Honda Power Unit Hardware & Software

[godlameroso]

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.

Maybe, then again most engines don't have these pre-chambers, and if they do, they have more than one injector or spark plug. Say fuel goes into the pre-chamber, but doesn't combust for whatever reason, and that some fuel lingers after the exhaust valve opens, when the next engine cycle starts the lingering fuel mixes with another fresh charge, the incredibly rich pre-chamber ignites easily and by consequence the main chamber. The pre-ignition happens before TDC, and instant spun rod bearing/bent rod/melted piston.

[MrPotatoHead]

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.

Maybe, then again most engines don't have these pre-chambers, and if they do, they have more than one injector or spark plug. Say fuel goes into the pre-chamber, but doesn't combust for whatever reason, and that some fuel lingers after the exhaust valve opens, when the next engine cycle starts the lingering fuel mixes with another fresh charge, the incredibly rich pre-chamber ignites easily and by consequence the main chamber. The pre-ignition happens before TDC, and instant spun rod bearing.

Incredibly rich (although we aren't discussing actual lambda) is actually difficult to ignite.
This discussion would be so much easier if we could see what they are actually doing.

[gruntguru]

Agree. "Incredibly rich" is difficult to ignite - particularly without spark. Best implementation of TJI would have slightly richer than stoich' in the pre-chamber - probably 0.9 - 0.95

[MrPotatoHead]

Agree. "Incredibly rich" is difficult to ignite - particularly without spark. Best implementation of TJI would have slightly richer than stoich' in the pre-chamber - probably 0.9 - 0.95

Exactly. In my mind the only way to get it to work with any kind of precision is for the injector to be inside of (or to be) the pre-chamber. The idea that you could somehow convince the fuel from the main combustion chamber to go hide inside a pre-chamber with exactly the right ratio... is far fetched at best.

When you start to think about the time window available for these events to take place it's mind boggling. At 10500 rpm 1 stroke takes only 2.7ms. At 12000 rpm it's only 2.5ms.
What is the typical injector opening time? That will tell you a lot.

[godlameroso]

Piezoelectrics for the distances involved can do .3 msec at best I'd imagine. Maybe less with dual anchor?

[MrPotatoHead]

Piezoelectrics for the distances involved can do .3 msec at best I'd imagine. Maybe less with dual anchor?

Most of what I have seen is around 0.4 to 0.5ms.
At a certain point you run into the brick wall that is physics if you try to open them any faster. Inertia is a bitch. The same physics are also what keeps electromagnetic valves from being very practical.

[Andres125sx]

and revealingly, the only octane number limit is a minimum (to prevent the dieselisation of F1)

Might you please elaborate this a bit more for a non engineer reader?

[MrPotatoHead]

and revealingly, the only octane number limit is a minimum (to prevent the dieselisation of F1)

Might you please elaborate this a bit more for a non engineer reader?

They want the sport to remain spark ignition and not slip into compression ignition by having a low octane rating of the fue,l so they enforce a minimum octane.

[GoranF1]

The next Honda PU update will be a change to ICE(head,pistons,JTI) and new direction of development and a first step back from Gilles Simon.
Illmor is not working whit Honda,just Mario Illien as advisor.

[MrPotatoHead]

The next Honda PU update will be a change to ICE(head,pistons,JTI) and new direction of development and a first step back from Gilles Simon.
Illmor is not working whit Honda,just Mario Illien as advisor.

I'm amazed they haven't made any major upgrades yet. They have had 4 or 5 months since they knew they had problems on the engine dyno. That is a lifetime in an engine formula without tokens.
In a world of investment casting and CNC machines they "should" be turning around parts in days or weeks not 6 months.

[etusch]

The next Honda PU update will be a change to ICE(head,pistons,JTI) and new direction of development and a first step back from Gilles Simon.
Illmor is not working whit Honda,just Mario Illien as advisor.

I'm amazed they haven't made any major upgrades yet. They have had 4 or 5 months since they knew they had problems on the engine dyno. That is a lifetime in an engine formula without tokens.
In a world of investment casting and CNC machines they "should" be turning around parts in days or weeks not 6 months.

I don't think so. If they had already solved their problems and it were just a matter of producing parts it would not be take so long. But they have to reach a certain define of problem and find certain sollution of it. I don't think that this is just model and produce job. İf they produce it without more power and reliability, they will be really fool themselfs. They have to be sure they got more power and they have to be sure they are more reliable. This is not a small update related small part of engine. After finding correct solution I think molding process is not so short and after production, I think they have to do lots of test.
İn the other hand they did some small updates.

[MrPotatoHead]

The next Honda PU update will be a change to ICE(head,pistons,JTI) and new direction of development and a first step back from Gilles Simon.
Illmor is not working whit Honda,just Mario Illien as advisor.

I'm amazed they haven't made any major upgrades yet. They have had 4 or 5 months since they knew they had problems on the engine dyno. That is a lifetime in an engine formula without tokens.
In a world of investment casting and CNC machines they "should" be turning around parts in days or weeks not 6 months.

I don't think so. If they had already solved their problems and it were just a matter of producing parts it will not be take so long. But they have to reach a certain define of problem and certain solving of it. I don't think that this is just model and produce job. İf they produce it without more power and reliability, they will be really fool themselfs. They have to be sure they got more power and they have to be sure they are more reliable. This is not a small update related small part of engine. After findind correct solution I think molding process is not so short and after production I think they have to do lots of test.
İn the other hand they did some small updates.

My point is that they should be making Continuous improvements. Not some minor updates after 4 races.
They should be running new parts on the dyno every day.

[etusch]

I'm amazed they haven't made any major upgrades yet. They have had 4 or 5 months since they knew they had problems on the engine dyno. That is a lifetime in an engine formula without tokens.
In a world of investment casting and CNC machines they "should" be turning around parts in days or weeks not 6 months.

I don't think so. If they had already solved their problems and it were just a matter of producing parts it will not be take so long. But they have to reach a certain define of problem and certain solving of it. I don't think that this is just model and produce job. İf they produce it without more power and reliability, they will be really fool themselfs. They have to be sure they got more power and they have to be sure they are more reliable. This is not a small update related small part of engine. After findind correct solution I think molding process is not so short and after production I think they have to do lots of test.
İn the other hand they did some small updates.

My point is that they should be making Continuous improvements. Not some minor updates after 4 races.
They should be running new parts on the dyno every day.

What I said is that after analising problems, I think they found out that it is not worth wasting time to try small update becuase of the problem they had, so they decided to do cylinder and new head new cumbustion. And this is taking long.

[Sasha]

Must make sure the new CC Design really works in the real world.So they are doing the D in the R&D that they didn't do the first time because of running out of time.(they kept designing to the last moment)

The new CC was already designed just not chosen after dyno test because it was heavier(2kg per head) and burned little more fuel.I think with the help of AVL Japan they are developing it now.

[MrPotatoHead]

I don't think so. If they had already solved their problems and it were just a matter of producing parts it will not be take so long. But they have to reach a certain define of problem and certain solving of it. I don't think that this is just model and produce job. İf they produce it without more power and reliability, they will be really fool themselfs. They have to be sure they got more power and they have to be sure they are more reliable. This is not a small update related small part of engine. After findind correct solution I think molding process is not so short and after production I think they have to do lots of test.
İn the other hand they did some small updates.

My point is that they should be making Continuous improvements. Not some minor updates after 4 races.
They should be running new parts on the dyno every day.

What I said is that after analising problems, I think they found out that it is not worth wasting time to try small update becuase of the problem they had, so they decided to do cylinder and new head new cumbustion. And this is taking long.

Exactly my point! It should not take 6 months to make and test those parts.
I know a thing or two about this.
So they are either taking too long or they are lost and could not figure it out.