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Author Topic: Which would you choose????  (Read 30799 times)

needenginerunnin

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Re: Which would you choose????
« Reply #30 on: January 29, 2009, 08:57:28 PM »
sorry mate 'dieselguy'
i have to stop you there, if i have it rite.
quote.
'This engine weighs under 300 lbs. plus the generator and I would bet anyone this little 1,124 cc engine can outlast any Lister type engine between rebuilds, three times over. Don't get me wrong, I love my big singles.'

'any lister type engine'
if you are includeing a dursley cs in that quote, than i am afriad you are talkin crap!
'three times over'
thats 3 times 80-100,000 hours
no 1000+rpm engine can do approx 300,000 hours with out several rebuilds!!!!

needenginerunnin
« Last Edit: January 29, 2009, 09:01:08 PM by needenginerunnin »
1949 6/1 electric smooth flywheels & ST 7.5, som base x3, cast indoor silencer X2.
1950's 6/1 som x2, spoked 6/1, LD1 som.
listerpetter LV2, PH1,LD1,SR1, PAZ1, AA1, LT1, AC1. 3.5hp yan clone.
politician's are like nappies, they need changing for the same reason.
take the pi$$ , full of sh#t.

diesel guy

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Re: Which would you choose????
« Reply #31 on: January 29, 2009, 09:02:04 PM »
There is NO comparison from a 12/2 running at 325 rpm vs. a 6/1 running at 650 rpm, period. You are lucky to produce a useable 3-4 hp from the stated 325 rpm and I'm giving it some.

The 6/1 at 650 rpm will have 4 times the stored kinetic energy potential than the 12/2 at 325 rpm, for surge capability.

Frequency regulation would be "unusable" at 325 rpm in an AC application, with zero surge capability.

There also could be some lubrication problems when operating at 325 rpm for an extended period.

Lister states the 6/1 can start working at 500 rpm and produce 4 hp and no lower rpm is offered.

If 325 rpm was better than 650 rpm, Lister would of offered it.

Diesel Guy

diesel guy

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Re: Which would you choose????
« Reply #32 on: January 29, 2009, 09:07:50 PM »

You show me one Lister type that can do 100,000 hours or 1/3 that.

Don't confuse a Lister to a Lister type. They are NOT A LISTER and I am positive my wording is 1,000 % accurate in past post.

Diesel Guy
 

apogee_man

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Re: Which would you choose????
« Reply #33 on: January 29, 2009, 10:29:09 PM »
"Of course one could generate DC and run it through an inverter and there is no flicker at all."

That is the secret IMHO, but I don't hear it mentioned much...

It also moves away from the KISS theory...

However, the side benefit is it will also allow easy grid tie to be able to sell back if that is an option.

sarawnw

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Re: Which would you choose????
« Reply #34 on: January 30, 2009, 11:12:57 PM »
Hi all,


My ears are wet with lister green paint ;D

12/2 at 325 rpm get up to temperature in about an hour with a 2.5 KW load,  That temperature would be 200 to 205 F.  There is thermo stats for both sides and I am running WVO with injection line heaters. 

The maximium load before black smoke would be around 3.5KW using resistive heaters and 50 ohm water cooled loads ( 2 of each to be exact). Thats around 4.5  of usable hp with 23.5 inch fly wheels and 4.5 inch pully on the generator.  After a little over a hundred hours,  carbon build up is minimal,  engine wear un noticed as of yet.  After a few thousand hours,  if it makes it that long,  I may be in for a surprise.

Frequency stability;  for the typical household loads ( washer, fridge) ; frequency changes from 61 to 56 Hz.  It took some doing with the govener but not anything we have not all had to do with our engines.  Will this govenor configuration work at 650 RPM, no.  I have to change the spring which takes 30 seconds to a minute if the lights are not on ;D.


As for flicker,  it is noticeable without the line filter(auto voltage adjusting transformer, weighs half as mush as the generator but the price was right) but very usable.  The flicker at 650 RPM was less but occured more often,  and definatley more annoying.   The change in RPM of the refridgerator, pool filter and washing machine can get on the nerves in short order if music is not on at the lower RPM.  Running at the lower RPM was to match the engine with the typical load.  I was going to run 2 houses but one of the niebors complained about running cable thru a large pipe under part of there yard.  Maybe I should of asked before getting the engine and not after.  I guess I could not of asked at all :-X.

I have the power inverter, just need to find some batteries. 


If all you needed was 5 hp of usable power,  I don't think a  12/2 or even a 6/1 would  have been what the Lister company would have sold you.   I believe there where smaller, more cost effective engines available.

There was a scientist and an engineer talking about a very nice looking technician in the lab.  The scientist says to the engineer,  if you halfed the distance between you and the technician in each step, you still would not be able to kiss her.  The engineer replys,  In the end I would get close enough.   

I think that is what all I am trying to accomplish. 

Have a great weekend

sara

diesel guy

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Re: Which would you choose????
« Reply #35 on: January 31, 2009, 02:14:16 AM »
sarawnw,

The continuous power needed would be in the order of 5 HP with a 2.5 kw load and 7 HP with a 3.5 kw load. Your engine speed with the pulley ratio you stated is 345 RPM at 60 cycles. Your electrical appliances would need replacement in short order from such “poor frequency regulation” not the voltage.

What it comes down to is "I worked many hours with these engines” and know what they can do and can not do. I simply don’t believe your statements at all. 

Have a good day.

Diesel Guy

diesel guy

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Re: Which would you choose????
« Reply #36 on: January 31, 2009, 02:26:36 AM »
Jens your absolutely right about that.

What I'm saying is that is not the “correct numbers”. The engine speed would swing much further than 5 cycles at the stated low RPM. It would be all over the place and the governors reaction time from the loads engaging and disengaging would be atrocious.

Diesel Guy

ronmar

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Re: Which would you choose????
« Reply #37 on: January 31, 2009, 03:02:35 AM »
"Of course one could generate DC and run it through an inverter and there is no flicker at all."

That is the secret IMHO, but I don't hear it mentioned much...

It also moves away from the KISS theory...

However, the side benefit is it will also allow easy grid tie to be able to sell back if that is an option.


That is correct, and you could get real clean inverter generated AC that way.  It is probably not done so much due to added cost, and added inefficiencies.  No conversion is 100% efficient.  The engine converts fuel to torque at about 30%.  An AC generator converts torque to electricity at perhaps 80-85% efficiency.  If you turn that AC into DC, that will have a loss, and the inverter is only perhaps 85%-90% efficient depending on type and loading.  If you go the DC generator or alternator route, depending on how you make the DC, you are still turning torque to DC current at between 50% - 85% efficiency.  A 3 phase induction motor with a rectified output might beat this figure as I believe induction motors used as generators are pretty efficient, but it will still never be 100%  The fewest conversion method is almost always going to win, unless your need for absolutely pure AC is a non negotiable item.

For offgrid, DC has some advantages if you are mixing multiple power sources such as wind and solar that can take that 30% efficient engine out of the picture whenever possible.      
PS 6/1 - ST-5.

sarawnw

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Re: Which would you choose????
« Reply #38 on: January 31, 2009, 03:33:30 AM »
Hi Diesel Guy

The original govenor did exactly as you said,  choosing the right spring and adjusting the tension, this is what I get. 
The measurement were taken from a frequency counter that records min and max frequency.  It also measures average frequency but is not the issue. 
I believe the frequency counter since the company I worked for calibrated it regularly and measures line frequency of 60 hz on average.    I guess it could be wrong,  Ul and FCC believes its true to for testing 10 to 40 KW RF amplifiers and DC power supplies. 

What is acceptable for frequency change without causing harm to the appliances? 

From scope measurements,  if the second power pulse from the second cylider was not there,  the govenor would have to move alot more than it does now.  Is this what your refering to as the limitation of these engines?  If the govenor linkages do not move freely at there extents,  going from full load to no load casues the engine to run away.   The govenor opens up the injector pumps more before pulling them closed.  A file or two,  some oil and a few hours solved that. 

There has been some of talk about insufficient oil flow running these engines at lower rpm.  Some thing about oil film lasting long enough on bearing surfaces durning high pressure point during the engine cycle.   What can be done about this or should this be another topic? 


In any event,  the frequency range is correct,  actual RPM was wrong by 20 in favor of more horse power. 

thanks for the feedback

sara

still wet behind the ears with lister green paint ::)


oliver90owner

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Re: Which would you choose????
« Reply #39 on: January 31, 2009, 01:18:19 PM »
What is acceptable for frequency change without causing harm to the appliances? 

I would think plus or minus 10 per cent would be acceptable to a basic low tech device.  Modern electric motors are produced with much less tolerance than earlier devices.

On an old appliance there may be a problem with starting the load. With a modern one it should take out the start safety overload device, so as not to damage the motor.

So, I would think that plus or minus 5% is going to make no odds.  Preferably plus as previously stated.

Now to modern higher tech stuff.  Probably forget it.  Would just not work or might let the smoke out if the kit is real cheap rubbish (without adequate circuit protection).

I would up the revs slightly for Sara's generator set, so as to get 64 to 59 Hz rather than droop to 56.  63 to 58 might be the ideal(?) but I doubt it matters a jot.

I am wondering if Sara's engine is a proper Lister?  Can't remember from the Lister CSOG forum if it was mentioned.  If a proper Lister, the cam, if adequately lubed at the non drive end, should not be expected to give trouble - but if an 'oid it may be a lottery as to when a problem may arise.

Variation of HZ while a device is running will be simply be an audible annoyance rather than a serious hazard to the longevity of that device, I would have thought.

Sara, did you turn around the dippers for more splash lube?

Regards, RAB

sarawnw

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Re: Which would you choose????
« Reply #40 on: January 31, 2009, 05:19:24 PM »
Hi Rab,

I did not turn the dippers as of yet.  I am buying xyzers dippers and will do it then.  Maybe I should turn them sooner, I was going by a few statements made on the Utterpower website and or CD.  Is it feasable to drill out the far side top mounting bolt for cam shaft to drip oil on the undriven side of the cam shaft?  May be place a tube on the inside of engine from the mounting bolt to the cam?


This is a roid, a fieldmarshall at that.  From what I have read,  this engine is more of a mistake than the norm for most riods from that part of the world,  and I am thankful. 

Running at a little higher RPM is good news,  I was running a little low with the idea that appliances made today would run on 50 or 60 hz for a global economy.  I have no facts to support this for electric motors, only electronic equipment which uses switching power supplies. 

Thank you for the reply

sara

sailawayrb

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Re: Which would you choose????
« Reply #41 on: February 01, 2009, 03:36:43 AM »
Is it feasable to drill out the far side top mounting bolt for cam shaft to drip oil on the undriven side of the cam shaft?  May be place a tube on the inside of engine from the mounting bolt to the cam?

I just purchased a longer bolt...long enough so that when installed, the end of bolt is only 1/8 above the cam shaft hole.  Then I used a grinder to tapper the bolt to fine point at end.  Oil accumulates onto the bolt via splash lubrication and drips into the cam hole.

diesel guy

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Re: Which would you choose????
« Reply #42 on: February 01, 2009, 03:47:17 AM »
I hate to be the bad guy here, but those numbers displayed from sara’s 12/2, don’t add up.

I’ll start out with this:

If a diesel generator made 20 KW at 1800 rpm. The same engine would made about 50% of that rating at 1,200 rpm, 10 KW. The same engine would make 50% again that rating at 900 rpm, 5 KW. That is pretty consistent in general diesel engine capabilities.

Notice the KW capabilities decline rapidly as the engine approaches idle speed and they are not even operating done to idle speeds as sara’s 12/2.

This rapid decline is because the engines torque curve is not linear like an electric motor and uses much of its capability to overcome internal forces drag, compression, ect. at low speeds. There is little left to produce usable electrical output.

For example, a 12/2 operates at 650 rpm and produces 12 hp, 6 KW. A 10/2 operates at 600 rpm and produces 10 hp, 5 KW. Notice they are the same basic engine and with a reduction of only 50 rpm lost 2 hp, 1 KW.

That is because it is following the same downward power capability as demonstrated in the 1,800 rpm generator above and all engines follow.

Now if the 12/2 engine speed is reduced to about 450 rpm, it would produce about 50% of the 650 rpm rating, 6 hp, 3 KW maximum. If the engine speed is further reduced to half the 650 rpm - 325 rpm, it can only put out about 3 hp, 1.5 KW maximum.

Therefore, my first power estimates were accurate when I said the engine would put out about 3-4 hp and I was given it some.

So when sara if getting 2.5 KW continuous, 5 hp and 3.5 KW, 7 hp blowing black smoke. I don’t think so.  ???  ???  ???  ???

I sorry sara but I”ll say it again, “you are full of it” and your not fooling everyone and I’m all done with you and this subject.

Diesel Guy



mobile_bob

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Re: Which would you choose????
« Reply #43 on: February 01, 2009, 05:41:57 AM »
been sitting on the sidelines here, time to chime in :)

hp to rpm on these engines is surprisingly linear to a point, until
you get outside the geometry and spring that controls the governor

at which point you have to change springs and also altering the linkage to get
the flyweights to working in a more geometrically correct area

basically if the flyweights are out 50% or so at 1000rpm, then expecting the engine to run at 500
can be done, but will work much better if the linkage is reset so that the flyweights are now at 50% at 500rpm.
and the spring is tailored to work there.

in other words just simply lowering the speed from 1000 to 350 without some changes probably will equate to
either no power, irratic rpm swings under load to no load, and/or both.

there might also be timing concerns as well, perhaps retarding the timing might be in order the slower you get.

i have no doubt that Sara is getting pretty close to what she is claiming.

as for frequency +/- 3 hz is good enough for the vast majority of stuff, =/- 1.5 hz will cover all but the most sensitive
equipment.

bob g

otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

mobile_bob

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Re: Which would you choose????
« Reply #44 on: February 01, 2009, 05:50:35 AM »
dieselguy:

i gotta take you to task just a bit if i may :)

"an 1800rpm engine will make about 50% hp at 1200rpm"

yes, no and maybe

depends on what you have, and how the engine is setup

take for instance an 855 cummins, they are built from ~230hp all the way to at least 475hp
all the same engine, same block and same crank
there are also the old formula engines that had a deep torque curve and all sorts of variants

or another instance

a changfa 195 rated at 12 hp continous at 2000rpm
and then being able to get near 15 hp at 1800rpm
i can certainly get over 6hp at 1200rpm

its all  comes down to a series of factors, how is the governor setup and to what rpm is it optimized to run at?
what is the injection timing, what is the compression ratio,, and lest we forget... what fuel are we using?
oh yes, injection pressures , idi or di, makes a difference,, operating temperature, altitude etc etc.

i sure as hell would not call Sara out on this one, might get egg all over ones face?

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info