F1technical.net

godlameroso wrote: ↑

02 Oct 2017, 22:02

Wazari wrote: ↑

02 Oct 2017, 21:51

godlameroso wrote: ↑

02 Oct 2017, 01:28

The dimples would increase turbulence in this instance? The dimples would not be uniform in size or distribution? Perhaps to control the pressure distribution in the chamber during the compression and power strokes?

Final question, are the finishes on the ports similar to this old V10 head? (~320 grit uniform)
viewtopic.php?f=4&t=15385

Or is the finish not uniform on the intake?

No dimples on the ports. Port finish is uniform but finer than 320 grit.

Interesting that the ports use uniform finishes, I suppose using different finishes on the roof vs floor of the port has no benefit or they'd be doing it.

Is extrusion honing crude in comparison to the type of finishing taking place?

I think that rough finish is not for aerodynamics. But to prevent fuel from puddling on the walls. The V10 engines were showered in fuel from those port injectors so i assume that you want to prevent any coallescing which would happen on a smooth surface..

These V6 engines i suspect will have smooth ports and chambers. Also helps thermal efficiency too by reflecting radiation.

PlatinumZealot wrote: ↑

03 Oct 2017, 14:10

godlameroso wrote: ↑

02 Oct 2017, 22:02

Wazari wrote: ↑

02 Oct 2017, 21:51

No dimples on the ports. Port finish is uniform but finer than 320 grit.

Interesting that the ports use uniform finishes, I suppose using different finishes on the roof vs floor of the port has no benefit or they'd be doing it.

Is extrusion honing crude in comparison to the type of finishing taking place?

I think that rough finish is not for aerodynamics. But to prevent fuel from puddling on the walls. The V10 engines were showered in fuel from those port injectors so i assume that you want to prevent any coallescing which would happen on a smooth surface..

These V6 engines i suspect will have smooth ports and chambers. Also helps thermal efficiency too by reflecting radiation.

Rough port surfaces were a thing of the dark ages when carbs were still the fueling mechanism of choice

These days a little smoother is desired - but not too smooth. There is a sweet spot of around 10 to 20 microns cusp height on a cnc ported head that performs the best. This seems to produce a boundary layer that is about perfect.

- Honda demanded that Toro Rosso build the car around the engine.
- This is to avoid ridiculous requests made by Mclaren in the past.
- They even have already planned the year in terms of development.

HPD wrote: ↑

03 Oct 2017, 15:44

- Honda demanded that Toro Rosso build the car around the engine.
- This is to avoid ridiculous requests made by Mclaren in the past.
- They even have already planned the year in terms of development.

Or maybe they learnt from their mistakes.

Rough surfaces do help aerodynamics, otherwise birds wouldn't have feathers and sharks wouldn't have rough texture skin.

MrPotatoHead wrote: ↑

03 Oct 2017, 14:14

These days a little smoother is desired - but not too smooth. There is a sweet spot of around 10 to 20 microns cusp height on a cnc ported head that performs the best. This seems to produce a boundary layer that is about perfect.

Also I'd assume with 4 -5 bar of boost and 12000rpm port velocity must be pretty high too; with dimples wayyy too small to have any effect as the dimpled surface would just stall and act as a smooth surface anyway.

HPD wrote: ↑

03 Oct 2017, 15:44

- Honda demanded that Toro Rosso build the car around the engine.
- This is to avoid ridiculous requests made by Mclaren in the past.
- They even have already planned the year in terms of development.

Where do you read that? But sounds logical, McLaren demanded way too much from Honda. RBR can't demand too much from Renault either, just reliability and power.

HPD wrote: ↑

03 Oct 2017, 15:44

- Honda demanded that Toro Rosso build the car around the engine.
- This is to avoid ridiculous requests made by Mclaren in the past.
- They even have already planned the year in terms of development.

Didn't Arai already say McLaren made no such requests? I don't want to get into this debate but this whole "McLaren demanded size-zero" --- has went on too far because I clearly remember Hasegawa saying 2017 PU is going to be even smaller(and/or better packaged) and lighter than 2016 PU (which was size-zero). Sigh.

ncassi22 wrote: ↑

03 Oct 2017, 17:45

MrPotatoHead wrote: ↑

03 Oct 2017, 14:14

These days a little smoother is desired - but not too smooth. There is a sweet spot of around 10 to 20 microns cusp height on a cnc ported head that performs the best. This seems to produce a boundary layer that is about perfect.

Also I'd assume with 4 -5 bar of boost and 12000rpm port velocity must be pretty high too; with dimples wayyy too small to have any effect as the dimpled surface would just stall and act as a smooth surface anyway.

Apparently there's more to consider, Mr.Potato Head was kind enough to divulge that the ports are just a fraction of where gains and losses can be made. Apparently we are still at the black art of valve seat and throat sculpting, that the ports themselves are already well understood, and that there's a lot of gains to be had with the stuff that attaches to the ports. I.e. the intake pipes, the exhaust, the intercooler, the length of the intakes, and then how to benefit from all of that with the MGU-H.

My own musings:
I'd imagine there's a lot of dynamic pressure tuning, potentially a source of turbo destroying reverse pressure waves mixed in there. This would certainly be an issue if this area was left to the last moment, the issue wouldn't be seen until it was encountered in the real world.

makecry wrote: ↑

03 Oct 2017, 19:09

HPD wrote: ↑

03 Oct 2017, 15:44

- Honda demanded that Toro Rosso build the car around the engine.
- This is to avoid ridiculous requests made by Mclaren in the past.
- They even have already planned the year in terms of development.

Didn't Arai already say McLaren made no such requests? I don't want to get into this debate but this whole "McLaren demanded size-zero" --- has went on too far because I clearly remember Hasegawa saying 2017 PU is going to be even smaller(and/or better packaged) and lighter than 2016 PU (which was size-zero). Sigh.

Having the engine, its ancillaries and the ERS impede on the car’s aerodynamic performance was simply not an option,” said McLaren racing director Eric Boullier. “The chassis has been designed to wrap up so compactly at the rear that we had to include all elements into a tight package with nothing sticking out. In order to achieve this, Honda actually had to make several attempts and come up with three versions of the power unit because the initial two did not meet the chassis/aero technical specifications. It took them a lot of effort.”

http://en.f1i.com/magazine/10369-hondas ... esign.html

Squid wrote: ↑

03 Oct 2017, 19:35

makecry wrote: ↑

03 Oct 2017, 19:09

HPD wrote: ↑

03 Oct 2017, 15:44

Didn't Arai already say McLaren made no such requests? I don't want to get into this debate but this whole "McLaren demanded size-zero" --- has went on too far because I clearly remember Hasegawa saying 2017 PU is going to be even smaller(and/or better packaged) and lighter than 2016 PU (which was size-zero). Sigh.

Having the engine, its ancillaries and the ERS impede on the car’s aerodynamic performance was simply not an option,” said McLaren racing director Eric Boullier. “The chassis has been designed to wrap up so compactly at the rear that we had to include all elements into a tight package with nothing sticking out. In order to achieve this, Honda actually had to make several attempts and come up with three versions of the power unit because the initial two did not meet the chassis/aero technical specifications. It took them a lot of effort.”

http://en.f1i.com/magazine/10369-hondas ... esign.html

https://asia.nikkei.com/Business/Compan ... ear?page=2

Some analysts say that the technological troubles you encountered stemmed from McLaren's "size zero" concept, which called for an extremely small power unit. Do you intend to make any size changes in 2016?

No. F1 cars cannot go fast without proper consideration given to air resistance and the way suspensions move. It's important to minimize the size of power units so that they don't interfere with the car's design. ... McLaren once told us that we don't have to be aggressive in downsizing our power unit. But we are determined to shrink the size by whatever means possible.

See?

And then Hasegawa said 2017 PU is even smaller and better packaged. Size-zero being a deterrence has been blown way out of proportion, it was the entire concept that sucked, not it's size.

makecry wrote: ↑

03 Oct 2017, 19:09

HPD wrote: ↑

03 Oct 2017, 15:44

- Honda demanded that Toro Rosso build the car around the engine.
- This is to avoid ridiculous requests made by Mclaren in the past.
- They even have already planned the year in terms of development.

Didn't Arai already say McLaren made no such requests? I don't want to get into this debate but this whole "McLaren demanded size-zero" --- has went on too far because I clearly remember Hasegawa saying 2017 PU is going to be even smaller(and/or better packaged) and lighter than 2016 PU (which was size-zero). Sigh.

They're just a costumer team and look what they're expecting.

“We also have the possibility to work with them – to put ideas in the box for the future that might be taken into consideration. That will allow us to influence in the future. But yes, a full works team is different from our situation in 2018.”

https://www.grandprix247.com/2017/09/20 ... -red-bull/

etusch wrote: ↑

03 Oct 2017, 19:44

makecry wrote: ↑

03 Oct 2017, 19:09

HPD wrote: ↑

03 Oct 2017, 15:44

Didn't Arai already say McLaren made no such requests? I don't want to get into this debate but this whole "McLaren demanded size-zero" --- has went on too far because I clearly remember Hasegawa saying 2017 PU is going to be even smaller(and/or better packaged) and lighter than 2016 PU (which was size-zero). Sigh.

They're just a costumer team and look what they're expecting.

“We also have the possibility to work with them – to put ideas in the box for the future that might be taken into consideration. That will allow us to influence in the future. But yes, a full works team is different from our situation in 2018.”

https://www.grandprix247.com/2017/09/20 ... -red-bull/

Meh, Renault has already said that the deal is more than just a customer deal. I cba to find that article but they are not "just a customer team" and expecting too much. Look it up. I don't get your point but, I thought this is Honda thread so why are you bringing up Renault here?

makecry wrote: ↑

03 Oct 2017, 19:09

HPD wrote: ↑

03 Oct 2017, 15:44

- Honda demanded that Toro Rosso build the car around the engine.
- This is to avoid ridiculous requests made by Mclaren in the past.
- They even have already planned the year in terms of development.

Didn't Arai already say McLaren made no such requests? I don't want to get into this debate but this whole "McLaren demanded size-zero" --- has went on too far because I clearly remember Hasegawa saying 2017 PU is going to be even smaller(and/or better packaged) and lighter than 2016 PU (which was size-zero). Sigh.

I would expect that all PUs would become smaller and better packaged as that's part of year on year development. It's not just all about power increases.

We should not enter into old debates.
Of the statements we read, the blame was 50 - 50.
Honda has already admitted its share of the blame. Mclaren, I do not know.
Peace.