Visit The Dirt Forum for More Information

Author Topic:   How to re drill your rotors etc.
66jj
Member
posted November 08, 2003 09:08 AM
I thought everyone knew this but some guys on the mod forum sure didnt so I pasted it here also..

To find someone to redrill your rotors look in a mirror. How do you think all the shops do it??????

All you need is

1. hand drill & 1/4 bit

2. a wheel spacer, one inch that has all bolt patterns, I got mine new from JR motorsports in Ill. for 17 bucks delivered.

3. use the stock studs and a couple stock lug nuts to bolt the spacer on, the tapered nuts well center it.

4. you need a 5/8 od transfer punch, I ordered mine from a place for 4.00 and a 9.00 order fee. the same week I got a harbor frt flyer and they sell a whole set up to one inch for 29.99 mail order only.

5. obviously you drop the transfer punch in the 5 on 5 bolt pattern and hit it with a hammer.

6. remove adapter, knock out stock studs, drill with 1/4 bit, then drill with 43/64 drill bit for studs(use a drill press), available for 10 bucks at speedway if you dont have one.

heres JR website, http://www.jrmotorsports.net/

waltonjr1
Member
posted November 08, 2003 06:53 PM
Thats what i did and it worked great.The only thing i did not do was use the 5/8 center punch but it sounds like it works better than what i did.ijust bolted the spacer up and started off with the 43/64,once i got it started i switched to a smaller bit and drilled through the center then followed with the big bit.No problems.

------------------
DEANJR#22


istock59
Member
posted November 08, 2003 07:15 PM
Personally, I don't like the redrilled OEM rotors. An extra set of holes makes it weaker in the hub. I had one break the center out on the RF once. Man, that was a FUN ride... NOT...

For my money I only use the brand-new rotors (from Speedway, JRs, etc) that are drilled to 5X5 to begin with. I think they're acutally made by US Brake.

neil rucker
Member
posted November 08, 2003 07:34 PM
ive seen the metric rotors redrilled to 5x5 and 5x4 3/4 bolt patterns with 5/8 big studs already installed, but does anyone offer the 70 thru 81 camaro or 75 thru 79 nova rotors with the large 5/8 studs already installed? thanks, neil


cmiller9x
Member
posted November 08, 2003 09:15 PM
Most of the guys I know change spindles and rotors for the camaro.


neil rucker
Member
posted November 08, 2003 10:14 PM
hey miller, what are they using for spindles and a arms and rotors/ what other mods are nescesary? thanks in advance, neil


snowman
Member
posted November 09, 2003 12:01 AM
Really, for my money, I'm with Istock59.....

However, many do drill,or try to drill,or pay someone to drill for them.......I have drilled several sets for some guys who destroyed a set trying to get it right.....

Good thing they didn't read this post or I'd been out some cash......LOL

Nice post 66jj, well written....

Good Luck,
Snowman


PEDDLER
Member
posted November 09, 2003 07:41 AM
Just make sure they meet minimum thickness as IMCA requires.


66jj
Member
posted November 09, 2003 08:48 AM
According to IMCA any rotor built new, with 5 on 5 allready on it is illegal for IMCA stock cars.

If you ask thats what kirk says.

Tach Full
Member
posted November 09, 2003 08:51 AM
Great post 66jj!I have drilled many rotors for customers and myself.A properly drilled new hole pattern doesn't weaken the rotor enough to worry.Be sure to locate the new pattern away from existing holes and stay clear of casting supports.Grind the head of the new 5/8 stud on 1 side so it will clear the casting and press in straight.If available,a drill press makes much easier work but it can be done with a hand drill.


hughes
Member
posted November 09, 2003 09:27 AM
I redrilled mine and have raced them for a season and a half. The only thing I did different from 66jj is that I had access to a lathe and machined the face smooth. It allowed me to get my holes punched easier. I have learned from some guys that don't buy the fancy gauges or other for show stuff that doesn't make it go faster. If your in it to race for the long haul and have a budget (ie wife and kids) you got to cut corners when it doesn't compromise your personal safety. I say redrill the rotors because for every 1 that broke you probably have 500 out there racing every saturday with no problems.


istock59
Member
posted November 09, 2003 10:44 AM
Where did you get THAT info 66jj? I don't believe that's true.

The IMCA brake rotor issue was hashed over in several posts earlier this spring. And it was addressed in several articles in "Inside IMCA" newsletter. I believe the final verdict that came down from IMCA's own Brett Root, was that if the replacement rotor was NOT substantially lighter than the original OEM rotor, it was legal. No mention of redrilled vs 5X5 original rotors.

Perhaps SuperDave will get on here and confirm, because I know he kept up on that discussion. I believe he's a tech at an IMCA track...

Also, on IMCA's website there's all the past articles from Inside IMCA posted (Root's, Herbert's & Niehouse's columns). Read those and find out what the real rules are.

If I COULD, I'd run (on the RF) the billet steel hub that Coleman makes that uses bolt-on rotors. But that I'm sure would be illegal...

[This message has been edited by istock59 (edited November 09, 2003).]

66jj
Member
posted November 09, 2003 12:08 PM
kirk niehouse.

I asked if I could use my lefthander rotors. They probably wouldnt catch me, but they only are 5 on 5...

they are hardened and can be used with real brake pads, that will eat normal cast rotors.



66jj
Member
posted November 09, 2003 01:03 PM
hughes,

I forgot that step, I bolt it all on and mark with a pen then pull it off and grind if its in a bad spot with casting #s etc.

thanks jeff

istock59
Member
posted November 09, 2003 02:13 PM
Want the scoop, ask Brett Root. For instance, last winter I asked Kirk about alum PS pumps, he told me no. Later I asked Brett Root the same question, and he said they are okay. ?? Guess it depends on who you ask...

If they LOOK like OEM replacement rotors, and they weigh as much or more than OEM rotors, I'd run your Lefthanders.

Real brake pads? I assume you must mean Hawks, etc. You really think you need that much stopping power on dirt?

Eljojo
Member
posted November 09, 2003 06:53 PM
Niel, I think you can use the rotors and spindles off a Caddy Seville. But maybe someone on here will set me right on my thimkin!


66jj
Member
posted November 09, 2003 10:08 PM
istock59,

no you dont need stopping power like that on dirt.or probably even the precision braking since the traction to actually stop isnt going to be there.

but if you ever used them versus the best over the counter pads, you would never ever want to go back.

the pedal is right there, because the bite is right there, they come in diff ranges also depending on your heat range etc. it would be like comparing a brake system that is bled versus one that is not bled basically.

they also last forever, but the better ones with good cold bite eat stock rotors.

c21
Member
posted November 10, 2003 10:36 AM

Ive always redrilled the 4 3/4 pattern and used moser axles with 4 3/4.What exactly is the advantage of 5x5 when all racing rims offer the more common 4 3/4?

------------------
DEANJR#22


66jj
Member
posted November 10, 2003 04:44 PM
C21,

I just did my rotors by useing a spacer as a jig and I just barely had to remove any of the webbing, with my mill (die grinder).

the back of my rotors have 5 bumps sticking out, not really webs all the way accross.


79 camaro.


c21
Member
posted November 11, 2003 10:48 AM
Makes sense,I went with a ford 8 inch which came with the 4.5 pattern.I had trouble twisting the splines on the stock axles so i ordered a set from moser and went with the 4.75 to match the front.Thanks for the reply,I just thought there might have been something I was missing.

------------------
DEANJR#22


DMS CEO
Member
posted November 11, 2003 01:57 PM
I use the spacers from JR and take my rotors to my brake lathe at work and turn the inside out of granada rotors to make it 5x5 friendly.


66jj
Member
posted November 11, 2003 04:03 PM
thanks c21.

I wasnt bagging on you, just letting people know that I really did them, last week, and it was very fast and easy. before this I used large heavy impala stuff for years..

you need the studs with a almost 3/4 knurl my way. because thats how thick the rotor is there with out milling it down like the area where the oem stud seats.


superdave
Member
posted November 13, 2003 09:21 PM
The approved replacement rotors like Speedway and U S Brake are legal as long as the rotor matches the application on Stocks and Hobbies. Mods mix and match parts. Stocks and Hobbies must have parts that match their frame without having to modify anything to get them on.

Good luck,
Superdave

------------------
Superdave
______________________
www.salinaspeedway.com


istock59
Member
posted November 13, 2003 09:55 PM
Bingo! Thanks Superdave, I knew you'd know the true story.


66jj
Member
posted November 14, 2003 10:58 AM
I stock 59, Did IMCA take back all the DQs that they handed out at the Beatrice Spring Nat??

That race is where all the mods were getting Dq for useing the speedway light rotors that have a machined look on the snout the ones your so certain are legal now. Also several other races early in the season.


Super Dave posted pics back then of the stock rotor versus the speedway. And speedways was clearly lighter, and machined in places a oem one is not, or even a stock replacement isnt machined like that.


Before I would use them I would ask myself where is it in writeing that speedways light weight rotor is legal???????????????



istock59
Member
posted November 14, 2003 03:02 PM
They won't take back the DQs you should know better than that. That's what started this whole mess anyhow. And after that is when they decided they were okay. Read the IMCA.com articles.

Use whatever you want, just don't go spouting that the Speedway aftermarket 5X5's aren't legal, because you don't know either! And FWIW, I'll continue to use mine...



66jj
Member
posted November 14, 2003 08:18 PM
Ok, Ill stop "spouting off".



istock59
Member
posted November 14, 2003 09:35 PM
If you weren't an IMCA licensed driver in 2003, you probably didn't read the IMCA monthly newsletters. Go to the following website, and somewhere around May/June/July addresses the issue.
http://www.imca.com/news/archives.html


superdave
Member
posted November 15, 2003 12:27 AM
The only DQ's at Beatrice were for rotors that truly were machined and too lite. The Speedway rotor was approved at that race before any races were ran. I believe the Speedway rotor is slightly heavier than the OEM. The U S Brake rotor is lighter but still nothing compared to what guys were doing to the rotors on a lathe. The whole thing started because lightened rotors and hubs were coming apart at race speeds. Guys were thinning them down too much and the hubs too. Obviously it's bad for the driver but think about the stands and pit people when those parts start flying off the car. It's not like punishment, just trying not to put an eye out.

Good luck,
Superdave

------------------
Superdave
______________________
www.salinaspeedway.com


Back to the Archives