Volvo 240 4-pot (or 4-piston) caliper Girling brakes for Opel Ascona/Manta B - Kadett C - GT with 262x21x51mm vented discs from Honda Prelude 2.0i 16v
What you SHOULD grind and what you COULD grind on those calipers...
Alright now, here we have a famous modification for a CHEAP brake modification/upgrade/conversion for old RWD Opels that most of us first read in the article entitled "Bigger front brakes for old Opels". You will
most likely not spend more than around 150 euros to get a set of 2nd hand Volvo 240 4-pot caliper Girling brakes, a set of new ventilated discs (262x21x51mm for Honda Prelude 2.0i 16v or Accord) and a set of new
brake pads. We all read about this originally here: http://users.telenet.be/jov/opeltuners/gtbrakes/index.html - a great article by a guy named "Koen" that was also featured in the articles section of opeltuners.com -
however, I would like to add a few pictures and minor details about a couple of things that I thought were a bit unclear and to discuss them with anyone who has done this or who can give a piece of advice...
PLEASE NOTE: Things that have already been covered in Koen's article haven't been touched in this one as there was no reason to repeat them.
As for the dustcovers, Koen has done a great job, I just used the old ones that I bent a little bit (I would love to, but I couldn't be bothered at this exact moment, so, doh!).
I would like to focus specifically on the part where Koen said this:
"Well 51mm height instead of the needed 53 mm was not such a problem because the Volvo calipers are so thick and strong that it was no problem whatsoever to machine away 2 mm from the surface of the caliper where it will be connected to the car."
Just to get things straight, I went to 2 different machineries here (Heraklion, Crete - Greece) but they both said the exact same thing:
"I am quite afraid to do that as I can't really keep this straight and make sure that it's 100% aligned. If I machine 2mm away and don't do it straight even by a 10th of a mm, your calipers will be wrongly placed and this could be quite dangerous".
If you ask me, I think that we simply lack of good machineries where I live. However, I would like to give you an alternative if this is the case. It's not a better solution, it's not even the "politically-correct" solution, it's quite an unorthodox one, but hey, still is a solution!
We grinded away 1 or 2mm off the inside part of the caliper so that the disc would not hit on the caliper's surface. Normally this shouldn't be a problem as this part of the caliper's internal surface has nothing to do with the brake pads, the brake pads are properly installed and there should be no problem. Of course, by the time this article is written, I just brought the whole front axle with the new brakes on it in my garage and I still haven't tested my brakes, so, if I am not dead after the first test and everything seems correct, you can all drink a beer for me! If I am dead, well... Drink that beer again for me, beer rules! :)
So, first things first, here is the vented disc off that Prelude:
The old VS the new (okay, I know, the old was sitting away from the car for quite some time :P - But hey, makes the comparison even more sweet! :D )
(Click to Enlarge)
Here we can see how thick the "surface of the caliper where it will be connected to the car" is (as Koen also explained in his great article!):
(Click to Enlarge)
18.5mm! So, according to Koen, we should grind this part by 2 mm and bring it down to 16.5mm. So, more or less, if you machine the "lips" in the right part, that should do the job. It would even be easier if you split the caliper in 2 (yes, they are dividable).
Here is the part that we grinded:
(Click to Enlarge)
Now the discs rotate without problem. Generally though, keep in mind, the more you fuck with your brakes, the more dangerous it is and generally it is not a good thing to mess around with parts that take a lot of heat and sudden temperature changes (for example, if your brakes are really hot and then you fall into cold water, that means that these parts are taking a lot of stress). Same goes for the discs. We believe that what we did here is safe, but better also talk with your mechanic/engineer before proceeding, cause I definitely ain't gonna take any responsibility if you become cat food after the first test :P
I was also told stuff like "hey man, you should also drill your discs" and stuff like that, but seriously now, that's just plain stupid, especially with the discs! If you want drilled discs, better make a custom/special order and order a pair of discs that were ORIGINALLY made with wholes on them. In my humble opinion, you won't really see a lot of difference there, it doesn't really matter. Just get a good pair of high-pressure performance brake hoses (I got mine off a friend for 50 euros) and put DOT-5 brake fluids in there and feel the difference ;)
Oh, the only problem I haven't solved yet (but will solve soon) is that the Volvo 240 brakes come with 2 brake hoses while the old RWD Opels come with one. That means you will have to get something like a T joint to connect them - I will complete this article within the next few days/weeks as soon as I've done that.
Here's a few more pics off my new brakes and front axle:
Hope you enjoyed this small article, feel free to post back your comments in here or in my e-mail: asconan *at* gmail.com :)
