Rotor diameter ?

[osdmike]

Hi !

I have a Camaro -69 , with Wilwood Disc brakes in the front.

The brakes were assembled in the early or mid -90´s.

They look very much like 140-7675 , but they are a bit different.



The size of My rotors are: 10,75" dia. 5 bolt , 3,88" bolt circle.

Does anyone know if it´s possible to find 12" rotors 5 bolt , 3,88" b.c.,

that will fit My car ?

Or do I have to change the complete kit?

Michael

[derekf]

3.88" bolt circle? Are you sure that you're measuring that right? Stock Camaro would be 4.75" bolt circle and stock big-car would be 5" bolt circle... 3.88 seems awful small.

[Matt@RFR]

Just to verify, I drew 4.500, 4.750 and 5.000, 5 bolt bolt circles and measured every which way I could think of...nothing was close to 3.88. 3.88x2 (7.76) didn't match anything either. How are you measuring this?

[Salt Racer]

Dudes, he's talking about the bolt circle on the rotor/hub mount, not the wheel lug bolt pattern. The rotor shown below is their drag race stuff, but they used to use the same pattern on street rotors.



Michael,
I think you're out of luck. Your best bet is to upgrade the whole thing. Wilwood has done fair amount of re-engineering in the last couple of years. I bet your calipers are old cast Dynalites w/ no stainless wear plates (thin stainless plates where pads backing plates make contact with aluminum caliper casting).

If you can fabricate caliper mounts, it's better if you use 1.10" or even 1.25"-thick rotors as opposed to 12.19 x 0.810" rotors that are included in their standard 12" kit. Those thin rotors are marginal on a 3500-lb Camaro for anything other than moderate street driving (speaking from my own first-hand experience here).

[SHANE 73Z]

osdmike,

IIRC,The newer, heavier duty kits use an almost flat plate that bolts to the back of the hub and then the rotor bolts to it. You may be able to ditch the old rotor and just get the mounting plate and new rotors and use the existing hub. Wilwood should be able to give you the fitment information.

Check out the picture at this link:
http://www.wilwood.com/BrakeKits/Pages/06/index.asp

Notice the "plate" that the rotor mounts to (you can see the end s of the bolts sticking out through). That plate bolts to the back of the hub. That is the plate I was referring to above.

Shane

[osdmike]

Thank´s for Your answers !
Yes , that´s right. I mean the rotor/hub mount.
About the caliper , I think it is an old cast Dynalite.
Part nbr: 120-1052 (can´t find it in any catalog).
Front discs are 10.75" dia.
The disc width are .81" . (Street version).
I don´t think thicker discs will fit into these calipers.
They are not wide enough.

I´m asking these questions , because I have a lockup problem in the rear.
It´s a Ford rear end with the same calipers as in the front.
The discs in the rear are 12.19" dia. , .81" thick .
There are 8 bolts. ( I´m not sure about hub mount bolt circle dia.)

I have tried to adjust the propotioning valve , but I can´t get it right.
Thats why I´d like to put on 12" rotors.
I was also thinking of the flat plate , Shane mentioned , but I better talk to Wilwood , about different offsets and stuff.

Since My car weighs , like You said , approx.3500-lb , a new brake kit would probably be the way to go.


Michael