iīm really confused and need your help.

i want to convert my new striker, one of the early models with outboard shocks (vauxhall upright), to Ford PCD all around.

at the moment front is 4x100 (vauxhall / opel). Hub is chevette, Cavalier (Ascona), Manta, Kadett C

so i thought, why not buy this one:

http://www.montgomery-motorsport.co.uk/suspension/vauxhall-chevette-alloy-front-hub.html

when hubs arrived and i started dis-assembling my car...i was surprised that the hub, even it fits onto the upright, has a complete different geometry for fitting the brake disc.

disc-fitting pcd 4x92mm is correct, but the location of the disc is completely different.

the original 55mm high disc should be just 25mm to be in the same position.











i already made the same conversion, using the same hubs..and it was plug and play...but meanwhile i recognized that the other car had vented discs and widened calipers. (but no idea where those came from) see here:

The Montgomery Motorsport alloy one looks to me like an Viva HB & HC /Firenza not Chevette/Ascona part.

[Edited on 3/3/20 by britishtrident]

https://www.annteak.com/viva-gt-front-brake-upgrades/

We used to fit Viva front hubs & discs to Imps and Davrians.

Montgeommery ones are Chevette GRP4

viva hubs looks like this:




my steel hubs are Chevette, Kadett c, manta, ascona (cavalier) and they use the wheel bearings and the discs from those:





the Montgommery ones are drilled ford pcd, but the discs are fitted from backside (as with original vauxhall ones) with a fixing pattern of 4x92mm and 4 seperate bolts M10x20. they arent held in place by a small countersunk-bolt, fitted from front, slided over the wheel studs 4x108, like Ford

but the hub is 30mm thicker, so the original 55mm thick/high disc (see above diagram ) moves the disc 30mm towards the upright...so totally wrong.

my old sylva had vented discs fitted and i did not face any trouble when changing the hubs from the original steel ones to the alloy ones from Montgommery.

but i dont find discs which are just around 30mm thick/high and have a fixing pattern of 4x92 with a centre bore of 68mm (alloy hubs)
interesting is this 68mm measurement, as the vauxhall steal hubs have 73mm here.

or is the "secret" to forget about vauxhall discs and fit ford discs from front, means the original threads tapered into the hubs remain unused?

maybe i found a solution:

fitting escort mk1 discs:

not as easy as i thought

the vauxhall M16 calipers are machined to take 11mm thick disc, whereas the ford discs from above are 12.7mm
so the calipers need to be modified.

furthermore the ford discīs offset is not enough...i had to use a spacer of 9mm to get the disc in the middle of the vauxhall caliper. (further towards the upright)

[Edited on 7/3/20 by alfas]

Hi

I've done this exact change, but did it by having the original hubs redrilled to ford pcd.

Other than updating the pads, never bothered with bigger discs etc and that was for some fairly serious track work too.

HTH

i wanted alloy hubs for saving unsprung weight....and may even change to alloy-calipers in the future.

this said: today we stood in front of the hubs and thought "wouldnt it be easier to re-drill the hubs"..."but there isnt much material left between the original holes and the fixing holes of the disc...furthermore the ford pcd would be on the outer corner of the hubs"...so we were not really convinced that this is a safe solution (the car will be used on the road, as well as on the track).

Hi

Are you sure you've got standard Vauxhall hubs?
Not been turned down or something?
There should be plenty of meat left when re-drilling them, i've seen people take them to 5 stud / 4&1/2 inch?

If they're stock then IMHO they'll be fine, it was a pretty standard mod 'back in the day', mine have been done for about 12-13 years or so..

The unsprung weight of alloy hubs / vented discs and the resulting bigger calipers is more than the stock set up - you won't need bigger brakes, with the right pads it'll simply stop

quote:

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Originally posted by JimSpencer
Hi

Are you sure you've got standard Vauxhall hubs?
Not been turned down or something?
There should be plenty of meat left when re-drilling them, i've seen people take them to 5 stud / 4&1/2 inch?

If they're stock then IMHO they'll be fine, it was a pretty standard mod 'back in the day', mine have been done for about 12-13 years or so..

The unsprung weight of alloy hubs / vented discs and the resulting bigger calipers is more than the stock set up - you won't need bigger brakes, with the right pads it'll simply stop

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