TheSitRep,

Are you sure about those rpm figures?

If you have the larger 5" pulley and use it on a 23.6" flywheel and the generator needs to spin at 3,600 to produce 60 cycles/second.

Then your engine speed would operate at 762 rpm @ 60 cycles/second and 787 rpm @ 62 cycles.

If you install the smaller 4.2" pulley, your engine speed would operate at 640 rpm @ 60 cycles/second and 661 rpm @ 62 cycles.

Your flywheels are only rated at 650 rpm. I would put the smaller pulley on the unit, before anymore testing.

Diesel Guy

I pulled the top end off and removed the rod on my 6/1's and 14/1 and they all needed a good cleaning. I steamed cleaned the internals and put everything back properly.

I would recommend an offset idler gear bolt, and hollow dippers from xyzer and a bronze idler gear when reassembling. Also make sure your tappets rotate properly, if not I used some valve lapping compound to make them work smoothly.

I only use straight 30 weight oil in my engines. I used 15-40 to flush out the engines when new and there was more engine clatter when running the multi grade oil, I would avoid it. There are people here that might tell you the opposite.

Put a powerful magnet in the bottom, check your timing (valve and injection pump) and make sure your engine operates at low rpm at startup.

That's just my ten cents.

I would also agree with mbryner's comments, good luck.

Diesel Guy

SteveU,

There are many people on this forum that really know what’s going on when talking about these engines and generators and we are all teaching each other something. 

You started that you need lower compression. I’ll tell you what I’m working on and you might find something useable. I am looking to purchase another 14/1 or 16/1 and destroke it to lower the compression. Then I’m going to place a turbocharger on it and run medium to high of manifold pressure. The lower compression would allow me to make additional power reliably and not hammer the piston, rods, and main bearings.  Your 12/1 has a cylinder deck height of 9.275" and the 14/1 has a cylinder deck height of about 9.5”. Both have a 130 mm bore.

As far as proper timing goes, momentary cylinder pressure, load on the engine, either constant DC or variable AC, fuel type, flame speed, ect all contribute to proper timing. One of the reasons I stated lower engine speed, the 12/1 can make 6 Kw continuous @ 1,000 rpm, your needed 3 Kw would place a 50% load on the engine. This would be the lowest load you want on the engine. At your engine speed of 638 rpm, your engine makes about 8+ hp continuous. This places a 75% load on your engine, perfect balance for engine durability vs. fuel consumption.

If you were to use a small Dc charging system - low amp alternator, say at about 400 rpm. Your engine would make about 3 hp continuous. At 75% load you would have 2.25 hp continuous. About  56 amps @ 13.8 volts, 28 amps @ 27.6 volts and 14 amps at 55.2 volts.

I am also designing my own special cam grind, lift/duration especially for maximum low end torque, with no over rev capability. It would provide maximum volumetric efficiency in your engine at about 375 - 400 rpm. It would make greater torque at low speed, much more vacuum and smoother engine operation than a stock cam.

When I get it cut and find the time to install it, I’ll sent my results. As you can see I’m experimenting on many different designs, hope you can get something from this.

Diesel Guy

This is a neat setup:

http://www.youtube.com/watch?v=UAZKxYZ3QH0


I was thinking of something simular to it. Its nice to see a working unit to finalize my design.

Diesel Guy

I would run 4 - 1,500 watt heaters on high output, left outside to stay engaged, for an extended time. 48 hours run time should solve the problem. If not you might have to tear into the engine to deglaze it.

Diesel Guy

Bob,

I’m not a person to quickly react about comments made and like to use facts to help explain my point. I just completed my 3 day, not shutting down , 72 hour run on the permanent magnet alternator. I have a LB 1 Isuzu with a capacitor 6 KW generator on the back (not operating, disconnected) . It is used as my backup system in case my 14/1 needs repair, ect. and is equipped with an Amsoil bypass system.

I switched my inverters over to 24 volt and now use heavy duty transformer based industrial inverters. The battery bank is 24 volts - 2,000 amp/hours Surrette, 24 - 2 volt cells and weighs 3,600 lbs. I use a single DC-512 permanent magnet alternator. It has a 4 inch pulley attached and the LB 1 has a 4.625 engine pulley.

The engine ran a about 1,200 RPM and the alternator ran at 1,387 RPM. I ran it without a charge controller and the battery maintained 25.5 to 28.5 volts during the entire 24 hour day. The alternator put out a constant 35 amps and only got warm to the touch and “working on going up in flames” was the furthest thing from reality. The calculated power requirement is 3.2 HP.

My engines are connected to large fuel tanks so I cant verify fuel consumption. But I could tell you this, not only did it work flawlessly for 3 days continuous. But the system would have worked for a year straight 24/7 if I wanted it to. Only to shut down every 45 days for an oil and filter change.

As far as the 45% efficiency goes, I don’t have the data to disprove it but I personally think you are off by quite a bit. As we talked about in the past, I use only Electrodyne alternators and know all about the 7/8 shaft size and their efficiency.

http://www.electrodyne.com/index.html

The reason for the lighter duty permanent magnet design is that it is cheap and saves fuel. Conventional alternators need more fuel than a permanent magnet design so you get the conventional alternator cheap but you are continuously paying the price in increased fuel consumption.

http://www.eco-techalternators.com/alternators_calculator.htm

Also, I stated earlier that a big single and wrote 16/1 previously, or a twin for this application. I know a 6/1 wouldn’t pull the load that was needed. I have three of them. I do know that at the speed that I’m driving my alternator now and load, that a single 6/1 would almost pull two alternators (6.4 HP needed). So your calculation on a 6/1 barely pulling just one alternator, is a little off.

There are more than one way to skin a cat. I’m not claiming anything, but just clarifying why I stated what I did in an earlier post.

Diesel Guy

Tom is correct about the timing, being retarded a bit would help reduce the sharpness of the power stroke and increase engine life. My 14/1 has a big bore and long stroke and it’s a single. My belt don’t chirp and I have a 128 lbs. flywheel mass on my generator. My timing is set at 16 degrees BTDC.

But mine is direct injected and on an indirect injected engine, maybe 18 degrees BTDC, instead of 20 degrees BTDC. I also have 23.5 inch diameter heavy flywheels. I think as we went over this in the past, more flywheel mass and larger diameter flywheels are best. This would absorb the power pulses and totally eliminate the belt chirp.

The belt chirp is not because there is not enough traction between the flywheel and the belt, or there is a heavy mass on the generator head. It is the lack of stored kinetic energy potential (too small diameter and too little mass) in the flywheel system per given instantaneous torque output, that is the route of the problem. The heavier and larger diameter (with increased surface area) flywheels the better.

The Start - O - Matics flywheels were correct for generator use and  anything less has short comings. See how long it takes for this engine to build up stored potential at start up and then release the stored potential when shut down stop. Massive stored kinetic potential.

http://www.youtube.com/watch?v=wBhjwEBBuo4

These belts don’t slip and it has a heavy mass on the generator head because of the V belt, but also the flywheels are heavy and large diameter and the engine’s instantaneous torque output can not accelerate the flywheels fast enough to cause a slip. This is just my option, for what it‘s worth.

Diesel Guy