Topic: Diamond Cutting Cooling fins

[ElCheapo]

Does anyone have any idea of how this is done?

[tsflstb]

Very carefully....probably with 45 degree end mill. 

You've seen this on custom V-twin engines -- they just build that into the CNC code when they design the jugs.  They're machined from a huge chunk of billet, so it's just another step in the finish.

I imagine it's much harder to do after the fact.  If you're wanting to do this on a SOHC4 motor, you'd need to spend some time laying this out on the cylinders and heads.  Figure out a width for the grooves that won't have any "remainders" over the length of one side.  Also , watch for voids in the cooling fin castings -- this may be the biggest problem.  I'm not sure how good the die casting process was 30 yrs ago. 

It would sure look nice all polished up though, good luck!

[ElCheapo]

I have seen this done to existing units. Not sure if there is some easy way to do it. It has been done for over 30 years actually. I would just like to know the old school way it was done.

What I do know is that I do not want to pay $400-$600 to have it done. Seems like a lot of money for a simple mod. 

[tsflstb]

Here's a place that says they do it by hand.  I'm not sure what that means these days??  They don't reveal their methods, but you can send them $39.99 for an instructional course.

I guess in the old days it was done with a hand file.  I could see how a square file and a really steady hand would work.  It would take a while, but wouldn't cost an arm and a leg.

http://www.yourmachinist.com/new_diamondcuttinghist.shtml

[dusterdude]

you could call occ and ask the teutels,im sure they know.

[crazypj]

You can do it by hand if your patient. You need a die grinder and some thin cut off wheels ( you can get everything from Harbour Freight tools for less than $80.00, even less if you look for special offers) You need an electric die grinder, router speed controller and the 1/16 cutting wheels with 1/4 arbour. It will work without router speed controller but shaft gets hot and may vibrate due to the cheap bearings. Its also really useful at the lower speed for polishing into tight corners.
PJ

[ProTeal55]

Go pick up any V-Twin magazine and flip to the back. You will see a few different places that do diamond cutting. I am sure (if you wanted to spend the cash) they would do your Sohc motor.
I would take a crack at  it yourself, if you have the tools/time/etc....