GT6 Brake conversion to 4 pot Princess Callipers
Mark Digby
improve the brakes on my Mk2 GT6.
Does anyone have any details, in particular the mods required to the vented
discs ?
Do the callipers need spacers to fit over the discs ?
les
Yes, you will need spacers to fit princess calipers over any vented
disk. We sell them for 25 ukp per two caliper kit.
The calipers are the same fixing centre as a Dolomite Sprint which is
almost certainly the same as the GT6 so you should have no problem
from the caliper point of view ( we can also supply you with s/h
calipers & competition pads)
As for the disks, the centre hole is 68.4 on a Capri & 66.7 on a
Spitfire (possibly the same - dont have GT6 figure )
The overall hight is about the same for the Spitfire & capri with
solid disks so they are about the correct size.
You would probably have to have the disk fixing holes redrilled at 45
deg from the existing ones & they would need to be accurate unless you
have a spacer ring to locate the disk on the hub with the centre hole
being to big.
Fitting these calipers does make quite a difference over the 2 pot
caliper (on MKII escorts anyway) but avoid the external pipe work kits
normally used to convert them from dual to single circuit - it makes
bleeding them a pig & usually results in a "long pedal" (they should
be internally modified)
Hope this is of some help
Les
am018
discs also I am not sure if the Ford discs will fit the Triumph hub without
machining --- I am pretty sure they will need re-drilled at 45 degree to the
original PCD but suspect the hole in the middle will also be the wrong size.
4 pot calipers have advantages in that they are more ridgid -- but they could
upset the brake balance and result in premature locking of the front brakes
inthe wet which isn't dangerous but can be dammed frustrating -- it might be
best to retain 2 pot calipers.
Much cheaper spacers are available for Ford Escort/Cortina/Capri/Granada
calipers (Girling M16) which are almost the same as your exist calipers (Girling
P16) -- but I am not sure about the mounting hole pitch --- it might be the
same it is also possible the spacers for the M16 caliper might fit the P16 as
I have never tried it I can't say but I think the only real difference between
the two familys of calipers apart from the size of retaining pin (smaller on
the M16) is that M16 uses metric threads.. With brake calipers the mounting hole
pitch can also vary slightly from make to make.
am018
discs also I am not sure if the Ford discs will fit the Triumph hub without
machining --- I am pretty sure they will need re-drilled at 45 degree to the
original PCD but suspect the hole in the middle will also be the wrong size.
4 pot calipers have advantages in that they are more ridgid -- but they could
upset the brake balance and result in premature locking of the front brakes
inthe wet which isn't dangerous but can be dammed frustrating -- it might be
best to retain 2 pot calipers.
Much cheaper spacers are available for Ford Escort/Cortina/Capri/Granada
calipers (Girling M16) which are almost the same as your exist calipers (Girling
P16) -- but I am not sure about the mounting hole pitch --- it might be the
same it is also possible the spacers for the M16 caliper might fit the P16 as
I have never tried it I can't say but I think the only real difference between
the two familys of calipers apart from the size of retaining pin (smaller on
the M16) is that M16 uses metric threads.. With brake calipers the mounting hole
pitch can also vary slightly from make to make.
as I think the Gt6 and Lotus +2S used exactly the same caliper as the original
Austin 1800 landcrab.
Incidently 3 pot (yes 3 pot) calipers from a 18/85s (the twin carb version of
the Austin 1800 landcrab) or Austin 3 litre will also fit straight on to your
existing discs and brackets.
Ian Ellison
roughly) in the caliper. I don't know what the original discs on teh car
were; they had a conical section between disc and mounting flange, and
they warped terribly (in competition use). I replaed them with S&S
Preparations' vented discs, which comprise a machined hub adaptor and a
flat disc. These don't warp, and the disc will be cheaper to replace
being flat. Totally transformed the handling.
No experience of them on a GT6, but talk to S&S. I would be interested
to know as my Spit could do wwith more stopping power!
Ian Ellison
ie at grolier dot co dot uk
am018
brakets) they are much larger.
Ian Cowley
>
> I am told you can fit princess 4 pot callipers and 2.8 Capri vented discs to
> improve the brakes on my Mk2 GT6.
>
> Does anyone have any details, in particular the mods required to the vented
> discs ?
>
> Do the callipers need spacers to fit over the discs ?
There is a standard spacer kit to permit the Princess cabliper to fit
over these 260mm x 22mm (I think) disks. If short on numbers talk to
Gareth Lloyd of West Wales Rally 01559 363731. Further Ken Clark of
Boxridge Motors in Warwick 01926 484140 fits these calipers to Dolly
Sprints.
Ken may recommend a more modern setup, though I race on a similar setup,
albiet with the racing version of the caliper.
The spacer kit is about 30 quid.
The disks are about 60 quid/pr
The calipers are about 100 quid/pr
IanC
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Alan Eardley
>
>There is a standard spacer kit to permit the Princess cabliper to fit
>over these 260mm x 22mm (I think) disks. If short on numbers talk to
>Gareth Lloyd of West Wales Rally 01559 363731. Further Ken Clark of
>Boxridge Motors in Warwick 01926 484140 fits these calipers to Dolly
>Sprints.
>
Does anyone know if the Princess/Ambassador caliper is a (reasonable) bolt-on
to a Vauxhall Magnum upright? It uses a Girling P14 caliper - a bit smaller
than a P16, but the same as a Dolomite. The disk is bigger on the Magnum
(260mm) but the caliper mounting height (i.e mounting lugs to edge of disc)
must be the same surely? This disc width is about the same as a Dolomite.
Alan
les
Eardley) wrote:
Ive just nipped into the workshop & put a princess caliper onto a
dolly sprint swivel.
There is about 4mm of pad left above the disk ie it would stand an 8mm
larger dia disk.
If you want any dimentions of the princess calipers I could do you a
sketch & email it to you.
Your caliper may not be the same as the dolomite - I have come across
calipers which are identical but have the mounting lugs in a different
position.
Andrew W. MacFadyen
10.25 inch dia solid disc quite thick -- the central hole is smaller than
the Ford. They stand up to a lot of hard use without fade or warping.
nospamles <l...@cars.u-net.com> wrote in article
<3627a454....@news.u-net.com>...
Alan Eardley
>
>I used Firenza/Magnum 2.3 15 years back for Imp brake conversions its a
>10.25 inch dia solid disc quite thick -- the central hole is smaller than
>the Ford. They stand up to a lot of hard use without fade or warping.
>
just looking for the upright!
Alan
Alan Eardley
says...
>>
>Ive just nipped into the workshop & put a princess caliper onto a
>dolly sprint swivel.
>There is about 4mm of pad left above the disk ie it would stand an 8mm
>larger dia disk.
>If you want any dimentions of the princess calipers I could do you a
>sketch & email it to you.
>Your caliper may not be the same as the dolomite - I have come across
>calipers which are identical but have the mounting lugs in a different
>position.
>
Thanks - I already have the caliper, it's the Vauxhall upright I don't have
yet! I'm planning to put Magnum uprights on HA Viva wishbones (someone alse
has done it but kept the Girling calipers). The ball joints are the same, but
I don't know what the caliper mounting hole centres or mounting height are.
Alan.
am018
know they all used the same hub I don't know about clearing the diametre