Tomo Vinković 418 on woodgasdgas

So, l bought this litle beast last month :smile:

Its a 18hp 1cyl diesel. Its fuel consumption is not terrible, but once you feel how it is to drive for free every galon seems like a waste of money :smile:

Anyway, normaly l wuldnt consider gasifying a diesel but what struck me when reading trugh the specs is it has 1/17 compression ratio. That means it shuld run on woodgas without much modifications. And run good too!

This topic is more or less hypotetical in nature. I may, or may not decide to fidle with it. But for conversation sake, lets give it a go.

Obviously the easyest way wuld be to let it idle on diesel and just add woodgas/air mix via throtle body on demand. But there are 2 drawbacks. First, l dont know how the governor will react when diesel throtle is set on idle but rpm go up as woodgas is introduced. Will the governor close the fuel suply to the nozzle completely?

Second, the tractor is not particulary keen on starting up in winter time. Under freezing temps it just spits fog out the exhaut till the battery dyes. I need to heat the battery and the whole engine with a electric heater prior to startup. In my opinion, woodgasing it via pilot diesel ignition will only make things worse.

Part of the reason why l created this topic is SteveUs advice on installing spark ignition on a engine. Shuld be like childplay here since flywheel and its houseing are so easy reachable. I think it MIGHT allso be possible to keep the diesel nozzle and add a sparkplug somewhere on the head. This way l actualy have a dual fuel engine wich is nice by it self.

Again, a drawback. What do you guys think will happen with the nozzle and pump while runing on woodgas with the diesel lever shut off? Wuldnt want to melt/ruin it…


He, you posted that picture somewhere else too? I am looking for a thing like that too, small and very strong! No money/ different ways to spent it, but high on my list.
This is going to be a real interesting thread. Please continu. I cant contribute but only learn. Quite Similar with my plans.


What is the white wire and the plug/box on the flywheel shroud for? Would a glow plug in the intake manifold help cold starting? How about attaching the governor to the woodgas butterfly/throttle and disconnect it to the injector after manually setting it to idle?


Hi Kristijan,
nice little tractor.
My oppinion is that a spark plug conversion is better. With “diesel ignition” you still need about 30% of the diesel fuel (this number is from old books). As you said starting might be a problem.

Without knowing this special engine, in general the answer is “yes”. You need to fiddle with the governor to inject the idle amount at all revs.
Another problem is throttling of woodgas air mixture. You need to adjust the mixture, not the volume like in a petrol engine. This will lead to quite low gas consumption during idle and thus the risk of cooling down the gas generator.

Depends on your engine, but you might risk overheating of the diesel injector nozzle in the head (it is cooled and lubricated by the diesel flow). So it could be damaged or blocked by coked diesel.


Good morning Kristijan.

I see no problem running your little diesel on woodgas assist but incorporating the governor will require some head scratching .

On this video I was piping gas from may v-8 ford to a VW rabbit .


Hello friends, I read your publications and ask myself the question, why do you have a headache about the throttle valve for a gas-air mixture for a diesel engine? For my car, I have long known several ways to adjust power and speed. I think that one air damper on the mixer is enough to control a diesel engine, since wood gas has a very wide range of stereometric ignition ratios, and given a high compression ratio and ignition fuel, this range generally loses its meaning. I have practiced strong mixture leaning many times and each time it turned out that with an open throttle, controlling the gas-air mixture, it is possible to achieve both idle and full load, while the engine idling does not respond to the gas pedal. Another question is whether a high compression ratio causes detonation and how to deal with it? This issue is widely described in the books of Soviet authors. And the experiments they carried out gave the following results. The phenomenon of detonation in the gas-diesel cycle is present only in operation with very rich mixtures, and if the engine power is regulated only by supplying gas, without affecting the air supply, the phenomena of detonation did not appear until compression ratios of 1:20, although it was necessary to play with the injection advance. …


Hi Kristijan
Nice tractor for your steep hillside farm, eh.
PTO drive off of the back? 1000 RPM?

You engine certainly looks to be air cooled.
Try a low charcoal brazier underneath it, Mr Charcoalman. Then no outside electric.
And with the low profile and heavy wheel weights I am guessing that this engine is cast iron too?
If so cast iron loves to be brass brazed. You can add another skill-set to your capabilities.
You could then keep your diesel injector for the ready-use fuel. And then build up a cylinder head boss of brass. Drill and Tap for a spark plug.
I would then spark ignite your char gas fuel. Then NOT needing diesel and giving better precise ignition timing controllability.
Steve unruh

1 Like

1/17 compression ratio.

1/ 15 will be good

so , you go have problems?

1 Like

The engine will probably not run when you turn off the fuel.

What kind of engine is it?
If it is a pre-cup type of diesel you probably will need to continue to inject about 25% of the normal amount of fuel you would burn to keep the injector cool. you might be able to get the engine to run at less fuel but you need the flow of fuel to keep the ejector tip from over heating and cooking the fuel in it into carbon.

IF the engine is of the direct type there is the possibility you could remove the injector completely and modify the cylinder head to except a spark plug and then you would not need any pilot fuel at all.

I read some place in Poland when fuel was scarce they wold run the Ursa tractors on a mixture of old crank case oil ( these are not fussy semi diesel type engines ) and wood gas to conserve fuel. The semi diesel is extremely tolerant of wood gas. It has not valves to tar up…

This engine is no longer sold in the USA or any place else. I think Arrow screwed up and walked away from it.

You really have to know you engines to understand what you are seeing here.
Its is a clone of a Petter PHW-1 modified for spark ignition. Its probably an engine by KOEL engine but modified in the USA.
Its direct injection to gas engine conversion…

In India at the Combustion, Gasification and Propulsion Laboratory they modified an engine in this family called the RB-33 by KOEL and they did indeed run it on wood gas with nothing more than the injectors replaced with spark plugs. So it is a completely doable thing Kris. If you have a direct injection engine and you can get replacement cylinder head for it to modify you can run completely on gas.

Not that its all that relevant but here is Bradford Beaver with the air cooled version of that engine the PH-1. They were a stout little unit but heavy.

Last thing I am going to add…
If you find that tractor is hard to start cold I have some tips for you.

  1. Pour 10ml of engine oil into the combustion chamber through the intake to help seal up the rings before starting.
  2. get a heat gun like this…

    Warm up the fuel injector and fuel lines. Mmake then hot but not so hot you can not keep your hand on them,
  3. heat up the intake manifold so its hot to touch…
    4 Get someone to help hold the heat gun and put hot air directly into the intake and crank the engine.

Those 4 things will get 75% of cold diesel to start

This old PH-1 clone probably has low compression and its worn out will not cold start.
These guys are using the old flaming rag trick to preheat the incoming air to fire it up.

A lot of P range engines in my reply, I have a special fondness for the type from my days starting this way up north in winter.


Joep, yes, on the other thread. And its an exelent peace of machinery. Good transmission, 6 forward, 3 back, and l think at least 3 PTO speeds. Hadnt yet checked that much…

Don, that seems to be the dinamo part.

Steve, if l get you right, you suggested making a separate spark plug head?

Ha, charcoal heater will not work here. I have no shelter and its always windy outside.

Anyways, winter is preety much over now so l dont bother with bad starting any more, just wanted to point out it might be better to spark convert for easy startup reasons.
Oh, and l failed to mention the motor actualy has a litle cap on top that channels directly over the intake chanel, for exactly that reason, puting a few drops of oil on the cilinder. Tryed, not much better…

Ok. Thanks for the input guys. I am NOT a diesel guy. I always sayd if a gas engine has spark and compression l will make it run. Diesels have too many litle moveing bits and peaces :smile:

I googled some pics and specs on the engine. It seems here is where we currently stand.

Yes its air cooled, direct injection it seems. Seems to me, but l culd be wrong, that the cyl is cast iron and the head is aluminium


differential lock?..

1 Like

Yes it is 4x4 with diff lock on front wheels.

1 Like

then this is a verry good traktor!


Hi Kristijan,
That looks as a Direct injected engine ?
A little trick i use: look up the pump combo and have a little shim under the shoulders of the pump to change the timing of the fuel injection
That way you won’t get pre detonation with the woodgas.
The governor will not bother you unless you force that manual into fuel shut of.
With your level of inventor skills, you will enjoy and start growing lemons for sure… ( you will need them… )


No. Stupid me. I see an old engine and my mind says flat head wide surface valve-in-block type.
Stupid of me. Diesels were never this.
You have no cylinder head room for both a diesel injector AND a spark plug.

So use diesel as your pilot fuel with wood(char) gas.
Or remove the diesel injector and convert that hole with an insert to a spark plug.
Maybe with your chargas fuel improvements you will still be satisfied with the power?

As others have said you have a winner there for your farm.
Steve unruh


All engines require air. Even Nitrous can be used in a diesel to lean it out and gain a lot more power. I’m guessing that the reason you get a huge load of black exhaust smoke when you demand more instant power is that the turbo hasn’t had time to build enough boost to pump extra air into the cylinder. I know that this little engine isn’t using any boost but If Nitrous is used it is pumped in to the air stream. I know wood gas can’t be liquified, but if it could be pressurized enough to gain added volume in the air stream it would have to Increase power. It wouldn’t get you free from diesel fuel but could add to effeciency.

This is a completely new linage of tractor and engine from what i am used to seeing. BUT its a direct injection engine, pretty nice design too!

I would look around for another cylinder head and modify that head for a spark plug.
For ignition I would start looking around to get pieces from a 70s electronic ignition system.

Brian Miller in the USA ( very nice man I have the privilege to exchange a lot of email with over the years ) has provided some great information here on how to make an ignition system for single cylinder race engines that applies just as well and easily to a diesel to gas conversion