Larosa Brake drum design

Following the Mike Larosa brake drum gasifier design, does the size of the engine need to be taken in to account in regards to the diameter and length of the hearth in the reaction chamber?

Also, how does the exhaust (colored red in the design) worrk without also acting as a cold air inlet?

Joe, I’m not sure what drawing you refer to. I am pretty sure that I didn’t draw it. I have pictures of several builds on my website. I have a list of the dates somewhere and will post them when I spot them.
is my main picture list.
are a few pictures from June of 2008.
On my last build I went to a slightly larger rotor and hole (3.5") but had been running 3" holes. I am usually running wide open throttle. They do what they do. I was able to go a lot faster with the 2.2 liter cavalier but the tranny blew in that. My 4.3 liter full sized truck does fine with them but I won’t break any speed records. I can build one in a few days of spare time. I am a poor welder so try to do as little of that as possible.

Mike, thank you for your reply. I must say that I admire what you are doing: developing designs that are easily accessible using parts that are readily available. My apologies for the confusion. The drawing I am referring to is at this link: . My primary question is based on pg 52 of the fema document: “Construction of a simplified wood gas generator for fueling internal combustion engines in a petroleum emergency” about fire tube dimensions. An image of the page is attached… However, your reply gives me a good idea of the answer to my question. The images help a great deal as well. Is your air intake from the top of the fuel hopper or are you preheating the intake air by routing it through the reaction chamber? I am not a good welder either and have used high temperature silicon with some success to seal my bad welding. What type of cement are you using? Keep up the good work, it is inspiring me!

Ummmm… please don’t build a FEMA unit… do yourself a favour and try something that may at the first look seem a little more complicated. Problems with the fema is they make tar… not a problem if you’re only gonna just flare the gas, but it will stick up an engine is short order… speaking from experience here.

I built one based on that design but did not have consistent results with the gas. Therefore never ran and engine with it. Yes, tar was bad. I went through at least 2 blowers. What design do you recommend?

Hi Joe,
Welcome to the site. Having been there and done that, I agree with Arvid. Building the FEMA was fun, got me back to welding and gave me an outlet for creativity of a scientific nature.However, it is a tar producer and I wouldn’t run an ICE with it except in an extreme emergency. And you could lose use of the engine. I recently built a imbert type gasifier which I’m quite satisfied with. I have refinements to do, but I have a working hearth. I’ve chronicled my errors, er progress I mean in the FORUM, Small Engine User’s Corner. Scroll down the first page to; My first engine run on wood gas…Pepe
The design I built to Imbert line C (moving to line D now, however, for more gas production) has proven to produce a good quality gas. 8HP was the biggest engine I had to experiment with.
There are different hearth designs, I tried a fluidyne (ease of construction). I missed a weld on the fire tube and never found it until I tore the whole thing down. Shifted to my present design because I was into bending cones at the time and enjoyed the challenge of the hourglass hearth.
So take a look at just one of the many ways to go. I probably have specific pictures of all the parts of my system if you have any questions. Pepe

Yes, building it was fun and interesting, but never ran an engine using it and went through two blower motors trying to get it to work. It made more tar than burnable gas. Having pics and diagrams of your design would be great! I will be joining the premium membership within the next couple of weeks. I’n not much of a welder and I’m sure I need practice on my fabrication skills but I am determined and very inquisitive.

I never ran an engine on the FEMA either. I already have a bunch of pics in the FORUM, click Small Engine User’s Corner. Scroll down that page to; My first engine run on wood gas
The Forum is in the home page header, you should be able to view it. It’s long but a lot of pics and explanations. I’m taking mine apart now to install a larger hearth, so it’s a good opportunity for some
how it comes apart/goes together pics. You’ll notice I scrounged stuff where I could. I’m also working on a larger (10") fan. Maybe I need a new thread to present it in the proper sequence? The same propane tanks went through 2 major design changes so I have to pick a pseudo starting point that doesn’t confuse the two. Obtanium is everywhere although I am spending a few bucks on mild plate steel, pillow block bearings and hubs for my fan. Oh, and a 9/16" and 5/8" drill bits, $35 for the pair, ouch, but critical for accurate work.

we did manage to run an engine on a fema, with Terry L’s help… gummed that lil engine up pretty good too. thankfully briggs and stratton engines are pretty durable… and parts are plentiful

My Honda generator was my first choice until I found out that fuel injected engines could be converted. However, I just found out that my vehicles may not be good candidates because they have the OBDII. So I am now back to my Honda generator. Starting with small scale is probably better anyway. Sounds like I am talking to the right person. I will check out the small engine corner as you suggest. Thanks.

Hi All
The Small Engine Users Corner is here:

This is intentionaly kept out front in the Public section.
Mr Pepes work is there. Arvid Olsens work is there. Matt Ryders work is there. All different from each other systems. These all have diagrams/pictures in their threads there.
Other different builders designs and results are there too. I cannot remember if Terry’s GEK clone 4 cylinder Ford Ranger is there or on the Builders or Projects sections. Only the downsized Keith sysems have been moved off into the Premium section to be able to be detail advised with other actual experenced WK system operators.

Steve Unruh

Joe, After running an OBD2 car, I really don’t want to go back. Being able to plug in a diagnostic tool while driving provides a pile of information. My 97 cavalier rarely threw a code and ran better than anything I have run before. The only codes I remember would be due to an occasional miss while adjusting the air mixture or after I turned the idle screw up and it would occasionally idle higher than what the computer wanted for it “idle out of range”… ML

Mike, it sounds like you have had a good experience running woodgas in an obd2 car. Maybe my Lumina would be a good candidate. How much did your diagnostic tool cost? I’m assuming you still had to switch off or pwm the fuel injectors, right?

Hey Joe,
I should have mentioned that my primary goal is in running a 15 to 20 KW generator for home power,thus the small engine interest. I may build a unit for my 1961 Farmall Cub tractor but that only has 20 or so horse power so again I’m in the small engine range. My older Craftsman riding mower has 18 HP so I’ve got plenty to do with those first. I don’t think newer Toyotas are on the good list for conversion. I really can’t afford to mess with my 2009 4WD Tacoma. Mike I had a Celebrity and loved it right up til the day the front suspension let loose and luckily didn’t kill my daughter, not a scratch, Thank God.

Joe, My 97 cavalier has a single fuse for both the fuel pump and injectors. I ran 2 wires from those terminals and put a fuse in series to a 49 cent light switch on the top of the dash. I also experimented with some nichrome wire to find the sweet spot for running hybrid and added a second switch with it. This allows just a dribble of gasoline for climbing hills and in heavy traffic. The computer will deal with the timing. I bought a better diagnostic tool when I bought mine. I think it was $160 or so.
is a picture of the switches as well as my mixer “cable”.
That’s all I have for controls …
Pepe, They all rot away, don’t they ?? Mike

While sitting here puffing on my electronic cigarette I looked up the wiki on nichrome wire. Apparently there is nichrome wire in my e-cig that heats the liquid in the atomizer that makes the vapor; cool! Or do I mean hot; whatever. Anyway, so you have made a custom inline resistor to control the amount of fuel delivered to the cylinders. Is the nichrom wire in the injector electrical line, the fuel pump electrical line or both? You are very creative and innovative. I wonder if I could make this work with my 4.7 Dodge Dakota or 3.0 chevy Lumina.

Should work on the Lumina ?? It is in line with both on the cavalier. Too bad the transmission blew. The wire was from some old guy’s appliance repair stock to repair OLD fashioned heat plates and ovens.