Honda F1 project leader Yusuke Hasegawa has outlined a number of reasons why Honda has been struggling so badly in the beginning of the 2017 Formula One season. He confirmed that lots of problems were not discovered while running on the dynamo meter.
His talk is generic. There are not significant deviations from the features he describes, in any of the engines.
Please don't take offense as you are vastly more knowledgeable in this field than I am but there is certainly more than one way to accomplish tji type ignition.
@Sasha (I think) has some inside Honda knowledge and I heard directly from a highly knowledgeable birdie that Sasha is correct in stating the Honda version has a piston shaped like a volcano (think Mt. Fuji) with the pre chamber in the piston.
If injector was at the top then the injector could spray directly into the pre chamber then continue spraying to also fill the combustion chamber.
Seems like an efficient way to do it and potentially simpler and easier to get each chamber (pre and main cylinder) afr's exact.
''If the injector was at the top then the injector could spray directly into the pre chamber''. If the injector sprays directly into the pre-chamber it, the injection system will not be compatible with F1 rules, as spraying/injecting into the pre-chamber will be an indirect injection system. And that is why the Mahle TJI system as in illustrations pushed-out by many was never compatible with F1 rules, even when deducting the claimants push-out that the TJI second injector is not used in F1. (I personally went true all this with Mark Hughes a very long time ago when he claimed he discovered it and pushed it out, the end result was he banned me from his forum). As to the claim of the Honda pre-chamber being in the piston, and also to the claim of 'inside knowledge' these two claims are total BS. As these claims ''Honda pre-chamber is in the piston'' mount fuji and what not, means even the spark-plug is sparking into the main combustion chamber, which will render a pre-chamber in the piston just an added hole (in the piston top) and to the main combustion chamber, with no possibility of the 'claimed' jets out of the pre-chamber.
When injector injects into the pre-chamber, it is not accepted in this rules. I didn't think about that. Looks logical.
I am not remembering good but plasma ignition is also banned and one SP per cylinder right ? When SP located inside Passive Pre-chamber or if it is located inside Active one, will it be banned by rules, then ?
His talk is generic. There are not significant deviations from the features he describes, in any of the engines.
Please don't take offense as you are vastly more knowledgeable in this field than I am but there is certainly more than one way to accomplish tji type ignition.
@Sasha (I think) has some inside Honda knowledge and I heard directly from a highly knowledgeable birdie that Sasha is correct in stating the Honda version has a piston shaped like a volcano (think Mt. Fuji) with the pre chamber in the piston.
If injector was at the top then the injector could spray directly into the pre chamber then continue spraying to also fill the combustion chamber.
Seems like an efficient way to do it and potentially simpler and easier to get each chamber (pre and main cylinder) afr's exact.
''If the injector was at the top then the injector could spray directly into the pre chamber''. If the injector sprays directly into the pre-chamber it, the injection system will not be compatible with F1 rules, as spraying/injecting into the pre-chamber will be an indirect injection system. And that is why the Mahle TJI system as in illustrations pushed-out by many was never compatible with F1 rules, even when deducting the claimants push-out that the TJI second injector is not used in F1. (I personally went true all this with Mark Hughes a very long time ago when he claimed he discovered it and pushed it out, the end result was he banned me from his forum). As to the claim of the Honda pre-chamber being in the piston, and also to the claim of 'inside knowledge' these two claims are total BS. As these claims ''Honda pre-chamber is in the piston'' mount fuji and what not, means even the spark-plug is sparking into the main combustion chamber, which will render a pre-chamber in the piston just an added hole (in the piston top) and to the main combustion chamber, with no possibility of the 'claimed' jets out of the pre-chamber.
I dont know any specifics of injector placement, sp placement. Only that it's a Mt. Fuji inspired design. The rest I was hypothesizing.
When injector injects into the pre-chamber, it is not accepted in this rules. I didn't think about that. Looks logical.
I am not remembering good but plasma ignition is also banned and one SP per cylinder right ? When SP located inside Passive Pre-chamber or if it is located inside Active one, will it be banned by rules, then ?
Specifically for the injector to injects into the pre-combustion chamber the injector tip will have to be inside the said chamber or physically the tip be inside a hole in the said chamber, As clearly illustrated in the Mahle TJI picture, this system renders the injection as an 'indirect injection system, because the injector is injecting directly into the pre-chamber and not into the main chamber. Yes. only one spark-plug per cylinder is allowed by the rules, but its installed location, (inside the pre-chamber or inside the main chamber) is not dictated by the 'direct injection' rule.
''I don't know any specifics of injector placement, SP (spark-plug) placement, Only that it's a MT. Fuji inspired design. The rest I was hypothesizing''. The MT. Fuji inspired design claim is an instance of a wrong or misinterpreted perception of a sensory experience like strips that embellish a surface to create textures to the illusion of parous wood grain.
''I don't know any specifics of injector placement, SP (spark-plug) placement, Only that it's a MT. Fuji inspired design. The rest I was hypothesizing''. The MT. Fuji inspired design claim is an instance of a wrong or misinterpreted perception of a sensory experience like strips that embellish a surface to create textures to the illusion of parous wood grain.
''I don't know any specifics of injector placement, SP (spark-plug) placement, Only that it's a MT. Fuji inspired design. The rest I was hypothesizing''. The MT. Fuji inspired design claim is an instance of a wrong or misinterpreted perception of a sensory experience like strips that embellish a surface to create textures to the illusion of parous wood grain.
Wrong. But I'm done.
He’s not though.
I shared what Audi uses a bowl with a “spear” or in their words, “Mexican hat design”, where it’s a bowl with a spear and a dimple in the middle is about. For them, on their LeMans engines, it was about fuel economy / efficiency.
This design isn’t unique to Honda or these engines.
''I don't know any specifics of injector placement, SP (spark-plug) placement, Only that it's a MT. Fuji inspired design. The rest I was hypothesizing''. The MT. Fuji inspired design claim is an instance of a wrong or misinterpreted perception of a sensory experience like strips that embellish a surface to create textures to the illusion of parous wood grain.
Wrong. But I'm done.
He’s not though.
I shared what Audi uses a bowl with a “spear” or in their words, “Mexican hat design”, where it’s a bowl with a spear and a dimple in the middle is about. For them, on their LeMans engines, it was about fuel economy / efficiency.
This design isn’t unique to Honda or these engines.
Not that this defers your point, but wasn't the Audi a diesel with self-ignition? It's interesting that everybody ends up with the same design anyway.
I shared what Audi uses a bowl with a “spear” or in their words, “Mexican hat design”, where it’s a bowl with a spear and a dimple in the middle is about. For them, on their LeMans engines, it was about fuel economy / efficiency.
This design isn’t unique to Honda or these engines.
Not that this defers your point, but wasn't the Audi a diesel with self-ignition? It's interesting that everybody ends up with the same design anyway.
It was, but it was also a fuel limited lean burn, high boost, rapid combustion, Miller Cycle concept, with similar geometric compression ratios. It was very similar to the current F1 engines except combustion ignited vs TJI. However, I think it’s safe to say there is combustion induced ignition happening with the current F1 engines as well; Honda has shown that, Ferrari dubs it “super fast engine” referring to the combustion concept (with 5 injector events / cycle), and Merc has hinted at this for at least 5 years now.
I’d argue the current F1 engines are closer to a diesel than they are anything gasoline engine vehicles we drive.
''Wrong. But I'm done''. Pity as not much of a useful contribution to a tech forum.
Whatever shape name given to Audi's in-piston combustion chamber it could not contain any in-piston pre-combustion chamber as there is no such thing as an in-piston-pre-combustion chamber. This because a pre-combustion chamber is a much smaller closed space with an opening into the main combustion chamber were combustion is initiated/started. in a diesel engine the triggering of combustion inside a pre-chamber is by injection inside said chamber, while in a petrol engine pre-chamber use combustion is triggered inside pre-chamber by spark-plug sparking inside said chamber. Defining combustion space between piston top and cylinder head face. High revving + high compression ratio + inclined valves dictates a combustion space inside the cylinder head face as much as inside piston top face. These two spaces can only be minimized but not one of them can be avoided.
Dubs combustion as ''superfast'' doesn't necessary mean combustion induced ignition. As the term 'combustion induced ignition' means combustion is induced by heat build-up and without a spark, which will contradict the spark-plug rule. It is best explained as 'spark induced' combustion with rapid induced flames igniting the rest of the compressed fuel/air mix. Or the rest of the fuel air mix being combusted by the rapid heat build-up by the first part of the spark induced combustion.
A link to Honda saying/admitting to using of combustion induced ignition will be appreciated.
While am sure that more than one injection per cylinder cycle is permitted, doesn't know how many is allowed, but I understand that five sparks per cylinder per cycle are allowed.
Lots of similarity to diesel combustion but comparison fails on three counts.
- Compression ignition.
- Heat addition at constant pressure after TDC.
- Rate controlled combustion.
Lots of similarity to diesel combustion but comparison fails on three counts.
- Compression ignition.
- Heat addition at constant pressure after TDC.
- Rate controlled combustion.
I think Honda’s video and statements suggest there is compression ignition.
Edit: and Pat Symond’s statements. See post below n
Last edited by Hoffman900 on 22 Mar 2023, 23:41, edited 1 time in total.
Lots of similarity to diesel combustion but comparison fails on three counts.
- Compression ignition.
- Heat addition at constant pressure after TDC.
- Rate controlled combustion.
I think Honda’s video and statements suggest there is compression ignition.
It's probably a grey area that requires the compression ignition to occur after the spark ignition.
Technically the rules forbid pure compression ignition, although I'm not sure how one could prove that manufacturers were not just using a "token" spark ignition system that was firing incidentally... In theory one could argue that any pressure rise occuring before the spark firing was a "loss of control"
Lots of similarity to diesel combustion but comparison fails on three counts.
- Compression ignition.
- Heat addition at constant pressure after TDC.
- Rate controlled combustion.
I think Honda’s video and statements suggest there is compression ignition.
It's probably a grey area that requires the compression ignition to occur after the spark ignition.
Technically the rules forbid pure compression ignition, although I'm not sure how one could prove that manufacturers were not just using a "token" spark ignition system that was firing incidentally... In theory one could argue that any pressure rise occuring before the spark firing was a "loss of control"
Ferrari is quoted in a recent RET of using 5 injection events / a cycle. I can’t imagine the spark plug is firing 5 time either.
Honda’s video plus illustrations shows a flame propagating from the chamber / piston edges meeting a flame being dispersed from the jet in the roof of the combustion chamber centered over the piston.
Pat Symonds himself called them hybrid combustion concepts.
14:05 he has a slide too. He says they’re difficult to classify but calls them “spark assisted HCCI” which Honda’s video also shows.
In the context of Ferrari’s info, Honda’s information, and Pat’s statement, it’s fair to say they are using the injector to create a stratified or a homogenous charge in the combustion chamber before lighting off an additional charge of fuel in the TJI chamber, and likely using in-situ cylinder pressure sensors to control the timing of the spark plug so the TJI combustion event is timed with the homogenous or stratified charged combustion event.
In theory one could argue that any pressure rise occuring before the spark firing was a "loss of control" 