Honda Power Unit Hardware & Software

[gruntguru]

The concept is to copy the diesel cycle as much as possible, autoignition by compression. Neither is my theory, is what I read.

TJI enables ultra-lean combustion (which is the only "diesel like" feature).
The cycle is Otto ie pre-mixed combustion. It is closer to the classic Otto cycle (instantaneous, complete combustion at TDC) than most SI engines ie further from the diesel cycle than typical SI engines.
Ignition is by spark.

Slowing down and better controlling the spread of the combustion flame and delaying the onset of detonation (or knock) it is more than being able to burn a poor mix.

It might not sound logical but the reduced knock of TJI engines is due to the faster burn which allows less time for the end-gas to heat up.

The ignition is by spark .... of the mini combustion chamber, the rest is burned by the first deflagration.

Yes - but there is no auto ignition (compression ignition).

[JuanjoTS]

TJI enables ultra-lean combustion (which is the only "diesel like" feature).
The cycle is Otto ie pre-mixed combustion. It is closer to the classic Otto cycle (instantaneous, complete combustion at TDC) than most SI engines ie further from the diesel cycle than typical SI engines.
Ignition is by spark.

Slowing down and better controlling the spread of the combustion flame and delaying the onset of detonation (or knock) it is more than being able to burn a poor mix.

It might not sound logical but the reduced knock of TJI engines is due to the faster burn which allows less time for the end-gas to heat up.

The ignition is by spark .... of the mini combustion chamber, the rest is burned by the first deflagration.

Yes - but there is no auto ignition (compression ignition).

1 How do you get to heat the gases more to burn the mixture faster? With the compression trying to get as close as possible to the auto-ignition point.

2 Delaying the detonation allows more compression and accumulating more temperature in the lean mixture, it is attempted to reach the auto-ignition point so that the entire mixture is burned at the same time and more efficiently.
Do not take my words literally, I say that they are introducing many characteristics of diesel to gain efficiency.
I think they would not need the spark once the combustion cycle started, but they still use it as a perfect control mechanism for detonation.

[Singabule]

I don't think the F1 prechamber looks like the Mahle TJI, It would be more like this with jet holes to the side of the pre-chamber.

https://data.epo.org/publication-server ... Id=5875756

Agree, and i think injector drilled in no 15 in your diagram, hence you can direct some of fuels directly to prechamber. Prechamber dont need very precise AF ratio, just very rich.

[Craigy]

Is it possible to inject a selective amount of air along with the fuel via the injector?

Put this another way: could there be (for example) two injections via the injector per cycle, one which is "fuel only" that gets squirted out of the TJI holes, filling the chamber below the crucible with fuel mist, and then another later with fuel and a metered amount of air into the TJI crucible?

Without this, I don't see how air can get into the TJI crucible in order for the spark in there to achieve anything.

[aral]

There seems to be a lot of opinions as to what Honda are doing wrong and the conversation is getting very heated with "I am right" , "no, I am" etc. Honda are probably more aware of what is wrong than thos on here, so there is little need for all this dispute. Please calm down and avoid all the wild speculation.

[McHonda]

There were some rumour articles which mentioned that Honda TJI project started only in May 16

That is a whole year after the TJI rumours started in the forums. Any reason for the delay? Man power resources?

May.2016 is a few weeks after Mahle announced they'd been working with Ferrari and Mark Hughes wrote his piece on it so it seems a reasonable date for Honda to look into it.

There are lots of rumours on forums and as far as I can recall HCCI was a lot more common around forums than TJI before that announcement.

[Andres125sx]

If only Honda had the same rate of improvement as this thread's page count...

Without free track testing? They´re engineers not magicians


Anycase I think most replies on last pages do not belong to this thread specifically, but to the V6T PUs general thread, as they´re only wild speculation about how these PUs, in general (not Honda particullary), are designed and work

[godlameroso]

Back to the TJI topic. Seeing as how only the spark plug is shrouded.

Let's say I have a turbocharged 4 cylinder engine with port injection. Can I get at least some TJI benefit if I, cap the spark plugs with anti-foulers that have little holes drilled in them at a 45 degree angle at the tip? Tuning is not a problem just curious is all.

This is a spark plug spacer/non fouler/anti fouler

https://www.willysjeepparts.com/gallery ... FOULER.JPG

People also put them on their secondary O2 sensor with the main hole bored out, it fools the ECU on Hondas to think the downstream O2 sensor is working properly so when people run a test pipe they don't get a check engine light.

Those exist, and they call them passive pre-chamber spark plugs. There is an SAE paper on them. They worked well with LNG, but fouled up quickly with Petrol. There was not a "clean way" to control the mixture inside the plug with petrol, so a lot of deposits. Even regular open spark plugs have a bit of deposits with petrol. It is anyones guess how fouling of the nozzles in managed in F1. I know that the spark plug is free to change. So by extension the nozzle cap may be free to change between sessions?

Wazari probably seen what's inside but he can't tell us.

Fouling of the plug is no issue, as long as the gap is correct, and there isn't much electrode erosion (unlikely with iridium or platinum plugs). You just remove the plug and burn it with an acetylene torch until all the carbon deposits burn away.

[JuanjoTS]

If the shooting in the foot refers to Mark mistakenly using Mahle's two injector picture and explanation with it then he corrects it in a latter piece where he explains they shroud the spark plug only instead to form the mini chamber.
http://www.motorsportmagazine.com/opini ... ine-update

"Within the F1 regulations, only a single injector is permitted and the key to applying the principle within that limitation was shrouding only the spark plug to form the mini-chamber above the main combustion chamber and not – as in the drawing – the injector and spark plug together.

In the F1 application the injector injects the fuel-air charge into the main combustion chamber. Around 3 per cent of that charge from the turbo is forced into the mini-chamber under pressure through the orifices in the ring separating the mini chamber from the main chamber. Getting this transfer right and ensuring the correct mixture is in the small chamber was a major part of the challenge for this project."

I am not arguing about the second injector. Been there done that. There was a thread on it and I think it was only two or three very creative people, including myself, that held the two injector view. Everybody agreed to disagree and left it there. Util we see photos of the cylinder head or some brave soul leaks the details, there is no need enter that discussion again. Notice, I only mentioned my two injector theory once and stopped there? I don't want to go down that rabbit hole in this thread. There is a thread waaaay back about it.
I took him on for the unsubstantiated and otherwise totally false claims he made. (like he said TJI cannot work for formula 1 when it is a fact that Ferrari use a variant of it! ) He has too many "alternative facts" in his posts.

Well I think he just meant TJI isn't in F1 in the strictest possible sense in reply to people posting the patents from Mahle and who can't move past the two injectors being used by Mahle when talking bout TJI.

Semantics maybe but it's true enough that it's actually an adapted form of TJI being used in F1 to deal with only being allowed to use one injector.

At least that was my take on what he meant by "TJI can not be set to F1". Otherwise he wouldn't be posting Hughes's article or the video of Ted and Hughes talking about Mercedes in support of it being used in F1.

(Unless he was being sarcastic and I've completely missed the point, then apologies).

That's exactly what I meant.

In addition, I think that no brand can copy the other, all pre-combustion systems must have the necessary variation with each other to not infringe on the other's patent, when we say that Honda is awkward for not copying directly to Mercedes Or Ferrari this is not so, must copy the concept varying, being the last to incorporate this system I think they have it more difficult because there are already 3 variations of the same concept.

Honda has its own system of this concept since the 70's is called CVCC (Compound Vortex Controlled Combustion).

[FW17]

May.2016 is a few weeks after Mahle announced they'd been working with Ferrari and Mark Hughes wrote his piece on it so it seems a reasonable date for Honda to look into it.

There are lots of rumours on forums and as far as I can recall HCCI was a lot more common around forums than TJI before that announcement.

Maybe you are right

But listen to this statement

The company's latest annual report quotes Fred Turk, head of Mahle Motorsports as saying: More than five years of development preceded that crucial phone call to Maranello with the proposal: ‘We’ve found an interesting new solution for you.’ Mahle Jet Ignition is the name of the innovation that gives the engines from Maranello a boost. Within a few weeks, in spring 2015, we adapted our solution to the Formula 1 requirements, allowing Ferrari to compete in Canada with this solution for the first time.”

Ferrari System was put together in a few months and this was in a period when the engines were token limited.

[GoranF1]

is it possible to introduce things like intake or exhaust on reliability grounds?

[dren]

How much lead time is there from pre chamber to main chamber full combustion? In other words is the full process comparable to standard spark ignition? Or even with the pre chamber lead time is it still faster?

Also do the majority of the species develop in the pre chamber or main chamber?

I don't recall the numbers but from memory there is very little delay from spark to main-chamber ignition. It doesn't matter much because there is very little pressure rise during the pre-chamber combustion phase. The important thing is the very short period required for main-chamber combustion to complete as well as the very lean combustion limit.

The Purdue paper I linked to earlier showed around a 12ms delay. They didn't use petrol, though. The mixture in the prechamber was close to stoic.

[dren]

is it possible to introduce things like intake or exhaust on reliability grounds?

Yes, if those parts are failing due to reliability issues.

[McHonda]

May.2016 is a few weeks after Mahle announced they'd been working with Ferrari and Mark Hughes wrote his piece on it so it seems a reasonable date for Honda to look into it.

There are lots of rumours on forums and as far as I can recall HCCI was a lot more common around forums than TJI before that announcement.

Maybe you are right

But listen to this statement

The company's latest annual report quotes Fred Turk, head of Mahle Motorsports as saying: More than five years of development preceded that crucial phone call to Maranello with the proposal: ‘We’ve found an interesting new solution for you.’ Mahle Jet Ignition is the name of the innovation that gives the engines from Maranello a boost. Within a few weeks, in spring 2015, we adapted our solution to the Formula 1 requirements, allowing Ferrari to compete in Canada with this solution for the first time.”

Ferrari System was put together in a few months and this was in a period when the engines were token limited.

Yeah but Ferrari were helped by Mahle. They also had the Mercedes combustion expert Cedric Cornebois to help who knew the Mercedes system.

We don't know what Honda are doing specifically or what help they have so we can't realistically expect the same sort of timeline. I'm pretty sure I read they were going to introduce a version in Malaysia last year but the results weren't as good as expected so they put it back to work on it further.

Hasegawa said they were trialing several different combustion concepts so If they have no outside help then they have to develop solo what they think Mahle did to adapt the TJI to F1 so they have something to test their own solutions against.

It's a big task to be fair.

[Selvariabell]

May.2016 is a few weeks after Mahle announced they'd been working with Ferrari and Mark Hughes wrote his piece on it so it seems a reasonable date for Honda to look into it.

There are lots of rumours on forums and as far as I can recall HCCI was a lot more common around forums than TJI before that announcement.

Maybe you are right

But listen to this statement

The company's latest annual report quotes Fred Turk, head of Mahle Motorsports as saying: More than five years of development preceded that crucial phone call to Maranello with the proposal: ‘We’ve found an interesting new solution for you.’ Mahle Jet Ignition is the name of the innovation that gives the engines from Maranello a boost. Within a few weeks, in spring 2015, we adapted our solution to the Formula 1 requirements, allowing Ferrari to compete in Canada with this solution for the first time.”

Ferrari System was put together in a few months and this was in a period when the engines were token limited.

Yeah but Ferrari were helped by Mahle. They also had the Mercedes combustion expert Cedric Cornebois to help who knew the Mercedes system.

We don't know what Honda are doing specifically or what help they have so we can't realistically expect the same sort of timeline. I'm pretty sure I read they were going to introduce a version in Malaysia last year but the results weren't as good as expected so they put it back to work on it further.

Hasegawa said they were trialing several different combustion concepts so If they have no outside help then they have to develop solo what they think Mahle did to adapt the TJI to F1 so they have something to test their own solutions against.

It's a big task to be fair.

It is a big task indeed, but I hope Honda would make it through, especially with Sauber as a possible customer.