Slow Speed Changfa Project

[BruceM]

Nice work, Veggie!

Hmmm, 2500 watts continuous sounds like a reasonable Listeroid 6/1 replacement.  How is the noise compared to the 6/1?

[mobile_bob]

if you are only at 150 degree's i would expect the engine to pull the full 3 kwatts when it is up to around 200 degree's F
then the game starts where you check the big end brg for signs of stress near the area of highest pressure (up in the top
shell) and if necessary retard the timing another 2 degree's or so.

personally i think you are right on the sweet spot for that engine at 3kwatt, when it gets fully up to temp
if the red indicator is staying up and not bobbing up and down like a frantic groundhog you got enough oil pressure
so that everything should work just fine.

at 3kwatt you will be at the peak efficiency for that setup as measured in bsfc, at 150 degree's you are just barely over
the hump of the efficiency curve.

if used with a 48 volt alternator i would have no issues with allowing the engine to pull this hard, because as the batteries begin
to regain their charge the amperage will start to fall off anyway, so i wouldn't expect the engine to have to pull at 3kwatt for a protracted
length of time anyway.

this is where a balmar would be a fantastic match for this setup, you can program not only the three steps, voltage setpoints, but
you can also program the max amperage which sets the max load on the engine, right down to 2% increments.

it also has a port that if you feed it 12 volt it will cut the output to 50%, that is something you can daisy chain in temp limit switches
on the alternator, engine coolant or whatever else you want.

but that might be down the road for you , i dunno  

for now i think we need to see you get some hours on the unit and determine what if any issues pop up, i don't expect any but
i don't know for sure either.

very cool project,

btw, we need to get a copy/paste thing going for your test results and put them in the "testing"  section too.

personally i want to see copies of all testing either in the "testing" section or the "white paper" section

maybe all testing posted in the testing board, and final conclusion writeups in the white paper board?

just don't want to see things like this project getting lost in the pile so to speak, you have done something
different and are getting very good results.

bob g

[Henry W]

Hello Veggie,

I am with Bob, I think once you get it broken in and run at around 200F. you should be able to pull more. It might even run quieter.

We don't want this lost. Please post copies in white pages.

Henry

[rcavictim]

Veggie,

Very fine work there!  Those videos were very interesting to see and hear.

Everybody,

Some may recall seeing on the other forum, how I had been trying to spin a very large heavy flywheel with my JD175A engine and the problem I had of destroying my soft coupling between the original flywheel and the larger one. This package got rewired to belt drive.  I don't have a lot of hours on it but probably 250'ish. I've had an odd vibrtation that got worse with increasing RPM that has been a puzzlement to me for a while.  Something has apparently gone wrong in the engine because the vibration just all of a sudden got a whole lot worse the other day.  It was running about 1300 RPM at the time. I shut it down before anything exploded. I may have fried a lower rod bearing, or cracked crank, I have no idea.  I am hoping to get to look at it soon after I get another project here out of my way.  I could have damage caused by operating with too much ignition advance (stock setting) for the slower speeds I was trying to run.  I will report my findings when I have news to share.

[veggie]

Nice work, Veggie!

Hmmm, 2500 watts continuous sounds like a reasonable Listeroid 6/1 replacement.  How is the noise compared to the 6/1?

Thanks BruceM,

Regarding the noise, I would say it's just a bit louder than the Listeroid once it has a proper muffler and the exhaust is routed outside. It's only comparable because I slowed it down. That was a big issue for me because I'm in a residential area.
The main difference is the mechanical noise from the square cut gears on the counterbalance shafts.
At 900 rpm I was recording 80 db @ 3 meters distance. Under load it was a bit louder.
At 1/2 the price of a listeroid, it may be an good economical choice for some people.

veggie

[oliver90owner]

Just read through some of this thread.

Couple of points that might be important to get to lower rpms:

IP head:  This might need to be smaller.  Pumps are sized according to maximum injection requirement.  That is obviously at full rpm and full power.  If it is the rack that does not have any adjustment at the speed you are operating a pumping head from a lower power engine (of same original design speed) would be more appropriate, allowing governor control nearer the optimum for that pump head.

Injector:  The injector nozzle may also need to be downsized, either fewer holes of same size or a smaller hole or holes.  This will affect the penetration of the atomised spray into the combustion area and also the size of the droplets.  Pop pressure may also need to be optimised, but I would not wish to make any further comment than that.

Regards, RAB

[veggie]

**** UPDATE ****

LIGHTER SPRING INSTALLATION:

I was able to locate a spring which matches the desired speeds.
I don't have a fish weigh scale so I don't know the tension of the spring.

Diameter = 11/32"
Length = 1-1/4" (without the end loops)

After installing the spring I first tested the engine at various loads.
.9Kw,... 1.8kw,... 2.6kw,... and 3kw.
The unit held speed perfectly through the whole load range.
At 3kw she was blowing some gray smoke, but the speed held solid at 910 rpm (3600 on the gen head).

Now the fun part....
I released the loads and began to slow the engine down.
750....700...650....600.....550....500 !
She sounded really nice at 500. I did not want to add any loads at that speed, but it's nice to know it can go there.
Gives me more confidence that the design rpm of 900 is well above the minimum speed.

I took it up to 750 rpm and added a bit of load.
Voltages were off, but I used the kill-a-watt the measure the load.
I took it to 1.2 kw before I could notice any sound change. Still the speed held at 750 rpm.
I did not go any higher because I was not sure if it would damage the electrics.

Below is a picture of the original spring vs. the new spring.

I won't be doing any more mods or testing on this engine.
As far as I'm concerned, it's ready to spend the rest of it's life burning WVO at 900rpm producing 2.5kw (3kw max.)
I installed a Stop in the linkage which is set at 900 rpm.

**** EXPERIMENT FINISHED ****

veggie

[BruceM]

Bravo Veggie!  I think 2400 watts is a very nice wattage for off grid use, and it's good to know even lower is possible for say a battery charger setup.  I think you have a winner! 

[veggie]

Jens,

Those are valid questions.
The oil pressure indicator still pops up, but I don't know the exact pressure.

I only took it to 500 to see if it would go there.
Live or die, the engine is now fixed at 900.
Time will tell. I will keep an eye on things.
After the first 50 hours, I'll pull the head and see how she looks.

I will stick to the recommended oil change intervals.
Running WVO, I may even change a bit sooner.

veggie

[Shipo]

Hi Veggie,

What did you use to make the new muffler exhaust on your s195?

Is that I want to replaced the original muffler exhaust with a new configurations that I have on mind.

Thanks in advance...

[veggie]

Hi Veggie,

What did you use to make the new muffler exhaust on your s195?

Is that I want to replaced the original muffler exhaust with a new configurations that I have on mind.

Thanks in advance...

Shipo,

Here's some info on the exhaust system.

Hope this helps,

veggie

[Shipo]

Thanks Veggie..Excellent picture & presentations...

[veggie]

*** UPDATE ***

The completed project has the engine mounted on stationary feet.
The Changfa 195 runs very smooth at 900 rpm and produces 2.5 kw with clear exhaust and 3kw with slight smoke.

During a regular run, a neighbor walked by my garage and inquired about the gentle pop....pop....pop of the exhaust.
I showed him the unit and he fell in love with it.
20 minutes later we shook hands and he paid me for it.
He's a retired mechanic and just loves it. Every so often I can hear the engine running in his garage as I go by.

http://www.youtube.com/watch?v=aOhg1Q1rd6E

on to the next project..... a Listeroid GM90 CHP system for greenhouse heat, light, watering, and air circulation.

veggie

[mobile_bob]

traitor!

;(

its ok, i fogive ya,, you'll be back

once  you go changfa you you will never be happy with another!



bob g

[Henry W]

That is horible news!!! Sold the nice compact slow speed Changfa S195 genset.  Now what will take the place of it? I hope there is a better design in the works with another Changfa.

Henry