SN95/Cobra brakes on Bump?

[canadiancobra]

When I restored my 1966 Mustang I purchased caliper bracket kits which allowed me to install 2004 Cobra disc brakes on all four corners with stock drum hubs and 8" rear. Just thinking out loud and wondering can or has this been done on F-100's? I'm guessing the 9" rear isn't a problem but what's the story on the front? Can Cobra rotors fit on F100 Hubs/spindles?

It would look sweet with 20" rims! Anybody??

John

[ultraranger]

The F-100 spindles use the same A12 and A13 bearings that the early Mustang V-8 drum hubs use. However, early Mustang drum brake hubs won't fit onto the F-100 spindle pins. The distance is greater between the outer and inner bearings on the F-100 drum hub than the distance of the bearings on the early Mustang hubs.

Trying to put a 13" Cobra rotor on an F-100 drum hub poses some problems that probably make it impossible to do. The Cobra rotor is drilled for a 5-on-4.5" lug pattern. The F-100 drum hub has a 5-on-5.5" lug pattern. I'm not certain if the outer diameter of the F-100 hub would fit inside the back, inner diameter of the Cobra rotor's hat. It's likely the outer diameter of the hub is too large to fit.

The other thing I do know that would be a problem is the large diameter of the F-100's hub center register diameter is too large to fit through the center hole of the Cobra rotor. If the center of the Cobra rotor was machined out, the hole would intrude into the existing 5-on-4.5" lug holes in the Cobra rotor. This would eliminate there being a continuous, solid surface of material to keep the rotor hub centric.

The stock 5-on-5." lug pattern on the 9" rear and the large wheel flange diameter of the axle would present similar problems trying to fit the rotor on the rear as it would be on the front. The only Ford 9-inch rear I know of, that '94-'04 Cobra rotors/calipers could be adapted to, without machining modifications to the axle flanges, would be to install a 1980-1983 Ford F-100 9-inch rear end assembly. These 9-inch rears had the 5-on-4.5" lug pattern with smaller outer diameter axle wheel flanges.

...but, putting Cobra rear disc brakes on an '80-'83 9-inch rear puts the problem back on the front of having the wrong lug pattern there with stock F-100/F-150 discs. The only options I know of for 5-on-4.5" discs on the front would be to do a 2003-2011 Crown Vic front suspension swap or, install a Mustang II based front suspension.

[ultraranger]

...some of my experience with disc brake conversions;

in 2001, I had some prototype brackets machined, from my designs, to adapt '84-'90 Lincoln Mk VII 11.25" ventilated rear discs to Ford 8-inch and 9-inch small axle bearing rear ends for early Mustangs, Cougars, Falcons, Comets,and related Fords.

http://ultrastang.com/info11.php


In late 2003/early 2004, I began working on a bracket design to adapt '94-'04 SN95 Mustang V6/GT 10.5" solid rotor rear discs to Ford 8-inch and 9-inch small bearing rear ends.

My brackets to adapt SN95 Mustang V6/GT rear discs to an early Mustang.




Drum brake assembly removed from 8-inch rear, (1965 Mustang fastback), and caliper adapter bracket installed.




Caliper, rotor and splash shield mounted on axle housing.







After producing the V6/GT rear disc adapter brackets , I designed a bracket set that would adapt '94-'04 SN95 11.65" ventilated Cobra rear discs.










6061-T6 aluminum brackets I had machined to adapt 13" Cobra rotors to the front of my '68 Mustang

[canadiancobra]

Great points. Thanks for the reply. I wondered if the hub centre would be to big. I also had forgot about the difference in bolt pattern.

John

[canadiancobra]

Well I've found a machine shop to accomplish what I wanted. Milling down the drum hub perimeter and centre to fit the late model rotor. Also redrilling wheel stud holes to 5x4.5 bolt pattern. Then I'll have to mock up some caliper brackets. Hopefully post some Picts soon.

John