Honda Power Unit Hardware & Software

[KAIZEN]

RA620H engine block (casting)




RA621H engine block (cutting)

[KAIZEN]

HONDA F1 turbine 3D printer

[Zynerji]

THIS is Formula 1!

[Hoffman900]

HONDA F1 turbine 3D printer
https://i.imgur.com/L7EYTdy.jpg

https://i.imgur.com/2D7Fao7.jpg

https://i.imgur.com/aMHKzl1.jpg

https://i.imgur.com/AFFyMAs.jpg

Reminds me of a dam water turbine.

[Hoffman900]

It looks like they propagate a Shockwave across the cylinder roof, and another across the crown of the piston, and make them converge in the head-gasket crevice.

Maybe that's how the 2021 Honda heads shrunk? Maybe they used the BMW head-on-cylinder casting method, and it's a machined crevice of particular design?

I doubt there is any crevice there. It’ll be in the crevice space from the top of the compression ring to the crown. This area is notorious for hiding unburnt fuel and extending the burn duration (and hurting emissions). You always make it as small as possible for the application.

[Hoffman900]

RA620H engine block (casting)
https://i.imgur.com/H1G6dwh.jpeg

https://i.imgur.com/5KEvzYv.jpeg

RA621H engine block (cutting)
https://i.imgur.com/lnalylF.jpeg

https://i.imgur.com/oqdx1Xn.jpeg

https://i.imgur.com/AEA2tzz.jpeg

Can you share what increased fatigue strength? I notice the 620 has the liners in it, but something in the center valley is blurred out.

Thanks!

[Zynerji]

It looks like they propagate a Shockwave across the cylinder roof, and another across the crown of the piston, and make them converge in the head-gasket crevice.

Maybe that's how the 2021 Honda heads shrunk? Maybe they used the BMW head-on-cylinder casting method, and it's a machined crevice of particular design?

I doubt there is any crevice there. It’ll be in the crevice space from the top of the compression ring to the crown. This area is notorious for hiding unburnt fuel and extending the burn duration (and hurting emissions). You always make it as small as possible for the application.

So, it would make sense to ignite that part first?

[Zynerji]

RA620H engine block (casting)
https://i.imgur.com/H1G6dwh.jpeg

https://i.imgur.com/5KEvzYv.jpeg

RA621H engine block (cutting)
https://i.imgur.com/lnalylF.jpeg

https://i.imgur.com/oqdx1Xn.jpeg

https://i.imgur.com/AEA2tzz.jpeg

Can you share what increased fatigue strength? I notice the 620 has the liners in it, but something in the center valley is blurred out.

Thanks!

Turbo oil feed and drain back in the blurred area?

[KAIZEN]

RA620H engine block (casting)
https://i.imgur.com/H1G6dwh.jpeg

https://i.imgur.com/5KEvzYv.jpeg

RA621H engine block (cutting)
https://i.imgur.com/lnalylF.jpeg

https://i.imgur.com/oqdx1Xn.jpeg

https://i.imgur.com/AEA2tzz.jpeg

Can you share what increased fatigue strength? I notice the 620 has the liners in it, but something in the center valley is blurred out.

Thanks!

It is explained that the fatigue strength increased by about 70% by changing from casting to cutting.
It is a cutting process of aluminum alloy.

[Hoffman900]

It looks like they propagate a Shockwave across the cylinder roof, and another across the crown of the piston, and make them converge in the head-gasket crevice.

Maybe that's how the 2021 Honda heads shrunk? Maybe they used the BMW head-on-cylinder casting method, and it's a machined crevice of particular design?

I doubt there is any crevice there. It’ll be in the crevice space from the top of the compression ring to the crown. This area is notorious for hiding unburnt fuel and extending the burn duration (and hurting emissions). You always make it as small as possible for the application.

So, it would make sense to ignite that part first?

In a typical port injected engine, fuel ends up caught in this crevice as the piston moves up the bore during the compression stroke. When the spark plug ignites, there can be raw fuel in these regions and it is the last exposed to the flame front. So you have a double whammy of being the last exposed as the piston descends as well as having potentially raw fuel in these regions. In a naturally aspirated engine, you run the top ring very close to the top of the crown to minimize this crevice volume.

On a turbo (or supercharged engine) you typically need to move these down further to expose them to less combustion heat. It could be down 7.6-11.5mm. It's also because those rings are a little thicker.

These engines are special cases though as there isn't any raw fuel floating around, I'm still trying to wrap my head around the process of what is happening here. I know a few people who have a better idea, so I'll have some offsite sidebars about this.

I do think of @Wazari 's comments about Fuji-san (a volcano) being the inspiration for the piston crown. Since this engine is now essentially a HCCI type engine (https://en.wikipedia.org/wiki/Homogeneo ... n_ignition), it would seem it would be similar-ish to Mazda's SkyActive engine which is a SCCI engine:


So similar, but it still relies on a spark plug as opposed to a jet ignition.

If you want to read more about Honda and HCCI engines, check out this 2015 white paper (it's free to sign up):
https://www.hondarandd.jp/point.php?pid=1043&lang=en

Spark-Assisted HCCI combustion, which assists ignition by igniting direct injection spray with a spark, has been proposed to help enable the practical realization of homogeneous charge compression ignition combustion, thereby achieving high thermal efficiency. This method increases the controllability of ignition, an issue of homogeneous charge compression ignition, and expands the range of ignition combustion by a maximum of three times compared to the conventional method.
The fuel efficiency of Spark-Assisted HCCI was verified, with results indicating a decrease of 16% in steady-state fuel consumption against cooled EGR combustion technology and a JC08 mode fuel efficiency simulation showing an increase of 4.5% in fuel efficiency.

Honda has been playing with HCCI since 1999.

[Hoffman900]

RA620H engine block (casting)
https://i.imgur.com/H1G6dwh.jpeg

https://i.imgur.com/5KEvzYv.jpeg

RA621H engine block (cutting)
https://i.imgur.com/lnalylF.jpeg

https://i.imgur.com/oqdx1Xn.jpeg

https://i.imgur.com/AEA2tzz.jpeg

Can you share what increased fatigue strength? I notice the 620 has the liners in it, but something in the center valley is blurred out.

Thanks!

It is explained that the fatigue strength increased by about 70% by changing from casting to cutting.
It is a cutting process of aluminum alloy.

Interesting. I'm assuming it needs to be heat treated then after cutting, did they mention anything along those lines? I'm surprised with the torsional loads of the each bank being load carrying for the rear suspension, that they don't need braces through the valley. Maybe there are in the assembled engine (the manifold?).

[ispano6]

RA620H engine block (casting)
https://i.imgur.com/H1G6dwh.jpeg

https://i.imgur.com/5KEvzYv.jpeg

RA621H engine block (cutting)
https://i.imgur.com/lnalylF.jpeg

https://i.imgur.com/oqdx1Xn.jpeg

https://i.imgur.com/AEA2tzz.jpeg

Can you share what increased fatigue strength? I notice the 620 has the liners in it, but something in the center valley is blurred out.

Thanks!

It is explained that the fatigue strength increased by about 70% by changing from casting to cutting.
It is a cutting process of aluminum alloy.

あまり教えちゃうと真似されるんじゃない？ｗ
せめて２０２２年開幕戦まで秘密にしておいたほうが。

To the person who downvoted me with the comment:
"Writing in Japanese? Really rude for the rest of the forum members"

This message was meant for the poster, don't take it personally. the use of the "w" has a specific meaning that Japanese people use.

Mod note: Please use English at all times in the future

[Hoffman900]

Can you share what increased fatigue strength? I notice the 620 has the liners in it, but something in the center valley is blurred out.

Thanks!

It is explained that the fatigue strength increased by about 70% by changing from casting to cutting.
It is a cutting process of aluminum alloy.

あまり教えちゃうと真似されるんじゃない？ｗ
せめて２０２２年開幕戦まで秘密にしておいたほうが。

They’re not sharing anything others don’t already know or have figured out.

[ispano6]

It is explained that the fatigue strength increased by about 70% by changing from casting to cutting.
It is a cutting process of aluminum alloy.

あまり教えちゃうと真似されるんじゃない？ｗ
せめて２０２２年開幕戦まで秘密にしておいたほうが。

They’re not sharing anything others don’t already know or have figured out.

But you're very keen to find out as much as you can and share with industry people right?

[Hoffman900]

あまり教えちゃうと真似されるんじゃない？ｗ
せめて２０２２年開幕戦まで秘密にしておいたほうが。

They’re not sharing anything others don’t already know or have figured out.

But you're very keen to find out as much as you can and share with industry people right?

They don’t work in F1. Two have involvement in NASCAR, so don’t worry.