Brake Upgrades

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PeteHickson
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Joined: Tue Apr 11, 2006 1:00 pm

Brake Upgrades

Postby PeteHickson » Tue Dec 04, 2007 6:40 pm

There is a cost-effective alternative to the Coopercraft 4-pot conversion in the form of the Volvo 240 4-pot caliper.
Apparently these calipers have the same bolt spacings as the mk2 and can be made to fit quite easily.
This is a popular mod with e-types - see articles on the JCNA website at http://www.jcna.com/library/tech/tech0031.html - but can also be make to work with the mk2.

One benefit is that the car can be returned to standard quite easily too.


I've now acquired a pair of these calipers (for about 30 quid I think it was)
The unventilated disk version is what is needed, although due to an error by the specialist Volvo breaker I ended up with two sets, ventilated and unventilated! The only difference seems to the the width of the bodies so make sure you know which one you are buying.

I understand that the mods are simple enough - the bolt holes need to be taken out to half an inch (from 12mm) and then a choice of either taking 6mm off the circumference of the mk2 disks, or removing metal from the caliper body to allow clearance.
Obviously skimming the disk is less risky but needs to be repeated on any future replacements whereas removing metal from the caliper should be a one-off operation.

Anyone tried either method here?

These calipers also enable dual circuit braking on each caliper if required, although it seems there could be issues with routing dual pipes tidily.
I was wondering about using these in conjunction with a 420-type master cylinder which I understand is dual circuit and currently available new.
It just seems like a better engineering solution to keep a full dual circuit system if possible.

For the rear brakes I've been told any XJ6 calipers can be fitted to the mk2 - anyone able to comment?

thanks
Pete





PeteB
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Joined: Wed Jun 10, 2009 8:35 am

Postby PeteB » Wed Dec 05, 2007 1:44 pm

It is physically possible to fit XJ brakes to a Mark 2, but in practice, it's a mod thats far more appropriate for circuit use than for the road.

The only safe way of doing this on the front is to fit the XJ uprights too, but because of the difference in the shape & position of the steering arms, the outer track rod is then working at the wrong angle. This can cause bump-steer and geometry issues, but its effect can be lessened if the car is at the lowest ride-height possible.
Because of the larger 'capacity' of the XJ calipers, a standard master cylinder won't displace enough fluid to give a good brake pedal - particularly if you're changing the rears to XJ ones too. You can get round this by fitting a 1" bore master cylinder instead of the original 7/8" one.
It will also be necessary to change the wheels to 6" rims with more offset in order to clear the calipers.

Regards,

Peter Bell





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piman

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Postby piman » Wed Dec 05, 2007 6:38 pm

Hello Peter H,

an interesting option? I too have a MK 2 under restoration and also plan to improve it, particularly with stiffer suspension and a mild upgrade to the engine.

Returning to the Volvo calipers, and after seeing the link you posted I would be very wary of removing metal from the caliper body as the internal ports (see the photographs of the calipers split) are very close to the inner caliper body.
For me, having a lathe, the option of turning the discs down is the way I would go.

Incidentally I asked a question, but had no reply, if there were any tests done of 6-3-1 (or 2) exhaust manifold configuration, rather than the conventional 6-2 design. The former is an effective design for Triumph six cylinder engines and gives a performance bonus over conventional 6-2 or even 6-1. To elaborate, the convention is to join primaries 1,2 and 3, 4,5 and 6 but the other option is 1 and 6, 2 and 5 3 and 4.

Alec




PeteHickson
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Postby PeteHickson » Mon Dec 10, 2007 3:20 pm

Peter, Alec, thanks for your replies.
From what you've said it looks like the Volvo conversion with the discs cut down rather than the calipers, and Series3 XJ brakes at the rear is the way to go. This should be a lot better and cheaper than re-instating the originals.

Alec, I dont know much about exhaust manifolds but agree it is worth looking into alternatives to the original cast items which are expensive to recondition and I very much doubt they are particularly efficient.
I do like the looks of the originals though.
There are a number of after-market tubular systems available - anyone done a before and after bhp test?

I'm planning to post a number of topics here on the various plans I have for upgrading my car - but rather than put one big posting I'll do separate topics for each aspect and hopefully others will join in with experiences or plans of their own.

cheers
Pete







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piman

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Location: Oswestry

Postby piman » Mon Dec 10, 2007 6:36 pm

Hello Peter,

I have seen a few tubular manifolds by various vendors, and one in particular looked very wrong to me as the primary lengths were all different. But all are the 'conventional' style coupling 123 and 456. The alternative I outlined gives excellent results on the Triumph six cylinder engine and I wondered if the same would be true of the Jaguar?

Alec




PeteHickson
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Joined: Tue Apr 11, 2006 1:00 pm

Postby PeteHickson » Mon Dec 10, 2007 7:17 pm

do you know if the firing order is the same on Jaguars and Triumph?
I imagine it could have an effect on the optimum arrangement.



GrahameW
Posts: 2
Joined: Sat Oct 27, 2007 8:14 am

S Type Brake Master cyl

Postby GrahameW » Sat Feb 07, 2009 9:39 am

I am fitting 420 front callipers and uprights to my S type together with a
vented conversion at the rear ( to keep the diff cool). I accept I will
probably need a 1" master cyinder, Does anyone know where I can lay my hands on one?

Grahame.

smiffy
Posts: 157
Joined: Tue Dec 09, 2008 11:52 pm

Master cylinder

Postby smiffy » Sun Feb 15, 2009 11:39 am

Hi Grahame
I've fitted the Zeus 4-pot calipers on the front and the Zeus uprated rear cylinders on my Mark 2 and the standard master cylinder works well with no increased pedal travel.
Best wishes, David

GrahameW
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Joined: Sat Oct 27, 2007 8:14 am

Postby GrahameW » Wed Feb 18, 2009 6:03 pm

Thanks David thats good to know...fingers crossed.

Grahame

john_cunningham
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Joined: Thu Jul 30, 2009 4:36 pm

Coopercraft or Zeus?

Postby john_cunningham » Thu Jul 30, 2009 7:26 pm

Hello I am a bit of a newbie, and have just bought my first classic car, a 1960 Mk2, 3.8L Automatic. I was thinking up upgrading the brakes, and am not particularly technical (no lathes in sight). What do people think of both Coopercraft and Zeus brakes front and back, Zeus are cheaper? Was also thinking of then adding kevlar break pads, amd I just veering toweards hype and marketing, I see in another section an item on green break pads and reduced dust... should I do the lot, or just add in some new pads? I live on a very steep hill, so good handbrake capacity is a must. Thanks in advance.

smiffy
Posts: 157
Joined: Tue Dec 09, 2008 11:52 pm

Postby smiffy » Sun Aug 02, 2009 10:48 pm

Hi John
I fitted the Zeus upgrades to my 2.4L Mk2. They were an easy 'bolt on' upgrade, although you have to dispense with (or modify) the backing plate for the front discs - you would have to do this for any of the conversions though. I've done over 1500 miles since fitting them, and have been very pleased with the braking effort. Don't have any experience of the Coopercraft setup.
As far as pads are concerned, I would suggest sticking to the standard ones for road use (the Zeus conversion uses XJ6 front pads). The uprated pads are better for fast road / rally use, where they run hotter and resist fade better.
Best wishes, Dave

john_cunningham
Posts: 5
Joined: Thu Jul 30, 2009 4:36 pm

Now to find a man that can...

Postby john_cunningham » Mon Aug 03, 2009 1:55 pm

Cheers Dave, now all I have to do is find a good garage near me in South East London, or Croyden.

John.


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