Rover 800

jago · Posted: Thu Mar 11, 2010 11:26 pm Post subject: 4 pot conversion

hi all i changed my wheel bearing on tuesday and noted that my discs are needing changing, so....i'm bidding on some 4 pot princess calipers and i'll make a kit up for the 285mm 827 discs...if this works we could all have 4 pot brakes for not a lot
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currently: R827Si Auto (modified) - Black
Clifford cox
previously:
lots

CHR15E · Posted: Thu Mar 11, 2010 11:30 pm Post subject:

Are new ones easily sourced?
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Chris

91 827 Si Manual + matching trailer
90 827 Sterling Project
94 Espace 2.1 DT
94 Espace 2.1 DT Spares car

Richard Moss · Posted: Thu Mar 11, 2010 11:32 pm Post subject:

I thought that Princess calipers were scarce and/or expensive these days.
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Site owner (for my sins)
2000 Alfa Romeo 166 3L. 1990 XJ6 4L Sovereign and 1969 MGC GT.

jago · Posted: Fri Mar 12, 2010 9:25 am Post subject:

they are no to hard to get hold of, however at a later date if i want to upgrade them it's a std fitment
_________________
currently: R827Si Auto (modified) - Black
Clifford cox
previously:
lots

Mark827 · Posted: Mon Mar 15, 2010 12:53 am Post subject:

Most people use the Princess calipers to put on MK2 Escorts.

I'll be really interested to see if this works because I've for ages been trying to source a cheap 2 or 4 pot caliper that fits the standard disc.

I managed to do that on my Merc by adding some washers to space out the caliper but it took a lot of groundwork first to get some to fit.
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Mark

'92 827 Coupe

jago · Posted: Mon Mar 15, 2010 9:33 am Post subject:

There are plenty of kits to modify them for vented discs, also if this does work i'm hoping i wont have a repeat of the disc cracking issues....

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currently: R827Si Auto (modified) - Black
Clifford cox
previously:
lots

Mark827 · Posted: Mon Mar 15, 2010 11:48 am Post subject:

I've had a lot cracked disc problems in the past on my 827's, even with new Brembo discs. I once had one crack so badly that you could feel it catching when braking.
I don't have such problems with my current car but then I don't tend to brake as hard now for that very reason.
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Mark

'92 827 Coupe

Richard Moss · Posted: Mon Mar 15, 2010 12:25 pm Post subject:

Look where that cracked - right through one of the drilled holes. They may aid cooling but they will introduce weak points into the disc.
_________________
Site owner (for my sins)
2000 Alfa Romeo 166 3L. 1990 XJ6 4L Sovereign and 1969 MGC GT.

jago · Posted: Mon Mar 15, 2010 1:13 pm Post subject:

if i remember rightly i only had the discs 2 months and only did about 600miles....

still these std discs i have now are fine but low on material (17.3mm)
_________________
currently: R827Si Auto (modified) - Black
Clifford cox
previously:
lots

MikeMedford · Posted: Mon Mar 15, 2010 2:07 pm Post subject:

Most drilled discs are prone to cracking, unless they are a monsterous size and cost a small fortune.

Better off with bigger and thicker grooved discs.

Disc basically acts like a heatsink, larger the size and thickness the more heat it absorbs/dissapates.

Cracking and warping is caused by heat build up, 4 pots wont remedy this.

If keeping the same size and thickness disc as standard the performance difference between 1pot, 2 pot and 4 pot won't be much at all as it still has the same surface area and clamping force (unless changing brake servo as well).

Wear on pads and discs would be a bit more even, that's about it.
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Med

jago · Posted: Mon Mar 15, 2010 2:34 pm Post subject:

i totaly understand about that, what i'm after is brakes that will reduce the chance, so in the end yes thicker discs and maybe larger diameter as well, but for now 4 smaller pots and new groved discs will do.
_________________
currently: R827Si Auto (modified) - Black
Clifford cox
previously:
lots

BRG · Posted: Tue Mar 16, 2010 1:30 am Post subject:

I totally despair of my front brakes. Mainly the discs. I'm on my 3rd pair (in 3 years). They just warp.

I've put progressively better 'quality' discs on. Still bog standard OE or equiv., but dearer. Last pair, I think, were something like £35+ each. Not massive money, sure, but come on....
I got Mintex pads last time, same. I think I get about 3 months, tops, before my right leg's in danger of getting broke by the juddering.

If I've checked the hubs once I've checked them 10 times for 'true' and they are.

I've always thought the Vitesse had inadequate brakes. Is it just heat? Purely getting too hot and getting splashed cold?

Richard Moss · Posted: Tue Mar 16, 2010 2:18 am Post subject:

I've never had 800 brakes warp. Maybe I've been lucky.
_________________
Site owner (for my sins)
2000 Alfa Romeo 166 3L. 1990 XJ6 4L Sovereign and 1969 MGC GT.

MikeMedford · Posted: Tue Mar 16, 2010 2:48 am Post subject:

Mark827 · Posted: Tue Mar 16, 2010 3:23 am Post subject: