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Re: Honda Power Unit
Posted: 18 May 2017, 05:27
by wuzak
kptaylor wrote: ↑17 May 2017, 18:00
I wonder if all of this talk about Mercedes "helping" other teams is nothing more than contractual terms they signed with a supplier. Think TJI. If they spent money with a supplier to develop certain technology fully for F1 use, they may have the right to refuse to allow the supplier to work with other teams unless they formally agree. Maybe "helping" Ferrari and "helping" McLaren is nothing more than allowing a supplier to work with those teams.
I think Mercedes helped Ferrari in the same way that Red Bull helped McLaren when Peter Prodromou moved.
Re: Honda Power Unit
Posted: 18 May 2017, 08:15
by n4rf
godlameroso wrote: ↑16 May 2017, 19:23
etusch wrote: ↑16 May 2017, 17:10
There must be standart oil and fuel
From what I can gather, there is no restrictions on the oil type, there are restrictions on the fuel composition, however there is still development in the fuel. I'm curious as to what they can develop in the fuel, how do they tailor it to the combustion concept? Do they use lower or higher octane, or special anti-knock additives, or what?
It's not that simple, really. The big problem with most turbocharged engines, especially the current F1 engines, is not knocking but rather pre-ignition. The difference being that knocking occurs after the spark in the still unburned zones of the cylinder, in general after TDC, and pre-ignition occurs before the spark and before TDC. Pre-ignition is usually a much more serious problem than knocking, which can be tolerated to quite a degree, depending on the needed engine-life and piston material.
Pre-ignition is as of yet not completely understood. The process itself is much better understood than the influence of different fuel characteristics. There's some serious research going on in trying to identify something like the octane number for characterising the pre-ignition tendency of different fuels. As of now, this research has not come to a proper conclusion. This also fits to how the fuel development seems to happen at the teams. It appears to be a very iterative process, where a lot of stuff is tried. If one fuel component helps with pre-ignition, a lot of tests are run with this component. However, it is my understanding, that no one knows a priori, which component will help to what extent (general tendencies can be observed, but nothing major).
This is actually a field where there might be a direct transfer from F1 to road cars, because pre-ignition is quite relevant for highly boosted gasoline engines on the road as well. Hence the research into pre-ignition behaviour of different fuel types.
Re: Honda Power Unit
Posted: 18 May 2017, 11:21
by Tommy Cookers
the octane number of F1 fuel is unlimited
so the FIA has reverted to its position pre-1958
and revealingly, the only octane number limit is a minimum (to prevent the dieselisation of F1)
Re: Honda Power Unit
Posted: 18 May 2017, 17:57
by Anony Mous Engineerd
n4rf wrote: ↑18 May 2017, 08:15
godlameroso wrote: ↑16 May 2017, 19:23
etusch wrote: ↑16 May 2017, 17:10
There must be standart oil and fuel
From what I can gather, there is no restrictions on the oil type, there are restrictions on the fuel composition, however there is still development in the fuel. I'm curious as to what they can develop in the fuel, how do they tailor it to the combustion concept? Do they use lower or higher octane, or special anti-knock additives, or what?
It's not that simple, really. The big problem with most turbocharged engines, especially the current F1 engines, is not knocking but rather pre-ignition. The difference being that knocking occurs after the spark in the still unburned zones of the cylinder, in general after TDC, and pre-ignition occurs before the spark and before TDC. Pre-ignition is usually a much more serious problem than knocking, which can be tolerated to quite a degree, depending on the needed engine-life and piston material.
Pre-ignition is as of yet not completely understood. The process itself is much better understood than the influence of different fuel characteristics. There's some serious research going on in trying to identify something like the octane number for characterising the pre-ignition tendency of different fuels. As of now, this research has not come to a proper conclusion. This also fits to how the fuel development seems to happen at the teams. It appears to be a very iterative process, where a lot of stuff is tried. If one fuel component helps with pre-ignition, a lot of tests are run with this component. However, it is my understanding, that no one knows a priori, which component will help to what extent (general tendencies can be observed, but nothing major).
This is actually a field where there might be a direct transfer from F1 to road cars, because pre-ignition is quite relevant for highly boosted gasoline engines on the road as well. Hence the research into pre-ignition behaviour of different fuel types.
100% THIS!
Pre-ignition in Forced induction DI cars is bit different than normal NA engines. Sometimes the worst instances of it occur at surprisingly low rpms. In road cars, the phenomenon is calls LSPI (low speed pre ignition) and is a relatively mundane 2.0 Liter for a family sedan, I have seen LSPI create in cylinder pressures as high as 3x4 times pmax (max cylinder combustion pressures) and in some cases, much higher! 30 to 50MPa is not uncommon. Under these severe conditions, connecting rods buckle, piston ring lands are obliterated, piston skirts crack, oil films on bearing are squished away completely. Basically, things break, catastrophically.
Now that I think about it....... I wonder if Alonso's engine blowing up on the 3rd turn of practice, while he was still warming up, was a result of this... kinda lugging around,, not hammering on it,,, but holes out the side of the block... as I think about it, almost text-book LSPI failure???
As for causes, if i recall correctly, in road car engines, we had seen strong correlations with LSPI and oil particles getting past the rings as a source of ignition. I few hot tiny drops of oil making their way into the combustion chamber caused the autoignition, and BOOM!! test stopped, engine destroyed.....
Re: Honda Power Unit
Posted: 18 May 2017, 18:16
by godlameroso
In other words lugging the engine around, and then giving it the beans at low rpms?
Re: Honda Power Unit
Posted: 19 May 2017, 01:27
by J.A.W.
Anony Mous Engineerd wrote: ↑18 May 2017, 17:57
Pre-ignition in Forced induction DI cars is bit different...
As for causes, if i recall correctly, in road car engines, we had seen strong correlations with LSPI and oil particles getting past the rings as a source of ignition. I few hot tiny drops of oil making their way into the combustion chamber caused the autoignition, and BOOM!! test stopped, engine destroyed.....
Except as previously noted, 'oils aint oils' when they are defacto fuel additives - which are formulated to prevent this..
..unless again, a 'chaotic' convergence occurred which propagated so rapidly that it defeated the ECU override..
..runaway fuel events not being amenable to ignition control, & fuel control was unable to be cut, in due time..
Re: Honda Power Unit
Posted: 19 May 2017, 03:17
by PlatinumZealot
I disagree... Pre-ignition woukd have extremely disastrous consequences for these engines. Why would you go so extreme to say this problem exists! Crazyness crazyness.
It has been said many times Knocking is the problem in these engines.
Honda has generally non-competitive combustion with Mercedes and Ferrari.
It is good that the vibrations were reduced with inlet and injector upgrades. Possibly that these new parts allowed Honda to tune the engine to work as the want it..
Re: Honda Power Unit
Posted: 19 May 2017, 14:55
by mclaren111
Off topic a bit.
Does anybody know if they have started a separate / new project for 2018 yet ??
Re: Honda Power Unit
Posted: 19 May 2017, 15:27
by lio007
TBH I wasn't aware of, that Illien is working with Honda, but it's also possible that I'm not up to date
. Christian Horner confirmed that in a recent interview on formula1.com
Christian Horner wrote:There has been mention of Mercedes possibly lending a hand to Honda on engine development. Have Mercedes ever made such an offer to Renault? They produce road cars that share engines, after all…
CH: Not that I am aware of. And I would be highly surprised it the Honda/Mercedes thing were to happen. Honda has with Mario Illien a very capable man who I think will be able to sort out the issues. ...
Re: Honda Power Unit
Posted: 19 May 2017, 19:27
by MrPotatoHead
Pre-Ignition occurs LESS in Direct Injected engines by nature of how they work.
As far as oil causing pre-ignition this would be less of a problem than a Port Injected engine also.
Some of the theories presented here make me scratch my head.
Raise your hand if you have built and tuned a high strung high boost engine because experience in these things tells you a lot more than the Internet does.
Re: Honda Power Unit
Posted: 19 May 2017, 20:48
by godlameroso
MrPotatoHead wrote: ↑19 May 2017, 19:27
Pre-Ignition occurs LESS in Direct Injected engines by nature of how they work.
As far as oil causing pre-ignition this would be less of a problem than a Port Injected engine also.
Some of the theories presented here make me scratch my head.
Raise your hand if you have built and tuned a high strung high boost engine because experience in these things tells you a lot more than the Internet does.
Pre-ignition can happen with these engines due to the pre-chamber combustion, and multiple injection events before TDC. The closer you can have full combustion near TDC the more power you make, and you need serious performance from the injectors to achieve this. If you have a misfire and don't burn enough fuel, or enough lingers in the pre-chamber, the next engine cycle can have an overly rich mixture and pre-ignite.
Re: Honda Power Unit
Posted: 19 May 2017, 20:55
by MrPotatoHead
godlameroso wrote: ↑19 May 2017, 20:48
MrPotatoHead wrote: ↑19 May 2017, 19:27
Pre-Ignition occurs LESS in Direct Injected engines by nature of how they work.
As far as oil causing pre-ignition this would be less of a problem than a Port Injected engine also.
Some of the theories presented here make me scratch my head.
Raise your hand if you have built and tuned a high strung high boost engine because experience in these things tells you a lot more than the Internet does.
Pre-ignition can happen with these engines due to the pre-chamber combustion, and multiple injection events before TDC. The closer you can have full combustion near TDC the more power you make, and you need serious performance from the injectors to achieve this. If you have a misfire and don't burn enough fuel, or enough lingers in the pre-chamber, the next engine cycle can have an overly rich mixture and pre-ignite.
A misfire will mostly result in excess fuel in the exhaust not the cylinder at the end of the exhaust stroke. This will then be seen as overly lean on the oxygen sensor due to the excess oxygen that wasn't consumed. The next cycle will not see much leftover fuel especially on engines of such high compression ratio.
Re: Honda Power Unit
Posted: 19 May 2017, 21:23
by Anony Mous Engineerd
MrPotatoHead wrote: ↑19 May 2017, 19:27
Pre-Ignition occurs LESS in Direct Injected engines by nature of how they work.
As far as oil causing pre-ignition this would be less of a problem than a Port Injected engine also.
Some of the theories presented here make me scratch my head.
Raise your hand if you have built and tuned a high strung high boost engine because experience in these things tells you a lot more than the Internet does.
Raises hand....almost a decade at an OEM working on DI engines.
LSPI is a very real thing.
Literally everything you wrote is completely backwards. Highstrung DI turbo engines are MORE prone to LSPI. Fact.
http://bfy.tw/BtVR
Re: Honda Power Unit
Posted: 19 May 2017, 21:30
by MrPotatoHead
Anony Mous Engineerd wrote: ↑19 May 2017, 21:23
MrPotatoHead wrote: ↑19 May 2017, 19:27
Pre-Ignition occurs LESS in Direct Injected engines by nature of how they work.
As far as oil causing pre-ignition this would be less of a problem than a Port Injected engine also.
Some of the theories presented here make me scratch my head.
Raise your hand if you have built and tuned a high strung high boost engine because experience in these things tells you a lot more than the Internet does.
Raises hand....almost a decade at an OEM working on DI engines.
LSPI is a very real thing.
Literally everything you wrote is completely backwards. Highstrung DI turbo engines are MORE prone to LSPI. Fact.
http://bfy.tw/BtVR
Did I mention LSPI? No. I was referring to high load and high speed.
Oh and thanks for the lmgtfy.
Re: Honda Power Unit
Posted: 19 May 2017, 21:34
by MrPotatoHead
I must have missed where a topic on an engine that idles at 4000 rpm and spends most of its time at 8000 to 12000 is a low speed engine that will suffer from LSPI.