Making your own cross-drilled rotors
 

Hey guys,

I was wondering if anyone had any input on me cross drilling my own rotors?

What I have at my disposal is a complete set (front + rear) brake rotors for my '85 Volvo 240GL. Cross drilled for that car are hard to find and expensive, plus I have a full set that's just hanging out that I recently stripped from a salvage car (for free). The fronts are vented and the rears are solid, I was thinking of maybe finding a template, then drilling at specific points (yes I know it has to be balanced since the tire spins pretty fast).

The front has 4 piston calipers, the rear has 2 piston calipers (hey this car weighs 2 tons). The most money I would be out of (aside from trashing the rotors) would be having the machine shop resurface them ($7 per rotor). Yeah I realize I could goto the auto parts store and save a buck or two on turning, but then risk having them screw it up. Plus I like the machine shop I've been using, shall send all my business to him.

Call it ghetto, call me stupid - if anyone has heard of this kinda thing working and know the process, hook me up.

Thanks.
-Ryan

Re:Making your own cross-drilled rotors
 

wow, 21 posts and you already have come up with something I want to try if you don't ---- up. You're one of my favorite noobs so far.

I don't know what kinds of things go on with the factory cross drilled rotors, hopefully someone else does.

Re:Making your own cross-drilled rotors
 

don't experiment with your life. Its a good thought but leave the saftey components to the engineers

Re:Making your own cross-drilled rotors
 

I've actually been hitting this site on and off the past 3 years, started my membership a year ago, only recently I've been posting on quite a few threads.. I dunno boredom?

I've been doing crazy things to cars for the past 10 years, if you read my other posts you can tell I don't talk like a noob, I rarely mispell words and I don't say stupid ---- like "dat wud be so tite dawg!"

But thanks anyways for the comment, if I get enough research done and do attempt the project, they are gonna get thrown on my dad's car - 240 Wagon (maybe without him even knowing LOL) since he does a good bit of highway driving and I normally drive my truck (4x4 action baby).

Re:Making your own cross-drilled rotors
 

wow, i guess you were writing that when I was writing my last post, else I would have acknowledged this in my last one.

Yes, you are so right on that one.. might just get them turned and say the hell with it. I ran the idea by my brother the other night, he said not to try it and "I saw on speed vision where they said not to do that" but then again I never have taken his automotive advice into consideration in the past (it's always me the one working on HIS car.. stupid DSM).

I wouldn't be worried about the structural interference issues, when they make cross drilled rotors it's just a cnc machine cutting at exact specs. One time when I was working parts counter for an auto parts store this guy came in with a front rotor that was wore all the way down to the slotted fins (in the center) - no meat left, I think it was on an 80s full size pontiac. All he could say was "tell everyone it was a woman driver" I hung it on the wall for a while until my boss threw it out. I thought it was a good business ploy, make people want to buy more brake parts from us ::)

So knowing that the metal could withstand the drilling of holes at certain points, the weighing factor would be positioning the holes in such a way that it doesn't offset the balancing of the rotor that is spinning at a good rate.

I guess this one is still in the air for me, but if anyone else has any input, please share.

-ryan

Re:Making your own cross-drilled rotors
 

a friend of mine did this on his dodge dakota.. actually, he had a professional(close friend of his) do it. when i first saw it it looked perfect. however, its been a year and a half now and there are tiny cracks just beginning to develop around the drilled areas. it was good for a while, but obviously it isnt meant to last long. :-\

Re:Making your own cross-drilled rotors
 

that reduces the serface area. get slotted. they just as good.

Re:Making your own cross-drilled rotors
 

cross drilled rotors crack...Even seen cracked ones on Porshe's. And they come with them OEM...I think slotted are better though or just get a bigger rotor.

Re:Making your own cross-drilled rotors
 

yeah you need to be careful, they crack when you do them yourself (not sure about high quality drilled rotors) i have heard that slotted is better

Re:Making your own cross-drilled rotors
 

well, i'm not sure if you're going for looks here, but a simple way to keep it balanced would be to just follow the simple little rule of algebra, 'whatever you do to one side, you have to do to the other'. just do one hole at a time and then go exaclty opposite of it nad work it in a good pattern. :-\