most elecricity demand is low and constant.
Constant noise/vibration. Engine speed is high.
Constant wear, long running hours.
No power on demand.... generator must be running.
Unless a standby plant available, no redundancy.... all eggs in one basket. total blackout with breakdown.
If standby plant available, wasted investment when not being used
Relatively expensive, with a one off large initial expense.

This was my first system, it drove me nuts  having to start and stop it all the time, and most times it would run so lightly loaded it would carbon up the exhaust and smoke. I did add batteries and alternators as below, but it became a frankenstein with belts/pulleys and wires everywhere, with  confusing multiple circuits inside the house and garage.

DC generator, battery bank and inverters.

Cons:

Larger less compact installation
More to go wrong
More expensive  plant costs long term..... maybe.... see later
maintenance time higher and slightly more involved
Less peak power available

Pros


Initial startup costs less... the installation can evolve with time and money availability.
True power on demand
Redundancy.... less reliance on one source of power
Little  likelihood of complete blackout with major breakdown
Cleaner more "accurate"  power, especially with sine wave inverters.
Lower engine stress and noise
Increased engine efficiency, constant and heavy loading


Just to elaborate a few things with this system... my preferred method..
An initial installation of this type requires just the engine, one car/truck alternator, suitable battery, and one inverter. The next phase would be to add a second and third and fourth inverter to have redundancy.... they wont all fail a once. For instance, one inverter could run essentials such as freezers and refrigeration. A second inverter would be dedicated to  lighting circuits, a third to electronics, radio/TV etc, another fot the workshop, lights and small power tools.If one inverter fails, another can simply be swapped in/take over.. Inveretrs are cheap now and pretty much a disposable item. Buy cheap ones, none seem to be better than others in this price range, and they WILL fail eventually. In my experience, they will destroy literally  dozens of mosfets and the time spent to replace them is just not worth it. Remember too not to have more than one freezer/fridge on the one inverter. If several randomly try to start at the same time, the inverter will be toast.
Next would be to add another alternator to reduce charging times, and to more heavily load the engine. These items are very cheap from scrap dealers , they sell for the scrap value. These are also disposable, and will last between one and two years. Many alternators can be added, increasing redundancy, they each have their own vee belt.... they wont all fail at once.
Increasing the battery capacity by adding more batteries can be done at leisure. A larger bank will allow several days between engine run times. Batteries can be had from scrap dealers, approx 50 percent will be wrongly diagnosed as faulty. Auto batteries will last around 12 months, deep cycle up to 10 years.
Solar panels, hydro and wind systems can be easily be integrated into the system by just running a few wires.
Inverters are not capable of running big loads reliably, this is the major caveat when using this system, but there are clever ways around this. To run my MIG welder for instance, I feed 48 volts  from , 4 seriesed 12 volt batteries, straight into the DC filter capacitors s of the welder, and use a 12v tap to supply the electronics and  and wire feed control board. With elecrtic motors, say for a lathe, several single phase motors are strapped together, the start windings are disabled in all but one to reduce starting current. Once running, motors draw little current. Use 24 volt systems if possible, the current requirement is half that of 12 volts, increasing inverter reiability. Keep batteries, inverters and alternators close together, dont run long DC cabling.  A few teaspoons of mineral oil poured into a flooded cell battery will stop evaporation, reducing battery maintenance time.
All the above allows me to have a "seamless"  to use a modern up to date word, off grid system with instant power always. If I head off into town I will run the generator while Im gone. In the summer, the solar panels take over. Its totally reliable with very few breakdowns, and takes very little of my time to keep it working. I usually pick up "bargain" priced batteries and alternators when they appear and they then wait patiently to be used.....