Does this engine exist?

[artificer]

Bio; 

How much electricity and heat do you want from the system?  On one of the other forums someone mentioned a shift in perception.  We talk about making electicity and recovering the heat.  If you really need the heat, the amount produced while meeting your electrical needs isn't that much.  At least not in the north.  The perception change was:  the lister/changfa/whatever engine was a fuel oil burner that would let you have electrical power.  You'll have more electricity than you need, but if you're going to burn the fuel to get heat anyway, the added equipment cost is worth it.  If I was one of the people with free natural gas on their property, this is what I'd be doing.

Bergmanj;

Are you saying less cylinders, but with the same displacement will get you a big savings in fuel use, or is it just that fewer cylinders means a smaller engine?  Smaller engines almost always do better for a set load, since they're more highly loaded.  Larger engines are more efficient if they have the same percentage of max load applied, but who needs megawatts of power in their home shop?

Michael

[bergmanj]

Michael,

Less Cylinders with the same displacement will reduce parasitic friction, thus increasing "efficiency" of fuel use: There are several white papers out on the web specifically addressing this and piston-ring design (one from MIT - I'll try to post the paper during my lunch break here at work). Some really interesting information; one point is that if the compression rings (especially the top one) has a "positive" twist (that is "upward" at the cylinder wall from the piston wall) built-in, this substantially reduces friction without substantially affecting compression and ignition sealing!

Most modern low-friction "european" designs now have this "twist" manufactured into the rings.

More later.

Regards,   JLB

[artificer]

Bergmanj;

Have you seen any data on the comparison between displacement and speed?  I'm thinking listeroid vs. changfa.  1/4 the displacement, but 4 times the speed.  Which is more efficient?  What predominates:  heat loss through the cylinder walls or better combustion?  Is it a wash?  I know that direct injection helps on a diesel.  Hmm... a DI listeroid.  Talk about blown head gaskets, probably.

Michael

[bergmanj]

Michael,

In very general terms: For constant lower-speed engines (such as for 1,800 RPM generators), IMHO, least-cylinder count, large-mass (big flywheel) engines will beat anything else hands-down for fuel efficiency due to much lower parasitic losses.

Most of us "modern" folks are so used to automobile engines, that we don't think about the application.

Auto I. C. engines have historically been designed to provide maximum peak horsepower in the smallest package with "smooth-running" (read that many cylinders with overlapping power pulses), and very quick RPM-change response. This has lead to 8 or more cylinder engines of small individual cylinder displacement (relatively speaking) with very lightweight materials for "economy" and quick acceleraion.  And we all tend to "stick our foot through the floor"!

Stationary I. C. engines used for constant-speed generators are much more fuel-efficient if they are built as the smallest average-horsepower needed, with a large (more massive) flywheel to "average-out" the power pulses; and, to provide "peaking" power when needed for electrical motor starts, etc.


The Geo Metro 3-cyl  engine has a particular attribute of readily-available engines: It's very best fuel-use-to-power-output performance is at about 2100 RPM; and, 1,800 RPM is close to that, so it's actually very good for this generator application.

As for your question about listeroid vs changfa: I don't know. There are a lot better-informed people on here than I to answer that question.

Regards,   JLB

[SteveU.]

Fella's Fella's!
Artificer there ARE IDI and DI versions both Changfa and Listeriod clones having been manufactured and used by members here. Use this sites search function and read up on the pro's and cons.

Yep correto mundo that the fewer cylinders per displacement the less ring and bearing drag.
The better the ring designs the less drag.
Heck the thinner the oil the less pumping losses.
Higher the loading the higher the the potential efficiency.
Higher the compression ratio the higher the efficiency.
Higher the operating temperature the higher the efficiency.
Yada. Yada. Yada. All become an futile exercise in counting how many Angels can dance on the head of a pin.

JBL is correct that pick a realistic usable generator RPM of 1800, then an engine matched to your available fuel/power requirements that is LOCALLY available with service parts that you, your family and neighbors can live with. Build it. Just do it. Then kick you own butt finding NOS and used commercial systems for a dime on a dollar.
The 3 cylinder Metro/Suzuki type four strokes are the smallest, lightest, smoothest inline most economical GM spec'ed configuration. They wanted more power so Suzuki in there own Swifts added one more cylinder as a 1300 cc with a ~25 loss in economy. Then even up powered turbo'd that for the braggin' rights.
Fuel efficiency wise on gaseous fuel i can kick Kubota 3 cyclinder Butt with an air cooled indusrial V-twin NOT having to water pump drive, less ring and bearing drag requiring less oil pumped energy loss.
And I in turn can have my Butt kicked by a big massive ton of metal cast iron single cylinder Thumper. Or . . . a tiny modern single cylinder purpose built $30K dedicated inverter system. Posted up here to. Search it out.
Buts, and Butts add up and all cost money and time.
Efficiency costs BUCK$$$. How much money and time you willing to burn through chasing numbers and claims to fame??
Ha! Ha! $10k + and 6000 hours in the last three years chasing this stuff by me. Just ask the wife. Ask member Jens.

Regards
Steve Unruh

[bergmanj]

Steve,

Thanks for the continued interest and reply.

I need to point-out, though, that gaseous-fueled (propane / NG) is of higher efficiency when kept cooler (even cold); the drawback is that if "too" cold, condensation problems rear their ugly head in the engine, causing other "issues".  My personal opinion is that about 160 deg F is a good compromise for those fuels.

Regards,   JLB

[BioHazard]

Bio,

F. Y. I: There is a very specific reason I went for the Geo 3-cyl: Less total cylinders means less "parasitic" friction internally (plus it has a "low-friction" piston-ring design).  A lot of folks don't realize that this particular issue can make a very huge difference in the effective fuel "efficiency", as with less internal friction, there is more power available for external use, while using the same amount of fuel.  Put another way, it will use less fuel for the same amount of external power needed.  This can be upwards of 30% difference for the same application!

Regards,   JLB

Right...I totally understand that, but my first objective is heat, so engine efficiency isn't a major concern. Less efficient just means more heat. Plus I have a thing for inline sixes. I'm thinking of using a dual engine approach, the larger I6 and then something smaller for lower heat demand, like maybe a 2 cylinder.

[Horsepoor]

BioHazard

Thank you posting the information on the Generac Kit with the correct part number for the step motor. I was reading posts last year with great interest on this very topic. As I recall, another member had compatibility problems getting the controller to connect properly with the step motor. These issues caused me to hold off until I got renewed interest after reading your post. I shared your recent post (March 20th) with a couple of my friends who are also very interested. Here are a few questions, if anyone can answer, this information would be greatly appreciated:

1.   My plan, is to leave the mechanical governor / spring system in place and adjust it to run at turn the ST generator head at 60 Hz with "no load". Then, mount the Generac kit with electric switches so that I can engage precise governor control. I would like to set the Generac kit up such that it "bumps" or pulls on the mechanical governor when RPM droops thus bringing the RPMs back up to maintain a 60 Hz at the ST Gen Head. Is this reasonable?
 
2.   Before I spend $150 for the controller and $120 for the proper step motor, I really would like to know if anyone else is using these specific components to achieve precise governor control. Please advise.


3.   I have actually awaken from sleep at night to go surf the web hoping to find a reasonably priced and simple kit that senses Hz from the AC lines at the generator head. Emphasis on reasonably priced and simple. Nearly everything requires a magnetic speed sensor. Regulating the governor based on ST Hz is just what I have been looking for. So here is my question after reading the service / installation manual references to the "Hz meter". Does the Generac kit actually sense AC Hz coming from the Gen Head or do the references to the Hz meter imply there is some type of Hz meter which has to be specially ordered which is compatible with the Generac controller? I know this is probably a naïve question, but if I didn't ask, I might wish I had later on, after spending almost $300. So can anyone confirm the Gererac Kit senses Hz directly from the AC L1 or L2 lines?  

Bruce    

[Derb]

Hi Fellas. A lot of the chasing around for high thermal efficiency etc becomes accademic in the end when the twin overhead toothbrush, turbo-convaluted .5cc wizz-bang only lasts about 2 weeks and costs a small fortune to repair and drives you nuts because it is running at 33,000 rpm (OK I may be pushing the boundaries of credibility here but you get my point) . Sometimes hard to argue against a good reliable dozy thump-thump-thump which uses an acceptable amount of fuel producing an acceptable amount of energy can be fixed by someone with an acceptable amount of know-how for an acceptable cost but only once in a blue moon 'coz the damn thing runs forever and sounds bloody fantastic! Of course this would be my humble opinion. Cheers, Derb.

[bergmanj]

Horsepoor,

IMHO, several years back, I pondered the same plan to use the mechanical governor, with the electronics as assist, because it seemed as if it would work great.  Never did impement it to try, though.  I'd certainly be very interested in the results of your implementation; as, probably, are many others here.

As previously posted here (above someplace), I used a stepper motor (free) out of an old printer: It just needs to be 12V / two-winding (4-lead), as I recall (haven't looked at it recently - and, many other "irons in the fire").  One of the Generac wiring diagrams should confirm that.

Regards,   JLB

[Horsepoor]

bergmanj,

Thank you for your reply. I am waiting to hear other comments from other members. If favorable, I am going to spend the money, buy a Generac kit and build / install the system.

Bruce

[bergmanj]

Bruce,

Sorry tht I didn't reply to your #3 question before: I did a lot of "bench testing" with the Generac governor electronics drive.  I was able to use a signal generator at 60 Hz +/- (for testing stepper motor direction and shaft acceleration speed) down to just a few volts with it still operating properly; and, it was spec'd to bettter than 250 VAC for sensing inputs too!  Very wide sense-lead operating range.

I'ts designed to be directly connectable to 120 VAC - maybe even for 240 (check some of the generac drawings to confirm); I'd use'd it directly on the 120 output (with 1K ohm 1-watt [for their 1000 V voltage rating - yes, resistors have voltage ratings!] resistors in series with each of the sensing leads, and a 0.1 uF 300V-rated non-polarized capacitor across the leads at the electronics module (to "filter" for "noise") - just for extra "protection" of the governor electronics.

Hope this helps you (and others).

Regards,   JLB

[andymil]

Craigslist has supplied me with a 3813 Honda lawn tractor.  It has a 13 hp water cooled V-twin engine.  I still find them listed from time to time. I also picked up a 5 hp, 230 volt, single phase, 3515 rpm induction motor from Craigslist.  I would like to get them put together before winter. 
I plan to get it working on gasoline then convert it to natural gas after working some of the bugs out.  I'm going to set it up for a 2 KW output and recover as much heat as possible.  I'm hoping that being connected to the grid will give a fairly constant load for the governor to maintain.

Andy

[SteveU.]

Hey AndyM.
Sounds like an excellent plan.
If you post up a model/spec number for the actual engine those interested here can look it up and follow along.

For the natural gas conversion be sure and follow some of the latest discussions going on the Fuels Alternatives Board -> Methane  too by Mr Bio and Mobile Bob and others.

I just this last weekend at an estate sale picked up a 10 YO Scotts rider with a puked deck to make up a co-gen system for the green house this winter using it's Kohler engine, pulleys belts and some old 80's take off DC Electrodyne alternators. Air cooled the plants won't mind the noise or a little CO/CO2 leakage. Use the engine flywheel blower to dstribute the engine/oil/exhaust heat.

Pictures now much easier to post up if you are of a mind. (use the "Additional Options" button, then "Choose File")

Regards and Welcome aboard here
Steve Unruh

[SteveU.]

Hi AndyM.
www.tractordata.com gives good base info on this machine and engine including fluid capacities. Is a 358cc/21.9 cid engine. Compression ratio is not listed but with the HP and being a Honda probably right up there at 9/1.
Is this a pushrod OHV engine or overhead cam engine?

www.planopower.com/store/honda lists model ranges and is a possible alternative parts source.

Regards
Steve Unruh