I have replaced aluminum mower flywheel with industrial cast iron style.
I have used the one wire alternator regulator but learned to appreciate the standard 3 wire version or build your own external regulator. I like the 22SI, looks more industrial and still produced. I should order a few more of them.
Hi Carl , on this engine you have got , do not bother fixing the recoil starter , just use a socket on a short extension on your cordless or electric drill makes starting so much easier than pulling away and trying to get the air mixture right all at the same time while huffing and puffing and catching your breath , oh thats me … sorry
Have you decided on your nozzle design yet ,are you going in the side of your drum/reactor horizontally or will you be fixing a vertical nozzle into the side or bottom ?
dave
That is smart - I wish I had thought of that. I will have to reconfigure stuff a little bit, and it will maybe stick up sort of high, but I see the advantage.
I did notice that the pull-cord jerked back on me when I was just playing around with it to see if it would fire on ether. The shaft seems like it is going to be much longer than needed to line a belt up with the alternator, so I might look for a large diameter pulley to stick on the end to give it a little more mass. Thanks for the info on RPMs as well, the alternator I ordered still hasnt come, but I am hoping it will come with some sort of spec sheet.
I got a 24 volt version that is rated for 50 amps. It is a single wire alternator. I am planning on running the output through a shunt so I can monitor the voltage/amps/kwh it is generating with a little multimeter. My battery bank is pretty small, so I am limited to about 30 amps of charging current. I have been trying to get my diversion loads all figured out - which in theory should allow me to apply 30 amps of charging current indefinitely without ever cooking the batteries - in practice, I am running into problems with the charge controller flipping out when it tries to go into absorb.
I have not really decided on the nozzle design, and I still need to track down a good reactor vessel. Part of me thinks this is a great excuse to buy that $600 slip-roller I had been thinking about getting… I had given some thought to the idea of a horizontal threaded pipe, a 90" elbow, and then either a cap (or maybe a plug would be even better) that has a 1/2 hole drilled in it. I could then just replace the caps as they wear out. I feel like a horizontal port would make lighting easier, but the general consensus seems to be that vertical jets are less destructive on the nozzles?
Hi oregoncarl, yeah the engine start will kick-back, without any rotating mass like a blade or a heavy flywheel, soft aluminum flywheel key will often become sheared during engine testing when you have no rotating mass, the vibration of the engine while testing will be excessively intense…rotating mass fixes that. However once you get the alternator/pulleys/belt bolted up to the engine crank the alternator itself will give you a good amount of rotating mass, quite probably enough that the kick-back & vibration will not be as noticeable. The belt tension with the alternator must be adjusted fairly tight, any slippage in the driveline rotating mass will be seen as starter kickback/excessive vibration/broken flywheel keys…
If it is true the crankshaft is too long in your application, you can permanently alter the thing by cutting-off the excess length, but if you go in that direction, I would make sure to redrill the hole[blade bolt hole] much deeper to the depth of about 4.5" before you cut-off the excess length, in this way the [blade bolt hole] hole will remain after you whack off the excess length…as you might need that straight bolt hole to help hold the pulley on there. At best that engine model is a 5 HP on gasoline, as it is only a 12 cu. in. displacement, so additional rotating weight could be a very helpful thing as far as torque & engine smooth running goes. Maybe you can hang some extra rotating mass on that 3 5/32" shaft, if it becomes practical.
As for the PCV Positive Crankcase Ventilation, that valve is generally used to keep a ‘partial vacuum’ within the engine crankcase. That partial vacuum inside the crankcase is important, because it helps keep the engine from consuming excessive oil, and it helps keep the crankshaft oil seals from leaking, that PCV valve keeps the vacuum inside the engine, and pulses of air pressure come out the discharge pipe. So then where to plumb the PCV to? You could plumb it into your homemade fuel/air intake manifold, or you could vent it to the atmosphere [not the best air emissions result], but think about plumbing it toward your wood or charcoal hopper of the gasifier itself. Plumbing directly to the gasifier fuel supply hopper should reduce the PCV pulsating effect upon your system, & keep the emissions of it, incinerated.
As for the ‘Blade Brake Compliance stopping device’, on the front of your engine, yes that can be safely removed, by simply removing it, but ONLY because your changing the application, you are no longer intending to mow grass with a blade, your intending a generator, of which the BBC laws do not require such a stopping device [as far as I know]. The device can remain tho, as a practical ON/OFF switch, the heavy spring may have to be replace to a lighter duty spring, where you can actually work the thing easily. I would recommend you have an working ignition switch of some kind…to solely rely upon fuel shut-off is OK for a diesel engine, but not so much on a spark ignited engine. If you don’t like the BBC device on there, a simple ON/OFF toggle switch will give you the ability to control the ignition.
My 2 cents question on this picture, or with other words, what am i doing different ?
I used to see throttle control between engine and T junction, hence doing my thing that way… now i see some different setup and i am wondering, was i doing wrong ? 
Good morning all.
I once was experimenting with a lawn mower motor pulling an alternator . To avoid the above mention kick back I attached a small car distburter to the lawn mower shaft.
With the dist I also used a 12 volt battery and the coil. The dist was attached to the shaft of the lawn mower motor just below the belt pulley with a short peace of flexible rubber hose and hose clamps.
I ran an insulated wire from one of the pegs of the dist and had a quick release to the spark plug. The time was set very retarded . I could crank the motor very easy with no kick back and after the motor was warm and running good I could switch the plug wires back to the original for running woodgas .
So, if this is a “one wire” alternator, shouldn’t its internal regulator automatically reduce current as the batteries charge up?
I don’t understand why you would want to waste your precious woodgas by using “diversion loads” Besides, I don’t think you are going to have all that much engine power to spare anyway.
On another subject:
I saw your picture of your intake system with the iron pipe and the brass valves. All the weight will be hard on your intake adapter, due to engine vibration I think.
Since you are going to change your valving anyway, you might consider going with lightweight PVC valves.
Regarding the slip roll:
I see your point about getting one.
But, why not take your plan to a fab shop and have them roll that part for you?
I assume you’d want one that is will handle at least 36 inches of 16 ga mild steel. I don’t see any out there for much less than about $1000, so maybe you SHOULD get that $600 one.
I agree on re-plumbing to lessen the stress on the intake adaptor. If you decide to re-plumb, consider using gate valves instead of ball valves. Gate valves are easier to adjust for accurate air/fuel ratio and ball valves (especially PVC ones) are hard to turn creating more stress. Yes, you can get PVC gate valves. You can also remove seals from PVC ball valves to make them turn more freely.
Back to the EGR question. To prevent ashes from glazing your nozzles and to limit catastrophic oxidation of metal nozzle parts it is helpful to recirculate some exhaust gas to take the reaction from white hot down to bright orange. 900-1000C (1650-1800F) is about right. There is a long and interesting discussion on nozzle design here: Nozzles for Charcoal gasifier's - #320
Thanks everyone, lots of helpful info.
I did think of this, and might just put a momentary switch on the wire that grounds the plug. Wouldnt hurt to have a way to shut the thing off…
We may both be confused, what configuration do you use on your air and gas valves, Koen? Are they plumbed the way I have it set up above, or do you put your “throttle” valve below the T and have woodgas coming unrestricted into the T opposite the air intake?
Do you have a picture of this setup? I am not sure I am following you entirely, but it sounds like you are changing the timing of the engine by using an independent power supply to fire the plug? I am not an expert on small engines, so I dont quite understand how the change in timing will change how the engine behaves. Now I am curious, though.
This may well be the case, I am more of a DC guy, so alternators are a little bit confusing to me. I suppose It would have a system to prevent the engine from overcharging the start batteries that it is designed to charge.
As for the diversion loads being a waste of precious woodgas, I disagree. My primary diversion is a 20 gallon hot water heater that preheats water for my propane on-demand heater, and once the thermostat kicks that off, I start space-heating my shed where my shower is. I am not sure if it is really very efficient, but If i can burn less propane I consider it a win.
This seems like a very good point, which I had not considered. I might actually think about mounting the intake manifold directly to the frame I am going to build, and then use a section of flexible hose to make the final connection to the engine. What do you think of that idea? That might make it easier to swap out valves and reconfigure everything anyway.
I went with the brass ball valve because it seemed the least prone to having parts that would melt. I know that in theory the charcoal gas should not be hot, but I wasnt sure if it would be better to err on the side of caution. At some point the engine is going to start running poorly if the gas is too hot, right? Has anyone tried to measure the upper limit for gas temp before an engine either stops running or gets damaged?
Haha, I was looking at a 24" model, but now that you mention it… I DO want to be able to roll 36" material! 
Hey OrCarl, nice rainy day,eh.
It is well proven that an actual 5 horsepower engine will only be able to belt drive generator make at most 1000-1200 watts.
Now factor your 5 horsepower back for charcoal gas fueling a low compression; flat head flows restrictive; somewhat worn-out engine and you will do well to make 800 watts charging. Hope for at least 500 watts.
No problem on the pre-ordered 24VDC “one-wire”. When/if you wish I can step you trough too making it fully externally controllable.
In my best Tom Cruise, Days of Thunder: “There is nothing I can’t do, and haven’t done on auto alternators”.
SI brushless. Dual 12/24 volt. Dual 24/32 volt. NOT SI - - - diode-less charging. 12,000 hour service life conversions upgrades. Totally, and semi-sealed explosion proof units. (marine and mining) Roundy, rounder car low drag 10 amp units. Bloodmoble refrigerator charging units. GeoMetro electric oven pizza delivery cars. Boys Scouts Christmas lights boats. Crane swing generators(alternator-chargers).
For 16 years it was how I earned my salts. Doing nothing else. After 16 years, I got bored. The newer factory units designs actually got better and better, more and more capable. But less and less repairable.
I moved on to other DYI power-making pursuet’s.
Use this first system as your trainer. Improve from then known experiences.
Very, very few only ever make just one system!
Regards
tree-farmer Steve unruh
Hi Carl, I’ll concur with Koen that the throttle control should be between the engine and the “T”. Where you currently have it will probably work, but for some reason I do feel it is optimal. Do not worry about too much chargas heat at this location. The chargas heat remains fairly constant until the charcoal bed gets depleted to a certain point. At that point, the temperature starts to rapidly rise. This is also the time when the CO can escape from the charcoal reducing zone and enter your engine as CO2. In other words, when the temp gets up to 150 or so, shut it down. Therefore all of your fittings on the engine can be made of plastic. I use plastic because I keep the carburater in place and since it is made from pot metal, is inherently weak. Since your arrangement is directly screwed into the engine block, the weight is really not an issue.
Go ahead and buy a slip roll, but a 5 gallon sheet metal pail with a lid will get you going and will be a lot cheaper. For now, I’d recommend a bottom nozzle made from a 1" pipe flange. Don’t worry about nozzles for now, just get the engine running on chargas. I’d even tell you to forget about the filter for now. Use a 10 foot legnth of sump pump hose to connnect the gasifier to the engine. A lot of the dust will settle out in the pipe.
So,oooo with a five gallon steel pail with a gasket lid, two pipe flanges, a short 1"pipe nipple, eight #10 screws, a little RTV gasket material, 10 feet of sump pump hose and your present engine set up, you are ready to run. Whooops, you also need the charcoal graded to 1/8" to 3/4", and then you are ready to run. With all that material at hand, you should be able to get this engine running in three hours.
Ready?
Gary in PA and also a Tree Farmer (love those trees)
This is excellent advice, and I will try and provide some meaningful measurements and results for anyone else who decides to go where i am headed. I think I may have hit a bit of a bump in that the alternator that I received is marked as as 12volt model. I am hoping they will get it straightened out and send me a replacement. This is the one drawback to ordering things online.
1200 watts is the max rating of my alternator, so shooting for 500-600 watts seems like a good place to start. I found a 6" pulley that should let me get ~2.4x gearing once I get my engine actually turning and that might add a little more mass to the shaft.
I will make a point of sorting out some charcoal maybe sometime this week, and then i can start doing some testing on actually producing gas.
You can buy all kinds of regulator if that is a GM alternator and easy and cheap to replace.
Just heard back from the customer service department, and it sounds like the regulator on my alternator was switched out - but the sticker on the side still says 12 volts because that is the base model that they use. They say it should start charging at 800 RPM, so my 1:1 gearing might actually work. If not I can try the larger pulley.
As a side note; the faster an alternator is turned the more efficient it is, to a point. I think the reason is that less current needs to be pumped in to the rotor. But that is a minor point right now. Keep going !
My goal is to build gasifier that runs on charcoal I want use gas with a tankless water heater in my house, considering all its advantages,if we believe this review . What advice do you have for my question?
Doable, but using carbon monoxide indoors is no joke. High quality CO detectors required. I recommend an antique copper coil water heater. These were widely used along side tall copper tanks before WWII. I picked up a couple of these 30 years ago. They look cool and come with a gas burner that works great with charcoal gas.
I love my tankless water heater. What I would never do, is allow wood or charcoal gas in my house.
Put the water heater out side and insulate it well. Get a large ag bag and. Convert it into a gas bag. Make a skeleton silo to put the bag in. Once a day or so fill the bag up with gas. The water heater can draw from the bag as needed.
☺I have always had gas instant water heaters in the houses i had in the UK they were dual units that also ran the central heating as well as well as hot tap water and the units were normally fitted in the kitchens or pantry out of the way , now living in Australia and was surprised to see that here they are nearly always fitted on a outside wall and running away in all kinds of weather conditions with no problems at all and no insulation , it would be a fairly easy job to re jet our unit for wood gas i would imagine ,
we also have outside ducted gas house heating and that unit sits outside next to the water heater , if only the wife would allow me to wood gas them both 
The white unit is the water heater and brown unit is ducted heater .
