After some governor adjustments, the Changfa is comfortable at 600 rpm.
( I have had it as low as 500 rpm)
Seems the spring tension adjuster on the stock engines is set for optimal control at speeds above 1200 rpm.
Even with the stock governor spring, better control at lower speeds can be gained by adjusting the threaded spring tension rod to allow a bit of tension (less linkage slack) at the lower speed position of the throttle knob.
I wonder if a changfa at 600 rpm could drive a 50 amp 12V alternator? (600 watts) SWEET !!!
http://www.youtube.com/watch?v=qajvVfqqI7o//
veggie
PS: At 600 rpm there is very little knock or mechanical noise. The unit is as quiet as my Listeroid at the same speed.
well ain't that just neater than a skeeters peeter?
:)
now we need to see it pulling a load at 600rpm, and track how the big end brg holds up
at this timing level?
pretty cool
now i gotta try this, see what you have done!
not like i didn't already have a pile of experiments to do already!
:)
bob g
Veggie,
It sounds pretty good to me.
So all it needed was a lighter governer spring to run at 600.
Good job.
Henry
Quote from: hwew on February 05, 2010, 06:53:22 PM
Veggie,
It sounds pretty good to me.
So all it needed was a lighter governer spring to run at 600.
I think all of these were necessary to make it run stable at 600....
- Lighter gov.spring
- Heavier flywheel
- retarded injector timing by 2 degrees
veggie
As Bob suggested, I would like to set it at 650 and apply a little load.
The speeds are all wrong for me to use the generator head and to solve that I would need a 3" sheave on the gen head.
That does not leave very much belt contact on the small sheave.
I'll see if I can dig up one of those from somewhere.
Alternatively, what I would really like is a Leece bi-directional alternator :)
My Delco 12si would spin backwards if I tried to use it in the current mounting configuration.
veggie
Quote from: mobile_bob on February 05, 2010, 06:16:18 PM
well ain't that just neater than a skeeters peeter?
:)
now we need to see it pulling a load at 600rpm, and track how the big end brg holds up
at this timing level?
pretty cool
now i gotta try this, see what you have done!
not like i didn't already have a pile of experiments to do already!
:)
bob g
(skeeters peeter ?)
I think that's a technical term for:
Highly toposetic incated bi-lateral spacial reverberational algorithmics. ???
I bet Skeeter is Bob's dog ;D
Veggie,
Yes the heavier flywheel, retarding the timing and lighter governer spring helped getting it to run that slow.
I was surprised that it would run so well at 600 rpm.
Now the thing to do is run it through some tests and see how it holds up.
As Bob wrote, Keep an eye on the bearings.
You might want to retard the timing another 2 degrees and see how it runs.
If it starts and runs fine try another 2 degrees.
If you start having problems then go back.
If you can retard the timing a bit more from what it is now it will take some more stress off the bearings and other parts which should help in longevity. It might also help quiet it down some more.
Again, Good job! And we are looking forward to hear any updates.
Henry
WOW!
Any idea what the power and efficiency are like at low rpm?
Kevin
Quote from: V5CVBB on February 06, 2010, 12:19:54 PM
Any idea what the power and efficiency are like at low rpm?
Kevin
Hi Kevin,
No idea at this point. Power and fuel consumption charts seem to be non existent for these engines.
veggie
Most of the engines I've seen BSFC curves for show the lowest value just above peak torque. I can't grasp why fuel usage is higher at low rpm when windage and frictional losses are lower. Is it thermal trasfer that is killing efficiency?
Kevin
Do Changfa's have the same EPA problems and are not available in the US now?
I'm thrilled with Veggie's low speed Changfa work, that might be a very nice alternative for off grid folks desiring low speed/noise.
BruceM,
To my knowledge the same rules apply as the Roids (May be under the radar at the moment.)
You can also get them on eBay. I think it was the Carol Stream Motor company (eBay store) that has them.
veggie
After increasing flywheel mass and retarding the injector timing the problem I still see with really slowing down the Changfa types is in maintaining the functionality of the internal oiling system.
In the case of my JD175A I have an oil pump that sucks oil off the bottom of the sump and the pump pressurizes two passageways. One feeds oil to the rockers and valves where it returns to the sump through the pushrod galleries. That will work OK as long as the oil pump can move oil. The other passageway is designed to fire a solid stream of oil sideways towards the crank throw where for a few degrees per rotation a hole drilled into the side of the throw picks up some oil and through a slant in the drilling angle of this hole in the crank and centrifugal force, it feeds it under pressure into a feed hole cut into the lower rod crank journal to lubricate the lower rod bearing in the usual way. When you remove the con rod the hole in the journal looks like any pressurized automotive crankshaft setup. When the engine is hot and the oil is thin the oil pressure in the gallery on the output side of the pump drops like a rock from about 6 PSI cold to less than 1 PSI. I have added a pressure gauge and external spin on full flow filter so I know what the pressure is. That stream being shot at the target hole in the rotating crank may start to droop and miss the target at some low RPM. If these engines had sleeved bushing bearings on the ends of the crank the crank could be truly pressurized by a cirumferencial slot around the crank within an end bushing sleeve bearing near the oil pump (timing cover side). Being that most of these engines use ball bearings on both ends of the crank, it is more difficult by design to pressurize a passageway internal to the crankshaft. The method used in my JD is rather clever.
In order to increase the lubrication to the camshaft, the wrist pin bushing, and even the main crank ball bearings that all get lubed merely by splash from what is hurled off the rotating crank I added an actual diper to the lower of the two big end con rod bolts. This mod worked out very well. There is a LOT MORE oil being hurled around now where it can do good.
Perhaps it would be possible to add a restrictor orfice to the hole in the block where the oil jets from towards the crank throw target hole. This would up the hot oil pressure by a large margin if sized appropriately and produce a real jet of oil under slower RPM conditions. How the big end bearing of the con rod gets lubed in my Changfa 1115 is still a mystery to me but I suspect it is the same design as most of the modern 195 engines.
I saw a photo of a 195 engine once that appeared to use bushings, not ball bearings on the outer ends of the crankshaft. In that particular engine I suspect it possible to pressurize the crankshaft the same way it is normally done in a common automobile engine. I don't think many of our China diesels are made that way. Ball bearings seem to be much more common.
Quote from: rcavictim on February 06, 2010, 04:52:49 PM
After increasing flywheel mass and retarding the injector timing the problem I still see with really slowing down the Changfa types is in maintaining the functionality of the internal oiling system.
In the case of my JD175A I have an oil pump that sucks oil off the bottom of the sump and the pump pressurizes two passageways. One feeds oil to the rockers and valves where it returns to the sump through the pushrod galleries. That will work OK as long as the oil pump can move oil. The other passageway is designed to fire a solid stream of oil sideways towards the crank throw where for a few degrees per rotation a hole drilled into the side of the throw picks up some oil and through a slant in the drilling angle of this hole in the crank and centrifugal force, it feeds it under pressure into a feed hole cut into the lower rod crank journal to lubricate the lower rod bearing in the usual way. When you remove the con rod the hole in the journal looks like any pressurized automotive crankshaft setup. When the engine is hot and the oil is thin the oil pressure in the gallery on the output side of the pump drops like a rock from about 6 PSI cold to less than 1 PSI. I have added a pressure gauge and external spin on full flow filter so I know what the pressure is. That stream being shot at the target hole in the rotating crank may start to droop and miss the target at some low RPM. If these engines had sleeved bushing bearings on the ends of the crank the crank could be truly pressurized by a cirumferencial slot around the crank within an end bushing sleeve bearing near the oil pump (timing cover side). Being that most of these engines use ball bearings on both ends of the crank, it is more difficult by design to pressurize a passageway internal to the crankshaft. The method used in my JD is rather clever.
In order to increase the lubrication to the camshaft, the wrist pin bushing, and even the main crank ball bearings that all get lubed merely by splash from what is hurled off the rotating crank I added an actual diper to the lower of the two big end con rod bolts. This mod worked out very well. There is a LOT MORE oil being hurled around now where it can do good.
Perhaps it would be possible to add a restrictor orfice to the hole in the block where the oil jets from towards the crank throw target hole. This would up the hot oil pressure by a large margin if sized appropriately and produce a real jet of oil under slower RPM conditions. How the big end bearing of the con rod gets lubed in my Changfa 1115 is still a mystery to me but I suspect it is the same design as most of the modern 195 engines.
I saw a photo of a 195 engine once that appeared to use bushings, not ball bearings on the outer ends of the crankshaft. In that particular engine I suspect it possible to pressurize the crankshaft the same way it is normally done in a common automobile engine. I don't think many of our China diesels are made that way. Ball bearings seem to be much more common.
All of the china singles I have had apart have a ball bearing on one end of the crankshaft and a sleeve bearing on the other end. Oil is fed under pressure from the oil pump to the sleeve bearing where it enters the crankshaft under pressure. The sleeve bearing may have a groove all around its od where its pressed into the block to receive oil under pressure. I have not had one of my 1115's apart to see if they are the same.
flywheel
my changfa s195 has bushing brgs at both ends of the crank, the oil pressure it admitted to the main
bushing behind the flywheel, where it feeds the x drilled crank, rod big end and the other end of the crank
main bushing in the gear case.
there is also a variant known as a "roller" version, which has a ball brg at the flywheel end and a bushing at
the gear case end where the oil is admitted to the crank shaft x drilled to feed the rod.
i think as long as the engine keeps the little red indicator showing the engine will have enough oil pressure
to run at the intended speed.
bob g
Thanks for the info, Veggie. Another low speed option is a wonderful contribution.
That does not leave very much belt contact on the small sheave.
Much less power to transmit as well, so no particular bother?
Regards, RAB
I'm just looking at the factory supplied manual for my Changfa ZS1115G engine. It has ball bearings at each end of the crankshaft. Large one at flywheel end is a 314, GB276-82. At the timing gear end is a NJ312, GB283-87.
Quote from: rcavictim on February 07, 2010, 05:49:32 AM
I'm just looking at the factory supplied manual for my Changfa ZS1115G engine. It has ball bearings at each end of the crankshaft. Large one at flywheel end is a 314, GB276-82. At the timing gear end is a NJ312, GB283-87.
The "G" in ZS1115G means double bearings, I believe the 314 is a ball type and the NJ312 is a roller type bearing.
flywheel
Quote from: flywheel on February 07, 2010, 11:46:29 AM
Quote from: rcavictim on February 07, 2010, 05:49:32 AM
I'm just looking at the factory supplied manual for my Changfa ZS1115G engine. It has ball bearings at each end of the crankshaft. Large one at flywheel end is a 314, GB276-82. At the timing gear end is a NJ312, GB283-87.
The "G" in ZS1115G means double bearings, I believe the 314 is a ball type and the NJ312 is a roller type bearing.
flywheel
How do you know all this stuff? :D
Flywheel is the only guy i know with more chinese diesel engine's that i have!
thats how he knows this stuff
his picture hangs next to chairman mao in chinese engine factories, i am told
lol
bob g
Quote from: rcavictim on February 07, 2010, 12:07:26 PM
Quote from: flywheel on February 07, 2010, 11:46:29 AM
Quote from: rcavictim on February 07, 2010, 05:49:32 AM
I'm just looking at the factory supplied manual for my Changfa ZS1115G engine. It has ball bearings at each end of the crankshaft. Large one at flywheel end is a 314, GB276-82. At the timing gear end is a NJ312, GB283-87.
The "G" in ZS1115G means double bearings, I believe the 314 is a ball type and the NJ312 is a roller type bearing.
flywheel
How do you know all this stuff? :D
Amazing what you can find out with a computer! I get my hands dirty sometimes also.
flywheel
Quote from: mobile_bob on February 07, 2010, 12:10:55 PM
Flywheel is the only guy i know with more chinese diesel engine's that i have!
thats how he knows this stuff
his picture hangs next to chairman mao in chinese engine factories, i am told
lol
bob g
No thats not quite right Bob - I remember the scout motto, Always be prepared!
flywheel
After running the 195 under load for while today, I dropped the speed down 450 rpm to see how she performed.
The engine is now running on a WVO blend and seems to be quite happy with it. (no more stink >:( )
At 450 rpm, the engine is super quiet with virtually no vibration. FUN! :)
Although my roid is getting a bit jealous. 450 rpm surely puts the Changfa in the "slow speed engine" class.
veggie
Sorry Veg,
But as cool as this is (and it's VERY cool), painting it 'roid green is going a bit too far imho...
As hard as you try, it can turn like a duck, quack like a duck, sip like a duck, and even LOOK like a duck... but alas, it's NOT a duck.... LOL!
Where did the heavier flywheel come from?
Nice job!
Steve ;D
Quote from: Apogee on March 20, 2010, 10:24:24 PM
Sorry Veg,
But as cool as this is (and it's VERY cool), painting it 'roid green is going a bit too far imho...
As hard as you try, it can turn like a duck, quack like a duck, sip like a duck, and even LOOK like a duck... but alas, it's NOT a duck....
Where did the heavier flywheel come from?
Nice job!
Steve ;D
Thanks Steve,
That's not roid green.....it's John Deer green.!!
The heavy flywheel was custom fabricated for the "Slow speed Changfa" project.
http://www.microcogen.info/index.php?topic=477.0 (http://www.microcogen.info/index.php?topic=477.0)
cheers,
veggie
Very cool!
Any idea of the output @ 450 and 600 rpm?
And btw, the green does look very nice even if it is blasphemy....
:-)
Apogee,
Sorry, no idea of the BHP output @ 600rpm. The speeds are all wrong on the gen head for me to test at that speed.
The engine normally runs at 900 rpm and can generate 3kw of electrical output.
Based on the 2:1 rule of thumb, that would put the engine at 6HP@900rpm.
My wild guess is that 600 rpm would net about 3HP, and 450 rpm might be about 1.5hp.
veggie
if you paint it any other color than green, you will pickup an easy hp or two
:)
bob g
Just finished reading the other thread that you linked to Veggie.
Very, very nice job!!!
It has my wheels turning now... That's a very cute setup!
You also did the same as I was planning with mounting the gen head above. That was exactly my plan to save space...
Excellent work! :)
Steve
Veg, that is awesome! and so compact! I want one!
I worry about the stresses on the counterbalance shaft drive gears and bearings running these engines at low RPMs. You can really hear them thrashing about in your 450 RPM demo.
I am building a vertically stacked plant right now with my Changfa 1115 and a 24 kW STC 3-phase head. Stacked because I want to put it in a small room that already contains my Petter plant for the necessity of some noise control and I had to reduce the footprint. It is rather huge compared to your very nicely compacted design. I have gone the metal and sand equivalent of a massive concrete block however and once completed my machine which is on 4" steel castor wheels will weigh about 2000 lbs. Being purpose built for a need it incorporates a day tank for the fuel which holds three to four times what the factory tank on a 1115 holds with option to hook up a remote fuel supply. That is almost as large as your entire plant. I also fabricated a first stage of a neighborhood nighttime critical grade exhaust silencing system on board to replace the original oversized lawnmower engine muffler. I should be able to pull a worthwhile amount of heat off this in addition to that from the radiator for indoor winter use in the shop.
You do nice work!
Very impressive, Veggie! With a micro-controller for governor and one of the Midnight charge controllers that would make a quiet, efficient battery charger! The governor could back off on speed as current demand drops, and an AVR could used if needed to keep voltage up withing range for the Midnight despite dropping frequency. Since the new Midnight does boost, it wouldn't need the AVR, probably, but a lesser and cheaper unit such as the Tristar PWM unit would .
rcavictim,
I would be very interested to see your residential grade exhaust system once it's built.
Being that I have neighbors close by, a quiet exhaust is important for me.
Especially if I want to run at night.
veggie
Quote from: BruceM on March 21, 2010, 12:07:12 PM
With a micro-controller for governor and one of the Midnight charge controllers that would make a quiet, efficient battery charger! The governor could back off on speed as current demand drops, and an AVR could used if needed to keep voltage up withing range for the Midnight despite dropping frequency. Since the new Midnight does boost, it wouldn't need the AVR, probably, but a lesser and cheaper unit such as the Tristar PWM unit would .
BruceM,
Thanks for those suggestions. The unit was designed primarily for battery charging.
A 55 amp Iota 4 step charger plugs into the generator 120 outlet.
It's a very simple setup at the moment.
Your idea of a variable system is good because I keep running into the same concern.
That is....what happens when the charger flips into float mode and the engine load drops to 15%?
The engine could run unloaded for hours until the charging is completed.
A system that scales back according to load would be ideal.
I am running the engine a lot lately for two reasons.
1] Testing the WVO fuel blend.
2] Durability testing on the Voltamaster generator head. (More to follow on that subject)
So the Changfa has become a test engine for fuels, generator heads, and battery chargers.
veggie
Quote from: veggie on March 21, 2010, 01:30:20 PM
rcavictim,
I would be very interested to see your residential grade exhaust system once it's built.
Being that I have neighbors close by, a quiet exhaust is important for me.
Especially if I want to run at night.
veggie
I plan to post about my project at some point and will include any details about the silencer system I develop. I did make one years ago that worked out eventually as good or better than what one would call a Hospital Grade critical silencer. It is on a vertical stack on top of my shop and when I stand on the roof next to it I cannot hear any exhaust noise, just conducted sound of the engine running in the steel pipe which is not audible a few feet away. Getting that to work was a bit of trial and error. I remember one setup I had coming out of the roof that had a brap so loud you could hear it over a mile away. I could hear backscatter echo from it from every tree and house in my immediate neighborhood.
Perhaps I should manufacture this as a product for the kind of folks here and on Lister Engine Forum. The quiet one, not the loud one. ;)
Veggie, There is likely a limit to how low a frequency AC input the Iota can handle, probably not so low as you'd like. (~20Hz) Maybe in a couple years we can all switch to LiFePO4 batteries, and then you just charge them, flat out to full, with only a brief low current topping time (often less then a minute).
If Ya'll don't get off'n the John Deere Green kick, yore a-gonna give me a complex. :D :D
Ron