This is an old page, I leave old stuff on my pages so you can see how things have evolved, there is other info here that you might learn from..   I suggest you never build a generator like this one, the cast iron legs are likely to come loose and cause you a problem. I leave this page here as an example of what some people build, and what I did earlier. See 'articles' pages for a better design.

There are many DIYers using the 1115s and 195s, Allmand direct drive to the better built ST heads. I have several accounts from Electrical Engineers who are simply amazed by the ability of these old engines and heads to start big AC loads! I have found only one person who posts he doesn't like these engines, what's amazing is he claims to be using it daily for the past three years, and to be burning FREE oil, including used motor oil! I wish all the stuff I don't like was that good :-) 

DIY CHINESE Diesel powered Generator Set

Some people love diesels; other people hate them.

They're  noisy and they stink (My wife says)

On the 'pro' side, they seem to live long lives, and run with far greater efficiency than gas powered generators. Maybe equally important, the fuel keeps longer than gas, I have at least 12 gas powered devices, and it is a real chore keeping fresh gas in them, I've had to take several carbs apart and de-varnish them. the smell of oxidized gas stays with you for a week.

Over the last few days; I've been hand starting a 195 Chinese built-German designed 12HP single with amazing ease. People often refer to this engine as12hp, but the information on the tag claims 9.98 kW at 2200 rpms which amounts to about 13.38 hp. We can get into elevation and it's effect on horsepower, but as we all know, the higher the elevation the less horsepower. My tests are being conducted at around 300 feet above sea level and at about 50 degrees F.

 195a.jpg (50616 bytes)

The generator head is rated at 10KW continuous and weighs 265 pounds (ST10), we know this device is not 100 percent efficient, we know the belts and pulleys are going to cost us some horsepower as well, so how much rubber can we put to the road?

 March 1, 2002

I have chosen to use two 4 by sixes (wood) as the 'base' for the generator set.   It's taken some time to come up with the initial set up, but I think it will work well. The home made adjusters allow for an exact alignment when tensioning the belt. Having them on opposite sides of the generator head where one adjuster pulls the head away from the engine on the belt side, and the other adjuster pulls the gen head toward the engine is key.

March 6, 2002

The cooling system is very important, the amount of useful power and the longevity of the engine have a lot to do with maintaining the engine at the proper temp.  If you have a hopper cooled engine beware of minerals I the water, if you continue to add water as required, you could create enough deposits to develop hot spots around the cylinder and ruin your engine.

The other day I had my electric space heater plugged into the Gen. set, I plugged in my 2 hp chop saw and stalled the motor. The generator didn't seem to notice the load! Sounds like I need to make up a good test load.  Stay tuned for the results and more pictures. Just how conservative were they when they rated this engine?

tension.jpg (28804 bytes)

The picture above is the home made generator head adjuster. It is nothing more than a piece of threaded rod purchased from the hardware store, and a scrap piece of flat steel bar. Simply hit the center of each surface with a punch and drill the proper sized hole, and run the tap for threads. I found 1/2 inch bolts work well to fasten the head to the mounts.


adjuster.jpg (43180 bytes)

Here's a view of an 'adjuster' installed inside the square tube. The adjusters provide very accurate alignment of the belts and pulleys and provide a means to apply the proper tension. Once the alignment and tension are correct, tighten the 1/2 inch bolts and the head will stay put.

cool1.jpg (42490 bytes)

This is a picture of a test adapter plate. After removing the stock water tank, I used the gasket to manufacture a plate to cover the hole. The goose neck houses the thermostat, the 190 degree unit seems to be doing the job. The hoses will eventually be replaced with high temp (flexible) hose. Note:  the cold water side has a specially fabricated pickup to assure proper thermal siphon.  The hot side enters just below the plate. After so trial and error, the volume of water moved is pretty amazing.

cooltemp.jpg (49111 bytes)

Here's a picture of a manual gauge installed, note the gauge is reading a little below 210, this was just before the thermostat opened. You can place your hand on the hose just above the thermostat and feel the thermal start when the valve does open. In this test set up, the temp in the head is held between 190 and 200 degrees F. 

cooltank.jpg (46335 bytes)

Above is the cooling tank, The two larger hoses run back to the gen set, the thermostat goes to the top connection, cold water return to the bottom.  The hot water connection (at the top of this tank) is left open for expansion. During final installation, the tank will be fitted with an overflow tank like that found in a car and it will become a pressurized system for the higher elevation where it will be installed. the smaller hose was used to monitor the height of the water in the tank while it was being filled via the stock drain valve at the bottom of the tank. You can easily substitute an auto radiator for the tank and tilt it at a slight angle to encourage the air to 'thermal' through the radiator. If the radiator is sized correctly, you won't need a fan.


fitting.jpg (52835 bytes)

Of possible interest is the above fitting, it's barbed on one end and has pipe threads on the other. This fitting screws into the standard threaded holes used to hold the electric heating elements in a standard hot water tank. In addition, you can use a two part epoxy to 'bond' this fitting into the Chevy thermostat housing making for a simple connection. the barbed end makes a tight connection to the hose,  adding a stainless steel hose clamp makes for a leak proof trouble free connection even when the system is pressurized.

Of course you could use a heater core and fan,  but there's less to go wrong when you eliminate parts and sensors. Using this waste heat for domestic hot water could be an added bonus. I shut down the engine at 8:00 PM last night, the tank was still 100 degrees this AM (no insulation), This would beat a cold shower any day, and we all know there's a way to store this energy with less loss.

belts.jpg (49214 bytes)

Here's a view of the stock pulley that comes with the 195 diesel, and the pulley mounted on the generator head. The ratio sets the engine at 2000 rpms when the head is turning at 1800 rpms which is required to make 60 cycle AC at the FULL rated RPM/HP of the engine. I learned to buy decent belts! Don't buy your them at a discount automotive parts store. Go to a parts house that carries industrial stuff and buy common back belts if you need more than a single belt to effectively transfer the power. a "common back" belt is two or more belts with a common backing, one advantage is they are the same size and always share the load equally. Mark in PA emailed me the other day and explained that the two belts he got were slightly different sizes and couldn't be used, he went back for the common backs at the suggestion of his supplier. The individual belts below are high quality and work well, but I think the common backs will live longer and do a better job.

If you're wondering if a person might be better off dropping the speed of the engine 200 RPMs and driving the head with a coupler, so am I... the belt driven unit goes up against a wall and takes up little space, the exhaust can be plumed right out the same wall. The coupler layout is not so tidy, it requires more 'walk around room and would fit best in a corner. I will build both sooner or later and learn the real pros and cons of both. 

Note added 12/2/02, Utterpower now supplies a nifty cast iron adapter to direct drive an 1800 RPM generator head! see the 4Sale page for more information.

Alignhead.jpg (41657 bytes)

Good alignments reduce losses and reduce belt wear. Note the straight edge in the above photo of Harry Anderson's Generator set.

Here's something I think works well....., when you are placing your major components, mount your engine and then align the generator head in a way where it is easy to check alignment. In this application, the belts will be next to the back wall of the "power shed", enough room will be left to replace belts and to bend over and check alignment.

The mounts with the slotted holes were set in position when the back side of the head fell in line with the edge of the fly wheel. Once this alignment was made, the pulley on the gen head was adjusted and locked into place to be exactly in line with  the engine pulley. Adjustments are precision and quick as follows.

1. back off the four bolts at the gen head base, 2. Apply the proper tension by tightening the  back tensioner. 3. Lay the straight edge across the back of the fly wheel and gen head and adjust the front tensioner until the edge makes even contact along the fly wheel and the back of the head.  4. Recheck the belt for proper tension,   5. Tighten the four Gen Head base bolts......... You're done!

dumyload.jpg (57703 bytes)

And here's the dummy load. This is a 10 kW electrical element out of a forced air electric furnace. The generator feeds the test load through a circuit breaker. 

So what happened you ask? How much load can a 195 make? The answer is still not clear. The furnace coils have a thermal sensor that opens the circuit if they get too warm, as you can see I have no air blowing across them so I have a limited time to conduct the test before the thermal switch is triggered. 

Here's what I did observe.

After warming the engine, I brought it to the  governor speed (2000 rpms) which is 1800 Rpms for the generator head. After the engine had run at this speed for a minute or so I slammed the 5.7 ohm load across the 220 volt output. I watched the 'read out' of my FLUKE volt meter bounce off 210 volts and start heading upwards. At 221 volts the thermal protection fired and I lost my load. I'm thinking the voltage would have continued to climb, but who knows for sure. Another factor is the engine, it is new and not yet fully broken in. It might become more efficient after another few hundred hours of running?

Doing the math, it looks like we were handling an honest 8570 watts when the load kicked out. The engine was NOT smoking black at the time and the voltage was climbing, this may be an indicator that the engine would continue to carry this load ?

If we take the rated 9.98 kW output of the engine and compare it to the observed output of the gen set we would see that 86% of that ((RATED)) output found it's way to the load. A loss of only 14 percent is a little too much to wish for... ( I think).

I end up wondering...

What is the real horsepower of this engine ?

What are the typical losses found in a generator? As of March 30th, I have torn down the ST head, it has 'very' fine laminations and a fairly tight airgap, this could be partially responsible for the efficiency I think I'm seeing.

What's typical in the way of losses for Vee belts and pulleys? Seems like it's enough to investigate using a cogged belt like the Harley Davision uses.

Did I forget to factor something? YES I DID!

April 18th 2002 Update:  I received a nice email from Darryl Phillips today, Darryl pointed out that Nicrome wire will create more resistance as it heats. This means that my test was junk! As you can see from above.. I was skeptical of what I was seeing, and now we know I had reason to be. I recently bought a clamp on amp meter, next test, I'll put the fluke and the clamp on amp meter in a place where I can snap a picture of the readings, we'll have a better idea of the 'real' load at that time, might as well set up for the frequency too. I will leave this information here for a while so others don't make the same mistake.

If we look back at my observations, I saw an initial 210 volts, so it is possible that the engine was only carrying 7736 watts. When it's fully broken in, I'd bet we'll see the full 8 KW.

I will fit the test load with a blower to keep the coils cool (so the load doesn't kick out) and retest this genset once the engine is fully broken in, (probably this summer), What's your guess on the final output? If you have suggestions or comments; please email me.

Come back and visit, I'm building a controller for this  genset that will handle auto start, and all kinds of things you might find fun or interesting, there's no rush, but I do plan to get it done before Harry Anderson gets his piper in the air:-)

May 16th 2002

As of this date, I've had time to play with Petters and Listers, although they have their strong points, nothing I've played with in the way of one cylinder diesels comes close to being as smooth as the counter balanced Horizontals. I'm sure it has a lot to do with the counterbalance shafts in the design, bring it up to speed and it is far smoother than the others.

After checking out some other installations, I noticed the exhaust systems get kind of twisty and turnie, you'd think this could affect peak power and the ability to start that really big load? How about making a straight shot out of the exhaust port... straight out the wall? In doing so, you eliminate two 90 degree bends in the stock system.

EXHAUST1.jpg (44481 bytes)

This flange is made of 1 1/2 inch black iron pipe commonly used to plumb natural gas. the flange was cut from some flat stock using the stock flange as a guide. Since you have plenty of room, leave an additional .100" of an inch margin over the stock flange.

EXHAUST2.jpg (57522 bytes)

I used a cheap 1 1/2 inch hole saw with lots of oil for lube on the drill press to cut the hole in the flange. Butt the pipe up to the flange, center it, and weld it from the inside. The pipe is slightly larger than the stock exhaust, and should help make more peak power.

George B.

Home Page