Some lovely CNC ported/Dimpled 20v heads

[badger5]

We've had a couple of 20v heads full CNC machined, with dimples for a couple of ongoing project builds..
They just look sexual.. (is that wrong?)

One head was largeport, one was smallport, ported to largeport, one with combustion chamber reshape, both with 3 angle seat cuts for the Supertech valvetrain... Full CNC machined, new guides, skim, dimpled...

Flowbench data including port velocities coming shortly..

Lovely work..
Enjoy

 

[sparrow]

Very interested in the outcome of this.

 

[andy68]

Having never really looked into head work, whats with the dimples?

 

[badger5]

Higher airflow and port velocity

Google is your friend

 

[Lavis89]

I'm guessing it's to do with speeding up the airflow, same kind of reason a golfball is dimpled

 

[VAG-Slag]

I was always under the impression this kind of thing creates a bit of turbulence which makes the air fuel more atomized so it burns better... No?
Which is why you shouldn't polish inlets.... Or am I talking sh!t?

You're right though, it does look almost sexual... I would ask how much this kind of work costs but I actually do not want to know!

 

[Gops]

I want @badger5

 

[Alex C]

I'm guessing it's to do with speeding up the airflow, same kind of reason a golfball is dimpled

suspect so, a non dimpled golf ball doesn't go very far compared to a dimpled one

 

[badger5]

Comparison to "other" ported head I have here for another build.. "other" not a jp/jnl one btw..

Prices from £590-£650 region +vat for this work for your information.

 

[badger5]

suspect so, a non dimpled golf ball doesn't go very far compared to a dimpled one

apparently so - not being a golfist myself

 

[badger5]

interesting modelled animation of the dimple airflow on golf ball

 

[badger5]

another one. cool vids

 

[superkarl]

That isn't a bad price at all really.

With the small port to large port, I wasn't aware this was 100% doable due to possible hitting water jackets?
I know it's common place to open up the entry to large port, but the rest of it I wasn't sure

 

[badger5]

That isn't a bad price at all really.

With the small port to large port, I wasn't aware this was 100% doable due to possible hitting water jackets?
I know it's common place to open up the entry to large port, but the rest of it I wasn't sure

indeed, which is why I thought I would try it out.. and its flow figures exceed the largeport too..
higher flow achieved at less lift with increased port velocity at lower valve lift.

 

[Gazwould]

Aye .

 

[Alex C]

More on golf ball physics http://www.math.ucr.edu/home/baez/physics/General/golf.html

Stupid question time: why do the exhaust ports not benefit from increased air flow velocity? Would it help spool? Or would it just coke up too much?

 

[superkarl]

More on golf ball physics http://www.math.ucr.edu/home/baez/physics/General/golf.html

Stupid question time: why do the exhaust ports not benefit from increased air flow velocity? Would it help spool? Or would it just coke up too much?

My guess is any imperfection, like the sharper ridges between dimples, might become hot spots. Perhaps not as good managing heat. Although with the increased surface area you could argue the opposite

Also i read the dimples are to create turbulent flow. pretty sure this is not what you need with exhaust.
And exhaust isn't as homogeneous a fluid as the air on the intake side

 

[<tuffty/>]

Having seen these in the flesh I can honestly say you can park an actual bus in the exhaust ports on these... very much doubt flow is an issue there lol

<tuffty/>

 

[Alex C]

I was thinking that flow separation might promote coking up as carbon drops out of the air flow as it passes over the peaks of the dimples? you know where I'm coming from Karl

 

[superkarl]

I was thinking that flow separation might promote coking up as carbon drops out of the air flow as it passes over the peaks of the dimples? you know where I'm coming from Karl

I wonder what style of bedforms would be preserved

 

[Alex C]

Having seen these in the flesh I can honestly say you can park an actual bus in the exhaust ports on these... very much doubt flow is an issue there lol
<tuffty/>

yeah i get you, i was thinking that massive ports like that allows it to exhaust a large volume at relatively low flow velocity? so maybe increasing the air velocity with dimples would help? Or maybe because a large port has a lower surface area/volume ratio then surface effects would have negligible effect on flow velocity....

either way it looks pretty cool

 

[harvey01]

did you shop do this or was it cnc heads or someone like that ?

 

[badger5]

not cnc heads no. i'm not aware they have the kit to do dimples... and are way way more expensive

 

[Gops]

I like those! Interesting videos too, I really should of had mind ported from the start but I'm guessing this us my chance now!!

 

[sparrow]

indeed, which is why I thought I would try it out.. and its flow figures exceed the largeport too..
higher flow achieved at less lift with increased port velocity at lower valve lift.

Have you measured them already? Interested to see the values if you have them.

 

[badger5]

Have you measured them already? Interested to see the values if you have them.

I have the flowbench data for the heads I've had done yes

 

[harvey01]

who ever did it got skills