Fuel Dilution "Burn-Off"
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Originally Posted By: Jetronic
Originally Posted By: Ducked
Originally Posted By: SonofJoe
I half joked about Honda bolting a 'mini steam stripper' on to their fuel dilution prone engines. Realistically this would be impractical. You would keep a separate distilled water reservoir, have a HP steam generator, a condenser, a fuel/water separator, etc, etc. Too bulky, too costly, not going to happen, ever.
Most of these requirements (and the fuel dilution problem itself) seem to be mitigatable by running at a higher temperature. Other than "safety margin" I'm puzzling to come up with a reason why the coolant and oil isn't run hotter.
Perhaps you'd need higher viscosity oil which would make preheating necessary for cold starts?
Specifically:-
Separate distilled water reservoir doesn't seem like too big a deal, depending on your location. Aircon condensate is available for free in huge quantities and is essentially distilled water. Such a system wouldn't necessarily have to operate continuously so a limited capacity might be acceptable.
An HP steam generator doesn't seem like too big a deal either. IF the coolant was running at, say 120C, which should be achievable with current systems, a separate coolant-heated boiler at a lower pressure could produce steam at say 110C. IF the sump oil was over 100 this steam would not condense in it. Higher pressure rad caps are available which implies there must be some scope to increase pressures on standard systems, though large increases would presumably require a stronger (and therefore heavier) system.
A condenser/fuel water separator seems potentially optional, since you can probably just burn the steam and stripped hydrocarbons in the engine (as is done with blowby currently).
A condenser might be necessary for water recovery for continuous operation, but continuous operation might not be required.
If the stripping increases oil carry over and intake tract coking (which the steam might be expected to somewhat mitigate), you could have a catch can/fuel/water separator arrangement, but then you have an environmental disposal problem.
The main problem for running a total loss system would be convincing the punter to top it up. I believe that's largely what killed the mass-market water injection on the 1962 Oldsmobile F-85 turbo.
Originally Posted By: SonofJoe
You obviously couldn't put the entire sump under vacuum.
Er...my entire sump is under vacuum, and I think this is normal.
I think you generally only get positive crankcase pressure at high power/boost levels when the blowby exceeds the capacity of the crankcase ventilation system.
Your description sounds, at least qualitatively, like normal operation, except for the gassing of the (presumably bulk sump oil) with air or blowby, which AFAIK is not done, though I think the oil spray is in effect purged in this way.
Perhaps its a question of degree, and you propose enhancing the vacuum or increasing the capacity of the crankcase ventilation system?
I suppose you could also increase the amount of oil fling, which might be simpler than pumping gas through the bulk oil. Either way you'd have to be sure to avoid foam.
exhaust gas is hotter than 120°C by a big margin. and available in large quantities...
You could easily use it for generating steam, but I think that might be more appropriate for promoting early engine heat-up via a heat exchanger. I've been thinking of improvising something like that for years so I probably won't ever get around to it.
Using enhanced coolant heat to generate steam for direct oil-cleaning has the advantage that it won't do it until the engine is good and hot, so its to some extent self-protecting. Obviously you don't want to be putting steam into cold oil.
Originally Posted By: Ducked
Originally Posted By: SonofJoe
I half joked about Honda bolting a 'mini steam stripper' on to their fuel dilution prone engines. Realistically this would be impractical. You would keep a separate distilled water reservoir, have a HP steam generator, a condenser, a fuel/water separator, etc, etc. Too bulky, too costly, not going to happen, ever.
Most of these requirements (and the fuel dilution problem itself) seem to be mitigatable by running at a higher temperature. Other than "safety margin" I'm puzzling to come up with a reason why the coolant and oil isn't run hotter.
Perhaps you'd need higher viscosity oil which would make preheating necessary for cold starts?
Specifically:-
Separate distilled water reservoir doesn't seem like too big a deal, depending on your location. Aircon condensate is available for free in huge quantities and is essentially distilled water. Such a system wouldn't necessarily have to operate continuously so a limited capacity might be acceptable.
An HP steam generator doesn't seem like too big a deal either. IF the coolant was running at, say 120C, which should be achievable with current systems, a separate coolant-heated boiler at a lower pressure could produce steam at say 110C. IF the sump oil was over 100 this steam would not condense in it. Higher pressure rad caps are available which implies there must be some scope to increase pressures on standard systems, though large increases would presumably require a stronger (and therefore heavier) system.
A condenser/fuel water separator seems potentially optional, since you can probably just burn the steam and stripped hydrocarbons in the engine (as is done with blowby currently).
A condenser might be necessary for water recovery for continuous operation, but continuous operation might not be required.
If the stripping increases oil carry over and intake tract coking (which the steam might be expected to somewhat mitigate), you could have a catch can/fuel/water separator arrangement, but then you have an environmental disposal problem.
The main problem for running a total loss system would be convincing the punter to top it up. I believe that's largely what killed the mass-market water injection on the 1962 Oldsmobile F-85 turbo.
Originally Posted By: SonofJoe
You obviously couldn't put the entire sump under vacuum.
Er...my entire sump is under vacuum, and I think this is normal.
I think you generally only get positive crankcase pressure at high power/boost levels when the blowby exceeds the capacity of the crankcase ventilation system.
Your description sounds, at least qualitatively, like normal operation, except for the gassing of the (presumably bulk sump oil) with air or blowby, which AFAIK is not done, though I think the oil spray is in effect purged in this way.
Perhaps its a question of degree, and you propose enhancing the vacuum or increasing the capacity of the crankcase ventilation system?
I suppose you could also increase the amount of oil fling, which might be simpler than pumping gas through the bulk oil. Either way you'd have to be sure to avoid foam.
exhaust gas is hotter than 120°C by a big margin. and available in large quantities...
You could easily use it for generating steam, but I think that might be more appropriate for promoting early engine heat-up via a heat exchanger. I've been thinking of improvising something like that for years so I probably won't ever get around to it.
Using enhanced coolant heat to generate steam for direct oil-cleaning has the advantage that it won't do it until the engine is good and hot, so its to some extent self-protecting. Obviously you don't want to be putting steam into cold oil.
Ducked,
In answer to your many questions...
I still don't see the mini steam stripper as a viable option. For me, it dies from one of two things. If you condense the steam/fuel strip-out and separate the two immiscible phases (which would be normal), then what do you do with all that foul water? If you don't condense the steam/fuel strip-out and direct the entire flow to the intake system, then you do one of two things. First you risk changing the dynamics of the whole intake gas flow. Water is 'funny stuff' compared to virtually all hydrocarbons in that for a given weight, it expands to a far greater volume. Given that gas flow rates are so critical to tumble and swirl, I can only see change as being negative. The other scenario is that the vapourised steam/fuel strip-out hits the cold air in the intake system and instantly condenses to create fast moving stream of water & fuel droplets. Might these erode the top of the inlet valves and valve seats? I don't know but I suspect they could.
Regarding the vacuum thing. Is your crankcase really operating at that much vacuum? I sort of doubt it. If the crankcase is sealed, then the natural order of things is for the blow-by to over-pressure the crankcase. As well as doing other things, the PCV system exists to prevent this over-pressurisation by linking the crankcase to the vacuum side of the air intake system. At idle, the vacuum is very high. Unchecked, the high intake vacuum would impose a negative pressure on the entire crankcase, increase blow-by and suck great gobs of oil mist into the air intake. To stop this, you have a very cleverly designed PCV valve which tends to close when the intake vacuum is at its highest. This restricts flow and imposes a high pressure drop between the crankcase and intake. As load is put on the engine, the intake vacuum drops off and the PCV valve opens up more to allow the naturally higher level of blow-by gas to pass through it. I'd always assumed that if everything is working correctly, then the aggregate pressure in the crankcase would be more or less atmospheric pressure across the normal operating range of the engine.
If you were to think of designing a vacuum stripper to remove fuel from oil, then you would have to avoid putting the entire crankcase under vacuum. That's why I talked about isolating part of the oil and then exposing it to full intake vacuum. The system would need to be very careful designed. The oil would need to be hot enough to allow the oil to boil off the fuel (vacuuming cold oil is probably useless) but you don't want vacuum to be so high that you start pulling substantial parts of the engine oil into the vapour phase as this would cause all sorts of downstream problems. I still however think that a simple, cheap, fuel/oil vacuum stripper for GDI engines should not be beyond the wit of man and might solve a multitude of problems, including potentially LSPI.
In answer to your many questions...
I still don't see the mini steam stripper as a viable option. For me, it dies from one of two things. If you condense the steam/fuel strip-out and separate the two immiscible phases (which would be normal), then what do you do with all that foul water? If you don't condense the steam/fuel strip-out and direct the entire flow to the intake system, then you do one of two things. First you risk changing the dynamics of the whole intake gas flow. Water is 'funny stuff' compared to virtually all hydrocarbons in that for a given weight, it expands to a far greater volume. Given that gas flow rates are so critical to tumble and swirl, I can only see change as being negative. The other scenario is that the vapourised steam/fuel strip-out hits the cold air in the intake system and instantly condenses to create fast moving stream of water & fuel droplets. Might these erode the top of the inlet valves and valve seats? I don't know but I suspect they could.
Regarding the vacuum thing. Is your crankcase really operating at that much vacuum? I sort of doubt it. If the crankcase is sealed, then the natural order of things is for the blow-by to over-pressure the crankcase. As well as doing other things, the PCV system exists to prevent this over-pressurisation by linking the crankcase to the vacuum side of the air intake system. At idle, the vacuum is very high. Unchecked, the high intake vacuum would impose a negative pressure on the entire crankcase, increase blow-by and suck great gobs of oil mist into the air intake. To stop this, you have a very cleverly designed PCV valve which tends to close when the intake vacuum is at its highest. This restricts flow and imposes a high pressure drop between the crankcase and intake. As load is put on the engine, the intake vacuum drops off and the PCV valve opens up more to allow the naturally higher level of blow-by gas to pass through it. I'd always assumed that if everything is working correctly, then the aggregate pressure in the crankcase would be more or less atmospheric pressure across the normal operating range of the engine.
If you were to think of designing a vacuum stripper to remove fuel from oil, then you would have to avoid putting the entire crankcase under vacuum. That's why I talked about isolating part of the oil and then exposing it to full intake vacuum. The system would need to be very careful designed. The oil would need to be hot enough to allow the oil to boil off the fuel (vacuuming cold oil is probably useless) but you don't want vacuum to be so high that you start pulling substantial parts of the engine oil into the vapour phase as this would cause all sorts of downstream problems. I still however think that a simple, cheap, fuel/oil vacuum stripper for GDI engines should not be beyond the wit of man and might solve a multitude of problems, including potentially LSPI.
Last edited:
Originally Posted By: SonofJoe
Ducked,
In answer to your many questions...
Ahem. I asked some questions earlier because I didn't/don't intuitively understand oil carry-over by fuel.
This bit was mostly statements, though you may well be correct to disagree with them.
Originally Posted By: SonofJoe
If you condense the steam/fuel strip-out and separate the two immiscible phases (which would be normal), then what do you do with all that foul water?
Yeh, I said that was a problem (twice, IIRC), and gave it as one reason for running a total loss system.
Originally Posted By: SonofJoe
If you don't condense the steam/fuel strip-out and direct the entire flow to the intake system, then you do one of two things. First you risk changing the dynamics of the whole intake gas flow. Water is 'funny stuff' compared to virtually all hydrocarbons in that for a given weight, it expands to a far greater volume. Given that gas flow rates are so critical to tumble and swirl, I can only see change as being negative.
You'd clealy have to limit/control the water delivery, (and the available quantity will be limited anyway) but "I can only see change as negative" seems to ignore the fact that water injection has known real benefits. Our imaginary system won't be optimised for those benefits, but they do demonstrate that water is not inevitably negative in its effects.
Originally Posted By: SonofJoe
The other scenario is that the vapourised steam/fuel strip-out hits the cold air in the intake system and instantly condenses to create fast moving stream of water & fuel droplets. Might these erode the top of the inlet valves and valve seats? I don't know but I suspect they could.
Well, again, water injection is a partial precedent here, and as I said above, the experience with direct injection engines is that they get coked up with blowby condensate, so a bit of erosion might not be a bad thing. I doubt the water will cure the coking problem completely, but it might help.
As I said, I think the real killer of any such system is not the cost, but that it would complicate the ownership experience (because they'd have to put water in it) and that is never going to be commercially acceptable. Commercial experience with water injection systems again provide a comparable example.
Originally Posted By: SonofJoe
Regarding the vacuum thing. Is your crankcase really operating at that much vacuum? I sort of doubt it.
What much vacuum? I didn't give a level, and I've never measured it. Suppose I should, but my understanding was that in general old-fashioned throttle controlled petrol cars tended to maintain the crankcase at negative pressures. If you mean it isn't exposed to FULL engine vacuum at idle, then you are probably right, but I didn't say it was.
I tried to find some examples of typical crankcase pressures a long while ago for something else. Here they are, though I don't know if the links are still live.
Its quite hard to get figures for “normal” petrol-engined cars, especially bangers.
This thread goes into “How to test the BMW E39 pressure-controlled crankcase ventilation system (CCV)?” in rather obsessive detail
http://www.bimmerfest.com/forums/showthread.php?p=5989795
That’s of course a rather different car and system to mine, but 4WIW
“A properly functioning pressure control valve is designed to maintain a slight vacuum (approximately 10 - 15 mbar ) in the crankcase which assures reliable crankcase venting during all engine operating conditions.”
This at least seems to establish the general principle. (which is the opposite of that stated in the Detroit Diesel link below)
A few pages down, actual readings are reported for an M62tu engine
“Eng Temp-----RPM---------Vacuum in inches [of water]
Cold-----------1300--------4.64" (at startup, Sec air pump running)
54°C------------600--------3.61" (Sec air pump just stopped)
70°C------------550--------3.58"
80°C------------500--------3.37"
93°C------------500--------3.32"
102°C-----------500--------3.29"
108°C-----------500--------3.28"
If the engine was held (1500-4000 RPM) the vacuum was 2.92"
The RPM didn't matter.”
I'm not sure my system has any control valve, the crankcase seems to simply connect to the air cleaner via a baffle. I might be wrong about that though.
This guy
http://www.eng-tips.com/viewthread.cfm?qid=304717
reports on a 1971 Triumph 2.5 litre saloon (nice shape, IIRC) which is arguably a more comparable level of (lack of) technology.
He was getting - 6psi (i.e below atmospheric) at idle, and -1 to 2 psi at 80 mph. Above that no reading, but he apparently couldn’t read positive pressures on his gauge, so it’s a fair bet it went + flat out.
He was testing a second DIY breather that he’d added, so perhaps a stock system would go positive earlier. OTOH, he did suggest that Triumph used a one-size fits all system which was under-capacity for the 2.5L.
In high performance (especially turbo’d) engines, blowby, piston pumping and heating all increase and may cause crankcase pressurization, to the point that some racers apparently fit vacuum pumps to their sumps (?). I suppose the higher compression of diesels might also result in more blowby.
http://speedtalk.com/forum/viewtopic.php...tart=15#p260224
At least some diesels (not throttle controlled, of course) seem to be different.
http://constructioncranes.tpub.com/TM-5-3810-293-14-P-3/TM-5-3810-293-14-P-30119.htm
I found some specs for some Detroit Diesel engines which seem to max out (as in, reach the limit of acceptability) at 1” of water at 28000 rpm.
They suggest that “A slight pressure in the crankcase is desirable to prevent the entrance of dust.”
This implies (though it doesn’t actually say) that slightly positive pressures are “normal”.
However, according to Racor, who make crankcase ventilation systems (surprisingly, emission control of diesel crankcase vapours apparently wasn’t required in the US until 2007) at least some diesels may be at negative crankcase pressure during normal operation.
http://www.parker.com/literature/Racor/7678%20(CCV%20Technical%20Brochure).pdf
“The third integrated feature of the CCV is the pressure regulation valve. It balances the pressure in the crankcase, protecting it from the high vacuum created by a dirty air filter and todays high mass flow turbocharged compressors. Our pressure regulation valves monitor crankcase pressure ensuring that it maintains a range of -4 to +4 inches of water ”
There are various graphs showing crankcase pressure against turbo restriction, inlet pressure, etc. They are mostly negative, and the implication seems to be that, without the Racor system, they would be more so.
Ducked,
In answer to your many questions...
Ahem. I asked some questions earlier because I didn't/don't intuitively understand oil carry-over by fuel.
This bit was mostly statements, though you may well be correct to disagree with them.
Originally Posted By: SonofJoe
If you condense the steam/fuel strip-out and separate the two immiscible phases (which would be normal), then what do you do with all that foul water?
Yeh, I said that was a problem (twice, IIRC), and gave it as one reason for running a total loss system.
Originally Posted By: SonofJoe
If you don't condense the steam/fuel strip-out and direct the entire flow to the intake system, then you do one of two things. First you risk changing the dynamics of the whole intake gas flow. Water is 'funny stuff' compared to virtually all hydrocarbons in that for a given weight, it expands to a far greater volume. Given that gas flow rates are so critical to tumble and swirl, I can only see change as being negative.
You'd clealy have to limit/control the water delivery, (and the available quantity will be limited anyway) but "I can only see change as negative" seems to ignore the fact that water injection has known real benefits. Our imaginary system won't be optimised for those benefits, but they do demonstrate that water is not inevitably negative in its effects.
Originally Posted By: SonofJoe
The other scenario is that the vapourised steam/fuel strip-out hits the cold air in the intake system and instantly condenses to create fast moving stream of water & fuel droplets. Might these erode the top of the inlet valves and valve seats? I don't know but I suspect they could.
Well, again, water injection is a partial precedent here, and as I said above, the experience with direct injection engines is that they get coked up with blowby condensate, so a bit of erosion might not be a bad thing. I doubt the water will cure the coking problem completely, but it might help.
As I said, I think the real killer of any such system is not the cost, but that it would complicate the ownership experience (because they'd have to put water in it) and that is never going to be commercially acceptable. Commercial experience with water injection systems again provide a comparable example.
Originally Posted By: SonofJoe
Regarding the vacuum thing. Is your crankcase really operating at that much vacuum? I sort of doubt it.
What much vacuum? I didn't give a level, and I've never measured it. Suppose I should, but my understanding was that in general old-fashioned throttle controlled petrol cars tended to maintain the crankcase at negative pressures. If you mean it isn't exposed to FULL engine vacuum at idle, then you are probably right, but I didn't say it was.
I tried to find some examples of typical crankcase pressures a long while ago for something else. Here they are, though I don't know if the links are still live.
Its quite hard to get figures for “normal” petrol-engined cars, especially bangers.
This thread goes into “How to test the BMW E39 pressure-controlled crankcase ventilation system (CCV)?” in rather obsessive detail
http://www.bimmerfest.com/forums/showthread.php?p=5989795
That’s of course a rather different car and system to mine, but 4WIW
“A properly functioning pressure control valve is designed to maintain a slight vacuum (approximately 10 - 15 mbar ) in the crankcase which assures reliable crankcase venting during all engine operating conditions.”
This at least seems to establish the general principle. (which is the opposite of that stated in the Detroit Diesel link below)
A few pages down, actual readings are reported for an M62tu engine
“Eng Temp-----RPM---------Vacuum in inches [of water]
Cold-----------1300--------4.64" (at startup, Sec air pump running)
54°C------------600--------3.61" (Sec air pump just stopped)
70°C------------550--------3.58"
80°C------------500--------3.37"
93°C------------500--------3.32"
102°C-----------500--------3.29"
108°C-----------500--------3.28"
If the engine was held (1500-4000 RPM) the vacuum was 2.92"
The RPM didn't matter.”
I'm not sure my system has any control valve, the crankcase seems to simply connect to the air cleaner via a baffle. I might be wrong about that though.
This guy
http://www.eng-tips.com/viewthread.cfm?qid=304717
reports on a 1971 Triumph 2.5 litre saloon (nice shape, IIRC) which is arguably a more comparable level of (lack of) technology.
He was getting - 6psi (i.e below atmospheric) at idle, and -1 to 2 psi at 80 mph. Above that no reading, but he apparently couldn’t read positive pressures on his gauge, so it’s a fair bet it went + flat out.
He was testing a second DIY breather that he’d added, so perhaps a stock system would go positive earlier. OTOH, he did suggest that Triumph used a one-size fits all system which was under-capacity for the 2.5L.
In high performance (especially turbo’d) engines, blowby, piston pumping and heating all increase and may cause crankcase pressurization, to the point that some racers apparently fit vacuum pumps to their sumps (?). I suppose the higher compression of diesels might also result in more blowby.
http://speedtalk.com/forum/viewtopic.php...tart=15#p260224
At least some diesels (not throttle controlled, of course) seem to be different.
http://constructioncranes.tpub.com/TM-5-3810-293-14-P-3/TM-5-3810-293-14-P-30119.htm
I found some specs for some Detroit Diesel engines which seem to max out (as in, reach the limit of acceptability) at 1” of water at 28000 rpm.
They suggest that “A slight pressure in the crankcase is desirable to prevent the entrance of dust.”
This implies (though it doesn’t actually say) that slightly positive pressures are “normal”.
However, according to Racor, who make crankcase ventilation systems (surprisingly, emission control of diesel crankcase vapours apparently wasn’t required in the US until 2007) at least some diesels may be at negative crankcase pressure during normal operation.
http://www.parker.com/literature/Racor/7678%20(CCV%20Technical%20Brochure).pdf
“The third integrated feature of the CCV is the pressure regulation valve. It balances the pressure in the crankcase, protecting it from the high vacuum created by a dirty air filter and todays high mass flow turbocharged compressors. Our pressure regulation valves monitor crankcase pressure ensuring that it maintains a range of -4 to +4 inches of water ”
There are various graphs showing crankcase pressure against turbo restriction, inlet pressure, etc. They are mostly negative, and the implication seems to be that, without the Racor system, they would be more so.
I think it's safe to say that conventional PCV systems of engines in good condition maintain very slightly below atmospheric crankcase pressure normally, perhaps slightly positive under heavy load or if blowby is excessive due to wear, etc.
Originally Posted By: CR94
I think it's safe to say that conventional PCV systems of engines in good condition maintain very slightly below atmospheric crankcase pressure normally, perhaps slightly positive under heavy load or if blowby is excessive due to wear, etc.
Thanks. I felt pretty safe saying it.
I felt a bit less safe saying that my engine sees higher levels of vacuum, but I suspect that might be the case, since I can't see a conventional PCV on it.
I think it's safe to say that conventional PCV systems of engines in good condition maintain very slightly below atmospheric crankcase pressure normally, perhaps slightly positive under heavy load or if blowby is excessive due to wear, etc.
Thanks. I felt pretty safe saying it.
I felt a bit less safe saying that my engine sees higher levels of vacuum, but I suspect that might be the case, since I can't see a conventional PCV on it.
Originally Posted By: Ducked
Originally Posted By: SonofJoe
The other scenario is that the vapourised steam/fuel strip-out hits the cold air in the intake system and instantly condenses to create fast moving stream of water & fuel droplets. Might these erode the top of the inlet valves and valve seats? I don't know but I suspect they could.
Well, again, water injection is a partial precedent here, and as I said above, the experience with direct injection engines is that they get coked up with blowby condensate, so a bit of erosion might not be a bad thing. I doubt the water will cure the coking problem completely, but it might help.
Further reassurance on this point might come from the accumulated experience with fuel droplets hitting inlet valves and valve seats, since that is how fuel has got into non-direct-injection engines since the beginning of time.
Originally Posted By: SonofJoe
The other scenario is that the vapourised steam/fuel strip-out hits the cold air in the intake system and instantly condenses to create fast moving stream of water & fuel droplets. Might these erode the top of the inlet valves and valve seats? I don't know but I suspect they could.
Well, again, water injection is a partial precedent here, and as I said above, the experience with direct injection engines is that they get coked up with blowby condensate, so a bit of erosion might not be a bad thing. I doubt the water will cure the coking problem completely, but it might help.
Further reassurance on this point might come from the accumulated experience with fuel droplets hitting inlet valves and valve seats, since that is how fuel has got into non-direct-injection engines since the beginning of time.
https://www.hondarandd.jp/point.php?sid=41&pid=1027&did=1027&lang=en
Simulation of Oil Separating Behavior for Engine Breather System
is a paper I referenced here some time ago.
the old days of taking off the walking stick breather and plugging in a PCV and maybe putting in a baffle are long long gone
Simulation of Oil Separating Behavior for Engine Breather System
is a paper I referenced here some time ago.
the old days of taking off the walking stick breather and plugging in a PCV and maybe putting in a baffle are long long gone
Originally Posted By: Shannow
the old days of taking off the walking stick breather and plugging in a PCV and maybe putting in a baffle are long long gone
Probably depends how old your car is. In my case I suspect they have not yet arrived.
the old days of taking off the walking stick breather and plugging in a PCV and maybe putting in a baffle are long long gone
Probably depends how old your car is. In my case I suspect they have not yet arrived.
Originally Posted By: Shannow
https://www.hondarandd.jp/point.php?sid=41&pid=1027&did=1027&lang=en
Simulation of Oil Separating Behavior for Engine Breather System
is a paper I referenced here some time ago.
the old days of taking off the walking stick breather and plugging in a PCV and maybe putting in a baffle are long long gone
Will look forward to reading this as soon as Honda send me my registration e.mail. I wouldn't be surprised if the engineers at Honda studied this in great detail and still managed to get it wrong!
https://www.hondarandd.jp/point.php?sid=41&pid=1027&did=1027&lang=en
Simulation of Oil Separating Behavior for Engine Breather System
is a paper I referenced here some time ago.
the old days of taking off the walking stick breather and plugging in a PCV and maybe putting in a baffle are long long gone
Will look forward to reading this as soon as Honda send me my registration e.mail. I wouldn't be surprised if the engineers at Honda studied this in great detail and still managed to get it wrong!
OCI's are a pain on this new Civic, they have the oil pan covered with a skid plate that has eight fasteners with two different type heads?? when it's 0F and the dip stick is a qt. over full the oil dump is no fun..crazy dip stick tube is too narrow and elongated so the mity vac extraction tube won't reach the sump, not even close.
Went to the hardware store looking to modify the 1/4" extraction tube diameter and found success, a 5/32" brass pipe slips tite inside then placed it in a vice to elongate similar to the dipstick..was able to extract 3.5qt. of a 3.75 w/filter capacity, so that's almost all of the oil. managing the fouled lubricant just became a whole lot easier for me.
Went to the hardware store looking to modify the 1/4" extraction tube diameter and found success, a 5/32" brass pipe slips tite inside then placed it in a vice to elongate similar to the dipstick..was able to extract 3.5qt. of a 3.75 w/filter capacity, so that's almost all of the oil. managing the fouled lubricant just became a whole lot easier for me.
Originally Posted By: Shannow
Enjoy that site, there's lots of great stuff, including their assessments of the future of the oils that became labelled as the 16 grades.
Thanks for the link, Shannow. This site also contains an article about the development of the engine in my CRV (K24W). Included in the article is a discussion about 3 fuel injector spray pattern alternatives: Honda chose the pattern that resulted in the lowest cylinder "wetting" and fuel dilution, but it still produced fuel dilution of 5%.
The alternative injector patterns were tested at WOT@2,500 rpm (no indication of for how long), so probably not representative of typical driving. But the important news for me is that considerable fuel dilution seems to be expected with this engine. And even if typical driving produces less, realizing that once in the sump only part of the fuel will ever leave makes my fuel dilution results seem normal if not welcome. I think I'll stop fretting and just drive the thing...
And if all the compromises that led to this result for the K24W were OK with Honda, Dblshock and other 1.5 TDGI Honda owners shouldn't be surprised to see similar results.
Enjoy that site, there's lots of great stuff, including their assessments of the future of the oils that became labelled as the 16 grades.
Thanks for the link, Shannow. This site also contains an article about the development of the engine in my CRV (K24W). Included in the article is a discussion about 3 fuel injector spray pattern alternatives: Honda chose the pattern that resulted in the lowest cylinder "wetting" and fuel dilution, but it still produced fuel dilution of 5%.
The alternative injector patterns were tested at WOT@2,500 rpm (no indication of for how long), so probably not representative of typical driving. But the important news for me is that considerable fuel dilution seems to be expected with this engine. And even if typical driving produces less, realizing that once in the sump only part of the fuel will ever leave makes my fuel dilution results seem normal if not welcome. I think I'll stop fretting and just drive the thing...
And if all the compromises that led to this result for the K24W were OK with Honda, Dblshock and other 1.5 TDGI Honda owners shouldn't be surprised to see similar results.
Originally Posted By: Danh
Originally Posted By: Shannow
Enjoy that site, there's lots of great stuff, including their assessments of the future of the oils that became labelled as the 16 grades.
Thanks for the link, Shannow. This site also contains an article about the development of the engine in my CRV (K24W). Included in the article is a discussion about 3 fuel injector spray pattern alternatives: Honda chose the pattern that resulted in the lowest cylinder "wetting" and fuel dilution, but it still produced fuel dilution of 5%.
The alternative injector patterns were tested at WOT@2,500 rpm (no indication of for how long), so probably not representative of typical driving. But the important news for me is that considerable fuel dilution seems to be expected with this engine. And even if typical driving produces less, realizing that once in the sump only part of the fuel will ever leave makes my fuel dilution results seem normal if not welcome. I think I'll stop fretting and just drive the thing...
And if all the compromises that led to this result for the K24W were OK with Honda, Dblshock and other 1.5 TDGI Honda owners shouldn't be surprised to see similar results.
o.k. so known all that Honda went ahead and spec'd 0/20 oil on 12k OCI's...they're nuts.
Originally Posted By: Shannow
Enjoy that site, there's lots of great stuff, including their assessments of the future of the oils that became labelled as the 16 grades.
Thanks for the link, Shannow. This site also contains an article about the development of the engine in my CRV (K24W). Included in the article is a discussion about 3 fuel injector spray pattern alternatives: Honda chose the pattern that resulted in the lowest cylinder "wetting" and fuel dilution, but it still produced fuel dilution of 5%.
The alternative injector patterns were tested at WOT@2,500 rpm (no indication of for how long), so probably not representative of typical driving. But the important news for me is that considerable fuel dilution seems to be expected with this engine. And even if typical driving produces less, realizing that once in the sump only part of the fuel will ever leave makes my fuel dilution results seem normal if not welcome. I think I'll stop fretting and just drive the thing...
And if all the compromises that led to this result for the K24W were OK with Honda, Dblshock and other 1.5 TDGI Honda owners shouldn't be surprised to see similar results.
o.k. so known all that Honda went ahead and spec'd 0/20 oil on 12k OCI's...they're nuts.
Sorry,but if your oil level is rising with gasoline then there is a mechanical problem. We 2.4 drivers have to use the severe service ocis (5,000)as a starting point and go down from there if necessary. Sorry for your trouble. When in Doubt...Pump it out...! JMO.
Originally Posted By: FZ1
Sorry,but if your oil level is rising with gasoline then there is a mechanical problem. We 2.4 drivers have to use the severe service ocis (5,000)as a starting point and go down from there if necessary. Sorry for your trouble. When in Doubt...Pump it out...! JMO.
No question somethings not right with that engine...
He's masking a defect with thicker oil...
Sorry,but if your oil level is rising with gasoline then there is a mechanical problem. We 2.4 drivers have to use the severe service ocis (5,000)as a starting point and go down from there if necessary. Sorry for your trouble. When in Doubt...Pump it out...! JMO.
No question somethings not right with that engine...
He's masking a defect with thicker oil...
Originally Posted By: FZ1
Sorry,but if your oil level is rising with gasoline then there is a mechanical problem. We 2.4 drivers have to use the severe service ocis (5,000)as a starting point and go down from there if necessary. Sorry for your trouble. When in Doubt...Pump it out...! JMO.
I dunno. If the engine is going to dilute the oil by design and if, at best, maybe 50% of the fuel that winds up in the crankcase will ultimately evaporate, progressively increasing fuel dilution seems inevitable. And if there's no actual oil consumption, an increase in oil level may be inevitable, too. I sure get that in my 2.4 during winter months: about 1/3 quart above full after 1,200 miles.
Looking at the Honda article, it looks like the objective was to hit a fuel economy target. Other objectives, like fuel dilution, were second or third-level priorities or afterthoughts. So while I doubt there's anything mechanical to be fixed, this sure doesn't seem like an ideal situation. And I think we Honda owners have every reason to feel duped.
Sorry,but if your oil level is rising with gasoline then there is a mechanical problem. We 2.4 drivers have to use the severe service ocis (5,000)as a starting point and go down from there if necessary. Sorry for your trouble. When in Doubt...Pump it out...! JMO.
I dunno. If the engine is going to dilute the oil by design and if, at best, maybe 50% of the fuel that winds up in the crankcase will ultimately evaporate, progressively increasing fuel dilution seems inevitable. And if there's no actual oil consumption, an increase in oil level may be inevitable, too. I sure get that in my 2.4 during winter months: about 1/3 quart above full after 1,200 miles.
Looking at the Honda article, it looks like the objective was to hit a fuel economy target. Other objectives, like fuel dilution, were second or third-level priorities or afterthoughts. So while I doubt there's anything mechanical to be fixed, this sure doesn't seem like an ideal situation. And I think we Honda owners have every reason to feel duped.
Originally Posted By: Danh
Originally Posted By: FZ1
Sorry,but if your oil level is rising with gasoline then there is a mechanical problem. We 2.4 drivers have to use the severe service ocis (5,000)as a starting point and go down from there if necessary. Sorry for your trouble. When in Doubt...Pump it out...! JMO.
I dunno. If the engine is going to dilute the oil by design and if, at best, maybe 50% of the fuel that winds up in the crankcase will ultimately evaporate, progressively increasing fuel dilution seems inevitable. And if there's no actual oil consumption, an increase in oil level may be inevitable, too. I sure get that in my 2.4 during winter months: about 1/3 quart above full after 1,200 miles.
Looking at the Honda article, it looks like the objective was to hit a fuel economy target. Other objectives, like fuel dilution, were second or third-level priorities or afterthoughts. So while I doubt there's anything mechanical to be fixed, this sure doesn't seem like an ideal situation. And I think we Honda owners have every reason to feel duped.
I think you posted this before, but have you ever had poor wear metals with any of your used oil analysis showing high levels of fuel in the oil? I know it is very concerning to see such high levels of fuel dilution, but if it doesn't seem to result in a lot of engine wear, it may not affect engine life that much.
Originally Posted By: FZ1
Sorry,but if your oil level is rising with gasoline then there is a mechanical problem. We 2.4 drivers have to use the severe service ocis (5,000)as a starting point and go down from there if necessary. Sorry for your trouble. When in Doubt...Pump it out...! JMO.
I dunno. If the engine is going to dilute the oil by design and if, at best, maybe 50% of the fuel that winds up in the crankcase will ultimately evaporate, progressively increasing fuel dilution seems inevitable. And if there's no actual oil consumption, an increase in oil level may be inevitable, too. I sure get that in my 2.4 during winter months: about 1/3 quart above full after 1,200 miles.
Looking at the Honda article, it looks like the objective was to hit a fuel economy target. Other objectives, like fuel dilution, were second or third-level priorities or afterthoughts. So while I doubt there's anything mechanical to be fixed, this sure doesn't seem like an ideal situation. And I think we Honda owners have every reason to feel duped.
I think you posted this before, but have you ever had poor wear metals with any of your used oil analysis showing high levels of fuel in the oil? I know it is very concerning to see such high levels of fuel dilution, but if it doesn't seem to result in a lot of engine wear, it may not affect engine life that much.
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