Small engine mobile fuel station


First off let me say thank you for posting and taking me to school.

Here is my version 1.5 system.


Built from junk I had and materials that were available within 1 km of my farm. My goal was to build a mobile fueling station. We run a variety of small engines to process crops, power generators, and pump irrigation.

It is a classic simple fire scaled up to a 50 gal. drum. My nozzle is a 8" long section of 1" diameter pipe. That is wrapped in two layers of 1/16th" thick stainless as a sheath. I have a coffee can water drip system to boost and cool things off.


I mount the mixing manifold near the reactor and not the engine. The logic being that I only have one set of filters and valves for multiple engines. The engine specific part is a fitting to adapt to the air intake. Adjusting the mix is a little tricky. Longer plumbing makes for a time delay between adjustment and reaction.

We start on gas/diesel warm it up and use the engine vacuum to start the burn. When things are running smooth we switch over to char-gas. For diesel we trickle in about 20% liquid fuel for lubrication and pilot ignition.

We run until the top gets hot. Switch back to dino fuel. Open, stir, and top off with charcoal, then reseal. Once the air we introduced is evacuated we switch back to char-gas.

This particular gasifier ran a 8hp Honda GX clone for 6 hours pumping 4" pipe full of water from a shallow well. We found that approximately 35 → 40% of the charcoal was consumed in the the drum. After refill we ran for an additional 5 hours before quitting for the day.


That fine folks is a productive run time.

Version 2.0 will have a different nozzle.

I was able to find a 8’ section of steel steam pipe that is OD 2" and ID 1". Wall thickness is .5". I plan on cutting it up into multiple 8" nozzles. Thread one end to fit into a 2" coupler. Then weld a stainless drum bulkhead plate around that coupler. A pipe wall that beefy should have a long lifespan.

I chose to use a KVL style retort because my environment matches his. The fuel materials available to me are piss-poor to down right sh_tty. Soft, punky saplings. Mostly fence row and road side clean-outs. Any wood of quality is too valuable burn up. Furniture, tool handles, etc.


I am building a wood chipper and charcoal grinder as we speak. My hope is that I can speed up the wood drying time, and lower the prep labor, by chipping it before I bake it.

For us the Holy Grail of fuel would be pressing pellets from charcoal-ed grass / leaves with manure as a binder. If that is even possible. Those tests are a few months off.

Here is what gave me the idea in the first place.

Biomass Briquette

Thank you once again.



This is an excellent post! I hope it will inspire many who need this technology most. Oil prices will likely keep climbing throughout the year, so your system could be a life saver for small farmers.

Your cyclone is the only thing that looks a bit “off” to me. A smaller diameter, may give better spin and better particle separation. Put the words “air ramp” in the search option above and read my posts for an alternative approach.


Thank you Mark for your pictures and what you have written and keep posting your excellent work you are doing on the other projects too.


Thanks, Mark for sharing with us. Lots of great pictures. We love those. Looks like you have a really well thought out practical solution for your needs.


Here in the RP, Diesel has increased 20% in the last two months. Petrol 30%.

You are right on the cyclone filter. I got a technical paper around here somewhere that charts the specs of what works best.

The main problem is the fabricators skill level … oops … To be honest I am just glad the thing does not leak at this point.

I only used 50 pounds of brass rod glopping it together.

In a future version I am thinking to combine the functions of cyclone filter and the charcoal/fiber filter into one canister.

Thank you for the tip. I’ll search out the ramp reference right now.


I have done this too. Take a look at my Škoda thread. My filter is a cooler, cyclone and a sack filter in one pack. Shuld work even better with the updraft, less danger to overheat the filter media


A good heavy duty body for an all in one cyclone bag filter body would be an old power line transformer case. They have locking tabs.


Thank you.

I’ve been though that thread once already. It is probably where I got the idea in the first place.

I will revisit it.

Our biggest problem is materials. There is no junk here.

I read DOW every morning with my coffee.

Most of the time I am green with envy. “Boron carbide” this and “Adruino” that.

I struggle to find hose clamps.

And stainless steel hose clamps involve a testicle mortgage.


Mark I’m the same way. It’s like pulling teeth to find open top 55 gallon drums let alone 30 or 20 gallon drums.

If I even look at a programmable computer it’ll probably short circuit. I’m just incredibly lucky to have charitable people around me to find scrap goods. Heavy plate steel is also hard to find for me due to money issues and general availability.


Link holder.

Gets kinda sporty at time 12:00


Really nice

Wondering how big of a engine you think this thing could power.

Swap bigger air inlet nozzle in and possibly add a blower, best way to increase output?

Also maybr drip a small amount of waiste oil for extra power?


1" nozzle can power a decent sized engine, if it was up to 1000cc you could have water drip and some engine exhaust gas return to cool the reaction if water drip isn’t enough. My B2000 had 5 .5" holes in the flute nozzle.
Water drip adds hydrogen to the gas as it’s vaporized and passed through the reaction so just plain water adds some power.
For reference, some of the old swedish motorcycle gasifiers had a half inch nozzle and powered up to 500cc engines.


I think the original Simple Fire was spec’d for 5 → 15hp engines. Need to double check that.

Once I get everything stabilized into a fielded unit, I will mount this unit on my Iseki 20hp tractor. That tractor is a Japanese copy of the Bolens G242 tractor.

If I under-power, overheat, or start burning up nozzles I will upgrade to a 1.5" nozzle.

I am in a place where there is no such thing as “waste oil”. Used oil is too valuable to just burn it up.


I don’t like using oil anyways. The one time I tested it for the Mazda I kept getting flames out the nozzle entrances and scared me, even with my copper scrubbing pads to keep embers from flying out. Great thing about water drip is it can be nasty water you’d never drink, or maybe old antifreeze water that’s contaminated.


Well … that was fun.

We finished the wood chipper. It works well for being built out of shi… stuff.

Chipped up a few barrow loads of scraps/stems/saplings/etc. Dried the chips out on a concrete pad for a few days.

Then loaded up the KVL retort. 35kg went in. 4 hours later 10kg came out. Charcoal-ed nicely. Good size. No need to process further.

So we let it sit till the next morning, then Yak-a-Yak’d, (sieved), it to separate out engine fuel from dust. Bagged up the fuel at about 11:00.

15:00 the store house filled up with smoke. The new fuel stored in the sack was on fire.

Well to quote Charlie Daniels we were “steppin -n- fetchin like our heads were on fire and our asses was a catchin”.

No body hurt, nothing outside of a rice sack damaged. Big mess to clean up. But …

There is an important PRO safety tip. Let the charcoal sit for a few days before you bag it.

Preferably sit outside.


Been there, done that. Not too long ago I sifted out some freshly made char and let it sit a couple days before I moved it for storage into a plastic tote. Got distracted and didn’t get the tote moved into the shed I store it in. Came back to find the tote melted into a puddle and the char all nice and glowing again.

I like me some Charlie Daniels. This has been my anthem long before he put it into words.


Happened to me too. I have found its important to leave the new sacks “in quarantede” before adding them to the rest of your charcoal stock.

I will be building a silo soon thugh, shuld be a lot safer thain the bags


I like to finish my Charcoal freshly made in water. The next day remove it. Let it dry out. It is safe to store.


I store my charcoal in the burn barrel with a lid and bricks to weigh it down, then I’ll move it to another drum with a gasketed lid to cut off any other oxygen. So maybe a day and a half before I crush it and bag it.

Edit: I forgot to mention I wait for the burn barrel to cool down before I transfer it to the sealed barrel.



First try on 2022.03.29 was a miserable failure. Too wet. Liquid sludge seeped, and in some cases sprayed every where.

Then too dry. Think dust bowl wind storm. Only this time in charcoal.

So we spent half a day cleaning up.

Second try 2022.03.30

Charcoal dust left over from yak-a-yak-ing. Smaller than 1/8th"


Flat die pellet Mill. Pretty basic. Under the green shroud is a right angle gear from a Suzuki Multi-Cab. Rpm’s controlled by pulleys.


This is the binder. Locally it is known as “Gow-gow”. A mixture of an undetermined ratio of the worst quality rice and cassava flour. Usually obtained from cleaning out the traps, nooks and crannies of the milling machine.

Most folks mix this with babang, (rice bran), and crack field corn for poultry feed. Costs about 12 cents a pound. And everyone knows how to make it the old style.


Mano-mano mixing. Trowel, metal bucket, etc. So far the mix is …

1 kg charcoal dust
200ml water
50g of binder.


Finished pellets drying in the sun.


Tomorrow, depending on dryness … we will clean up the bottom of a kettle and do a burn test in the kitchen rocket stove.

If that burns pretty clean, then I will kludge up a particle filter out of a paper towel and water bottles tops.

Put that inline right before the air intake on the motor. We want to have some sort of visual indicator of post filter - pre engine fuel quality. Lowest of tech of course.