Honda Power Unit Hardware & Software

[taperoo2k]

It looks like Honda is not going to change anything.

https://goo.gl/photos/49qrrFkANYpq6wvX8

goo.gl/photos/WovgAG45Tjm93Wj96

The fixes Honda are working on, are likely not ready for the track. No point in changing anything until they are, otherwise you just rack up grid penalties for no real reason and look even more silly if the changes don't improve the situation or indeed make them worse. I know quite a number of people have run out of patience with Honda, but that does not change the engineering realities of developing the fixes required.

[dren]

You know this for a fact? Surely, every PU manufacturer direct powers the K from the H for much of the lap.

You should read Wazari

Just did a search, thanks. I must have missed that topic because I've read most of his posts.

[glenntws]

Only time can tell what Honda will make out of the existing engine. I'm still confident that Honda uses the right technologies to make the most powerful engine in F1, however they have little problems which can be fixed.

I hate to say this because this may sound weird or whatever, but it seems that my idea of a bad mixture in the pre-chamber was somehow right. It fits to the fact that the combustion process gets hugely affected by the other cylinders. A change in the outlet or inlet pressure can have a big impact on the cylinder internal motions which in turn change the charge you have in the pre-chamber.

To fix this problem, it should be enough to change the valve timing and the exhaust pipe length, maybe a little change on the chamber but that should be enough. The neccessary changes aren't big but they require much fine tuning.

This were my 2 cents on this whole discussion, if you agree then good, if not then not. Because some persons here seem to always have the opinion that everything they don't say is wrong. But we're here to discuss so hey, it's fine

On and: It seems like so many topics get retold all the time, people don't seem to read the 10 last pages before posting something. Maybe it's all our duty to change that a bit

[godlameroso]

In other words they just have to tweak what they have? That some subtle precise changes need to be made? How will they realize the correct changes? Simulation or trashing different heads, or cam grinds? I think it's a bit more complex than simple cam timing (lift and duration more likely) because changing cam advance or retard is a trifle even for us mere mortals.

[dren]

Glen, Are you assuming the prechamber is fed with the same chamber charge, or is it fed by a separate nozzle on the injector? If it's two nozzles on one injector, I'd say the combustion instability at very lean mixes in the main chamber wasn't an issue with one cylinder, but it was with 3. Thus, they are having to run richer in the main chamber now, which explains the bad FE. That's my guess

[fellowhoodlums]

If it was easy it wouldn't have taken Ferrari that long to get it right.

[glenntws]

In other words they just have to tweak what they have? That some subtle precise changes need to be made? How will they realize the correct changes? Simulation or trashing different heads, or cam grinds? I think it's a bit more complex than simple cam timing (lift and duration more likely) because changing cam advance or retard is a trifle even for us mere mortals.

Yeah, I should have take more time to write the text, of course duration is more important. Lift isn't as important, because the cam is tweaked for maximum airflow so they will probably not play with that too much. Valve opening Profile could be different also, but this is a very restricted area because of the motions.

The tweaks alone are not that big - at least in perspective to the whole PU - but without changing all these elements I think they won't able to get a combination which works out well. The way they could get that "combination" is by using a more extensive PU simulation. It's iumportant for them to achieve a relation between exhaust turbine, the exhaust manifold and the main chamber to get the exhaust pressure values as correctly as possible. When this relation is made right, it's a thing of CFD ressources and try and error (where you can get closer with every simulation by taking the charging motions as a standpoint).

I expect them to already have this relation, which didn't exist before january or so (at least I expect that). When they are close to a good solution they could again reduce the simulation complexity and use existing results as a additional value to get good approximations.

When you talk about subtle, it must be seen in perspective, a timing or duration change can be seen as a little change in perspective to PU complexity. I believe the hardest part will be the redesign of the exhaust because I expect them to have some problems there, because that's the spot where the backpressure get's to the cylinder. They have to rethink pipe layout and most importantly pipe length.

Glen, Are you assuming the prechamber is fed with the same chamber charge, or is it fed by a separate nozzle on the injector? If it's two nozzles on one injector, I'd say the combustion instability at very lean mixes in the main chamber wasn't an issue with one cylinder, but it was with 3. Thus, they are having to run richer in the main chamber now, which explains the bad FE. That's my guess

I am assuming that the main chamber get's filled with the complete charge, while leaving a "high fuel ratio cloud" close to the pre-chamber nozzles. This design is complex to achieve because your charging motion needs to work hand in hand with the fuel spraying. However, if you get this right, you profit from the transient flow from rich to lean mixture which further improves burning quality and by that ICE efficiency. Yeah your guess was what I sadi some pages ago The charge motion is not working out right in some situations and by that, the fuel is not correctly positioned and the charge quality in the pre-chamber get's very bad. So they need to run richer to get a acceptable jet quality. And yes, that would be the reason for the bad efficiency

My approx.: If they get the problems fixed, they will have increased ICE efficiency by at least 5%, if not even more (something like 8-10%).

[Richard C]

Glen, Are you assuming the prechamber is fed with the same chamber charge, or is it fed by a separate nozzle on the injector? If it's two nozzles on one injector, I'd say the combustion instability at very lean mixes in the main chamber wasn't an issue with one cylinder, but it was with 3. Thus, they are having to run richer in the main chamber now, which explains the bad FE. That's my guess

Long time viewer, first time poster!

I hate to even bring this up given the arguments around the Mahle diagrams, number of injectors and what the regulations allow. But I am curious as to how creative you can be with respect to Reg 5.10.2 (one direct injector per cylinder). Specifically how do you define what exactly an "injector" is. As mentioned in the quote above, can you have multiple nozzles per injector? Can a single injector be designed to have different modes of operation? Either actively (some type of secondary solenoid) or passively (mechanical design such as I mention below)? I see no definition in the technical regulations as to the design of a fuel injector such as number of solenoids, needle valves, input signals. I believe these components have to be approved by the FIA in advance and that means someone has to make a judgement call on the design. If I was the FIA, I can see limiting the design of a single injector to having a single input signal and maybe a single solenoid and single needle valve. What if the needle valve had a complex design so that fuel flows out more than a single high pressure nozzle and may even have different timing and flow profiles for each nozzle. In short could a single (complex) injector still work somewhat like the Mahle system. With one path flowing into an enclosed pre-combustion chamber and a second path into the main combustion chamber. That with correct design you would allow for correct conditions in both (rich in pre and lean in main). With the difficulty in getting a mechanical design to operate under all conditions.

Thanks for considering my comment and be kind to me!

Richard

[PlatinumZealot]

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.

Fouling of the nozzle holes were the issue in the petrol application in that Passive prechaber spark plug study (which was mostly about LNG as fuel). Note that pre-chamber spark plugs are a different beast to TJI. There is some amount of soot still even on the best "sootless" gas engines there is soot recorded in visible light spection (Orange colour). Most of it gets burned off as it passes through the exhaust but it is still there in the chamber and very likely is present even in these High AFR liquid fuel engines.

Remember that orange powdery coating inside the exhaust pipes? There is definitely some fouling going on inside the engines. Whether they have some sort of cleaning cycle or the teams are allowed to change certain parts I don't know.

[PlatinumZealot]

Only time can tell what Honda will make out of the existing engine. I'm still confident that Honda uses the right technologies to make the most powerful engine in F1, however they have little problems which can be fixed.

I hate to say this because this may sound weird or whatever, but it seems that my idea of a bad mixture in the pre-chamber was somehow right. It fits to the fact that the combustion process gets hugely affected by the other cylinders. A change in the outlet or inlet pressure can have a big impact on the cylinder internal motions which in turn change the charge you have in the pre-chamber.

To fix this problem, it should be enough to change the valve timing and the exhaust pipe length, maybe a little change on the chamber but that should be enough. The neccessary changes aren't big but they require much fine tuning.

This were my 2 cents on this whole discussion, if you agree then good, if not then not. Because some persons here seem to always have the opinion that everything they don't say is wrong. But we're here to discuss so hey, it's fine

On and: It seems like so many topics get retold all the time, people don't seem to read the 10 last pages before posting something. Maybe it's all our duty to change that a bit

Maybe they don't have two injectors so they are prone to poor pre-chamber filling.

[godlameroso]

Somewhere in one of these engine threads, multiple stage injector has been discussed but nothing much came of it. Ferrari apparently has a "dual anchor" injector in the works, or maybe already has it, that's supposed to inject fuel with more precision. As far as I know that's the ticket, not just how good your combustion chamber, and the things supporting it, but also how precisely you can inject fuel(how fast, and in what dose relative to piston speed.) At 12,500 rpm mean piston speed is ~80km/h and it's only moving about 56mm so to be able to make multiple injections to set up your combustion event takes a very fast and precise injector.

https://www.youtube.com/watch?v=j8gvgISVHak

Just look at how fast pistons move, now imagine having to make two injections, one on the down and one on the up stroke, there's not much time to do it.

[gruntguru]

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.

No. TJI burns the mixture faster by creating multiple ignition points all through the mixture (wherever the jets penetrate)

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.

There is no auto-ignition - no "deliberate" detonation - no compression ignition - the engine would not run if the sparks were stopped.

[gruntguru]

Maybe they don't have two injectors so they are prone to poor pre-chamber filling.

I tend to agree with this:

If the pre-chamber only needs 2% - 3% of total fuel it would be very difficult to meter accurately if for example the pre-chamber was supplied using one nozzle of a multi-nozzle injector. Such a strategy would fix the ratio of pre-chamber fuelling at say 2% regardless of total fuel quantity.

The pre-chamber needs to operate at a fairly consistent AFR - say 0.8 - 0.9 whereas the main chamber would conceivably need to be varied between 1.0 and 2.0. So if you set the pre-chamber mixture at 0.8 when the main-chamber is at 1.0, the pre-chamber will be at 1.6 when the main-chamber is at 2.0.

I think the FIA should loosen up the "single injector" rule sufficiently to allow full implementation of the Mahle system and all its benefits. (eg they could allow a second injector providing its capacity was less than 5% of total fuel) This would simplify the process of optimising chamber design - save a lot of money and improve the chances for lagging engine teams to catch up.

[gruntguru]

At 12,500 rpm mean piston speed is ~80km/h and it's only moving about 56mm so to be able to make multiple injections to set up your combustion event takes a very fast and precise injector. . . Just look at how fast pistons move, now imagine having to make two injections, one on the down and one on the up stroke, there's not much time to do it.

Simplifying - @ 12,500 rpm, the entire intake and compression strokes take a total of about 5 ms - you have to fit all your injection events in there somewhere.

[Tommy Cookers]

on the previous page one post refers to injection solenoids .....
but surely all F1 uses piezoelectric injectors ?
maybe those who study the photos know this

for now, though these may not be the best of links
http://www.keko-equipment.com/Piezo_Injection.php
https://sharpautos.wordpress.com/2013/0 ... -solenoid/
http://www.caranddriver.com/features/te ... -explained