Does any one know if its safe to spot drill and groove my own solid cortina discs, until i can afford better. Has anybody tried this? What were the results? I dont want it to cause the disc to shatter or warp due to it building any stresses around the spots. Thanks.

I'd have thought they would stop a locost without any mucking around with them.

Then get some new ones later!

it is possible to drill your own discs BUT
you must ensure that there are a consistant number of holes around the disc at matched distances and it is advisable to chamfer the holes. If you get it wrong then it is possible for the disc to get too hot and due to the holes drilled in it cause a chunk to come off. which is not ideal. Have you looked at the cost of a set of ebc green stuff discs as they are fairly resonably priced.

I would have thought it would be far safer to leave the discs as they are.

If you start drilling them you can introduce all sorts of stress problems as you don't know how well they are coping to date.
If you were talking of buying new ones and then drilling them then you could possibly get away with it, but it would be far better if you got them heat treated to remove any stressed areas due to drilling.
I wouldn't recommend trying to groove them!

If your brakes are stuggling to stop you then try different pads. There are a good selection about.
I think your question should really be; Can you afford catastrophic brake failure due to modifying, or would it be cheaper to get new discs?

Terry

According to Willwood, drilling your brakes doesn't do much but DECREASE their efficiency. How that works, I don't know, but I guess there's no direct air flow into the holes so they carry the same hot air around and around with them.
Sounds familiar

Running a groove or two supposedly 'cleans up' the pads, but what's meant by that, I'm not sure.

The NZHRA says that they should only be drilled by "recognised automotive proffessionals."

In Carroll Shelby's "Engineer to win" he talks a bit about drilling and grooving disks.
As well as chamfering the holes for stress, the layout is important - you can't have a radial row of holes. Shelby had a diagram of a drilled brake a bit like a hopscotch - two holes, then one hole in the middle, two holes, one hole (look at a porsche).

Personally, I'd be looking at flasher pads before I drilled.

- Greg H

Thanks, it was just a thought id had from when i looked into the ebc discs which are grooved drilled and vented but i was told that a vented disc wouldnt fit a standard calliper. What they said was trade in my old callipers (which id just reconditioned) and for £250 they supply new discs and modified callipers. Is it just a spacer that theyd be putting inbetween then??

u can by a spacer kit for the ford m16 caliper from http://www.peterlloydrallying.co.uk/catalogue/brakes/brakes.html

or get the complete kit inculuging discs for £74

I don't think messing around with old discs is a good idea. They have stresses induced by long use and many heat cycles. If you want to drill a set of discs, use new ones.

Having spoken to someone that builds and races cars, drilled disks are vastly overrated. The cheapish performance drilled disks you can buy were never designed to be drilled, and they can suffer from cracking.

Grooved disks are supposed to allow any gasses generated by the pads under duress to escape and also ensure that any glaze gets removed from the pads, (no doubt along with more pad material than normal).

TBH, if the original were capable of stopping a Cortina, they should have absolutely no problems with a LoCost.

I figured that although you're going to bash the locost around more the the original car, it weighs bugger all.. so I guessed dinky brakes would be ok for road use, at least.