New Minilites don't fit the disc hub. What to do?

[Ford.P51]

Hi all,

I ordered some Minilites back in August and they finally arrived. Unfortunately the center hole doesn't fit over the disc brake rotor hub.   They do fit on the rear axles just fine. The front disc brakes are the 73-76 A-body disc brake swap.

It seems like I could 1) have the wheel holes milled to increase the diameter roughly a 1/4" or 2) mill the hub down a 1/4". It seems like milling the wheel is the way to go, as rotors may need to be replaced down the road.

Any thoughts? Also, if I mill the wheels, I'm not sure what to do about the center caps. Are aftermarket caps available? Never looked into these. 

[brads70]

Don't machine down the front rotors for clearance!    I'd contact minilite and ask them what they have for caps if you machine out the centers for clearance.
Post up some pictures, I'm curious?

[burdar]

What diameter are the wheels.  Are the A-body rotors the same as the ones that came on the Cordoba/Magnum/Chargers?  I tried installing road wheels over those rotors and they wouldn't fit.

[Ford.P51]

brads70 - I talked to minilite yesterday and they are going to look into what size caps they have and get back to me. Hopefully we'll work something out there. I'll post some pics tonight.

burdar - they are 15x8 wheels. The rotors are the 73-76 Valiant/Dart/Duster rotors.

I'm going to call around today and try to find out how much it will cost to machine the wheels. I didn't have time yesterday.

[HP2]

I have noticed changes in diameter/appearence to the center hub on replacement discs over the past few decades. It might be Minilite has an old database number that they machine the wheels to. After all, at one time the front and rear registers were identical. On your set up, the rears fit, the fronts do not.

You can go either way on this and I've seen forum posts around the web of guys doing it either way. Milling the wheel createsa a unique front. Milling the rotor will allow rotation.

[Super Blue 72]

Sorry the hubs have trouble.  Even the stock E-body rotors have their issues.

   Out of curiousity why would milling the rotors be bad?  As HP2 said, milling the rotors would allow tire rotation but I understand you might need new rotors soon.

Wouldn't milling the rotors be easier and less costly?  Can't you just put them on a brake lathe and turn them down?  I would imagine turning a wheel would be more complicated, but I dont know how that would be done aside from a big lathe of some sort.

I wonder if the A-body and E-body rotors have the same hub diameter?    I think last time I measured the stock E-body ones are about 2.75", give or take a little.  I know Ford rims won't fit the center hole.  I think they are like 2.5 from what someone told me.

A cheaper way to fix this MIGHT be to use wheel spacers but then the wheel wouldn't ride on the hub, more stress on the studs.  Finding spacers that are the height of the hub to clear the ridge might work, although perhaps not the best solution.  Also you may get tire rub on the fenders.

Hope it all works out!

[cudazappa]

I've re-machined wheels and rotors to get them to fit cars.  I hate doing rims.  Just a big PITA setting them up on a surface plate on a lathe, especially if they are (ab)used.  I've bored them on a Bridgeport, a bit easier that way, but time consuming setup.  (I actually made a fixture for them to speed up the process)

The last setup I machined my 'doba rotors register down to fit mustang rims.   Oh wow, much quicker.  Helped that I started with NEW rotors.  I have mustang register size from the end (outside) of the rotor up until 3/4" from the hub.  Still mopar diameter from there to the hub.  (I run 1" spacers with Mustang Rims).

Next project is to find some junk 73+ rotors and machine them into hubs for 13" Mustang rotors.

[Ford.P51]

Here's two pics of the wheels:





I finally got out the measuring calipers and took some accurate measurements. The rotor hub is 2.8 inches in diameter.

You can see on the second pic the shoulder around the center hole. The shoulder diameter is roughly 3.1 inches in diameter, and the center hole is 2.7 inches in diameter. So I need less than 1/8 diameter change, which is really just a radus change of 1/16". I've got to wonder if just removing the powdercoat in the center of the wheel would take care of the issue.

Like others have said, just a little off of the rotor would be much easier to deal with. Decisions, decisions ....

Thanks for all the comments by the way! Very helpful!!!

[HP2]

Hmmmm, genuine Minilites!   

[brads70]

Hmmmm, genuine Minilites!   

 

If it was me I'd just set up the rim and machine it once and be done with it. Rotors are going to be a consumable?  Mind you that's easy for me to say as I have the equipment but you still have to pay someone to machine the rotors everytime, I'd just do it once?

Most of my experiance with stock rotors breaking is with stock car racing. I've seen the centers of rotors ripped out before, the end result is not pretty? 99% of the time it's due to Chinese crappy rotors though. The steel in them is different than say a Wagner or Raybestos that are made in USA or Canada. I machine them for racers ofter for bigger studs. Even the chips coming off the tooling is different. So that's why I made the coment against machining the rotors. Of course you most likley will never subject them to forces experianced in racing, but....? Another point is if they could get away using less metal when making rotors don't you think they would have so they could save money ? If it's on a critical part like a rotor I wouldn't be machining it down and using it on my car. Even though I'm a bit of a weight freak and save every ounce I can on my car.
I know on my rims they do have different caps to suit the center hole size . I'm sure minilites do also?

http://www.performancewheels.com.au/SiteMgt/ww_Standard.asp?SitePageId=202

[Super Blue 72]

  Don't the center caps fit in from behind and the lip sits in that 3.1" recess?

So if that is the case and the hub just fits nto the center hole on the rim, doesn't that mean the center cap can't be used?     It'll have to be affixed from the outer side of the rim, yes? 

[Ford.P51]

Yes, the center cap slips through the hole from behind, so the center hole has to be opened up enough to fit the hub and center cap.

I took a little more accurate measurements last night.

The center hole of the wheel is 2.65 inches.
The rotor hub diameter is 2.75 inches.
The thickness of the hub is 0.5 inches.

If we ignore the center cap issue, there is a 0.1 inch difference between the wheel and hub. I had been leaning towards taking a little material off of the hub, but 0.1 inch represents 20% of the material there. That seems like a little too much for me, and brads70's comments are pushing me towards milling the wheel.

I've called a few machine shops about opening up the wheel diameter and they all turned me down. "We do engine blocks not that kind of stuff. We don't have a lathe that big." Guess I better make some more calls today. It doesn't seem like this should be that big a deal???

[Strawdawg]

sounds to me as if the center cap will not be able to be used even if you enlarge the opening in the wheel as it will still be the same size and will not slip over the hub as it is...either before enlarging the hole, or after.

Sounds like you need a set of rotors that will fit, or turn the hub down.

[brads70]

Yes, the center cap slips through the hole from behind, so the center hole has to be opened up enough to fit the hub and center cap.

I took a little more accurate measurements last night.

The center hole of the wheel is 2.65 inches.
The rotor hub diameter is 2.75 inches.
The thickness of the hub is 0.5 inches.

If we ignore the center cap issue, there is a 0.1 inch difference between the wheel and hub. I had been leaning towards taking a little material off of the hub, but 0.1 inch represents 20% of the material there. That seems like a little too much for me, and brads70's comments are pushing me towards milling the wheel.

I've called a few machine shops about opening up the wheel diameter and they all turned me down. "We do engine blocks not that kind of stuff. We don't have a lathe that big." Guess I better make some more calls today. It doesn't seem like this should be that big a deal???

First thing I would do is aquire a bigger cap ( they do make them, I'm 99% sure as mine fit and I'm running a C-Body rotor!) then find a machine shop ( not nessesaraly automotive) then with cap in hand tell them to machine out the center to make it fit.  It can be done on a regular bridgeport mill I'd say about 15 minutes each wheel. Not a big deal...really!  To bad we didn't live close  I'd do it for you.

[Ford.P51]

I found a place to mill the wheel for $60 a wheel. Summit has a ton of center caps, looks like several will work. Ebay also has a huge selection.

Tonight I'm going to pick out and order a center cap, and then take the wheels in to be milled a bit larger than the cap diameter.

My biggest concern is what the wheel's paint will look like at the edge of the hole after milling. I guess we'll know in a couple of days!