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Fitting Sierra Cosworth brakes
Paradoxia0 - 14/10/07 at 10:21 PM

Hi All

I have decided to take the plung and do brake upgrade. The standard single pot Sierra calipers never felt quite up to the job on my (very heavy) Viento so I have got hold od a set of 4 pot Cossie calipers.

I know someone on here will let me know how easy this is but I am not certain what to do next...

I am running Sierra uprights with standard single pot calipers at the moment on 260mm disks (I believe). THe cossie calipers generally run on 283mm disks (that I have) but once fitted to the upright the disks and calipers don't quite line up... The caliper needs to be 2-3mm furter into the car to work (so no way of spacing it anywhere)


Image deleted by owner

Can anyone on here shed any light on what I should do before I get some crazy idea of skimming a bit off the caliper mounting points to get it to fit?

Thanks

Mark

[Edited on 14/10/07 by Paradoxia0]


robinj66 - 14/10/07 at 10:41 PM

I think that Cosworths had a different upright to standard Sierras.
[Also i think standard (2.0) Sierra vented discs were 240mm]


RazMan - 14/10/07 at 10:51 PM

Looks like an offset problem - new discs will be the quickest solution methinks. Also, are the Cossie discs a tad thinner? They look rather thick for the calipers. 21mm instead of 25mm (something like that anyway)

[Edited on 14-10-07 by RazMan]


MkIndy7 - 14/10/07 at 11:28 PM

If the caliper needs to be further into the car then put washers between the hub and be caliper mount, that will space it inwards.


mcerd1 - 15/10/07 at 07:45 AM

quote:
Originally posted by RazMan
Looks like an offset problem - new discs will be the quickest solution methinks.

This would be the answer - but you can't get discs of the shelf with the right offset, stud spacing & centre bore - but you could look through some of the cataloges for a suitable disc that would need the minimum mods

Its been done before with either cossie 2wd or cossie 4x4 discs (cant remember which - but 4x4's are 19mm shallower so would probibly not fit in the wheel)

I think they had to grind/ mill a little off the mounting lugs to make it fit (should only be 2 or 3mm out)

also you'll find that the 4 pot calipers use a size bigger bolts and arn't threaded like the std sierra ones

quote:
Originally posted by RazMan
Also, are the Cossie discs a tad thinner? They look rather thick for the calipers. 21mm instead of 25mm (something like that anyway)

All the sierra & granada vented discs should be 24mm thick

[Edited on 15/10/07 by mcerd1]


saigonij - 15/10/07 at 01:59 PM

the 260 brakes on a sierra are almost the same as RS Turbo Brakes - with this in mind, there is an article in this months fast ford about fitting those calipers to RS turbos - essentially they ground off the inside of the caliper lugs until they fitted.

personally i would not do this as its bound to weaken them - but in their "ask the expert experience" ( yea right! ) they recon they are safe!!!!!

IF you want bigger brakes, there is another solution which im currently test fitting...

sierra cosworth 4x4, or Escort cosrowth calipers and 2wd sierra Cossie discs. the discs are slightly bigger ( 283mm ) than the standard sierra 4x4 cossie - at 279mm, but they will work.

you just have to find a set of sierra saph cossie / escort cossie calipers and brackets...


balidey - 15/10/07 at 02:12 PM

I think I should add a comment here, mainly because they are my fingers in the picture

Anyway, I personally would not want to machine down either the caliper or the upright, especially when kits are sold with spacers, so whats gone wrong here?

So to get these calipers to fit it means moving them inboard about 3mm, then they can bolt on ok, but the disc will then foul and not sit in between the caliper, but is it ok to fit a thicker spacer between the two halves of the caliper? ie remove the 10mm(?) spacer and fit a 15mm(?) spacer? this should then make te caliper fit around the disc.

Is this a possible or sensible solution? I seem to remember that converting from solid to vented this is all you do, so why not in this case????

[Edited on 15/10/07 by balidey]


saigonij - 15/10/07 at 03:10 PM

like i said, go along to WHSmiths and have a laugh at FastFords solution.......

angle grinder = not very clever


RazMan - 15/10/07 at 04:06 PM

quote:
Originally posted by balidey
is it ok to fit a thicker spacer between the two halves of the caliper? ie remove the 10mm(?) spacer and fit a 15mm(?) spacer? this should then make te caliper fit around the disc.



Thats basically all there is to it ..... if the disc is simply too thick for the caliper. Wilwood use the same method for solid / vented discs. It will allow the caliper to fit the disc, and change the offset between them too.

Has the caliper got an external tube or is it internally connected between the two halves?

[Edited on 15-10-07 by RazMan]


Paradoxia0 - 22/10/07 at 09:57 PM

Hi Razman

I have checked and there is no pipe joining the 2 halves of the caliper so the spacers must also carry the fluid.

I have had a rummage around and seen no-where that sells these spacers (but then I might be searching for the wrong thing!).

Anyone got any idea where I can get these spacers from or the feasability of getting some made up?

Mark


RazMan - 22/10/07 at 10:12 PM

I am not really familiar with the Cosworth calipers but I am pretty sure Morgan use them and space them according to the size of disc used.
It might be worth a check here for starters


gttman - 23/10/07 at 07:15 AM

I fitted the brakes from my 2wd cossie on my Indy....

I wasn't the simple bolt on excersise that I thought it was going to be. and needed a little fettling mainly to the overall diameter of the disc (had it machined down 5mm), and I found the bolt holes are not actually exactly the same either.

I a pretty sure I didn't need to skim the caliper mount or the upright as I had aftermarket brakes on it and had skimmed the disc so they just fitted.

so before you go any further you need to check the actually can bolt on anyhow and will fit over the disc when the offset is sorted.

[Edited on 23/10/07 by gttman]


gttman - 23/10/07 at 07:46 AM

OK just to clarify, does the disc fit into the caliper off of the car, if so then I think spacering is not the best answer.

Others will not like it but what I would skim the caliper by 1-1.5mm and then take the rest off of the disc (you need to do both sides tho).

The reason I would skim the disc is because it is designed for a very fast car 3 times the weight and thus you will struggle to get any heat into it at all (see how thick it is let alone the extra diameter)..... you can skim the disc 1mm and still be within the std car tolerences anyhow.


Schrodinger - 23/10/07 at 03:28 PM

Before you go to far into this coversion you may want to check that the calipers and disks will fit inside your wheels. I tried the same conversion on my Cat and it fouled the inside of my wheels.


Paradoxia0 - 23/10/07 at 04:11 PM

Hi Keith

As I have 17" wheels I should be OK on wheel clearance...

But I will check none the less!

Mark


Paradoxia0 - 23/10/07 at 04:11 PM

Hi Keith

As I have 17" wheels I should be OK on wheel clearance...

But I will check none the less!

Mark