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Author Topic: 2cyl verse 1 cyl  (Read 12067 times)

Mark-k

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2cyl verse 1 cyl
« on: September 07, 2008, 02:42:37 PM »
Good morning everyone,
I have been lurking and reading for a while and finally joined the group. This site offers some great info many thanks. I have been looking at engines from Central Marine Diesel in Maine (has anyone done business with them?).
I am working on setting up a genset and work towards going off grid with a battery backup generator combo. Can anyone tell me what the difference would be for power generation output from a 12/1 verses a 12/2 would be? I am using this as an example basically for a 1 cyl verse a 2 cyl.

Many Thanks
Mark K

SteveU.

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Re: 2cyl verse 1 cyl
« Reply #1 on: September 07, 2008, 03:41:15 PM »
Good Morning to you too Mark K.
 Having puzzled through this decision process my self I can emphitize with you.
You will get better answers if can:
1) Say what will be you ultimate fuel source.
2) Give a general goegraphical area within 500mi (800km).
3) Figure out what your must have/ cannot live without power needs.
Why?
 Diesel engines need to be run loaded for cleanest fuel burning and least have to maintanence decarbonization teardowns. All of these are heavy. It will cost you hundreds of $$ to ship. Cheaper to be able to spend even a day or two to travel to pick one up. Your fuel source/location may mean it would be wiser to go with a GM90 Direct Ignition sytle versus the Indirect Direct Ignition types you are currenty considering.
Others will chime in.

Good hunting
SteveU.
Use it up. Wear it out. Make Do, or Do Without.
 Electrodyne 12vdc. AC MeccAlte 8.5kw
John Deere 950 w/Yammar 3cyl IDI; Peterson 21" sawmill w/20hp Kohler v-twin; four Stilh chainsaws,  Stilh weedeaters; various Kohler, Onan, Honda, Briggs, Tecumseh singles.

t19

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Re: 2cyl verse 1 cyl
« Reply #2 on: September 07, 2008, 06:14:58 PM »
Well, it seems the guys with the duals have double the issues.  I was thinking of getting a 12/2 but settled for a 10/1.  KISS is the way to go.

You really need to talk to JohnF, he had twins, but switched to singles as they are better suited to his off grid world and have proven to be more reliable than the Listeroid twins

Hope that helps
There is plenty of room for all of Gods creatures... right next to the mashed potatoes...

Mark-k

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Re: 2cyl verse 1 cyl
« Reply #3 on: September 07, 2008, 07:00:22 PM »
I am located in massachusetts, and am very willing to travel to pick up a motor. That is why i asked about central marine diesel as they are only 6-8 hours away. They say they ship within newengland for free, but we shall see. This is also why i have asked if anyone has delt with them. I dont want to end up dealing with someone who deals in lousey engines. I will mostlikely do a teardown and balance prior first run. Oh who am i kidding i will fire it up as soon as i get it home!!!  My fuel source will most likely be bio-diesel, used motor oil and or WVO (currently can get for $1:00 a gallon filtered to 5 micron) and process to biodiesel. That is another project i am currently working on.. As for power needs, we are assessing that now, we have a 1/2 hp 110v well pump, brand new frig, 14 cuft chest freezer, and a dryer, swiching elec hot water to solar/elec
and we heat with a corn-multifuel furnace, all lighting is compact florecent. Just quite tired of paying 450 a gallon for propane and 150 a month for electricity when we power 90% of the house down when we are not home, and are pretty frugel when we are.
Many thanks..
Mark



oliver90owner

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Re: 2cyl verse 1 cyl
« Reply #4 on: September 07, 2008, 07:08:11 PM »
Hi Mark,

Welcome to the forum.

12 hp is 12 HP whether 1,2 or more cylinders.  Power output from a given generator will be the same or thereabouts.

Single  - one fuel injection event every 720 degrees of revolution.

Twin - injection intervals at 180 and 540 degrees, so obviously 2 in 720 degrees.  That is with a 180 degree crank (one piston up, one down).

I would probably be preferring an IDI if considering alternative fuels at a later time. Di if staying with diesel or using natural gas in combination with diesel might be a choice but DI tends to be slighly more noisy, possibly.

I would be preferring an engine using the well tried and tested dimensions as used by Lister - spares are more available and probably consequently cheaper.

I would not want to be running at excessive revs to get the power - although that may improve the quality of the power produced (wave-form).  Low speed equalled longevity when these engines were state of the art.  Otherwise you might as well get a multicylinder modern unit.

I have no contact with CMD, other than comments on this forum as to some discrepancies in their 'pushy' advertising.

In fact, I am lucky in that I can source proper Listers rather than 'oids (all of which seem to have built in inherent faults and a deal of unwanted casting sand in many examples).

Going off grid is generally not a viable option cost-wise unless using the otherwise-wasted thermal energy for space or water heating, so water cooled is probably much more useful than air-cooled (aircooled are notoriusly noisy).

If  other forms of energy are expected to be harvested (solar thermal, photovoltaic, wind, heat pumps etc) then the size of your prime mover may, or may not, be adequate for your needs.  Depends how frugal you want to be, how much power must be available along with a multitude of other factors.

6 kW into a battery would very soon fully charge it.  Running more continuously with a 6/1 might be a better alternative and purchase a larger inverter(again there are efficiency issues in charging/discharging bateries and converting from AC to DC and back to AC from you bartteries.  Have you seen any off-grid set-ups?  I would recommend this before embarking on your own sytem if at all possible - there are all sorts of different ways to achieve an unsatisfactory system. :)

There are 'power on demand' systems out there (similar to the original startomatics)

So, there is a lot to think about.  Mistakes can be expensive.

I would at least pass your system ideas across the group before jumping in the deep end.  There are quite a few on here with lots of experience of running off-grid.

Regards, RAB

ronmar

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Re: 2cyl verse 1 cyl
« Reply #5 on: September 07, 2008, 07:38:50 PM »
I don't own a twin, but I have read quite a bit from people who do.
Differences:
Horsepower is torque over time.  A 12/2 gets it's rated power at 650 RPM(basically 2 6/1's grafted together).  A 12/1 with less displacement delivers it's horsepower at a much higher RPM(1000 I think).  But it does this with considerably fewer parts.  Since there is a RPM/rim speed limit on cast flywheels, it has smaller diameter wheels.  The 12/2 is also not setup like you would think, with the two cylinders firing directly opposite each other or 1 power stroke per revolution.  You get two very closely spaced power strokes 1/2 revolution apart and a delay while the other cycles take place, so their power delivery is not as smooth as what a twin should be, and they still exibit flicker like a single.  I have not compared them, but I would hazard a guess that a 12/1 may actually deliver smoother power than a 12/2.

It seems to me that the twins have as many drawbacks as they might have advantages.   The nature of the forces involved to run a valve train puts a lot of stresses on the cam and drive gearing, On a twin, the cam drive gear is the same size, and the camshaft is basically a lengthened version of the one in a single cylinder engine.  They seem to have more valve train/camshaft issues, especially for those who run them seriously.  The crankshaft is of course longer on a twin, but from what I have seen, not any larger.  the longer crank has longer moment arms and more bending forces which could cause more issues long term.  The twins are also more difficult to work with/on than a single.  Not much more, just more parts to deal with and re-assemble after a teardown.  The two injector pumps must also be adjusted/balanced properly for best performance.  

Knowing what I know now, I would not personally choose a twin over a single of same rateing.    

Are you sure you need 6KW of power?  These things are pleasant to operate at 650 RPM, but less so at 1000 RPM I think.  I would rather have a smaller single and run it a little longer.  As mentioned a diesel, particularly one running alternative fuels, if you are contemplating such a thing, likes to be run at a good heavy load.  Underloaded diesels develop issues and require more maintenance than one run harder at a proper op temp.  If I was contemplating what you are doing, I would VERY carefully evaluate my power needs to allow for proper sizing of he power plant/generator.

Good Luck          

    
PS 6/1 - ST-5.

MacGyver

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Re: 2cyl verse 1 cyl
« Reply #6 on: September 07, 2008, 08:17:08 PM »
I am located in massachusetts, and am very willing to travel to pick up a motor. That is why i asked about central marine diesel as they are only 6-8 hours away.



I know nothing about the quality of the engines that CMD sells, but I ordered a few spare 6/1 parts from them and found their shipping to be prompt and I had no complaints about the quality of the parts I received.
I ordered a second (larger) pile of parts from them last week and again the shipping was very prompt. I can't comment yet on the quality of the parts in the second order until UPS delivers 'em next week.
Phil seems like a decent guy and was responsive to all my email questions.

I don't know anything about their engines and generators.  I know I don't like their website much...
Steve

JKson (PS) 6/1 'roid & ST 7.5

SHIPCHIEF

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Re: 2cyl verse 1 cyl
« Reply #7 on: September 07, 2008, 11:19:18 PM »
I've got a twin. Ashwamegh 25/2, ST12 head.
Go with the single. Get an ST6 gen head. Dismantle the ST and clean/repack the bearings. THOROUGHLY INSPECT THE LISTEROID for sand and break-in damage, you may end up dismantling it too. Set the governor spring much looser to keep RPM low during the first start. (for safety)
Derate the engine to a lower RPM.(unless it's a 6/1)...Borrow a photo tachometer and run your engine. Find the smoothest RPM in the working speed, and get the pulley that runs closest to that speed.
In my case, the rated RPM (1000) was too close to the critical speed, it was pretty twitchy @ 1000 RPM and speed overshoots started the engine thrashing around. :o I got a smaller generator pulley (from George), and reduced engine speed to about 735 RPM. My particular engine runs smooth as I could wish for at 940 RPM. (go figure), But the available pulley landed me at 735 RPM which is almost as smooth, and the output of 9Kw will easily run my house. The safety factor alone is worth it.
Learn to live with 5Kw.
If you get hooked, consider a twin later.
Scott E
Ashwamegh 25/2 & ST12
Lister SR2 10Kw 'Long Edurance' genset on a 10 gallon sump/skid,
Onan 6.5NH in an old Jeager Compressor trailer and a few CCK's

t19

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Re: 2cyl verse 1 cyl
« Reply #8 on: September 08, 2008, 12:00:05 AM »
Yeah my 10/1 at 1000 rpm runs very well.  I had a 6/1 and I really dont notice much of a difference really.  The 10/1 runs my whole house, ridge, freezer, sump pumps, well pump and electric hot water heater... course the rad gets really hot when you loader her up with showers and cooking, but I figure thats what it likes

I could slow it down, but then I would not be able to run the whole house, maybe when I get my gas direct on-demand water heater and can lower my needs

Do like the heavier wheels though... damn sexy, and the ladies think so too !!!

There is plenty of room for all of Gods creatures... right next to the mashed potatoes...

SteveU.

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Re: 2cyl verse 1 cyl
« Reply #9 on: September 08, 2008, 08:54:15 PM »
Hi Mark K
  You see, good questions will produce quality advise.
I have purchased a 12/1 IDI Listeroid from CMD/Maine in the last three months. As the newest USA importing dealer I did quite a bit of background checking before I commiting myself.
In a nutshell:
They have been in business for longer than three years.
They have been able to sucsessfully bid as a supplier to different public and commercial enities in the NE and upper USA Midwest.
Their principals earn/support themselves from thier generators sales business.

I made all of my direct purchase interactions by phone and mail. with confirmations by Email. The sales agent, shipping clerk and partsman I dealt with were all promt, polite,and professionally businesslike. I recieved my engine well packaged, well labeled, undamaged and with all of the additional ordered parts.

The engine as recieved is as good of quality as these "India" second and third tier level manufacturers are ever going to be capable of producing. The castings , basic machining are all 1940's-50's Massey-Ferguson, Ford/Chevy car and truck quality. The fuel system and piston/sleeve are 1960's-70's IHC finish quality.The inside of the crankcase was unpainted and had at least 2 hours of hand grinding work.
I found only three grains of actual casting sand in six hours of, out in the hot sun, hand scraping, picking, oil washing and wiping down. Mostly what I found was one dirty been dropped on the floor govenor weight and black/grey/white assembly area debris. All oil washable.
It had been factory ran and I've now ran it lightly loaded 3-4 hours inspecting the con rod big end bearings and cylinder sleeve four times with no damage or wear. The rocker arm assembly DID requre some parts swapping around, washer spacing and remounting to get the alignments within reason. All removed fasteners have been properly torqued. Oh, except for the hammered in gibb keys of course.

My 12/1 has a BIG HEAVY non-Lister India only cast iron piston and the LARGE 23.6" diameter 180lb flywheels.
It runs smoothest at 630-760RPM. It gets way too energetic on only an 800lb temporary mount in my soil to run at 1000rpm safely. I figure it's goning  to need about 3600lbs of mass dampaning in the permanent mount for my for my silty volcanic ash area.
Thats OK with me. I only ever wanted 650RPM (noise-wife), and with the home grown low energy dirty,filthy gasious fuels I'm working towards I'm only going to get app. 6 hp for the 3kw that I actually need.

I suggest an all standard 6/1. Cheaper, more economical, least noise/mounting problems. Need more power, than use two. Others do.

T19 is your 10/1 aluminum piston? How/where is it mounted if I may ask?

Thanks
SteveU.
Use it up. Wear it out. Make Do, or Do Without.
 Electrodyne 12vdc. AC MeccAlte 8.5kw
John Deere 950 w/Yammar 3cyl IDI; Peterson 21" sawmill w/20hp Kohler v-twin; four Stilh chainsaws,  Stilh weedeaters; various Kohler, Onan, Honda, Briggs, Tecumseh singles.

RJ

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Re: 2cyl verse 1 cyl
« Reply #10 on: September 09, 2008, 01:28:18 PM »
Mark, I'm  just north of you in Vermont. I will be watching this thread as I can make a trip to Maine no problem as well. I actually looking for a 26/2 or 24/2 to run at ~550 rpm. So that would bring my HP down to around 12 or 13, then I was planning on running a ST 7.5 head with it. I have had trouble sourcing a 26/2. I have no idea who makes the Central Marine engines. I'm looking for an IDI engine.

Let us know how it works out.

-RJ

rleonard

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Re: 2cyl verse 1 cyl
« Reply #11 on: September 09, 2008, 02:31:40 PM »
You all know that I'd have to add my two cents worth in!

There have been some excellent points made.  If I can summarize;

A twin will deliver smoother power than a single (two power pulses per 720 degrees vs one), but it may not matter to you. 

If you are charging batteries and your power is supplied by a inverter, then run the smallest single necessary

If you are providing power directly from the engine driven generator, consider the twin to reduce flicker.

If you are running equipment other than a generator that relies on more even speeds, go with a twin.  For example; saws, pumps, or devices with inertial loads.

A twin will use more fuel when lightly loaded than a single.  Full load consumptions are quite close.

One of my twins was used in a wood shop before I got it.  It was traded in for a 4 cylinder engine to get smoother power and electric start.  The claim was that they could see the pulses showing up in the woodwork when running a planer or jointer.

There are more parts to a twin, more to maintain and replace when worn.  Longevity is the same in either case.  The parts are not stressed any more in the twin.  The valve train is so overdesigned that loading is not a factor.  I'd have to look but I think that only one valve is actuated at a time.

It comes down to careful analysis of the system that you are building and what your specific needs are.  After that exersize, you can make the best choice for your needs.  There is not one set of rules that dictates the equipment for every scenario.

Bob

Faster - Better - Cheaper  You can have any two, but not all three

diesel guy

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Re: 2cyl verse 1 cyl
« Reply #12 on: October 08, 2008, 09:38:59 PM »
 
I know this is a little late:

I would advise a 16/1 engine and operate it at about 750 RPM.

The single would make about 12 HP @ 750 RPM, the same as a 12/2 @ 650 RPM and would be more reliable and easier to maintain.

The soild flywheel's mass is greater on the 16/1 compared to the 12/2 lightweight spoked flywheels.

The stored kinetic energy potential from the 16/1 with its much heavier flywheels and spinning 100 additional RPM would be much higher than a 12/2.

This will help the flicker problems of singles from the power stroke, as well as provide greater short term surge potential compared to a 12/2.

The governor on the 16/1 will maintain much closer cycle regulation and quicker engine response from a produced  load, compared to the 12/2. This due to the additional 100 RPM engine speed.

The fuel economy would also be reduced overall in real world environment, due to greater thermal efficiency from higher RPM, direct injection and less mechanical drag, injection pump, ect.

Just my opinion, I know there are twin people out there that might disagree and that's OK.

Good luck.
Diesel Guy


diesel guy

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Re: 2cyl verse 1 cyl
« Reply #13 on: October 08, 2008, 09:43:10 PM »
I meant to write:

The fuel economy will be "increased" and the fuel consumption would be reduced.

Diesel Guy

halfcrazy

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Re: 2cyl verse 1 cyl
« Reply #14 on: October 08, 2008, 10:19:51 PM »
i recently purchased a 6/1 from central maine diesel. i was very happy and they immediatly shipped out 2 parts that where defective. i live 30 minutes from them so i was able to go and pick there brain and ask questions. they have a very large inventory of spare parts as well.

In a nutshell i highly recommend Bill and the crew at Central Maine Diesel