crankshaft counterweight shape

[Kevin Johnson]

If you examine a large number of engines from different manufacturers one of the hallmarks of good design is rounded-end main caps so as to promote good flow during bay to bay pumping exchanges.

Many aftermarket caps are not rounded. In the Suzuki G13B the cap material was switched from alloy to steel but the rounded ends were retained. Steel was chosen due to the higher output/rpm range of the engine versus the G13.

In the COPO block, the windows of the stock casting were rounded by the factory to promote superior pumping exchange flow.

[modok]

I don't know anything specific about this engine, just IMO it is best to Look at it IN the block, so you see what's actually going on. I saw a knife edge crank in a LS, and it looked very stupid. In those the counterweight is up against the side of the main cap pretty much all the way around, so one angle side of that "knife edge" is just directing flow at a wall. OOPS, but, it looked real streamlined OUt of the block I'm sure. That is one example with windows around the main caps, and you can round and port those out if there are any. And if there are not any, maybe you could find a creative way to do something about it, whatever the case may be.

[SchmidtMotorWorks]

I would not conclude that the shape is designed for aerodynamics, it has no difference from the shape one would design into a forging die to extend its life. Large draft angles and rounded pocket floors.

I think (hope) that the teams of engineers for the two areas would both have taken fluid dynamics and could communicate with each other.

In all my experience at OEMs and performance aftermarket, I have never seen that hope realized even once.

In fact, it is rare that designers are able to properly design a casting or forging with proper draft for manufacture.

It is an ordinary turn of events that while the tooling designers try to fix the draft issues (left by the designers) they introduce new problems into the design that need to be reworked later.

Overcoming these issues has been a central theme of my work in engineering software. Unfortunately it is rare that collaboration continues after I leave (except the very best companies). People prefer to work in isolated silos and do things they way they prefer.
In most cases, the tooling is made at lowest bid external suppliers, the tooling designers probably couldn't tell you the four strokes of a 4 cycle engine, let alone anything about fluid dynamics.

[inline__engine]

If you examine a large number of engines from different manufacturers one of the hallmarks of good design is rounded-end main caps so as to promote good flow during bay to bay pumping exchanges.

Many aftermarket caps are not rounded. In the Suzuki G13B the cap material was switched from alloy to steel but the rounded ends were retained. Steel was chosen due to the higher output/rpm range of the engine versus the G13.

In the COPO block, the windows of the stock casting were rounded by the factory to promote superior pumping exchange flow.

the main caps are round on the ends (vertical edge). happy snap i found online

[Kevin Johnson]

I would not conclude that the shape is designed for aerodynamics, it has no difference from the shape one would design into a forging die to extend its life. Large draft angles and rounded pocket floors.

I think (hope) that the teams of engineers for the two areas would both have taken fluid dynamics and could communicate with each other.

In all my experience at OEMs and performance aftermarket, I have never seen that hope realized even once.

In fact, it is rare that designers are able to properly design a casting or forging with proper draft for manufacture.

It is an ordinary turn of events that while the tooling designers try to fix the draft issues (left by the designers) they introduce new problems into the design that need to be reworked later.

Overcoming these issues has been a central theme of my work in engineering software. Unfortunately it is rare that collaboration continues after I leave (except the very best companies). People prefer to work in isolated silos and do things they way they prefer.
In most cases, the tooling is made at lowest bid external suppliers, the tooling designers probably couldn't tell you the four strokes of a 4 cycle engine, let alone anything about fluid dynamics.

Unfortunately I cannot spend a great deal of time on this because I have a lot of work to complete.

Here are the results of a brief patent search illustrating that aerodynamic counterweight design is in fact very well known and incorporated by OEM manufacturers around the world. I hope this is useful for you and you might be able to meet with some of the engineers during your consulting travels. They might be able to explain how they succeed in implementing the construction of their patented designs:

https://patents.google.com/patent/DE102009054405A1/en? MAN Truck and Bus AG

https://patents.google.com/patent/DE102014118673A1/en? Porsche SE

https://patents.google.com/patent/US7021268B1/en? Brunswick Corp (Mercury Marine)

https://patents.google.com/patent/JPH0527330U/en? Mitsubishi Motors

[SchmidtMotorWorks]

Unfortunately I cannot spend a great deal of time on this because I have a lot of work to complete.

Here are the results of a brief patent search illustrating that aerodynamic counterweight design is in fact very well known and incorporated by OEM manufacturers around the world. I hope this is useful for you and you might be able to meet with some of the engineers during your consulting travels. They might be able to explain how they succeed in implementing the construction of their patented designs:

https://patents.google.com/patent/DE102009054405A1/en? MAN Truck and Bus AG

https://patents.google.com/patent/DE102014118673A1/en? Porsche SE

https://patents.google.com/patent/US7021268B1/en? Brunswick Corp (Mercury Marine)

https://patents.google.com/patent/JPH0527330U/en? Mitsubishi Motors

Is any one of those patents implemented in a modern performance car?

Here is what IS actually implemented by the top 3 high performance engines in late model US performance cars.
Nothing significantly different than the forgings of the 60's or anything in between with regards to aerodynamics.

LS7

LS7.jpg

Chrysler Hemi

5.7_hemi.jpg

Ford Coyote

FordCoyote.jpg

[inline__engine]

OEM never fully optimize things for the absolute maximum performance of a mass produced vehicle.
that hemi certainly hasn't got sharp corners though.

I've been trying to find images of BMW motorsport 6cyl cranks to no avail

[Kevin Johnson]

Here is what IS actually implemented by the top 3 high performance engines in late model US performance cars.
Nothing significantly different than the forgings of the 60's or anything in between with regards to aerodynamics.
...

It's been amusing.

Look carefully at the Chrysler Hemi and then return to the article by Vizard where he cautions that racing rule books forbid the modifications made.

The Ford Coyote -- well, I am sure that you are aware of the extensive modifications made to the cylinder block to help with airflow, right? That testing went on for many years.

I already mentioned the mods to the COPO block.

[Kevin Johnson]

OEM never fully optimize things for the absolute maximum performance of a mass produced vehicle.
that hemi certainly hasn't got sharp corners though.

I've been trying to find images of BMW motorsport 6cyl cranks to no avail

A Ford engineer chimed into a discussion many years ago and noted that existing parts from other versions of engines would often be used to save money on lower tier engines. Sometimes these parts directly interfered with airflow.

Remember that many racing engines run the crankcase under a depressed atmosphere.

[LoganD]

Unfortunately I cannot spend a great deal of time on this because I have a lot of work to complete.

Here are the results of a brief patent search illustrating that aerodynamic counterweight design is in fact very well known and incorporated by OEM manufacturers around the world. I hope this is useful for you and you might be able to meet with some of the engineers during your consulting travels. They might be able to explain how they succeed in implementing the construction of their patented designs:

https://patents.google.com/patent/DE102009054405A1/en? MAN Truck and Bus AG

https://patents.google.com/patent/DE102014118673A1/en? Porsche SE

https://patents.google.com/patent/US7021268B1/en? Brunswick Corp (Mercury Marine)

https://patents.google.com/patent/JPH0527330U/en? Mitsubishi Motors

Is any one of those patents implemented in a modern performance car?

Here is what IS actually implemented by the top 3 high performance engines in late model US performance cars.
Nothing significantly different than the forgings of the 60's or anything in between with regards to aerodynamics.

LS7
LS7.jpg

Chrysler Hemi
5.7_hemi.jpg

Ford Coyote
FordCoyote.jpg

I think you are severely underestimating how profiled those crankshafts are. A crankshaft designed to minimize oil frothing and windage may not look the way you expect it to. CFD is often very counter intuitive.

Remember, the OEMs have access to tools and test equipment that no aftermarket or racing operation has outside of F1. Look at an F1 car, does its shape look intuitive for the most performance around a circuit?

[SchmidtMotorWorks]

Unfortunately I cannot spend a great deal of time on this because I have a lot of work to complete.

Here are the results of a brief patent search illustrating that aerodynamic counterweight design is in fact very well known and incorporated by OEM manufacturers around the world. I hope this is useful for you and you might be able to meet with some of the engineers during your consulting travels. They might be able to explain how they succeed in implementing the construction of their patented designs:

https://patents.google.com/patent/DE102009054405A1/en? MAN Truck and Bus AG

https://patents.google.com/patent/DE102014118673A1/en? Porsche SE

https://patents.google.com/patent/US7021268B1/en? Brunswick Corp (Mercury Marine)

https://patents.google.com/patent/JPH0527330U/en? Mitsubishi Motors

Is any one of those patents implemented in a modern performance car?

Here is what IS actually implemented by the top 3 high performance engines in late model US performance cars.
Nothing significantly different than the forgings of the 60's or anything in between with regards to aerodynamics.

LS7
LS7.jpg

Chrysler Hemi
5.7_hemi.jpg

Ford Coyote
FordCoyote.jpg

I think you are severely underestimating how profiled those crankshafts are. A crankshaft designed to minimize oil frothing and windage may not look the way you expect it to. CFD is often very counter intuitive.

Remember, the OEMs have access to tools and test equipment that no aftermarket or racing operation has outside of F1. Look at an F1 car, does its shape look intuitive for the most performance around a circuit?

I worked on the development of those tools for OEM, what would you like to tell me about them?

[Kevin Johnson]

I worked on the development of those tools for OEM, what would you like to tell me about them?

Well, first off, Georg Cantor was the Father of Set Theory yet he didn't anticipate Russell's Paradox. Shocking, I say.

Simply because you helped in developing the tools doesn't mean you know their complete implementation or all of their theoretical limits nor the underlying physics. When I wrote that hopefully the people involved are familiar with fluid dynamics I guess it was lost to the wind that designing forging molds with proper drafts and elements that help to allow dies last longer serendipitously can help air flow -- remember hot steel under pressure flows as a type of fluid, right?

Next up, note carefully the modern R1 crank with the profiled leading edge on the fifth counterweight (Yes, an R1 crank that we should aspire to emulate in its simplicity). If you want to perturb a complex physical system add a design element that does so.

2009_Crossplane_2009_yzf-r1_PS.jpg

Furthermore, OEMs do not broadcast all their engineering secrets to the world or consultants. Probably the only potentially worse intellectual property breaches could come from salesmen. I know because I was in technical sales for years and got to hear the horror stories from a myriad of industries.

Here is an example: Toyota proudly authored TWO (2) SAE papers on their ZZ engines. They were very proud that that the 2ZZ met a design criterium that reduced the number of components versus the 1ZZ but left completely untouched in both papers the obvious subject of the careful and differing control of air flow in bays 1-2 versus 3-4. Nor did they mention the ADDITION of multiple parts and tuning chambers for said pumping exchange in bays 3-4 of the 2ZZ. Shocking, I say.

Back to work...

zz1 a.jpg

zz1 b.jpg

F144681941.jpg

[SchmidtMotorWorks]

Where exactly on that r1 crank do you think it is designed for aero dynamics?

Your assumption about my involvement in various aspects of the design as it relates to the software development is the inverse of how that work is done.

As I have said to you many times, involvement in the real working world of design and manufacture will eliminate a lot of beliefs many people have.

[Kevin Johnson]

Where exactly on that r1 crank do you think it is designed for aero dynamics?

I am putting in a ticket as my simulated predictions of power output are off from the dyno results. I think it might be that the windage is incorrectly modeled so you'll have to do a full simulation of the crank at 12k rpm adjacent to the gearbox. Please make sure the droplets entrained in the cloud are accurately modeled through gear changes inside the volume of the gearcase and crankcase.

yam_gearbox.jpg

Your assumption about my involvement in various aspects of the design as it relates to the software development is the inverse of how that work is done.

I was merely trying to approach the grandiosity of your claim by invoking the Father of Set Theory; you should be flattered.

As I have said to you many times, involvement in the real working world of design and manufacture will eliminate a lot of beliefs many people have.

I try to apply Davidson's Principle of Charity and am sometimes disappointed. Still, I have encountered many extremely intelligent people.

[SchmidtMotorWorks]

Where on the r1 crank do you think it is designed for aerodynamics?