Honda Power Unit Hardware & Software

[godlameroso]

Do you Sound of the engine?

Other cars sound similarly actually but you have to adjust your equalizer to hear. Not an accoustic engineer but whatever phiysics are in play makes the Honda sound come through more. The teams have definitlely been comparing sounds and trying things on the dyno as a result. Don't you find it intriguing why the engine manaufacturers are not commenting on the sounds of the other engines? I feel they all know what each other is doing when it comes to late combustion, exhaust flows and harmonics etc.

I am actually more interested in Honda changing the shape of the combustion chamber to make the valve steeper. This reminds of the increased tumble flow method.

If you increase compression ratio you either make the piston protrude more into the CC, or make the CC smaller and keep the piston as is. Or you do a combination of the two. Naturally to optimize the compression ratio and CC shape, as well as the port angles requires repackaging of everything in the head. Also when you consider the aero advantage of having a shorter cylinder head. By reducing the thickness of the camshaft by half you cut its strength by 400%, ditto for the camshaft girdle, so to go to the extremes Honda has made means they have absolute faith in the materials they're using.

Honda runs the wastegate open more than before, so it is natural that you would hear the engine 'more' as the turbo spends less time absorbing soundwaves.

If you reduce the bore spacing you also reduce coolant flow between the bores.

https://www.youtube.com/watch?v=X_TFlG__cH0

Look at how transparent unstable detonation is.

Are pneumatic valve springs easier on the cam than a high strength spring?

It's actually the retainers that wear out first.

[gruntguru]

Are pneumatic valve springs easier on the cam than a high strength spring?

Yes. Pneumatic springs do everything better, especially if variable pressure is permitted.

[godlameroso]

If you increase compression ratio you either make the piston protrude more into the CC, or make the CC smaller and keep the piston as is. Or you do a combination of the two. Naturally to optimize the compression ratio and CC shape, as well as the port angles requires repackaging of everything in the head. Also when you consider the aero advantage of having a shorter cylinder head. By reducing the thickness of the camshaft by half you cut its strength by 400%, ditto for the camshaft girdle, so to go to the extremes Honda has made means they have absolute faith in the materials they're using.

Honda runs the wastegate open more than before, so it is natural that you would hear the engine 'more' as the turbo spends less time absorbing soundwaves.

If you reduce the bore spacing you also reduce coolant flow between the bores.

https://www.youtube.com/watch?v=X_TFlG__cH0

Look at how transparent unstable detonation is.

Piston bowl shape is really important in these engines. Honda can play with that to easily adjust compression ratio.

I feel making a more extreme tumble flow design was the leading reason for changing the valve angle. The camshaft is lowerd as a side-effect becuase the use of the direct lifters.

Hmm here's something to jog the ol' noggin, are the rockers inboard or outboard, think about what happens to valve orientation and angle depending on where the rockers are popping the valves open.

If the rocker is inboard it means the valve angle is lower than 90 degrees relative to the cylinder deck. Classic pent roof shape. If the rocker is outboard and the valve is inboard you can get diesel like combustion chamber with the valves opening directly over the piston, then you can use different sized valves to promote swirl.

A good way to shorten the cylinder head is to eliminate the rocker and use the cam to directly activate the valve, then you can get away with only making the cam a few mm thinner and not drastically compromise strength.

[saviour stivala]

Agree. The most efficient is to use maximum battery power allowed every lap (120kw for 33.33 seconds of each lap) provided the recharge cycle can be repeated/sustained each lap. If that electrical deployment can be maintained 160 electrical HP FOR 33.33 seconds each lap will be added to the ICE crankshaft. Anything less than the maximum the rules allows, the amount shortfall will translate into the same amount loss at crankshaft output end.

Why would that be the most efficient and what efficiency? The best use of the MGU-k is the one that cuts the most amount of time from the lap.

This!

The battery is just another tool to defend, attack or cut lap-time. Its not free, but limited.

What Honda is saying is not that they will be dumping fuel or compromizing their engine into being an air pump to charge the battery, I think they are designing the charge system and combustion in such away that it operates with a certain level of back-pressure (high MGUH use) while still making good power.
I don't subscribe the dumping fuel proposal. There is no evidence of flames or soot constantly shooting out the back. We see clean clear scintillation and 99% of the time.

Of course the battery is another tool to defend, attack and cut lap-time. apart from that it is also part of the 'power unit' which as such as long as it have electric charge inside it to supply, as regards supplying the 'K' which in turn supply the crankshaft it does so every time the driver steps on the gas pedal, the driver have no say into this, this extra electrical power supply to the crankshaft is of course limited by the rules to a maximum of power and time per lap.
As to designing the charge system in in such a way that it operates with a 'certain level of back-pressure' (high MGU-H use). thanks for at least confirming that the turbocharger turbine type used in formula one is a pressure turbine, unless the waste-gates are open, that is. and with the waste-gates open, the exhaust turbine is of no help to the MGU-H in regards exhaust harvesting.

[mzso]

Why would that be the most efficient and what efficiency? The best use of the MGU-k is the one that cuts the most amount of time from the lap.

Which means the most efficient, since there's a fuel limit...

[hurril]

Why would that be the most efficient and what efficiency? The best use of the MGU-k is the one that cuts the most amount of time from the lap.

Which means the most efficient, since there's a fuel limit...

It really doesn't. This has more to do with when the car is power limited _and_ the speed is the lowest because at that point in time, the conversion of power to track travelled is the best. So when a given quantity of energy translates to the best raise in mean speed, that is where you do it.

An example of this is the beginning of an acceleration phase because the faster you can raise the speed from a low outset and with a large relative speed delta, the less time you spend a low speeds. This means that it can be time-efficient to waste fuel and ES by running max MGU-k and opening the waste gate(s) because the "multiplier" is at its greatest here.

Other parts of a track that are either not power limited, are short or are already at a "high enough" speed can be run with the engine working at optimum thermal (or do I mean mechanical?) efficiency and perhaps even charging the ES using both the MGU-h and the MGU-k. The reason for this is that the loss propulsion translates to so much more ES and saves so much fuel that the potential that provides for those other parts of the track is amortised. The loss in propulsion here is offset by the gain at the other parts.

[Zynerji]

I've always said that the largest benefit to the manufacturers in the current Formula isn't the PU hardware, but the control strategies as well as the simulation software that they needed to develop for full optimization.

Those 2 knowledge wells should have the most direct road-car "relevance".

[saviour stivala]

Waste-gate/s open means ES power is being shared by both ‘K’ and ‘H’. Certainly not the most efficient use of ES power. The most efficient use of ES power is adding maximum power * time per lap allowed by the rules to the crankshaft via MGU-K.

[godlameroso]

Four-valve-per cylinder diesel cylinder heads have the valves rotated in the combustion chamber. Pay close attention to the way the area above the intake valves is shaped to direct air flow in the cylinder bore.

[hurril]

https://s19529.pcdn.co/wp-content/uploa ... M_0611.jpg

Four-valve-per cylinder diesel cylinder heads have the valves rotated in the combustion chamber. Pay close attention to the way the area above the intake valves is shaped to direct air flow in the cylinder bore.

What is the benefit to rotating them like this?

[Sasha]

Why would there be? Again, you have to hear it to believe it.

Do you Sound of the engine?

Other cars sound similarly actually but you have to adjust your equalizer to hear. Not an accoustic engineer but whatever phiysics are in play makes the Honda sound come through more. The teams have definitlely been comparing sounds and trying things on the dyno as a result. Don't you find it intriguing why the engine manaufacturers are not commenting on the sounds of the other engines? I feel they all know what each other is doing when it comes to late combustion, exhaust flows and harmonics etc.

I am actually more interested in Honda changing the shape of the combustion chamber to make the valve steeper. This reminds of the increased tumble flow method.

If you increase compression ratio you either make the piston protrude more into the CC, or make the CC smaller and keep the piston as is. Or you do a combination of the two. Naturally to optimize the compression ratio and CC shape, as well as the port angles requires repackaging of everything in the head. Also when you consider the aero advantage of having a shorter cylinder head. By reducing the thickness of the camshaft by half you cut its strength by 400%, ditto for the camshaft girdle, so to go to the extremes Honda has made means they have absolute faith in the materials they're using.

Honda runs the wastegate open more than before, so it is natural that you would hear the engine 'more' as the turbo spends less time absorbing soundwaves.

If you reduce the bore spacing you also reduce coolant flow between the bores.

https://www.youtube.com/watch?v=X_TFlG__cH0

Look at how transparent unstable detonation is.

Just making room in the heads for the larger PC.
People just don't understand this new engine philosophy 'efficiency'
Put 25% of CC volume in the PC and that solves alot engineering headaches with very high CR with better CC control with no knock worries.
PC will have many flame outlets/ inlets ( radial and Axial.
Must get that energy out of the PC to the piston crown with minimum heat ( energy)loss
My testing showed 7 radial and 5 axial PC outlets the best with CC in piston crown. Smaller outlets radial and larger outlets axial( less pressure so less heat lost to piston crown...keep flame from hitting it)
PC doesn't have to be only an igniter
Very little CC roof angle 3 % to PC
Matching piston crown with CC dead center with high squash area around it.
New cam and valve gear design ( piston crown doesn't need valve cut outs)

I know nothing and people just laughed at a PC larger than 3-4%. They be state too much heat loss to PC walls.
Nope if that happened, you just have a bad CC design

[godlameroso]

https://s19529.pcdn.co/wp-content/uploa ... M_0611.jpg

Four-valve-per cylinder diesel cylinder heads have the valves rotated in the combustion chamber. Pay close attention to the way the area above the intake valves is shaped to direct air flow in the cylinder bore.

What is the benefit to rotating them like this?

Promotes swirl.

[godlameroso]

Doesn't increasing PC volume reduce CC compression ratio?

You mean 5 on the tip and 7 on the cap periphery?

[hurril]

I don't think I can buy the 25% figure because that's a lot of gasses that must cross those "flame in-/ outlets." Basically the combined area of those channels must be in some relation to half a valve.

[godlameroso]

Just making room in the heads for the larger PC.
People just don't understand this new engine philosophy 'efficiency'
Put 25% of CC volume in the PC and that solves alot engineering headaches with very high CR with better CC control with no knock worries.
PC will have many flame outlets/ inlets ( radial and Axial.
Must get that energy out of the PC to the piston crown with minimum heat ( energy)loss
My testing showed 7 radial and 5 axial PC outlets the best with CC in piston crown. Smaller outlets radial and larger outlets axial( less pressure so less heat lost to piston crown...keep flame from hitting it)
PC doesn't have to be only an igniter
Very little CC roof angle 3 % to PC
Matching piston crown with CC dead center with high squash area around it.
New cam and valve gear design ( piston crown doesn't need valve cut outs)

I know nothing and people just laughed at a PC larger than 3-4%. They be state too much heat loss to PC walls.
Nope if that happened, you just have a bad CC design

Doesn't increasing PC volume reduce CC compression ratio?

You mean 5 on the tip and 7 on the cap periphery?

I don't think I can buy the 25% figure because that's a lot of gasses that must cross those "flame in-/ outlets." Basically the combined area of those channels must be in some relation to half a valve.

Depends on the size of your CC, if you have a nearly flat head with 3 degrees, and your piston crown is your CC, then making the PC 25% of that volume is not excessive, nor requires as much flow as you imagine.