Changfa S195 and ST7.5 Received

[OilCan]

Just uncrated my Changfa/ST combo this weekend that was purchased from Motors, Generators and Stuff on Ebay.  Everything was received in good order, the vendor Muhammed was very helpful throughout the process.

My next step is to order the Hopper Conversion from George at Utterpower and build a 8x12 shed. Here's a shot of the uncrated goods:

http://home.comcast.net/~wshj72/public/ChangfaSTuncrate.jpg

[mobile_bob]

i have the same setup, the 195 and a st 7.5 head

havent got it together yet, but we have run the engine, and i think you are going to be
well please with it.

good luck
bob g

[kyradawg]

Peace&Love , Darren

[Doug]

Man those things are UGLY....

Very Reliable I understand but ugly!

Doug

[Rainbow-Farm]

Congrats on the Changfa purchase. Do you, or anyone, have any real-world figures on what kind of usable power comes from this combination?

I have seen fairly reliable reports of Changfa 1115 with ST 15kW delivering 11.xx kWatts. I would very much like to know how much of the 7.5 kW comes out of the head, driven by the 195.

The horsepower and kilowatt figures from different sources (Changfa, sellers, users) ... well, there is a big difference between some of the numbers and reality.

I have seen the same engine called 20 HP and 28 HP and seen power estimates from that engine range from 11 to 18 kWatts.

I would not want to put something together, aiming for 6k-9k and ending up with 4k.

[mjn]

I have a Changfa 195 direct coupled to an ST7.5 head.  I am running at 3500 feet elevation, so I probably have about 10 percent less power available than someone at sea level.  I measure the power by reading the current with a clamp on meter, and multipying by the measured voltage.

I can get 6000 watts out of the generator before the engine starts to smoke.  At 6500 watts, it is really smoking, and I can't keep the frequency at 60hz. 

If you are at sea level, you might be able to get about 10% more.  If you belt drive the generator and run the engine at 2200 RPM, you might be able to get another 10% more power.

[Rainbow-Farm]

mjn, thank you for all that. I am now reading your tale on the google site of your purchase, pickup, repair/fine tune. Your methodical, clear and logical description, well illustrated, makes me more confident about doing this. You have done a great job of documenting the procedure!

I had not thought of the advantage of belt drive/faster running, in terms of higher output. I was fixed on 1800 RPM for longevity, the "efficiency" of direct couple.

[Rainbow-Farm]

MJN: May I ask where on eBay, from whom, you purchased the Changfa?

You mentioned Powersolutions, but not specifically that you bought the rig from them.

I followed the listings of Motors Generators Engines, and spoke to Muhammed.

[europachris]

I  bought my Powersolutions ChangFa 185 from John Alvin at power-co.net.  I already had a 3.2kW 2 pole Markon gen head I wanted to use, so that engine fit my application well. 

I ended up making a custom flywheel adaptor to mount a 1" shaft to drive the engine side pulley as I went with an industrial "L" section 6 rib belt setup.  The engine runs at about 1870 rpm with the generator at 3600.  It runs REAL smooth. 

I can make 3.5kW easy with almost no smoke at all. 

http://n9zes.zippyvideos.com/ I've got a few videos of my setup.  One is the stock muffler and one is a NAPA car muffler on a custom manifold.  The air filter is a Solberg air compressor filter/silencer.  I wasn't happy with the stock oil bath as it was loud and carried oil into the intake even with proper amount and viscosity of oil in the bath, so it'd drool on the floor after shutdown.

Chris

[mjn]

MJN: May I ask where on eBay, from whom, you purchased the Changfa?

I bought my engine and generator from Joel (sawyer335) on ebay.  He no longer is selling the Changfa engines.  He currently has an ST 7.5 head listed.  http://cgi.ebay.com/NEW-HD-7-5-KW-GENERATOR-HEAD-END-DIESEL-GAS-NR_W0QQitemZ110025989116QQihZ001QQcategoryZ106437QQcmdZViewItem

My generator project was lots of fun.  We had two weeks of very hot weather in July.  I ran my air conditioner on "free" electricity provided by the Changfa running on waste vegetable oil.  Everybody else saw their power bill jump, but mine actually went down.  I am working on repairing an old shed which will become the permanent home for the Changfa.  Once I get the engine situated in its new home, I'll be updating my website.

As far as belt drive versus direct drive.  The belt drive is much easier to get set up an aligned. I suspect that part of my initial vibration problems (broken muffler, leaking fuel tank) were are result of a mis-aligned direct drive.  When I set up the generator and engine, I made an initial measurement of the shaft heights.  All of my mounting was based on this initial measurement.  When I took the engine off the frame in order to add the radiator, I did a much more careful job of aligning the generator.  I was probably .040 off on my initial height measurement.  After adding some shims, the whole system is much smoother.  I have run the engine over 100 hours since that time with no more vibration related problems.

[Rainbow-Farm]

Chris, that is a great movie and that sled/cart/wood and wheels thing looks great!

I called Solberg, poked around the Web, trying to find out where to buy the right filter/silencer for the Changfa (11xx size). Solberg tells me the 19P comes with 1, 1.25, or 1.5 inch pipe.

Until my ChangFa arrives I don't know which Solberg, and where to get it (the company says they will find me a dealer if I don't find one somewhere else).

We also need a Solberg for a Listeroid (Jkson, I believe), also need to measure its air intake pipe diameter.

=======================

Doing some thinking-out-loud math, at a few hundred feet above sea level, belt drive, the 195 with the 7.5 kW gen. head (or maybe larger), at 2,000 - 2,200 RPM, should deliver well over 7 kW of usable power, which makes even this smaller engine feasible for many homes (thinking about a friend who is getting interested in a similar set-up).

[europachris]

I bought my Solberg filter from Grainger (www.grainger.com).  You should be able to find one from any air compressor dealer in your town/city that deals in the industrial stuff.  Not expensive, either - about $35.  Get the polyester element version - very heavy duty w/wire mesh reinforcement.  Make sure to get the silencer version, also.

I think McMaster-Carr sells them, also.  Doesn't state specifically Solberg, but that's what they are.  mcmaster.com will get you there.

Chris

[Rainbow-Farm]

Thanks, Chris, for the info on parts, upgrades, replacements.

I looked at your rig and puzzled over lunch about the pulley being larger on the engine, until I looked back and saw that your generator runs at 3600, just about twice the speed of the engine.

I am thinking that with an ST head, the pulleys would be almost 1:1, depending on engine speed.

[europachris]

Yeah, an 1800 rpm head would have made the drive system a lot easier.  I would just have used the pulley that came with the engine to drive a similar size vee pulley on the gen head. 

Instead I had to design and machine an adaptor to mount to the flywheel where I could weld in a shaft to mount the pulley and bushing to.  The pulleys were $$$, also.  But, it's a very smooth running drive setup, so I can't complain....

Only downside of an 1800 rpm ST head would be that I wouldn't be able to move the set.  It's heavy enough as it is!

Chris