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MG MGB GT V8 Factory Originals Technical - rv8 discs on a mgb

Have spent a while trawling through the archives, lots of info but not what i am looking for:

Can anyone tell me if i can use rv8 vented discs with 4-pot VENTED SD1 calipers on my MGB? I have rover 800 discs but need to modify whereas I can buy RV8 discs for 40quid a pair brand new, so there is no point messing with rover 800/pug505 etc for sake of 40quid (from rally design...) if they are a bolt on fit.

i have read heaps on the pros and cons for vented setup -having cooked non-vented set up before have made my mind up..yep my calipers are definitely vented, yep i have the sleeves for the mounting bolts and yep have the hose converters (v8 conversions dave vale top man)...it is a late model so excessive pedal travel should not really be an issue.

Thanks.
D Brophy

Hi
Look up ths site: www.brakeparts.co.uk
They have a section with all the dimensions of various discs (and prices). Compare the rv8 discs dimensions with the peugout ones and see if they are close. (I don't know if they are). I ended up getting a set of the peugout discs and spending £30 getting them redrilled. On some discs you may have to have a thin collar fitted inbetween the disc and the stub axle... that cost another £5 each side. I also used the vitesse 4-pot calipers and everything bolts together nicely.
Nick Bentley

I did the same as Nick, I also had a spare pair of disks made at the same time, I've got them here in Blackpool if you want to check them out.


One point to consider, the 4 pot calipers are considerably larger than the MGB ones, there is no way they will fit inside an ordinary MGB wheel, I ended up with 1/2" spacers, and extended studs, before I switched to 15" Minotaur wheels ( they have a much bigger off-set)....then you have to tackle the question of rear tyres rubbing....one step forward...two back sometimes.


Mike
M Barnfather

R800 discs are quite good for rear disc conversions as they fit on inplace of the drum very well.

On the front of a B the disc does not fit onto the wheel studs in the same way as the drum does at the back. The ring of bolts that holds the disc to the rear of the flange has a smaller diameter than the ring of studs. I don't know what it is off hand but it is worth checking before you go shopping for front discs. The redrilled Peaugot option is very old now and since it was first used there have been many more cars with vented discs so it is worth doing fresh reaserch.
David Witham

So will RV8 front discs bolt onto standard MGB front hubs?
Jake

Yes they will, but they are 240mm by 22mm. The pug discs are 273mm diameter and therefore suffer less with brake fade as they don't get so hot. If you are going to go to all the trouble of fitting vented discs, you may as well spend the extra few quid and get a pair of pug 505 discs redrilled to fit.
Best of luck whichever route you decide to take.
Nick Bentley

Thanks for all your help, checked out that website -bizarre but RV8 discs are 240mm dia (MGB 275mm)...? I have seen this measurement before and assumed it was an error (MGF-metro gti size disc) two separate sites now saying the same strange thing...

Anyway, if it is true, they are no good... My Rover 800 ones will do nicely, they will need the hub hole enlarging (64 to 73) and the stud holes doing (may need dia reducing as they are 285....){i need the granada cosworth rear discs doing aswell -so i can give my local machine shop some fiddly work...)

i have minator 15" alloys too, although not on car -i guessed i may have to roll the rear arch lip back as i have 195/50 -15 tyres...you just confirmed this...!

this is my first use of this site and it is great -ta!

more questions soon..
D Brophy

50 section a quite a bit smaller than usual.....I've got 65s and they give a nice soft ride...Geoff King and several others have 60 section (it's probably similar radius to originals)...50's will mean more revs per MPH... have you had the speedo re-calibrated ?

Mike
M Barnfather

This thread was discussed between 16/09/2005 and 25/09/2005

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