Honda Power Unit Hardware & Software

[gruntguru]

Compare this to a current F1 engine which can be assumed to run at 4 bar PR and say a CR of 14 with 100C air temperature after charge cooling. Assuming adiabatic compression with air as an ideal gas the conditions at the end of the compression stroke are about 160 bar and close to 800C. That is before heat even being released from fuel at more or less constant volume (not constant pressure as in a gas turbine). You can go on and calculate what the conditions are after say 50% of the heat has been released but I am hoping that the point I am making is quite obvious by now.

I did some rough calcs for the lean-burn F1 engine on another forum.

Assumptions.
- MAP=4.0
- Intercooling to 27*C (300*K)
- VE=100%
- CR=18
- AFR=2.0
- n= 1.28 (polytropic compression index)
- Fuel Heating Value = 41 MJ/kg
- All fuel burned at TDC with zero heat loss.
- Cp air @ TDC = 1.2 kJ/kg.K

At TDC after compression. Pressure = 160 bar, Temperature = 673*K (400*C)
At TDC after combustion. Pressure = 483 bar, Temp = 1815*K (1542*C)

[63l8qrrfy6]

I assumed adiabatic compression with gamma=1.4 so it will predict higher pressures.

The lowest temperature the charge air can have is more or less equal to water temperature coming out of the car radiator (for a water cooled charge cooler) so can't be too far below 100C unless there is a dedicated low temperature cooling loop.

[gruntguru]

With dedicated charge air cooling circuits I think F1 would be somewhere between your temp and mine. No doubt they will control CAT for optimum balance of TE and knock. So CAT will be whatever they want it to be.

[63l8qrrfy6]

As long as the heat rejection required does not impose too large a radiator. Otherwise the charge temperature will probably be the maximum that still allows MBT spark timing.

[godlameroso]

Turbine pressure ratios are not measured the same way as in what you're describing in an ICE compadré.

Pressure ratio is air coming in and thrust coming out, it is not the same as the compression ratio, which is much higher than 68:1.
If we measure like for like then you'd have to measure intake pressure vs exhaust pressure of the ICE.

Wrong again.
First of all I did not make a single reference to turbine pressure ratios. I have strictly talked about compressor pressure ratio which is the ratio of outlet pressure to inlet pressure.

I never said that pressure ratio is the same as the compression ratio either. For the ICE calculations I showed I only use the pressure ratio to estimate the initial conditions at the beginning of the compression stroke. I then use the compression ratio to calculate the gas conditions at the end of the compression stroke assuming adiabatic compression. It is all very basic thermodynamics.

As for aero engine compressor overall pressure ratios you don't have to take my word for it, just google it.

Edit:
Do you normally use the rate button when you run out of science?

I haven't used the rate button once as I don't take it personal. Also not a scientist in the academic sense, more of a get my hands dirty sort of sense. The current discussion would segway nicely into cylinder filling because reversion at these pressure ratios would certainly become an issue. If your ports can flow air into the cylinders well, it can flow out just as well. Also more ceefums(CFMs) doesn't necessarily mean more power for the aforementioned reason.

Again, I wonder what Honda is doing, if they're using teardrop vanes by the valves to induce swirl, or if they're like Ferrari, going to do something like this?

https://www.jstor.org/stable/44467045?seq=1

[godlameroso]

https://www.cycleworld.com/story/motorc ... uperbikes/

[bigblue]

https://www.cycleworld.com/story/motorc ... uperbikes/

Nice! Is that rotating pre-chamber outlawed by F1 regs ? Or not relevant to F1 appliction for some reason ?

[godlameroso]

https://www.cycleworld.com/story/motorc ... uperbikes/

Nice! Is that rotating pre-chamber outlawed by F1 regs ? Or not relevant to F1 appliction for some reason ?

The rules don't say anything about having a rotating pre-chamber in these engines. I don't know if they use that in F1.

Only rules I see is the cylinder bore must be circular and concentric as do the valve seats, and valves. The regulations do not control combustion chamber shape, features, or function, save for one spark plug and one injector inside the combustion chamber. Nor do they specify shapes of intake or exhaust ports.

[etusch]

We've got constructive discussions going on with Honda and the FIA, and I think that we are close to coming to a conclusion,” he said.

“The FIA are consulting the other teams. I think there's alignment regarding a freeze. It's just, should there be a safety net if an engine manufacturer under shoots from one season to the next? Otherwise, to lock in performance for three years, could be quite damaging.”

Honda is open to the idea of allowing Red Bull to continue using its power units, but admits finding an agreement is not easy, with manufacturing of components being split between Milton Keynes and Japan

https://www.motorsport.com/f1/news/red- ... n=widget-1

[etusch]

Honda had said that they wanted to bring some tech to their engine but fia didn't approved. I wonder if this prechamber tech is one of them.

Driven by the cam chain, this rotary valve solves one of the problems of prechamber combustion, which is that it’s difficult to completely purge exhaust gas from the prechamber during the exhaust stroke. Honda’s rotary valve arrangement opens a wide “door” to the prechamber during the exhaust and intake strokes, making sure all the burned gas is replaced with fresh charge. This “door” then closes during the compression stroke, allowing the second fuel injector to add more fuel to the prechamber without mixing any of it into the much leaner mixture in the main chamber.

https://www.cycleworld.com/story/motorc ... uperbikes/

[PlatinumZealot]

[quote=sn809 post_id=940262 time=1606179933 user_id=38858]

Wow, sad to say this but then they are in dreamland. Usually Honda is up there with Tech development but it seems to be missing in action now days.

Most countries would have banned ICE by then. If they need to do something its all electric now.
Hybrid tech at least Plug in might be useful for the next couple of years and that is it, it will be the end of the line.
[/quote]

Your theory is not realistic. I see you are being tricked by all the EV marketing!! Ha.
Going by observations of all sectors and some reading, I can say ICE technologies for passenger cars will be around for decades more, yet. Maybe even longer.

[PlatinumZealot]

https://www.cycleworld.com/story/motorc ... uperbikes/

Nice! Is that rotating pre-chamber outlawed by F1 regs ? Or not relevant to F1 appliction for some reason ?

It was considered by posters here iirc. The argument was whether it is called a valve or not and whether it counts as additional moving parts.

[Big Tea]

Wow, sad to say this but then they are in dreamland. Usually Honda is up there with Tech development but it seems to be missing in action now days.

Most countries would have banned ICE by then. If they need to do something its all electric now.
Hybrid tech at least Plug in might be useful for the next couple of years and that is it, it will be the end of the line.

Your theory is not realistic. I see you are being tricked by all the EV marketing!! Ha.
Going by observations of all sectors and some reading, I can say ICE technologies for passenger cars will be around for decades more, yet. Maybe even longer.

I know it may seem splitting hair, but are any countries banning ICE's?
There are several who have said they will not allow production of ICE only vehicles, but don't recall any ban on ICE, which would include gas (not gasoline, but the likes of hydrogen) Bio fuels with ultra low emission etc.

[Rodak]

It looks like the rotating pre-chamber setup requires two fuel injectors, one for a rich mixture in the pre-chamber and the other for the lean combustion mixture. F1 only allows one injector....

[rogazilla]

It looks like the rotating pre-chamber setup requires two fuel injectors, one for a rich mixture in the pre-chamber and the other for the lean combustion mixture. F1 only allows one injector....

Inject twice from single injector?