Accidental diesel in Rotax 912
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Some of the previous answers are obviously from people who are guessing rather than having any precise knowledge.
Here are some FACTS....
1. Diesel fuel is a natural lubricant. It WILL NOT cause cylinder scoring under ANY normal operating circumstances.
2. Diesel has a CETANE rating, not an OCTANE rating. The CETANE rating is the effective opposite of OCTANE rating. CETANE rating is the time lapse from injection to fuel ignition in a compression ignition engine. A high CETANE rating means a longer delay from injection to ignition of the fuel.
OCTANE rating is a gasoline/petrol rating, of a spark ignition fuels, resistance to detonation. A high octane fuel has good detonation resistance, and a low octane fuel has poor detonation resistance.
Simply put... if you use low octane fuel in a high-performance engine, you will experience detonation more quickly than when using high octane fuel.
3. Diesel fuel contains much more energy than gasoline/petrol. This is the reason diesel engined vehicles get better economy than gasoline/petrol-fuelled vehicles.
It also contains a vastly increased amount of carbon and other pollutants. For this reason, high detergent level oils are used in the crankcase of diesel engines, to cope with the massive production of carbon and other pollutants that are a by-product of diesel combustion.
4. Diesel can be used in spark ignition engines, if so designed. Allis-Chalmers, the tractor manufacturer, produced a spark-ignition diesel tractor engine in 1936. It was a low-compression engine whereby the diesel fuel was injected, and then ignited by a spark plug. Special spark plugs were used to combat fouling, and a low pressure fuel injection pump and injectors provided the fuel.
The problems with this engine that made it less than successful, were high fuel consumption, spark plug fouling, and high crankcase oil dilution, as the diesel fuel did not burn 100% successfully with this setup.
The greatest single problem with using diesel fuel in an engine designed to use spark ignition fuel, is the substantially increased energy content of diesel fuel, will lead to higher combustion temperatures, and therefore engine overheating.
Engine overheating results in oil thinning and oil breakdown, so it cannot lubricate properly. Engine parts wear more rapidly in an overheating engine. Engine overheating will result in cylinder wall scuffing, as the oil film on the cylinder wall breaks down.
In a worse case scenario, engine seizure will result, when the bearings commence to gall, and the bearing metal sticks to the crankshaft journals. The pistons will melt and gall, and seize to the cylinder walls.
The second greatest single problem with using diesel fuel in an engine designed to use spark ignition fuel, is rapid carbon deposit buildup, due to the vastly increased carbon content of diesel.
When diesel burns in a spark ignition engine, rapid carbon buildup results, which can result in rapid spark plug fouling, ring sticking, cylinder bore glazing, and exhaust port fouling.
The indications are, from the reduced oil pressure, increased oil consumption, and the reduction in differential cylinder pressures, that the Rotax has been seriously damaged by overheating and carbon buildup. You have no choice but to totally dismantle the engine and rebuild it.
Here are some FACTS....
1. Diesel fuel is a natural lubricant. It WILL NOT cause cylinder scoring under ANY normal operating circumstances.
2. Diesel has a CETANE rating, not an OCTANE rating. The CETANE rating is the effective opposite of OCTANE rating. CETANE rating is the time lapse from injection to fuel ignition in a compression ignition engine. A high CETANE rating means a longer delay from injection to ignition of the fuel.
OCTANE rating is a gasoline/petrol rating, of a spark ignition fuels, resistance to detonation. A high octane fuel has good detonation resistance, and a low octane fuel has poor detonation resistance.
Simply put... if you use low octane fuel in a high-performance engine, you will experience detonation more quickly than when using high octane fuel.
3. Diesel fuel contains much more energy than gasoline/petrol. This is the reason diesel engined vehicles get better economy than gasoline/petrol-fuelled vehicles.
It also contains a vastly increased amount of carbon and other pollutants. For this reason, high detergent level oils are used in the crankcase of diesel engines, to cope with the massive production of carbon and other pollutants that are a by-product of diesel combustion.
4. Diesel can be used in spark ignition engines, if so designed. Allis-Chalmers, the tractor manufacturer, produced a spark-ignition diesel tractor engine in 1936. It was a low-compression engine whereby the diesel fuel was injected, and then ignited by a spark plug. Special spark plugs were used to combat fouling, and a low pressure fuel injection pump and injectors provided the fuel.
The problems with this engine that made it less than successful, were high fuel consumption, spark plug fouling, and high crankcase oil dilution, as the diesel fuel did not burn 100% successfully with this setup.
The greatest single problem with using diesel fuel in an engine designed to use spark ignition fuel, is the substantially increased energy content of diesel fuel, will lead to higher combustion temperatures, and therefore engine overheating.
Engine overheating results in oil thinning and oil breakdown, so it cannot lubricate properly. Engine parts wear more rapidly in an overheating engine. Engine overheating will result in cylinder wall scuffing, as the oil film on the cylinder wall breaks down.
In a worse case scenario, engine seizure will result, when the bearings commence to gall, and the bearing metal sticks to the crankshaft journals. The pistons will melt and gall, and seize to the cylinder walls.
The second greatest single problem with using diesel fuel in an engine designed to use spark ignition fuel, is rapid carbon deposit buildup, due to the vastly increased carbon content of diesel.
When diesel burns in a spark ignition engine, rapid carbon buildup results, which can result in rapid spark plug fouling, ring sticking, cylinder bore glazing, and exhaust port fouling.
The indications are, from the reduced oil pressure, increased oil consumption, and the reduction in differential cylinder pressures, that the Rotax has been seriously damaged by overheating and carbon buildup. You have no choice but to totally dismantle the engine and rebuild it.
How did this happen, was it Jet-A1 from a pump? If hand-filled the fuel is so different in smell and viscosity it's hard to see how you would keep on filling after the first few seconds.
Not wishing to add to the chorus because we all make mistakes, but if such a basic error was made, how much else of the pre-flight wasn't done properly?
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Diesel fuel is a natural lubricant. It WILL NOT cause cylinder scoring under ANY normal operating circumstances.
Simply put... if you use low octane fuel in a high-performance engine, you will experience detonation more quickly than when using high octane fuel.
Diesel fuel contains much more energy than gasoline/petrol.
This is the reason diesel engined vehicles get better economy than gasoline/petrol-fuelled vehicles.
It also contains a vastly increased amount of carbon and other pollutants.
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Rod,
You misunderstand.
Putting the wrong fuel in a car is easily done, low hazard, etc. An understandable mistake. To err is human, etc.
The unforgiveable action is flying again. To indicate that my remarks rested upon that, I said '...face value...'.
If this is all too complex for you to comprehend, I could have a go at a 'Janet and John' version of my posts, but in my third decade in this industry, I lose patience...
You misunderstand.
Putting the wrong fuel in a car is easily done, low hazard, etc. An understandable mistake. To err is human, etc.
The unforgiveable action is flying again. To indicate that my remarks rested upon that, I said '...face value...'.
If this is all too complex for you to comprehend, I could have a go at a 'Janet and John' version of my posts, but in my third decade in this industry, I lose patience...
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I am with frontlefthamster and fear his post was misread.
I don't think it takes much brains to work out the premise of the post wasn't to disrepute the integrity of somebody accidentally filling up with the wrong fuel, whether it be car, aeroplane, submarine, etc, because yes, everybody makes mistakes.
However the reference to being unfit to hold a pilot's licence most certainly is applicable should somebody then make the decision to fly an aeroplane which they know has been filled with the wrong motion lotion.
But of course, we don't know that, do we.
I don't think it takes much brains to work out the premise of the post wasn't to disrepute the integrity of somebody accidentally filling up with the wrong fuel, whether it be car, aeroplane, submarine, etc, because yes, everybody makes mistakes.
However the reference to being unfit to hold a pilot's licence most certainly is applicable should somebody then make the decision to fly an aeroplane which they know has been filled with the wrong motion lotion.
But of course, we don't know that, do we.
Dimona.
You don't say whther the engine is a 912 or a 912S as generally we talk about the type as a 912 but of course there is a difference. The compression ratio for a 912 is 8 something to 1 and for a 912S it is up around 10:1. I would not expect the extra energy value of 50/50 to damage a 912 as musch as a 912S which is basically the same engine.
I would certainly flush the oil two or three times turning the engine over without plugs. While diesel does contain lubricants it also mixes with oil and lowers the viscosity. Your first hurdle is oil pressure and you certainly can't use the engine for anything until you have that fixed.
You also did not say whether the engine actually overheated. Since 912 engines are dual cooled I am guessing you have a water temp gauge. How high did it go? Do you have an oil temp gauge? If so how high did that go? (I have seen 220F on my water gauge.)
If the engine was seriously overheated then you may have cylinder damage but it would not usually come just from carbon build up. Those of us who worked on cars before the modern era of clean fuels etc used to spend quite a bit of our time 'decoking' our motors. The carbon builds up mostly in the middle of the piston but around the edges it does not affets the cylinder wall at all. It also builds up on the backs of the valves (as well as on the front) and eventually in the seal area (the seat.) we used to scrape that off and then reseat the valves by twisting them with a fine grinding powder in the seal until the faces were smooth and matching! However that was after 100K miles, I wouldn't expect anything dramatic after 15 mins! Having said that modern machines are a mite more pernickerty than those of the sixties. I have just seen a set of plugs in a VW utterly destroyed (electrodes burned to globs of welding splatter) in 300kms because the dealer supplied the wrong ones.
You also don't say how many hours your engine has so any comment on the causes of lost compression is just speculation. The oil consumption appears to show something amiss. My 912S is just a baby (150 hrs) but uses absolutely no oil at all between changes. Nada, none in 50 hrs.
You might certainly look for oil leaks around the important seals, crankshaft etc. If viscosity was lost I'd expect the seals to be the first thing to suffer.
I know of two or three 912 series engines that have been in "the lake," hauled out, dowsed in oil and then dried out and seem to work fine afterwards. Not perhaps my choice. Another thing to check after an overheat is the ceramic water pump seal. Mine dripped steadily for a while but it seems to cure itself if not too bad to start with.
By the way fuel injectors etc not affected by diesel in a 912. It's got carbs so less likely to have too much energy in the cylinders.
912 engines run on both Auto gas and Avgas, How long you had it actually running and under load with the 50/50 might have a bearing. You don't say, big circuit, long warm up etc?
You don't say whther the engine is a 912 or a 912S as generally we talk about the type as a 912 but of course there is a difference. The compression ratio for a 912 is 8 something to 1 and for a 912S it is up around 10:1. I would not expect the extra energy value of 50/50 to damage a 912 as musch as a 912S which is basically the same engine.
I would certainly flush the oil two or three times turning the engine over without plugs. While diesel does contain lubricants it also mixes with oil and lowers the viscosity. Your first hurdle is oil pressure and you certainly can't use the engine for anything until you have that fixed.
You also did not say whether the engine actually overheated. Since 912 engines are dual cooled I am guessing you have a water temp gauge. How high did it go? Do you have an oil temp gauge? If so how high did that go? (I have seen 220F on my water gauge.)
If the engine was seriously overheated then you may have cylinder damage but it would not usually come just from carbon build up. Those of us who worked on cars before the modern era of clean fuels etc used to spend quite a bit of our time 'decoking' our motors. The carbon builds up mostly in the middle of the piston but around the edges it does not affets the cylinder wall at all. It also builds up on the backs of the valves (as well as on the front) and eventually in the seal area (the seat.) we used to scrape that off and then reseat the valves by twisting them with a fine grinding powder in the seal until the faces were smooth and matching! However that was after 100K miles, I wouldn't expect anything dramatic after 15 mins! Having said that modern machines are a mite more pernickerty than those of the sixties. I have just seen a set of plugs in a VW utterly destroyed (electrodes burned to globs of welding splatter) in 300kms because the dealer supplied the wrong ones.
You also don't say how many hours your engine has so any comment on the causes of lost compression is just speculation. The oil consumption appears to show something amiss. My 912S is just a baby (150 hrs) but uses absolutely no oil at all between changes. Nada, none in 50 hrs.
You might certainly look for oil leaks around the important seals, crankshaft etc. If viscosity was lost I'd expect the seals to be the first thing to suffer.
I know of two or three 912 series engines that have been in "the lake," hauled out, dowsed in oil and then dried out and seem to work fine afterwards. Not perhaps my choice. Another thing to check after an overheat is the ceramic water pump seal. Mine dripped steadily for a while but it seems to cure itself if not too bad to start with.
By the way fuel injectors etc not affected by diesel in a 912. It's got carbs so less likely to have too much energy in the cylinders.
912 engines run on both Auto gas and Avgas, How long you had it actually running and under load with the 50/50 might have a bearing. You don't say, big circuit, long warm up etc?
Time to be blunt:
Any aircraft piston engine that has run for any length of time on diesel/jet A contaminated fuel must be disassenbled and inspected by a engine shop. To actually fly the aircraft knowing it had been run with contaminated fuel is complete and total lunacy
Any aircraft piston engine that has run for any length of time on diesel/jet A contaminated fuel must be disassenbled and inspected by a engine shop. To actually fly the aircraft knowing it had been run with contaminated fuel is complete and total lunacy
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OK, since dimona hasn't replied since his first and only post, perhaps it was a troll to spark off a discussion. A strangely technical one though, it reads like a question on a written Rotax maintenance exam...
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To actually fly the aircraft knowing it had been run with contaminated fuel is complete and total lunacy
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Accidental diesel in Rotax 912
I am grateful for this helpful reference.
I should re-assure those expressing concern that the aircraft was flown after the diesel accident, and after a change of fuel and oil, only after consultation with engineers and in view of the fact that there was, at first, no apparent damage. It was always flown within gliding distance of an airfield, which is fairly easy to achieve with a motor glider.
The engine is now awaiting a strip down and inspection.
Amongst those engineeers whom we consulted there seemed to be a general view that the short flight with a diesel/avgas mix would probably have done no harm. That still may be the view of our insurers' engineer but the views and experiences related in this forum seem to me to be nearer the mark.
I mistakenly filled my 20 lt jerry can by walking up to a 97 Octane pump but foolishly using the nozzle from the immediately adjoining diesel pump. Check and check again, as they say.
I should re-assure those expressing concern that the aircraft was flown after the diesel accident, and after a change of fuel and oil, only after consultation with engineers and in view of the fact that there was, at first, no apparent damage. It was always flown within gliding distance of an airfield, which is fairly easy to achieve with a motor glider.
The engine is now awaiting a strip down and inspection.
Amongst those engineeers whom we consulted there seemed to be a general view that the short flight with a diesel/avgas mix would probably have done no harm. That still may be the view of our insurers' engineer but the views and experiences related in this forum seem to me to be nearer the mark.
I mistakenly filled my 20 lt jerry can by walking up to a 97 Octane pump but foolishly using the nozzle from the immediately adjoining diesel pump. Check and check again, as they say.
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only after consultation with engineers and in view of the fact that there was, at first, no apparent damage
It was always flown within gliding distance of an airfield, which is fairly easy to achieve with a motor glider.
Amongst those engineeers whom we consulted there seemed to be a general view that the short flight with a diesel/avgas mix would probably have done no harm.
I mistakenly filled my 20 lt jerry can by walking up to a 97 Octane pump but foolishly using the nozzle from the immediately adjoining diesel pump. Check and check again, as they say.
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Sorry for your trouble. One circuit with a very low octane fuel , thats a lot of detonation and sounds likely to ruin the engine. But immediate loss of oil pressure? That doesn't seem to connect with a short trip; quite a lot of dilution sounds like the reason for that.
The increase in oil consumption might be due to soot fouling rings, that sounds like heads off at a minimum. You could fly at low risk in a MG over the airfield for a few flights, because if the fouling was the cause, and it subsequently burnt off, then oil consumption might return to somewhat like before. It might be worth a try based on the assumption that the safety risk and the incremental damage bill are both low?
The increase in oil consumption might be due to soot fouling rings, that sounds like heads off at a minimum. You could fly at low risk in a MG over the airfield for a few flights, because if the fouling was the cause, and it subsequently burnt off, then oil consumption might return to somewhat like before. It might be worth a try based on the assumption that the safety risk and the incremental damage bill are both low?
Not exactly related, but with respect to the effects on the engine and lubricant of high cylinder temperatures, this is the summary of one of this month's AAIB investigation reports:
Two aircraft with Jabiru 2200 engines fitted suffered similar engine failures. Both engines had achieved less than 50 hours of usage since they were manufactured. The failures were caused by high temperatures generated within the cylinders causing softening of the piston material which lead to the piston rings becoming trapped in their grooves. This allowed engine lubricating oil and/or oil vapour to enter the combustion chamber which allowed pre-ignition to occur, leading to burn-through of the piston crown. Once the burn-through was severe enough, combustion gasses entered the engine crankcase which pressurised it forcing the engine lubricating oil to be expelled overboard via the engine exhaust and crankcase breather tube. Both engines had been modified at manufacture to comply with Jabiru Service Letter JSL 002-1 titled ‘Jabiru Engine Economy Tuning’ which introduced lean burn jets into the carburettor.
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It also happened to me
Dear Forumites
Herewith an incident I had with diesel in petrol. I'm sharing this to create awareness, so here goes:
On Saturday I decided, on short notice, to fly to a meeting Outjo to Otjiwarongo (1/2hr), and from there to Tsumeb (2hrs). From the word go I was late for the meeting and had less than an hour to get my Hawk ready. I needed petrol and found my normal fuel container 3/4 full. Which was weird, because I always empty them (What doesn't fit in before a flight gets added after), but what was inside looked and smelled like unleaded, so I just added petrol at the pumps to fill them completely and off I went.
During warming up I noticed a little bit of blue smoke coming from the exhaust when looking at it against the sun. By the time I got the hangar doors closed I had already forgotten all about it. En route to Otjiwarongo I found that I burned 11.8l/h instead of the normal 11.0 @ 4,900rpm, but put it down to weird and ignored it further. The EGT's looked slightly lower than normal, but the weather was cooler so that explanation was tagged to the problem. In Otjiwarongo all was normal. I even took a friend for a short scenic flight before I departed to Tsumeb. During the pre-flight in Otjiwarongo I didn't check the oil level. How much oil can one lose in 40 minutes, right? En route I noticed that the 912 UL seemed to run slightly erratic, the revs dipped from 5,000 to 4,800 every now and then. When I applied full throttle the engine responded fast and willingly and settled back on 5,000 easily. This puzzled me, but it was turbulent and I was busy dodging rain showers, so I found another convenient explanation: Obviously the turbulence I ran into caused the motor to labour every now and then. Problem analysed and explained away.
On landing in Tsumeb I found my oil container brim-full and every drop of oil that couldn't fit into the tank (which was a lot) spread evenly over the tail feathers. After a whole day of trying to find an explanation (it isn't easy at all to explain 1.5l of oil gained during the flight) I latched onto a possible solution and traced the fuel supply. The "petrol" came from a diesel car that was wrongly filled with petrol at the pumps. The mixture was drained and stored for further use. I had actually witnessed the whole operation and was also concerned that "my aircraft fuel containers" were used for the job, but I'd mos know about it and not forget. Right.
The 912 is fine. Except for a red face, so is the pilot. The spark plugs were cleaner than I have ever seen them, it looked like a layer of coke had been loosened from the pistons. We drained and refilled both oil and fuel and changed all filters. The magnetic oil plug was clean except for a single sliver of metal. I'll have the oil analysed to check, but the Hawk behaved very well during the flight back to Outjo, which was conducted at ample altitude for a possible emergency landing.
I fly a low compression 4-stroke. With a higher compression engine like the 912 ULS the story may have ended differently, or finally. Thus to repeat my instructor's lessons:
• Don't be rushed when tending to your aircraft.
• Make sure about your fuel supply. Repeat, make *sure* about your fuel supply.
• Don't take deviances from normal lightly. My fuel consumption wasn't normal, neither were the lower EGT's and definitely not the fluctuating revs.
With that, blue skies, may you fly safer
Arthur
PS: Reading some of the posts, I may add that flying this motor without opening it up is perhaps not the best of ideas. There is, however, no evidence of any damage and my engine is fully instrumentated, so I will (more accurate, should) get ample warning before things go wrong.
Herewith an incident I had with diesel in petrol. I'm sharing this to create awareness, so here goes:
On Saturday I decided, on short notice, to fly to a meeting Outjo to Otjiwarongo (1/2hr), and from there to Tsumeb (2hrs). From the word go I was late for the meeting and had less than an hour to get my Hawk ready. I needed petrol and found my normal fuel container 3/4 full. Which was weird, because I always empty them (What doesn't fit in before a flight gets added after), but what was inside looked and smelled like unleaded, so I just added petrol at the pumps to fill them completely and off I went.
During warming up I noticed a little bit of blue smoke coming from the exhaust when looking at it against the sun. By the time I got the hangar doors closed I had already forgotten all about it. En route to Otjiwarongo I found that I burned 11.8l/h instead of the normal 11.0 @ 4,900rpm, but put it down to weird and ignored it further. The EGT's looked slightly lower than normal, but the weather was cooler so that explanation was tagged to the problem. In Otjiwarongo all was normal. I even took a friend for a short scenic flight before I departed to Tsumeb. During the pre-flight in Otjiwarongo I didn't check the oil level. How much oil can one lose in 40 minutes, right? En route I noticed that the 912 UL seemed to run slightly erratic, the revs dipped from 5,000 to 4,800 every now and then. When I applied full throttle the engine responded fast and willingly and settled back on 5,000 easily. This puzzled me, but it was turbulent and I was busy dodging rain showers, so I found another convenient explanation: Obviously the turbulence I ran into caused the motor to labour every now and then. Problem analysed and explained away.
On landing in Tsumeb I found my oil container brim-full and every drop of oil that couldn't fit into the tank (which was a lot) spread evenly over the tail feathers. After a whole day of trying to find an explanation (it isn't easy at all to explain 1.5l of oil gained during the flight) I latched onto a possible solution and traced the fuel supply. The "petrol" came from a diesel car that was wrongly filled with petrol at the pumps. The mixture was drained and stored for further use. I had actually witnessed the whole operation and was also concerned that "my aircraft fuel containers" were used for the job, but I'd mos know about it and not forget. Right.
The 912 is fine. Except for a red face, so is the pilot. The spark plugs were cleaner than I have ever seen them, it looked like a layer of coke had been loosened from the pistons. We drained and refilled both oil and fuel and changed all filters. The magnetic oil plug was clean except for a single sliver of metal. I'll have the oil analysed to check, but the Hawk behaved very well during the flight back to Outjo, which was conducted at ample altitude for a possible emergency landing.
I fly a low compression 4-stroke. With a higher compression engine like the 912 ULS the story may have ended differently, or finally. Thus to repeat my instructor's lessons:
• Don't be rushed when tending to your aircraft.
• Make sure about your fuel supply. Repeat, make *sure* about your fuel supply.
• Don't take deviances from normal lightly. My fuel consumption wasn't normal, neither were the lower EGT's and definitely not the fluctuating revs.
With that, blue skies, may you fly safer
Arthur
PS: Reading some of the posts, I may add that flying this motor without opening it up is perhaps not the best of ideas. There is, however, no evidence of any damage and my engine is fully instrumentated, so I will (more accurate, should) get ample warning before things go wrong.
I've been fortunate during my life not to have mistakenly put the wrong fuel in a tank. I don't feel particularly virtuous about that, just thankful really.
In the interests of contributing a bit of useless information that may amuse some and lighten the serious tone I thought I might mention a time when I did put kerosine in a [normally] petrol powered vehicle.
This was back in the 1980's when, here downunder, the Govt raised the price of petrol dramatically but omitted to do the same to kerosine for whatever reason. IIRC the cost difference was around 50% or more for petrol, but kerosine was available at the pump - predominantly for home heating purposes I guess.
I was running a particularly economic SII Landrover at the time; at around 11mpg in 2wd and somewhat less in 4wd on the paddocks I was keen to seek an alternative method of running it.
This particular LR had a 7:1 compression ratio and I figured it should run on kero, or at least a mix of kero/petrol. There was some thought I might have to start it on petrol and switch to kero but I shrugged my shoulders and just gave it a go.
Over the year or so I tried this I don't think I ever ran it on 100% kero, rather there was a variable ratio to the mix as I occasionally felt guilty or concerned about what was really happening to the motor. In the end nothing seemed to happen, possibly there was a bit of mild black smoke but that's about all I recall. Certainly it started reasonably well and didn't seem to suffer in performance much, mind you it was hardly a high-performance machine to begin with.
I later sold the LR to an acquaintance, I never heard that he had any problems with the motor [of course one _always_ had trouble with the drivetrain, but that's another story].
These days kero is considerably more expensive, and most of my vehicles are somewhat higher compression, and so I've never tried it again. It might be that the odd one may run well on AVGAS but I couldn't possibly comment
FP
In the interests of contributing a bit of useless information that may amuse some and lighten the serious tone I thought I might mention a time when I did put kerosine in a [normally] petrol powered vehicle.
This was back in the 1980's when, here downunder, the Govt raised the price of petrol dramatically but omitted to do the same to kerosine for whatever reason. IIRC the cost difference was around 50% or more for petrol, but kerosine was available at the pump - predominantly for home heating purposes I guess.
I was running a particularly economic SII Landrover at the time; at around 11mpg in 2wd and somewhat less in 4wd on the paddocks I was keen to seek an alternative method of running it.
This particular LR had a 7:1 compression ratio and I figured it should run on kero, or at least a mix of kero/petrol. There was some thought I might have to start it on petrol and switch to kero but I shrugged my shoulders and just gave it a go.
Over the year or so I tried this I don't think I ever ran it on 100% kero, rather there was a variable ratio to the mix as I occasionally felt guilty or concerned about what was really happening to the motor. In the end nothing seemed to happen, possibly there was a bit of mild black smoke but that's about all I recall. Certainly it started reasonably well and didn't seem to suffer in performance much, mind you it was hardly a high-performance machine to begin with.
I later sold the LR to an acquaintance, I never heard that he had any problems with the motor [of course one _always_ had trouble with the drivetrain, but that's another story].
These days kero is considerably more expensive, and most of my vehicles are somewhat higher compression, and so I've never tried it again. It might be that the odd one may run well on AVGAS but I couldn't possibly comment
FP
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FP - Many tractors and industrial engines were designed to run on either petrol (gasoline) or kerosene in the 1920's to 1950's.
However, the industrial-use kerosene available back then was known as "Power Kerosene", which consisted of a different formula to "Lighting Kerosene", due to a different refining technique.
"Lighting Kerosene" contains a much lower level of highly volatile ingredients, to reduce the risk of explosions when used for cooking or lighting (as in "Hurricane" lanterns).
Power Kerosene is no longer produced, because there is no longer any demand for it. The closest product to Power Kerosene today, is "bitumen cutter" (asphalt thinner), which produces "cutback bitumen" (which is thinned asphalt, for spraying purposes).
A special manifold with substantial preheating design inbuilt, is required to run on kerosene, as kerosene will not light off when cold.
Usually tractors and engines were started on petrol then turned over to kerosene once the engine reached operating temperature.
There are substantial amounts of unburned fuel going past the pistons and rings in any spark ignition engine running on kerosene-type fuels - leading to substantially increased crankcase oil dilution - not to mention increased ring-gumming potential, caused by high levels of carbon and other hydrocarbons in kerosene-type fuels.
Gummed rings fouled by carbon buildup will naturally lower compression - and also increase the amount of piston ring blow-by of unburnt fuel and hydrocarbon contaminants.
As I previously stated, diesel oils are extremely high detergency, to handle the increased oil contaminant load. Running a petrol/kero engine on kerosene requires reduced oil change times.
The savage attack on the OP as to his unfitness to hold a pilots licence is probably a little over-the-top - but the above incorrect refuelling exercises do hammer home a particularly crucial point - that you must be exceptionally diligent about the quality, cleanliness, and grade of fuel you put in any aircraft fuel tank - because, basically, your life (and any pax lives) largely depends on your diligence, if you wish to take to the skies.
However, the industrial-use kerosene available back then was known as "Power Kerosene", which consisted of a different formula to "Lighting Kerosene", due to a different refining technique.
"Lighting Kerosene" contains a much lower level of highly volatile ingredients, to reduce the risk of explosions when used for cooking or lighting (as in "Hurricane" lanterns).
Power Kerosene is no longer produced, because there is no longer any demand for it. The closest product to Power Kerosene today, is "bitumen cutter" (asphalt thinner), which produces "cutback bitumen" (which is thinned asphalt, for spraying purposes).
A special manifold with substantial preheating design inbuilt, is required to run on kerosene, as kerosene will not light off when cold.
Usually tractors and engines were started on petrol then turned over to kerosene once the engine reached operating temperature.
There are substantial amounts of unburned fuel going past the pistons and rings in any spark ignition engine running on kerosene-type fuels - leading to substantially increased crankcase oil dilution - not to mention increased ring-gumming potential, caused by high levels of carbon and other hydrocarbons in kerosene-type fuels.
Gummed rings fouled by carbon buildup will naturally lower compression - and also increase the amount of piston ring blow-by of unburnt fuel and hydrocarbon contaminants.
As I previously stated, diesel oils are extremely high detergency, to handle the increased oil contaminant load. Running a petrol/kero engine on kerosene requires reduced oil change times.
The savage attack on the OP as to his unfitness to hold a pilots licence is probably a little over-the-top - but the above incorrect refuelling exercises do hammer home a particularly crucial point - that you must be exceptionally diligent about the quality, cleanliness, and grade of fuel you put in any aircraft fuel tank - because, basically, your life (and any pax lives) largely depends on your diligence, if you wish to take to the skies.
Last edited by onetrack; 11th Apr 2014 at 07:32. Reason: clarification ...
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One track, good post, which shines above many of the more jingoistic ones prior to yours. Insulting the OP in the way that some have, because of a human error, is unjustified in my book and says more about them than the OP.
Power kerosene was probably very similar to what was known as "tractor vapourising oil", or TVO, here in UK, which is probably no longer available. I understand it was "cut" somewhere between petrol and paraffin. I was privileged (!) to learn to drive on a little grey Ferguson tractor which ran on it, it had a compartmentalised tank for petrol and TVO and a changeover fuel tap. I loved the smell of it when running on TVO. I also learned not to touch HT leads while the engine is running in the rain, but that's a different story.
Power kerosene was probably very similar to what was known as "tractor vapourising oil", or TVO, here in UK, which is probably no longer available. I understand it was "cut" somewhere between petrol and paraffin. I was privileged (!) to learn to drive on a little grey Ferguson tractor which ran on it, it had a compartmentalised tank for petrol and TVO and a changeover fuel tap. I loved the smell of it when running on TVO. I also learned not to touch HT leads while the engine is running in the rain, but that's a different story.
Contaminated bulk fuel caused this DC4 accident almost exactly 40 years ago:
https://www.google.co.uk/url?sa=t&rc...,d.ZGU&cad=rjt
It only managed to stayed in the air for six minutes after take-off on the mixture of avgas and jet fuel..
https://www.google.co.uk/url?sa=t&rc...,d.ZGU&cad=rjt
It only managed to stayed in the air for six minutes after take-off on the mixture of avgas and jet fuel..