VOLVO 4POT CALIPERS

i'm sure that many of you have heard about this conversion but not quite sure on the myth/fact of it. here is some info that may help.

the conversion was done using rover 216gti discs @260mm and volvo 4 pot girling calipers. spacers were machined and lobger bolts used. the calipers have 2 brake pipe feeds, so a t piece would need to be fabricated. clearance on the wheels can be an issue. either spacers or smaller et wheels may well be needed and they most definately will not fit under 14" wheels.
 i've had a trial fit using mk2 256mm discs and the calipers will fit nice and lovely, though the discs are about 1-2mm short of the pad.
the pistons are 35mm, so surface area is a bit more than the standard mk1 pistons, which are 47mm. i'm led to believe the the lucas54 calipers used in the mk2 valvers are 54mm pistons, which in turn is a larger overall surface area to the volvo calipers. bear in mind that although the mk1 has a single sliding piston, for these purposes, we calculate it as two. a servo and master cylinder upgrade would definately be helpful with this conversion.
 anyway, though the 256mm discs are a spot on fit with the caliper, clearance to the wheels become an issue



caliper


spacers machined for rover 216 gti discs


how the spacers would be used for rover 216 gti discs


i turned the spacers around, so the caliper would fit directly to the hub and used 256mm 16v mk2 discs. so the calipers will dolt directly on using shoulder bolts or sleeves, in the same fashion as being used for the vauxhall calipers


caliper on and disc sits perfectly central, but the pads overhang the disc by 1-2mm


the distance from the disc face to the caliper needed 58mm. or 38mm from the mounting face of the wheel. this should give an indication as to wether or not you'll need wheel spacers or not.


caliper and 256mm 16v disc. 140mm is the clearance you will need from the centre of the wheel with 38mm clearance from the mounting face of the wheel and the spokes or whatever. 155mm is the min clearance needed from centre of wheel to inside the rim.


remember, using 216gti discs will give full pad to disc contact and gain 9mm more play on the inside of the wheel.

hop this helps a bit

i've measured the surface area of the volvo pads and mk2 16v pads. i have no mk1 (vwII) pads lying around to compare. the volvo pads have have approx, 8% more surface area than the 16v ones, so as i understand it, it should therefor give better braking force. from what i understand and PLEASE do chip in to clarify this(or not)  a larger caliper piston means less pedal effort but more pedal travel. the fact that both the 16v/audi calipers and volvo have a larger piston area means that there should be less effort in braking but more pedal travel with the standard mk1 servo and master cylinder. iv'e had the 16v/audi set up on a mk1 with the standard servo and master cylibder and as far as i was concerned the braking was hugely improved. more pedal travel was not quite noticeable, compared to standard mk1 (gti). the 16v servo and master cylinder only affect pedal effort and travel. wholey desireable in a mk1. it's the larger diameter disc and or larger pad surface area that actualy gives better braking force/friction.

Was this the conversion done by dave walker in an early edition of the golf magazine, unfortunately recently dumped this copy  (along with all the others) but from memory it had aftermarket wheels fitted.

i wouldnt worry about the pad overhang mine are a little more with the vectra calipers

abfmk1 said

Was this the conversion done by dave walker in an early edition of the golf magazine,

yup, though it was c&cc magazine

sorry, i had to go out and drink lots of bulmers. i'l update with some specs and pics anon.

thats a a pretty good write up with measurments ect nice one wooders

yup, though it was c&cc magazine (quote)

think it may have been triple c mag first then went into the golf mag when it was started

I'm sure I recognise these pictures…did you do this recently or are they archive pics?  Nice objective write up tbh.

Volve set up is from the volvo 200 series iirc?

People laughed when people started (inc myself) doing the Vauxhall conversion up and now it's common practice…

new pics. had the calipers for years, only just got round to playing with them. yes 200 series volvos.

Fair play
 
The shoulder bolts I (and I assume others) use for the vauxhall conversion has a 25mm shoulder, the length from base of head to end of thread approx 42-43mm.  So looks like they'd do the job fine.

Ive just listed some of these calipers on ebay if anyone wants to have a go at this convertion cheers , the link can be found in 3rd party section

do you know which type of caliper fits from the vectra range??, ie to acheive 256mm??

Mak

I don't know for definite, but I assume this list could be a guide:

http://cgi.ebay.co.uk/FRONT-BRAKE-DISCS-VAUXHALL-VECTRA-1-8I-16V-95-02-/370379620057?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item563c587ed9

That gives the range of cars that accept the 256mm Vauxhall vented disc, so I 'assume' that they all have the same carrier/caliper setup.  Just a guesstimate mind, if you're not sure check carrier bolt spacing before you buy.

Essentially it's all the early 90s 2.0l 16V Vauxhalls, mine were from a Cavalier.

this got brought to our attention again on the polo3 forum, any chance this can get moved to the braking knowledge section