drilled/vented drums

airharley · #1 (**permalink**) 05-14-2008, 03:10 PM

I came across a site that offers drilling your drums. The concept is the same as rotors. But I think it would help more then most think. It allows for water to be slung out of the drum and for them to cool a bit faster then stock. What do you guys think? Drilled Drums

ddavidv · #2 (**permalink**) 05-14-2008, 04:19 PM

Less weight = not enough to make a difference
Water drainage = that may have merit
Better cooling = I'd argue no. There really isn't any airflow in or out of the drums. It may allow some heat to escape, but without the air being channelled somehow (disc brake backing plates have scoops, for example) I don't see it being very effective.
Cracking = there is a real risk of the drums developing stress cracks around the holes, which would be a huge safety issue.

Finned drums might be just as, or more, effective.

Ultimately, there is no substitute for disc brakes.

Hakk · #3 (**permalink**) 05-14-2008, 05:53 PM

My opinion - at least as bad as slotted or drilled rotors, possibly quite a bit worse. However, just like slotted/drilled rotors, they might look good at a car show on a non-moving/driving vehicle.

Altimas.net - Crossdrilled/slotted rotors-why they are like this, like that-final discussion

There's some light reading for anyone that cares to..

Pickupmanx2 · #4 (**permalink**) 05-14-2008, 06:47 PM

I read awhile back about cryogenically freezing them, and cross drilling, they were getting awesome results, I actually contemplated it before I switched to disc on my 2nd 66.
I HAVE cryoed and slotted rotors on my 02 Excursion, BIG difference from stock, I was just thinking about looking into it for my drums lately,,,

Col Flashman · #5 (**permalink**) 05-15-2008, 05:30 AM

Father used to do this for his Racing Friends, but he drilled More than just the Drums for water drainage, he drilled the Backing Plates as well for the Air Flow & he also did this to all the Family Vehicles too.
In all that time, I don't remember any of them Failing on Any of the Drums/Backing Plates that this procedure was performed on.

Finned drums are excellent for cooling, but water drainage is still a problem.
Try & locate any that fit our trucks, I've looked off & on for years & when I've found ones that Fit, the individual that's selling them wants an Arm & a Leg for them, so good luck.

Disc brakes are fine for those that are able to afford to spend the Rhino for them to convert their trucks, but some wish to keep their trucks as they came from the factory.
A finaly tuned drum brake system is quit effective, especially w/ the proper P/B system, thank'ee very much.

airharley · #6 (**permalink**) 05-15-2008, 10:04 AM

I read about a 1/4 of the link posted above about disc brakes. I agree with both sides of the arguement. If you add in one area you are going to sacrifice in another. Tires do make a difference when it comes to stopping. The better the tire grips the road the easier it is to keep them from skidding or sliding when you put a whole lot of foot on the pedal.

Col Flashman now I can see making slits and bending them toward the frame in the back plate to help route more air into the drum/pad contact area to help cool them. It would be just like some of the HP rotor backing plates used on SVT vehicles or even some of the brand X stuff. The drums with the fins was a huge improvement in cooling when they replaced the flat drums. They added a lot of surface area to disipate heat.

Back to my original thought though, it seems like a good idea to help those who want to keep their rig stock or can't afford to buy a disc conversion yet. Heck I am even thinking of doing this to my rear drums since I have power disc/drums. The only reason I can think of that disc brakes have an advantage over drums is there ability to sling off water. The clamping force needed to stop a 4000 lbs truck is way more then that of a drum brake.

royalchoppers · #7 (**permalink**) 05-15-2008, 11:18 AM

One of the major reasons for drilled holes and cross slotting is not necesarrily cooling as much as it is releasing gasses and dust created during the braking process. The gasses and dust build up between the braking surfaces reducing the the fricition. Drilling drums has been something done in vintage motorcycle racing for years. I would go for it.

ddavidv · #8 (**permalink**) 05-15-2008, 06:31 PM

Quote:

Originally Posted by royalchoppers

One of the major reasons for drilled holes and cross slotting is not necesarrily cooling as much as it is releasing gasses and dust created during the braking process. The gasses and dust build up between the braking surfaces reducing the the fricition. Drilling drums has been something done in vintage motorcycle racing for years. I would go for it.

This is mostly an "old mechanic's tale". The dissipation of gasses was something from the old days (1950s) and is no longer a factor with modern pad materials.
Check out the latest issue of Grassroots Motorsports if you want to learn more about brakes in general. They discuss this in a sidebar.

Hakk · #9 (**permalink**) 05-15-2008, 08:43 PM

I hope this doesn't sound rude, but since when is getting rid of water of any importance at all for drum brakes? Does not make any sense to me at all. Are you driving down rivers instead of on the road? Even if that's what you are doing, the holes will just as much let in water as let it out.

Any water that gets into a drum brake will naturally just drain right out. It's not like they are air or water tight in the least bit. They'll also work fine when wet too. I think most people have trouble grasping just how much force a hydraulic braking system will apply. Wet pads mean absolutely nothing, other than water will help the brakes shed heat and work BETTER.

Anyhoo, I guess the worst that can happen is really crappy braking from the rear of your truck and/or rapid damage to the rear brakes if you foolishly drill holes in the drum. Most of the braking is done in the front anyway, so you shouldn't get in too terrible of an accident.

Oh, and ddavidv is right on about the myth of out-gassing pads.

Col Flashman · #10 (**permalink**) 05-15-2008, 09:09 PM

Since when is it important & does it Look Rude?
It always Has Been & Yes it Does!
Water does naturally drain out, but Not very rapidily, leaving the brakes soaked for a longer period of time, so that's why the Mod helps.
From your statement I take it You've never experienced Brake Fade or Worse yet, No Brakes At All after driving through High Water/Flooded streets during a rain storm or under any situation?
And whether you like to see this in Print or Not, Yes, Drilling The Drums helps a Great deal in Drying the brakes out more rapidly once you're out of the deep water.
It has by my & my families experience that after the afore mentioned situation it only takes half the amount of time or less to Dry ones brakes out if the Modification has been performed.

Hakk · #11 (**permalink**) 05-16-2008, 06:02 AM

Quote:

Originally Posted by Col Flashman

Since when is it important & does it Look Rude?
It always Has Been & Yes it Does!
Water does naturally drain out, but Not very rapidily, leaving the brakes soaked for a longer period of time, so that's why the Mod helps.
From your statement I take it You've never experienced Brake Fade or Worse yet, No Brakes At All after driving through High Water/Flooded streets during a rain storm or under any situation?
And whether you like to see this in Print or Not, Yes, Drilling The Drums helps a Great deal in Drying the brakes out more rapidly once you're out of the deep water.
It has by my & my families experience that after the afore mentioned situation it only takes half the amount of time or less to Dry ones brakes out if the Modification has been performed.

I live in Minnesota and we get a lot of rain, snow and every other sort of precipitation.

Water will not fade brakes. Fade is due to too much heat in the brakes - water on your brakes will prevent fade and enhance braking.

I've also driven vehicles towing boats, so I do know what a vehicle drives like after the rear diff has been under water. That water naturally drains right out.

Probably what you experienced was your tires hydroplaning. The tires can ride up onto the water and then brakes, steering, etc do no good. Also in dry climates where it doesn't rain often there will be a layer of oil that comes up off the road during the first few minutes of rain. That oil can accentuate wet tires skidding. It's not uncommon for people who don't experience a lot of rain to be confused by hydroplaning.

jowilker · #12 (**permalink**) 05-16-2008, 06:04 AM

Fellows, A lot of opinions here, don't need another. Do have a question though, how do brakes get wet. The only time that I have had any wet brakes was after driving through deep water, and with wet shoes the vehicle did not stop the same until they were dried out again. When driving through rain tires dissipate water not direct it. There is only a small space the water could get in and it is tucked well inside of the tire/wheel.

John

airharley · #13 (**permalink**) 05-16-2008, 10:03 AM

I guess I chose a great debate topic.

All in all I think it comes down to personal beliefs or wants when we get down to it. If you live in a place like, oh lets say, New Orleans. The streets flood after every rain and you have to drive slow with the size of the pot holes they have lurking all over the place. So I think if it helps you to dry the brakes faster or you just want the coolness factor then go for it.

We can't always

on everything. This seems like one of those agree to disagree topics.

Col Flashman · #14 (**permalink**) 05-16-2008, 02:31 PM

Quote:

Originally Posted by Hakk

I live in Minnesota and we get a lot of rain, snow and every other sort of precipitation.

Water will not fade brakes. Fade is due to too much heat in the brakes - water on your brakes will prevent fade and enhance braking.

I've also driven vehicles towing boats, so I do know what a vehicle drives like after the rear diff has been under water. That water naturally drains right out.

Probably what you experienced was your tires hydroplaning. The tires can ride up onto the water and then brakes, steering, etc do no good. Also in dry climates where it doesn't rain often there will be a layer of oil that comes up off the road during the first few minutes of rain. That oil can accentuate wet tires skidding. It's not uncommon for people who don't experience a lot of rain to be confused by hydroplaning.

Well then you must be living in different reality then the rest of us.

I've pulled Horse Trailers all the way up to Slant 6's & have had to drive through just about every type of percepitition you can imagine & when all 4 brakes get wet, they Loose the ability to grab & I know the difference between Wet Brakes & Hydroplaining.

When it Rains here in So.Cal., it Really Rains & because we live in a Semi-Arid & Desert area, the rain Does Not soak up into the soil well & is one of the main reasons for the Flash Floods here. Then there's the Poorly Designed Drainage system for the city streets that causes Street flooding due to it backing up.
So you've Obviously never been here during the Rainy Season, because you do not know wherefore you write.

85e150six4mtod · #15 (**permalink**) 05-16-2008, 02:52 PM

Being from Washington state, and having experienced the So Cal rainstorm rivers, I can add my voice to the "water ruins braking" arguement. As for the cooling of drum brakes, the vented backing plate seems like a good idea. I saw some magazine do that, and they they drilled holes in the front of the drum...I think I'd leave the drum alone other than the small holes shown earlier in the thread.