Richard Grosvenor Posted February 20, 2006 Share Posted February 20, 2006 Hello, I have often wondered how is an engine Multi-fueled. Reason for asking is ZIL engines are often described as being multi-fuel and able to run on any thing, petrol, diesel or parafin. The ZIL V8 looks like a normal petrol engine, it has a carburetter and spark plugs. I was talking to a chap at a show last year who has 2 Reo's, a 2.5 ton and 5 ton, which truly are multi-fuel. He was explaining that they have a device on the fuel pump which senses the "weight" of the fuel and regulates how much is supplied to the engine. I think that the Reo engine is a compression ignition engine the same as a normal diesel? The ZIL's don't have anything like this. So is it possible for a spark ignition engine to be Mutil-fueled or is this sale's talk? Cheers Richard Quote Link to comment Share on other sites More sharing options...
John Pearson Posted February 20, 2006 Share Posted February 20, 2006 Interesting question: Most 'multi-fuel' engines are no such thing, they will just operate on a variety of deisel type fuels with the deisel, compression ignition system. For example, the Challenger engine in Iraq runs on jet engine fuel which resembles parafin/kerosene because the Abrams has to have it for its jet engine and the supplies are common. In theory, you could operate almost any liquid fuel in a deisel system, examples of LPG gas, injected in liquid form and petrol/gasoline are relatively common. The engine would ideally be fitted with variable injection timing, volume and pressure to cope with the different burning capabilities and detonation avoidance may necessitate either a variable compression ratio or an avoidance of the top dead centre locked position which is how the FV432 and Cheiftain do it by having opposed pistons that are out of sync with each other so one at least is always moving. Multi fuel with a carburetor is a different kettle of fish though as there is a need for the fuel to vaporise and partly evaporate in use. Alcohol and petrol can do this and kerosene can as well if the carb is heated in some way but the temperature that standard deisel will do this would be enormously high. Naptha, petrol, kerosene and deisel all share similar chemical relationships (and other chemicals) and all come from cracking crude oil. The stuff you buy as petrol is in fact a mixture of things towards the top of the scale and deisel a mixture towards the bottom end, the actual composition is changed by petrol companies, dependant upon the air temperature they are likely to be used at: an early cold snap frequently freezes the deisel in trucks which then does not happen for the rest of the winter because the companies add more 'light' crackings to the mix. I think the direct answer to your query is that the Zil will run on any REASONABLE fuel, basically petrol of the lowest possible grade or deisel/petrol mix but as for running on straight deisel, probably not! You could always try it! Quote Link to comment Share on other sites More sharing options...
Richard Grosvenor Posted February 20, 2006 Author Share Posted February 20, 2006 Thanks John, Your last point about the ZIL's running on low quality petrol or a slight diesel/petrol mix has always been the most plausible to me, rather than them being a true multi-fuel engine. I read somewhere, that in Russia they sometimes have incredibly low octane petrol But I've been told so many things about what a ZIL can and can't be run on it gets hard knowing who to believe, petrol, paraffin, petrol/paraffin mix, kerosene, diesel/petrol mix...the list goes on. So, if I've got this right, it's easier for a diesel compression ignition type engine to run on petrol than it is for carburetter fed, spark plug ignition engine to run on heavy fuels such as diesel. Is that right? I think I'll keep the Old Bitch on neat petrol though, just to be on the safe side :wink: Regards Richard Quote Link to comment Share on other sites More sharing options...
Degsy Posted February 21, 2006 Share Posted February 21, 2006 That's as good an explanation as I have seen, very clear John. Richard, as you are probably aware the recovery companies are awash with petrol /diesel mix, I would try connecting up a can of this mix and see how it runs. If it works OK then it's free fuel for the duration. :lol: Cheers Degsy Quote Link to comment Share on other sites More sharing options...
Big Al Posted February 21, 2006 Share Posted February 21, 2006 Thankyou john for your reply to richards question its very informative and clear. What fuel mix will not work in a muilt-fuel engine? Quote Link to comment Share on other sites More sharing options...
79x100 Posted February 21, 2006 Share Posted February 21, 2006 The Dutch name for parrafin is "Petrol" (What we call petrol they call benzine) Some of the garages in country districts used to sell it on a pump for the farmers who use it for heating glasshouses and things. When I first came to Belgium, I drove straight up to the "petrol" pump with my 2 1/4 ex military series 3 Rover and filled up both under-seat tanks. :oops: I drove all the way home wondering why it was so cheap. Apart from the thing smelling like a Primus stove, I had no permanent ill-effects, although I did drain it off once I realised. I didn't buy engine cleaner for about 3 years :lol: Quote Link to comment Share on other sites More sharing options...
John Pearson Posted February 21, 2006 Share Posted February 21, 2006 Thankyou john for your reply to richards question its very informative and clear. What fuel mix will not work in a muilt-fuel engine? Basically, anything fluid and inflammable could be made to work from carbon monoxide/air mix (called producer gas) to bitumin (ie road tarmac) and air which is used in a lot of large (ship) tankers and bulk carriers. The problem is that the basic engine design of compression ratio, heat transference and basic internal strength are all set once made and whatever set of parameters are chosen, they will only suit a quite narrow set of fluids. A case in point: the BSA 500cc motorcycle engine would run on 65 octane unleaded petrol in the 1920's, 72 and 92 octane in the 40's, 101 octane petrol in the 50's and methyl alcohol also in the 1950s. The compression ratio was about 4.5 to 1 in the 20's and had to have the valves ground in every 2000 miles, 72 octane ran about 6 to 1, 92 octane (old two star) was ok frm about 6 to 8 to one and the Gold Star ran about 11 to 1 when racing on 101. Alcohol needed about 15 to 1 and almost no cooling fins on the barrel when used as a speedway bike. You could say that this motocycle engine could use all the fuels but that is not really true because the engine had to be made/modified to use each one. Same with true multifuel engines, there are temperature limits for each fuel (eg alcohol will boil, petrol will evaporate at a temperature when a true oil will not even move down the pipes), similarly, viscocity limits, the amount of heat energy liberated varies etc. Almost anything inflammable can run the RIGHT engine, rather than the fuel itself being restricted. I did once read that a Cheiftain engine could run on fine coal dust and water but I have no idea if that is true!l Quote Link to comment Share on other sites More sharing options...
Richard Grosvenor Posted February 21, 2006 Author Share Posted February 21, 2006 That's as good an explanation as I have seen, very clear John.Richard, as you are probably aware the recovery companies are awash with petrol /diesel mix, I would try connecting up a can of this mix and see how it runs. If it works OK then it's free fuel for the duration. :lol: Cheers Degsy Hmmm.....I don't know if I dare. If someone could tell me that they have done it with their own ZIL and it's all fine with no problems I would. Probably :wink: I must share this story. I have it on good account that this is all true. A member of our local Historic Vehicle club ( rumoured to be the chairman!) who owns a rather nice MG sports car got fed up with paying high fuel prices. He'd heard of people converting their classics to diesel and getting much better MPG and cheaper running costs. So he decided he would "convert" his MG. So, off he goes to Tesco and fills the tank up with Diesel and drives home, about 5 miles. He makes it home...just, but try as he might it will not restart. He calls a mate "who knows about these things" and asks for his advice. His mate asks " How did you convert it?" "Well, I just put diesel in it" he replied. A complete fuel system clean out followed. A job not made any easier as the car had no fuel tank drain so the tank had to be removed :lol: Regards Richard Quote Link to comment Share on other sites More sharing options...
John Pearson Posted February 21, 2006 Share Posted February 21, 2006 When I first came to Belgium, I drove straight up to the "petrol" pump with my 2 1/4 ex military series 3 Rover and filled up both under-seat tanks. :oops: I drove all the way home wondering why it was so cheap. Years ago when I was a student, I had only a teacupfull of petrol in my Triumph 500cc motorcycle and had to get to my part time work as a forecourt attendant. I added half a gallon of my fathers parafin (kerosene) and drove off, about 15 miles. Ran a little bit rough but no problem. After work I pushed it up and down the road with no success, even though I had added 3 gallons of petrol. Mechanic came to my aid and I explained what I had done. Simple he says: bike started on neat petrol and once the parafin came through, the hot air from the engine kept the parafin in an evaporating state. Once it had cooled, no chance of a start as the carb was still full of almost pure parafin, even though tank now held almost pure petrol. Simple fix: drain carb, allow petrol to come through and bike started first kick! Quote Link to comment Share on other sites More sharing options...
Richard Farrant Posted February 21, 2006 Share Posted February 21, 2006 Once it had cooled, no chance of a start as the carb was still full of almost pure parafin, even though tank now held almost pure petrol. Simple fix: drain carb, allow petrol to come through and bike started first kick! hi John, That is why the old petrol/paraffin tractors had drain taps on the carb, in case you had forgotten to turn the tap back to petrol before stopping. Back to the messages regarding running a petrol engine on petrol / diesel mix. When I worked in army workshops, at the time that the Land Rover 90 and 110 were introduced, there was a spate of instances where the wrong fuel was put in by units. Not good if they put petrol in the diesel, but the other way around and all it did was smoke a bit, depending on the ratio of mix. Richard Quote Link to comment Share on other sites More sharing options...
AlienFTM Posted February 22, 2006 Share Posted February 22, 2006 I read somewhere, that in Russia they sometimes have incredibly low octane petrol In HM Forces they have (in my day anyway) incredibly low octane petrol. Anything "petrol" driven ran on Combatgas, which made 2star look powerful. This in the day when only Japanese cars ran on 2star: "real" cars like Rovers and Jaguar XK420s (can you see where I am going yet?) ran on 5star. So one bright sunny morning in 77 I am playing with my - er the Squadron Leader's - Landrover and I watch a delivery of "Combatgas" from a Shell(IIRC) tanker to our POL (Petrol, Oil and Lubricants) Point. As the tanker drives away, I cannot help but notice that the POL storeman is standing with chin on deck, so I bimble over and ask why. "He just gave us 100,000 gallons of 5star for Combatgas!" "Why?" "I asked him that. He said there'd been a Pimmel auf at the depot over work tickets. He'd been given the wrong load. Not his place to argue. 'Just accept your good fortune. Oh, and don't fill up at the Shell filling station in Burbage for a few weeks.'" The POL storeman continued to me, "Get yer Rover over here and get some real petrol in it. But don't shout it from the rooftops or the whole garrison will be filling up here." I didn't shout it from the rooftops, but you know how it is. Within half an hour there was a queue round Tidworth to fill every petrol-engined vehicle in the garrison with 5star "Combatgas." I have to tell you that for two weeks there wasn't a single fuel-related breakdown in the garrison. The Scorpions' XK420 engine may have been modified to run on Combatgas, but they went through plugs and points like toilet paper after a good Chili. Quote Link to comment Share on other sites More sharing options...
Degsy Posted February 22, 2006 Share Posted February 22, 2006 100,000 gallon's :shock: on a truck :?: :? :lol: Quote Link to comment Share on other sites More sharing options...
AlienFTM Posted February 22, 2006 Share Posted February 22, 2006 100,000 gallon's :shock: on a truck :?: :? :lol: Lol I agonised over whether or not to make a point there that for emphasis the number was made up. On other message boards I frequent I knew I'd be torn to shreds for that. ;o) Quote Link to comment Share on other sites More sharing options...
Degsy Posted February 22, 2006 Share Posted February 22, 2006 Sorry about that Alien but I had visions of the size of truck needed to take that amount. :shock: :lol: Cheers Degsy Quote Link to comment Share on other sites More sharing options...
Big Al Posted February 22, 2006 Share Posted February 22, 2006 Thanks john for your answer I will bring some coal dust and water for the weekend to TRY! Quote Link to comment Share on other sites More sharing options...
Rlangham Posted February 22, 2006 Share Posted February 22, 2006 Burbage? As in Leicestershire? That's about two miles from me, got a load of mates there, do you mean the petrol station on the A5? Quote Link to comment Share on other sites More sharing options...
AlienFTM Posted February 23, 2006 Share Posted February 23, 2006 Burbage? As in Leicestershire? That's about two miles from me, got a load of mates there, do you mean the petrol station on the A5? No, no, no, no no! This is Burbage in Wilts, just north of Tidworth on the road up to Marlborough. I'd like to think that after 30 years they've got rid of all the Combatgas! Let's face it, they got rid of 5star not very long at all after 1976 (but exactly when escapes me). ;o) Quote Link to comment Share on other sites More sharing options...
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