2014-2020 Formula One 1.6l V6 turbo engine formula

[henry]

The FIA imposed a limit for compression ratio of 1:18 a while back.

Can anyone confirm they are using a Miller cycle, because 1:18 is very high for an Otto cycle, even without turbo.

Miller would be a logical choice, to reduce the amount of exhaust gas, these ultra-lean burn engines produce. Sure the MGU-H can harvest it, but direct to the crank would be the best.

I doubt anyone outside the engine makers is likely to know. In 5 years very little has been confirmed about the actual operation of these power units.

A potential for Miller cycle would be to inject in such a way that some of the fuel/air is returned to the intake manifold where it could be mixing in preparation for the next cycle. This would help stratify the charge and emulate two injector jet combustion.

Honda released the info about the intake runner butterflies. I speculated at the time that they were pressurizing the intake runner during the compression stroke, or backfilling fuel into the plenum.

IIRC, lots of posters dismissed the concept out of hand. It's nice to read that it may have actually been done.

I’m not saying it’s done. I have zero information to allow me to do that. It’s a hypothesis, just as your suggestion was. Do you think operating butterflies at valve train frequency is practical? I would think that since the plenum is permanently pressurised a physical separator wouldn’t be necessary. The return volume would only be a small proportion of the cylinder volume.

[mzso]

Hi!

I just saw that there's an article of Ferrari's radio messages form the Russian GP on Racefans.
What do such might mean:

K1 plus available.
SOC 6.
Multi-function D O position four when you can.
Multi-function mix position 10 when you can.
Multi-function spark three.

[Zynerji]

I doubt anyone outside the engine makers is likely to know. In 5 years very little has been confirmed about the actual operation of these power units.

A potential for Miller cycle would be to inject in such a way that some of the fuel/air is returned to the intake manifold where it could be mixing in preparation for the next cycle. This would help stratify the charge and emulate two injector jet combustion.

Honda released the info about the intake runner butterflies. I speculated at the time that they were pressurizing the intake runner during the compression stroke, or backfilling fuel into the plenum.

IIRC, lots of posters dismissed the concept out of hand. It's nice to read that it may have actually been done.

I’m not saying it’s done. I have zero information to allow me to do that. It’s a hypothesis, just as your suggestion was. Do you think operating butterflies at valve train frequency is practical? I would think that since the plenum is permanently pressurised a physical separator wouldn’t be necessary. The return volume would only be a small proportion of the cylinder volume.

Honda's interview was clear that there were butterflies between the plenum and intake runner. I would imagine they would need to be operating at valve train speeds to work.

My hypothesis was to pressurize the 65cc-ish intake runners during the compression stroke, causing a high pressure flush of the cylinder at the moment of opening, and possibly entrainment from the plenum for cylinder packing.

[Zynerji]

Also, new KERS/HERS tech coming?

https://www.autoblog.com/2019/10/07/hun ... c-turbine/

[Mudflap]

Why not assume it operates just like a throttle? You know.. cause it's a throttle.. and it sits where a throttle is mean to sit ?

[henry]

Honda's interview was clear that there were butterflies between the plenum and intake runner. I would imagine they would need to be operating at valve train speeds to work.

My hypothesis was to pressurize the 65cc-ish intake runners during the compression stroke, causing a high pressure flush of the cylinder at the moment of opening, and possibly entrainment from the plenum for cylinder packing.

If your estimate of the runner volume is close then we might be looking at a doubling of basic turbo pressure. Do do that would require energy which would reduce crank power. I suppose if the combustion yields more power it would be net positive.

There was a video of the Honda emitting blue flames on the approach to a corner in Singapore, a situation in which they often run cylinder skipping. If there were fuel in the runners the skipped cylinders would pump fuel into the exhaust and that might show up as a blue flame. A long shot I know but who knows how these units actually work.

[hurril]

These high compression ratios are probably just a way to also have a greater expansion ratio. They probably bleed off some of that pressure by either having the intake our outlet valves open "too long." (Isn't this what's referred to as the Akin's cycle?)

Doing cylinder skipping and also dumping fuel out the exhaust sounds silly. Isn't the very purpose of the skipping that they may run an active few cylinders at an ideal efficiency rather than all of them in an inefficient manner?

[Zynerji]

Why not assume it operates just like a throttle? You know.. cause it's a throttle.. and it sits where a throttle is mean to sit ?

Because assumptions lead us no where. Speculation often expands understanding, and that is "truly" why I visit these forums.

[henry]

These high compression ratios are probably just a way to also have a greater expansion ratio. They probably bleed off some of that pressure by either having the intake our outlet valves open "too long." (Isn't this what's referred to as the Akin's cycle?)

Doing cylinder skipping and also dumping fuel out the exhaust sounds silly. Isn't the very purpose of the skipping that they may run an active few cylinders at an ideal efficiency rather than all of them in an inefficient manner?

Sometimes called Atkinson, sometimes Miller. Basicly as you say an making asymmetric compression and expansion.

Maybe silly, maybe counterintuitive. The fuel combusted in the exhaust/turbine would contribute to MGU-H power so not entirely lost. But you may well be right and the blue flames have some other explanation.

[hurril]

These high compression ratios are probably just a way to also have a greater expansion ratio. They probably bleed off some of that pressure by either having the intake our outlet valves open "too long." (Isn't this what's referred to as the Akin's cycle?)

Doing cylinder skipping and also dumping fuel out the exhaust sounds silly. Isn't the very purpose of the skipping that they may run an active few cylinders at an ideal efficiency rather than all of them in an inefficient manner?

Sometimes called Atkinson, sometimes Miller. Basicly as you say an making asymmetric compression and expansion.

Maybe silly, maybe counterintuitive. The fuel combusted in the exhaust/turbine would contribute to MGU-H power so not entirely lost. But you may well be right and the blue flames have some other explanation.

While I agree with that, I've come to understand that this is less efficient than having it expand against a/ the piston?

What if those mythical blue flames have something to do with the RPM range in that: suppose that the ICE has to be over some threshold in order for the valve timing to impose the correct "breathing" related to this? Underneath it, it'll leak (until they've re-map:ed it.)

[henry]

These high compression ratios are probably just a way to also have a greater expansion ratio. They probably bleed off some of that pressure by either having the intake our outlet valves open "too long." (Isn't this what's referred to as the Akin's cycle?)

Doing cylinder skipping and also dumping fuel out the exhaust sounds silly. Isn't the very purpose of the skipping that they may run an active few cylinders at an ideal efficiency rather than all of them in an inefficient manner?

Sometimes called Atkinson, sometimes Miller. Basicly as you say an making asymmetric compression and expansion.

Maybe silly, maybe counterintuitive. The fuel combusted in the exhaust/turbine would contribute to MGU-H power so not entirely lost. But you may well be right and the blue flames have some other explanation.

While I agree with that, I've come to understand that this is less efficient than having it expand against a/ the piston?

What if those mythical blue flames have something to do with the RPM range in that: suppose that the ICE has to be over some threshold in order for the valve timing to impose the correct "breathing" related to this? Underneath it, it'll leak (until they've re-map:ed it.)

Not mythical at all: here’s a link to a video of it, originally posted by @jaisonas.

https://streamable.com/31qsx

You’re right that in absolute power terms crank power is preferred. But if it were only a part of a full cycle fuel input then it might not be.

But @gruntguru’s suggestion that it is for turbo spooling is probably more likely.

[gruntguru]

Agree with @mudflap. Highly unlikely (and probably illegal) to operate butterflies at valve train frequency. You would be talking six actuators operating at very high speed. It is hard enough to get the intake valves to operate at these speeds - butterflies as well???

Using Miller cycle to help homogenise main-chamber mix - quite possible - interesting idea.

On definitions Atkinson cycle describes the general family of engines with CR<ER including those using weird mechanisms. (eg https://www.youtube.com/watch?v=CNsJOsnuIMA)

Miller cycle is a subset of these using valve timing to reduce CR without affecting ER.

[Zynerji]

Agree with @mudflap. Highly unlikely (and probably illegal) to operate butterflies at valve train frequency. You would be talking six actuators operating at very high speed. It is hard enough to get the intake valves to operate at these speeds - butterflies as well???

Using Miller cycle to help homogenise main-chamber mix - quite possible - interesting idea.

On definitions Atkinson cycle describes the general family of engines with CR<ER including those using weird mechanisms. (eg https://www.youtube.com/watch?v=CNsJOsnuIMA)

Miller cycle is a subset of these using valve timing to reduce CR without affecting ER.

It is proven that the "butterflies" exist as I've described. They look like an oddly formed cam shaft, so 3 cylinders operated per shaft.

At this point, how is there still an argument? It would only make sense that it would operate at valve train speeds as synchronization would obviously be required.

[wuzak]

Could these butterflies be part of the variable inlet system?

[Nickel]

I'm no expert but it seems to me the blue flames from the Honda are just run of the mill anti lag, as stated by others.

While it might seem redundant with the MGU-H, what if they've simply calculated that the electrical losses of charging the battery and then discharging to keep turbo spooled carry a larger penalty than the extra fuel weight needed to run anti lag timing?

As others have said as well, this would come with the benefit that a small amount of energy might even be harvested instead of depleting the energy store?

Has anyone managed to ascertain if this behavior is present in the Honda for the duration of the race? If not, it could simply be present in the higher power modes, saving ES deployment for actually propelling the car forward during we Quali and short bursts of the race.