[Cortina-list] Oh well...

John Miller jem at milleredp.com
Tue Sep 4 03:59:03 UTC 2012

On 9/3/2012 7:15 PM, Don gwynne wrote:
> John,
> So are SAAB 900 rear rotors suitable for rear disk conversions on Mk1
> Cortina and Mk1 Escorts?

They're late ur-900 rear rotors, '86-93, after Saab converted the 900 to 
the 4x4.25 bolt circle of the 9000.

258mm (10.1in) diameter, 9mm thick, 43.5mm hat depth.  This latter 
dimension's the important part, to minimize caliper-to-wheel clearance 
issues - most of the off-the-shelf 4x4.25 rotors you'll find are 
intended for FWD vehicles and have considerably shallower hats.

The hat's big enough to fit over an axle flange but there's still 
sufficient friction surface to accommodate the pads for the early 
solid-rotor Ford/Merkur Scorpio rear calipers I'm using.  The Scorpio 
rotor is 10in diameter and 10mm thick but 5-bolt and the hat's too 
shallow.  The caliper frame size is similar to the SN95 Mustang rear 
caliper (the Mustang uses a somewhat thicker solid rotor) and the pads 
are very close in size though, frankly, if you wanted to sort out the 
hydraulic-ratio issues any of the small Ford calipers that expect a 10mm 
solid rotor - Escort, Focus - might work just fine.

The hub bore on the Saab rotors is 2.68in vs Ford's 2.50 but that's easy 
enough to make a bushing for.

The Saab rotor/Scorpio caliper combination will require at least 14in 
wheels but my front setup - 11in Cosworth Sierra front rotors and 
Contour calipers per the previously-linked kit - may require 15s, so the 
rears are the least of my problem.

Please note, purists breathe easy, this is all going on a GT that was 
(still is, mostly) one step from scrap metal, I'm not hacking up a Locort...


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