Honda Power Unit Hardware & Software

[MrPotatoHead]

How would one feed the pre-chamber fuel if you're only allowed one injector. That's the tricky part, I'm just throwing stuff out there, there's the two anchor in between the main and pre-chamber. There's the main injector housing both the pre-chamber and main injector, there's the conventional injector that through clever head design creates the pre-chamber effect. Why not a design that borrows from all these concepts and creates something similar but different?

And we haven't even started talking about where the spark plug goes or how it's made. Or whether the pre-chamber has a way to heat the fuel, be it by heating element or a heat retaining material.

It's hard to know exactly what they are doing. But it sure is fun to speculate that's for sure.

My personal theory is that the pre chamber is a part of the injector assembly. Wouldn't that explain the new rule for 2018 on the engine side?
As far as how and where the fuel goes - I could see the injector having two outlets. One into the main chamber and the other into the pre chamber.
Purely speculation of course. Everything ive seen and have worked on has been external of the ICE.

As for the pre chamber heating the fuel I haven't really thought about that too much.

[Sasha]

Heating the fuel is a must.

[f1rules]

thanks for your posts, very interesting. so in your opinion/what youve heard, what can be expected this year, gains/position. They seem to be in a fortunate situation, that 4th best is up for grap, if honda delivers a decent step, or is this year a complete writeoff?

In un-educated terms.

Under load Honda's CC Design isn't working.The fuel isn't going where it is suppose to go in the main chamber that leads to very very lean areas in the main chamber=eating pistons and destroyed engine.

The bandage fix is running the engine rich=no power and bad MPG.

Mid-term fix is new CC design(Heads, pistons and injectors)

Long term fix is almost a whole new PU design.(because of vibrations)

[Tommy Cookers]

[quote=MrPotatoHead]
[quote=gruntguru]
[quote=n4rf]What I do know from reliable sources is, that the teams are running homogeneous lean charge in the main combustion chamber. The same sources also tell me, that there's no real "super-lean" stuff going on, certainly nothing above 2.0, usually some way below that. Also makes sense, when you remember that the fuel mass is fixed. That means, that increasing the air/fuel ratio leads to an increased boost pressure demand. So you need to balance the thermodynamic benefits in the cylinder (if there are any left above lambda 1.5-ish) against the losses due to higher compression work. That then also depends on your choice of turbocharger and your MGU-H strategy.[/quote]
I ran through the calculations some time ago. Increased boost pressure is fairly neutral, the extra compression work being cancelled by the extra turbine work available (at the higher PR and higher mass flow). That was for steady state turbine and compressor flows and isentropic efficiencies of 80%. Higher efficiencies favour increasing the PR and lower efficiencies the opposite.[/quote]

I'd love to see these calculations.
All this talk is making me want to build a single cylinder TJI test engine.[/quote]


gg posted a link at 0149 on 15 Jun 2015 P22 of TERS thread that iirc was the basis of his calculations
(I can't repost it, my PC being such an old clunker)

though (I wonder) how well does this represent blowdown energy ?
also c.P14/5 in the Renault thread seem worth a read

[PlatinumZealot]

Possible and extremely likely. You're not going to convince 3% of the fuel to magically go hide in a secret chamber with tiny entrance holes otherwise
At least not with the precision and repeatability required for it to happen under these kinds of loads.

There is at least one paper on TJI that discusses testing done with no injection in the pre-chamber at all. Provided the mix in the main chamber is rich enough (and that mix is adjacent to the pre-chamber (testing was PFI homogeneous mix)) it will flow into the pre-chamber during the compression stroke.

How would the pre-chamber be richer than the main chamber if that was the case? Isn't that one of the prerequisites of TJI?

I would not say it is pre-requisite for TJI. TJI will still work as long as enough fuel is in the pre-chamber. But I agree there is a challenge when you objective is lean combustion in the main chamber.

[PlatinumZealot]

How would one feed the pre-chamber fuel if you're only allowed one injector. That's the tricky part, I'm just throwing stuff out there, there's the two anchor in between the main and pre-chamber. There's the main injector housing both the pre-chamber and main injector, there's the conventional injector that through clever head design creates the pre-chamber effect. Why not a design that borrows from all these concepts and creates something similar but different?

And we haven't even started talking about where the spark plug goes or how it's made. Or whether the pre-chamber has a way to heat the fuel, be it by heating element or a heat retaining material.

It's hard to know exactly what they are doing. But it sure is fun to speculate that's for sure.

My personal theory is that the pre chamber is a part of the injector assembly. Wouldn't that explain the new rule for 2018 on the engine side?
As far as how and where the fuel goes - I could see the injector having two outlets. One into the main chamber and the other into the pre chamber.
Purely speculation of course. Everything ive seen and have worked on has been external of the ICE.

As for the pre chamber heating the fuel I haven't really thought about that too much.

This is the best way of doing it. Just have to hope it counts as one injector.

[MrPotatoHead]

This is the best way of doing it. Just have to hope it counts as one injector.

If an injector had one pintle and one driver coil - I don't see how anyone could argue that it wasn't one injector.
Using those parameters multiple outlets are no problem in my mind.

If I get time this week I'll model some things in Solidworks. Would be great for discussion.

[etusch]

This is the best way of doing it. Just have to hope it counts as one injector.

If an injector had one pintle and one driver coil - I don't see how anyone could argue that it wasn't one injector.
Using those parameters multiple outlets are no problem in my mind.

If I get time this week I'll model some things in Solidworks. Would be great for discussion.

Good idea.

[ziggy]

AMuS:

Engine damage in barcelona P1 was so powerfull, that the engine broke in 2 separate parts. Hence the waterfall after the car was hooked up.

New PU in Canada. Honda expects Melbourne 2017 level.

And offtopic: Mclaren stays with Honda.

[godlameroso]

AMuS:

Engine damage in barcelona P1 was so powerfull, that the engine broke in 2 separate parts. Hence the waterfall after the car was hooked up.

New PU in Canada. Honda expects Melbourne 2017 level.

And offtopic: Mclaren stays with Honda.

So the PU in Canada is going to be as bad as it was at the beginning of the year?

Having read the article in question it says that the Canada update is a big step forward, that they'll now have the power they were looking for to start the season, or ~Mercedes 2016 Abu Dhabi levels.

"New Honda engine in Canada

The Japanese are confident that a large part of the problems are solved as of GP Canada. Then Honda brings a new engine to the start. It has been greatly modified in the range of combustion. The Honda engine is equipped with a pre-chamber ignition.

In the Sakura development center, it is optimistic that the engine will bring the performance that Honda had targeted for the start of the season. First improvements have already been seen in Barcelona. Honda had modified the air intake and the petrol system. "

[ziggy]

So the PU in Canada is going to be as bad as it was at the beginning of the year?

No, they expect the PU will be as powerfull, as it should be in Melbourne. Better to say as it was calculated. If this is good or bad IDK.

Edit: it is also mentioned, that pre-chamber ingnition comes in Canada. So either it wasn't never there or they took it out after the testing shock.

[Vortex37]

Rather than me writing a long argument about indirect chambers. Let me point the technical people who are still viewing, to the work of Dr Dan Merritt [UK] and his lean burn technology. This is something I came across in 1988. If you take the time to read his notes, you will probably have a different view on the indirect chamber and what topology to select. Highly atomised fuel drops do not need to be spread out in the pre-chamber. In fact it is a disadvantage. My screen name was chosen to reflect my thoughts, about tumble and stratification. The latest Patents on the TJI principle look at intense swirl in a chamber that is very different to anything seen or suggested here. This also links into what might be a good main chamber topology - Excess air and keeping fuel away from cylinder walls. Merritt shows a method of creating a vortex swirl via a 'ramp shape', and the results. There was much discussion, back in the sensible days of the main thread, about stratification, and I think that a vortex injection from the pre-chamber is a better way to this end. The 'hose pipe' method seems intuitively wrong. The other issue is the problem of increased efficiency leading to lower exhaust temps and the effect on MGU-H/Turbo - change the pre-chamber/main chamber then affect downstream - reprogram and back to the beginning again. Thinking that just changing a few castings and off we go in a few weeks, is cloud cuckoo land for Honda or anybody.

Whilst the web link is substantially about lower emissions and improved fuel consumption, there are some lessons to be had.

https://www.pureburnengines.co.uk

[PlatinumZealot]

This is the best way of doing it. Just have to hope it counts as one injector.

If an injector had one pintle and one driver coil - I don't see how anyone could argue that it wasn't one injector.
Using those parameters multiple outlets are no problem in my mind.

If I get time this week I'll model some things in Solidworks. Would be great for discussion.

Two driver coils I would still consider one injector as long as they are in one barrel. The trick will be with the pintles.. And heat managment of said pintles. Two sets of pintles would require long neck as one set would be in the pre-chamber and the second set would be in the main chamber. Normally only the tip would be exposed to the heat, but now with this long neck, it would be exposed to combustion heat. Keeping that cool is a serious challenge!

I look forward to your design.

[MrPotatoHead]

Rather than me writing a long argument about indirect chambers. Let me point the technical people who are still viewing, to the work of Dr Dan Merritt [UK] and his lean burn technology. This is something I came across in 1988. If you take the time to read his notes, you will probably have a different view on the indirect chamber and what topology to select. Highly atomised fuel drops do not need to be spread out in the pre-chamber. In fact it is a disadvantage. My screen name was chosen to reflect my thoughts, about tumble and stratification. The latest Patents on the TJI principle look at intense swirl in a chamber that is very different to anything seen or suggested here. This also links into what might be a good main chamber topology - Excess air and keeping fuel away from cylinder walls. Merritt shows a method of creating a vortex swirl via a 'ramp shape', and the results. There was much discussion, back in the sensible days of the main thread, about stratification, and I think that a vortex injection from the pre-chamber is a better way to this end. The 'hose pipe' method seems intuitively wrong. The other issue is the problem of increased efficiency leading to lower exhaust temps and the effect on MGU-H/Turbo - change the pre-chamber/main chamber then affect downstream - reprogram and back to the beginning again. Thinking that just changing a few castings and off we go in a few weeks, is cloud cuckoo land for Honda or anybody.

Whilst the web link is substantially about lower emissions and improved fuel consumption, there are some lessons to be had.

https://www.pureburnengines.co.uk

Tumble is often used in intake port designs. I've personally made some intake port designs based around tumble because of some of the benefits it can bring. It helps a lot at part load especially.

But - I sense a lot of snake oil on that website. No offense.
Reading that reminds me of the super lean carborators or dimples like a golf ball inside intake ports (don't get me started on the dimples. Please)
If they all worked as advertised then people would have been using them for years.

Oh and you very much can make changes to designs and be testing new heads in weeks not months. Maybe not at Honda though.
I'll be at a shop in a few weeks working on a new billet cylinder head project (not F1). I'll see what pics I can share if any while I'm there.

[gruntguru]

The other issue is the problem of increased efficiency leading to lower exhaust temps and the effect on MGU-H/Turbo - change the pre-chamber/main chamber then affect downstream - reprogram and back to the beginning again.

That is a red herring. Efficiency gains in the piston section are paramount. If you trade any piston work for exhaust heat, the increase in turbine work will be a small fraction of the piston work lost.