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MG MGB Technical - V8 calipers

I believe the V8 front brake caliper is a hybrid standard MGB and a Triumph caliper?

Anyone got the exact information please?

Colin
Colin Parkinson

Oops, just realised I asked the question some while ago.

But doing the research it seems that the Triumph 2000 has 2 different calipers, and neither are available in pairs.

So guys, does anyone know which Triumph 2000 caliper it is?

colin
Colin Parkinson

I thought it was the Triumph 2000 or 2500 inner half of the calliper mated to the MGB outer half!
Allan Reeling

Allan you are indeed correct. Unfortunately the TR2000 used 2 different calipers.

My question is which is the correct one.

Colin
Colin Parkinson

"So guys, does anyone know which Triumph 2000 caliper it is?"

Not very scientific, but I would hazard a guess that later Triumph calipers may have been metric, as TR6 were, so probably early caliper.
Dave O'Neill 2

Triumph 2.5 saloon inner casting
MGB outer casting
William Revit

72-73 year model Triumph 2.5 at a guess as that would be when they were doing it
William Revit

Which explains why V8 pads are handed i.e. there is an inner pad and an outer and they are not interchangeable. Tricky when you get a box with three of one type and one of another ...
paulh4

I wonder if the TR callipers changed to accommodate different disc thicknesses. Hence an enquiry regarding the disc might produce the information you are after.
Allan Reeling

Dave, you might indeed be correct on metric / imperial.
The TR6 caliper was metric with a special bolt, metric shoulder with imperial thread.

Allan, yes Mk1 2000 had 0.35in disc, Mk2 was 0.5in disc.

But that still doesnt answer whether it is the early or late caliper which is used on the V8 hybrid, but we are getting nearer!

Colin
Colin Parkinson

Colin
just curious why you are asking about this
Surely if you need to upgrade your brakes you would go for something more modern-?

and it's Triumph 2.5 saloon that's listed not T2000
William Revit

It would have to be Mk2 if 2000 are the same as they didn't have Mk1 2.5 ,not here anyway
William Revit

Interestingly I fitted Princess 4 pots to my V8 Roadster and had to use TR shouldered bolts.
The factory V8 callipers didn't need special bolts. That could either have been because the hub carrier was drilled and tapped metric OR the inner calliper half was still imperial???
Should have noticed I suppose!!
(Notice should HAVE, not should OF!!!***)
Allan Reeling

I'm pretty sure a pal used Rover SD1 calipers and BV8 discs. I think shouldered bolts were required.
Mike Howlett

"(Notice should HAVE, not should OF!!!***)"

Beginning to think I was the only one left.

Parts Catalogue doesn't differentiate between 4-cylinder and V8 caliper bolts as it does for the pads and calipers, and elsewhere the bolts are described as 7/16 UNF X 1.300" HT GRD T BOLTS ZINC PLATED
paulh4

I have used Princess 4 pots and a modified Peugeot vented discs on one of my race cars.

I think the SD1 calipers are quite heavy, and maybe catch on the wheels, depending on what rim you use.

William, the current car I am building, I am trying to keep pretty much as it should be, hence sticking with the V8 brakes.

Colin
Colin Parkinson

Cheers Colin, I can understand that.

If you end up going the modified route ,most of the hotties here go Nissan ventilated rotors and calipers
Havn't gone that way myself. I like the big WB Holden ute rotors and calipers on the front and Nissan rears

----------------Nissan

DBA 4000 series rotor
Pt. No.2524
294mm X 22mm
The centre hole dia. and the stud holes have to be altered to suit the MG hub

R32 Nissan Skyline 4 piston calipers

Hawk HP+ competition pads

Rear--Nissan R31 rotors and calipers
William Revit

Not straying too far off topic, but recapping on where we are, the Princess 4 pot calipers are metric sizings and when I fitted mine needed GT6 shouldered bolts (Allan also referenced TR ones). Used in conjunction with V8 discs. On ebay you can buy all the overhaul bits for these calipers, but I also noticed that folk are selling replacement calipers for as cheap as £128.50 a pair delivered. I was going to overhaul mine, but if these are any good, at this price I'm not sure I'll bother. Anybody tried them?
Peter Allen

I've successfully fitted V8 pads to my standard B callipers. I noticed that the pads weren't symmetrical but nobody on the MGB register forum who recommended this action seemed to know which way up they went so I took a guess. They were a tight fit but they have been working fine now for a couple of years so it either doesn't matter or I got lucky.
Paul Hollingworth

Which way up? Surely not, although I have seen pictures of a pad that had been fitted upside down and the wear curve from the disc is clearly going the wrong way. A case of Murphy's Law (if one can still say things like these days) if ever there was one.

V8 pads can be fitted to either side of MGB calipers as there is no inner caliper half and outer caliper half as there is with the V8 calipers. They still need to be fitted with the projection on the one long edge facing away from the spindle. The V8 pads are said to have more contact area when used in MGB calipers, compared here, which also shows the handing of the V8 pad on the right. However the last set of V8 pads I bought have both leading and trailing edges heavily chamfered, which must significantly reduce if not eradicate that advantage until the pad is almost half worn.


paulh4

V8 pads with standard MGB calipers used to be the initial braking mod. Then smaller rear wheel cylinders to stop rear brake lock up (did they?).....It's funny how one used to glean this info before the internet - basically down the pub at a Club meeting, or passed on from somebody with an bit more knowledge.
Peter Allen

Presumably so, as they V8 got the smaller ones after the 4-cylinder GT had changed to the larger ones.
paulh4

You can see the asymmetry on the V8 pad in Paul H picture by the E1 marking.
Paul Hollingworth

So I solved it in the end, and found some donor calipers.

Late Triumph 2500 inner with MGB outer. Should be some pics of the restored V8 calipers attached.

No there isnt they are too large!!

Now I will have to find a way to take smaller photos!!!
Colin Parkinson

Colin-
The early Mk I Triumph 2000 disc brake caliper utilizes a 0.350"-thick solid disc brake rotor, while the late Mk I and Mk II Triumph 2000 disc brake calipers utilize a 0.500"-thick vented disc brake rotor. These disc brake calipers have the same distance between their mounting holes, but either thin-wall sleeves or special stepped machine bolts are required in order to adapt to the metric holes of their mounting lugs. The dust shield will have to be cut slightly in order to provide clearance for the marginally-larger disc brake caliper. In addition, custom-fabricated (bespoke) brake hoses (flexible pipes) are also required, having an imperial fitting on one end and a metric fitting at the other in order to connect the metric-threaded disc brake caliper to the existing Imperial-threaded hydraulic braking system of the MGB. With no other modification, the inner half of the disc brake calipers will bolt onto the swivel hub of the MGB. After removing and dismantling the MGB's calipers, the MGB inner disc brake caliper halves are discarded. After renewing the piston seals of the outer halves, the Triumph inner and MGB outer halves are bolted together using new components. The bridge machine bolts should be torqued to between 35 Ft-lbs to 37 Ft-lbs. The resultant disc brake calipers are hybrid replicas of the elusive Original Equipment MGB-GTV8 disc brake calipers at a fraction of the cost!
Stephen Strange

Colin
If you right click on your photo it should give you an option to resize
Just click on S(small) or thumbnail and it will resize to sendable size
Thought you would end up with the T2500 calipers eventually
William Revit

Stephen the calipers I got were Mk2 Triumph 2500 with the 1/2 in disc. They are imperial, so use the standard hose and the standard mounting bolts.

For information, these late Triumph calipers are very difficult to get. Not available new, and only available on exchange.

Luckily I found a pair on Ebay!

Colin Parkinson

Picture 2.

Colin

Colin Parkinson

Are there any identifying features?

I have a pair of Triumph calipers, but not sure if they’re the right ones.
Dave O'Neill 2

Can you get a 1/2 in disc between the ears?
Are the mounting holes in the same place as a B?

If the answer is No they are no use for V8 conversion. If Yes they may be!

I'll see if I can get numbers from them, but looks unlikely.

Colin
Colin Parkinson

Well done Colin, looking good
William Revit

Earlier on in this thread I mentioned that I use WB ute calipers, and on reading back through it hit me that you guys probably wouldn't have come across a WB ute
A WB ute is a comercial utility version of a Holden sedan and they were very popular here a few years back
The calipers fit 1" wide rotors and are self aligning, they have a cast mounting bracket that bolts to the spindle in the normal manner (slight bolthole rework required for an MG and a giant single piston caliper that simply slides on the bracket to self align--The best part (or maybe one of their features) is that there are no pistons on the outside of the rotor, just the one on the inside and a claw reaching to the outside pad-This eliminates any clearance issues with them nice new wheels you just bought that won't fit and makes rotor offset choice easy as the things will slide to fit whatever you've got

Useless information really but there you go-
Found a pic of some here-----------

https://www.ebay.com.au/i/123701098224?chn=ps&norover=1&mkevt=1&mkrid=705-139619-5960-0&mkcid=2&itemid=
William Revit

Dave, numbers off my Triumph calipers, lockheed,
Outer 1/2 marked 3245 573C and DA22019
Inner 1/2 marked 3244 598 and 599, and DA22018 and 017

If you want to build V8 calipers you discard the outer halves and use B outers.

Colin
Colin Parkinson

Colin

Thanks for that.
The numbers on mine look very similar and the dimensions look good.

Dave O'Neill 2

This thread was discussed between 07/07/2019 and 30/07/2019

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