Drilling Drums

* Disclaimer *


This page is to chronicle the drum work I did on my 68 falcon. It will be updated from time to time as I run it to different conditions with the drums altered. I.e. Heavy stop and go driving in hot weather, Wet conditions and so on. This page is not meant as a "HOW TO" and I do not advocate anyone else trying this. Should you choose to do this then any damage caused from problems that might arise are Your responsibility and yours alone.

The Arrows show the position of the holes in the drums. They were staggered two fins between the outside hole and the inside hole. Notice the top hole is up against the ridge where the drum drops of to the smaller diameter. It would be real hard not to get all of those holes in the same place because of the ridge of the ribs and the raised part of the drum. This makes a natural place to drill without the bit trying to walk. These drums are fairly new and were bought at a local auto parts store. I guess this must be a newer design because the original drums that came on the car did not have the fins and were considerable lighter.

I marked the positions of all of the inside and outside holes with a marker to make sure I hadn't goofed and that the holes came out as they were supposed to.

The outer hole is easy enough to drill also as the material to drill is a breeze and the ribs of the fin protrude out that far. The bit can't walk from side to side because of that, but I had to make sure that the bit stayed on the scribed line rather than walking either up or down. Actually I had no problem with that though.

The holes were drilled every 8th fin and that put the holes evenly spaced around the drum. I also used a #10 bit since it came out to be the right size without digging in to either side of the ribs.

View from the inside of the drum shows the staggered pattern of the holes. Note i covered the bearing area with duct tape to keep from getting the drill shavings in the bearing. This was done on both sides of the drum.

Close up of the staggered holes and their positions.

Another view of the inside drum. There were a total of 8 holes drilled on the inside and that many drilled on the outside for a total of 16 holes per drum.

Note the piece of sheet metal that I bent at a 90 degree angle to scribe the correct distance for the front holes. I used it and a scribe to mark the front holes before drilling them.  Also notice that I used an old set of mags to cradle the drums while working with them. I wouldn't have done that if they were nice mags. Instead I would have constructed wooden blocks or something else to secure the drums while drilling them.


After I was finished I tested the car and found that it seems to stop better with less effort on the brake pedal. As the summer comes on I'll try it in heavy stop and go traffic and wet weather to see the difference in the operation of the brakes then.

You might want to visit this page occasionally to see if any other information has been added.

Updated picture with the extra 10 holes I drilled. Have been running them for well over a year now.

Its been quiet some time since I did any updates to this page and because of a couple of requests I'll update it now. (10/20/2008). This will likely be the last update since a member donated a full Granada disc setup to me some years back and I upgraded or is that downgraded to them. I was extremely happy with the way the drilled drums worked. I had more than one occasion to try them out in 100+ degree stop and go freeway driving for about 120 miles at a time. There was no fade what so ever that I could tell from constantly ridding the brakes and the pedal force to lock them up was far less that they are now with the discs. I also did a small amount of driving in rainy weather, but didn't go through any high water. Never the less I'm sure the brakes got wet a few times and there was no fade to that either. I can remember in Years past both of those situations sent me heading for the bar ditch to avoid collisions because of fading brakes. (Prior to drilling the drums) You might say "Why did you switch to Discs if you were happy with them?" Well the answer to that is I assumed that the Discs would stop even better and be about the same pedal force to, but that didn't turn out to be true. That and them being given to me was all it took for me to swap. Looking back on it I'd have likely kept the drums and eventually drilled the back drums to. (I may do that anyway at a later date to see if it would help the discs stop with less pedal force?) One thing and one thing only that I've found that the discs have it over the drums is when the drum system gets a little out of adjustment there is that damn pull to one side or the other! That doesn't happen with the discs. As long as the drums are adjusted correctly I'd personally say they will beat the pants off of discs. Of course the discs could be drilled and slotted and that might make the difference. Maybe I'll try that some day?


Copyright (C) 2002 - 2008 By
David Thorne Smith
All Rights Reserved