10 posts....

But you wanted to post this one?

Nice drawing big R!! Can you do that by hand ? Or for this one you would need the machine? Are you trying to save weight also or just for better cooling ?

This is not my drawing but his.

Yes, I can do that w/o cnc.the rounding is easy with simple tools

Thank you for posting the picture.
Not Sure I saw this Heatsink on Collaris Car and I find it looks very nice.
For the machine I work on 5 axis machines and got as well a lidle cnc mill and a lidle cnc lathe at home. So the machine is not the problem. With a conventional machine I guess it could be very tricky to do this head.
For the advantage I´am not sure . Off course it will have less weight , but will the engine get enough cooling?

Lower weight is not as important as lower CG.....
Checkout the Bert design :

As mentioned all the fins are directly placed on the base of the head so they have the most direct heat transfer, the cooling will be OK. The holes in the lowest fins will not do much, once I did dril a head like the GRP engine heads and it did save 5 gram, in this case it will not be more than 1 or 2 gram.

Yes, I have seen it on Collari his car as well, not sure why he is not driving it, maybe more to do with sponsoring, keeping it original.

@Roleof, can you tell me where to get this extra long endmills?

Thank you Roleof got my 10 posts now :-)
This will be the final Heatsink version for my Nova Mito .Looking forward to get the first chips .

I did found them on Aliexpress like
https://nl.aliexpress.com/item/32724...chweb201603_55

https://nl.aliexpress.com/item/32880...chweb201603_55

But with open fins you could use a saw blade mill like these:
https://nl.aliexpress.com/item/40002...chweb201603_55

I have some in different sizes with a sideway mount to make such grooves.

Yes I know that with the blade but on my mill that can cause me some trouble... And I need a blad with minimum 80-100 in diameter.... Not that cheap.
I try it that way if it does take to long I will do it with a blade.
At the end it doesn't differ that much if you mill slots like on your heat or open fins like my one.
The only sucking thing is the time because I can't go deeper than 1-1,5mm per cut

Made a start for 2 more. Due the left over material, cutting it and making both sides flat they are 5mm shorter than a normal head, that is no problem due the better cooling that I have noticed.





And beside this material I have a meter in 50mm diameter of 7075 aluminum to play with

It took some time but a friend managed to startup his CNC machine and mill the slots.







A clubmember is willing to get them anodized through his work and can do a laser engraving. To get the visual picture how the engraving looks like he made a 3D drawing of the head but gave it a much better design to it.

looks amazing roelof!!!!

now the backplate of the OS engine

Perhaps you could consider trying the concept with a mid range PC CPU heatsink and machine the appropriate dimensions and fit for the engine?

Save on materials cost, and would resolve my curiosity.