Hello!

I´m fixing up a S 3.8 1966 for a long roadtrip next summer and I would like to upgrade the brakes.
I found out that volvo calipers fit on the S-type but I would like ventilated rotors too.

Can I fit e-type v12 rotors on my S 3.8?

Welsh Enterprises, Inc - Jaguar E-Type Series III Brakes Front Brakes Parts - Front Brake Rotor - E-Type V12 XJ6 XJS

I will probably have to do some machining to the diameters on the rotors and on my calipers but that should be fine as I have access to a complete machine shop.

I know there are kits with rotors and calipers but the cost 6-700 £ and I think I can get away with 150-200.

Any tips are welcome and I have also read that on the mkII one can fit the front calipers to the rear for a cheap upgrade. Is this possible with the S 3.8 as well and is it possible to keep the handbrake?

Thank you!

Karl

 

For the rear brakes on a 3.8s check with Jag Outlet, there is a later model Jaguar rear inboard brake that is larger that will go in without any modifications at all.

For the front I recommend the 4 piston Wilwood brake upgrade. Yes it is a bit of money but worth it. I have done both on my 3.8s and the set up works good.

 

Thank you Primaz, I have seen your S and it is absolutely marvelous!
Unfortunately I cannot spend the money on a brake kit, I´m fixing the car for a race from edinborough to rome over the alps. The race rules state that it should be dirt cheap cars, I will spend money on shock absorbers and other necessary safety equipment. Brakes will be upgraded but I don´t have enough money for such a kit.

The e-type rotors are cheap and ventilated but I need to know if they have the right dimensions. Today I test mounted a volvo 140 4 pot caliper and if I take of a few mm of the brake rotor diameter it fits perfectly! Im pretty sure that the volvo 240 calipers for ventilated disc also is a "almost bolt on".

So now I only need the right rotor, if I can find one for 45 GBP and 75 GBP for new volvo calipers the total will be 240 GBP instead of 600 GBP.

 

fit the uprights, discs, and clippers from the xjs for the front.

 

Thanks for the reply!
It seems like a lot of parts to buy just to change to ventilated rotors.

After a bit of discussion Coopercraft offer to sell ventilated disc with these dimensions:

Thickness 21 mm.
Diameter 279.40 mm
Total height 51

From memory the measurements seems right but I have to take som measurements on the car and on the stock rotors to be sure.
The price was not cheap but reasonable if it is a bolt on disc with only minor modifications to the caliper. I would still like to know the dimensions on the v12 e-type rotors. If they fit, they are half the price of the coopercraft rotors.

Karl

 

The E Type / XJS vented discs are
284mm diameter
23/24mm width
Height 61mm

E Type standard
280mm Dia
Height 51mm
8 / 10mm width

Volvo 240
263mm Dia
68mm high
20/21 wide

Mk2
280mm dia
51mm high

 

Thank you!

So the only big difference is the height which is 10 mm higher on the e-type. If I machine 10 mm of the backside of the hub and add a spacer beneath the rotor I could use e-type rotors. The problem then would be the diameter, the volvo caliper is used with 263 mm rotors and the e-type/XJS is 284 mm and that is to much to remove from the calipers so either machine the diameter of the rotor (which I would need to do with the coopercraft rotor too) or make an adapter to move the caliper further out. But then I could use any caliper...

Or coopercraft discs with 240 calipers mounting adapters and stock hubs.

Or I could machine of 17 mm from the hub, add an adapter under the rotor and use volvo 240 rotors and calipers.. But 17 mm off the hub seems a bit much...

A smarter person would buy the complete kit with rotors and calipers..

 

I realised that the simplest solution might be the coopercraft discs, then there would be no modifications to the hub. The diameter is too big for the 240 calipers for the ventilated rotor but the 140 for the unventilated disc only needs 10 mm widening.
With a little bit of grinding, 4 mm, it would accept the coopercraft disc and still use the stock mounting position without any adapter if it is widened ofcourse.

Karl

 

Karl,

I assume that the height difference puts the extra metal on the inside of the rotor on the Etype/XJS, whereas the Coopercraft will add the extra metal on the outside face, this only changes the mounting position of the caliper. The jag calipers mount on the inside face, so would it not be possible to pack the caliper inboard ?

Although the Volvo works with a 263mm rotor, it would be the relative mounting point again that effects the diameter of the rotor, what I mean is that if you mount the Volvo caliper on the Jag suspension, what is the actual clearance you have for the rotor then ? If the mounting holes on the Jag are 12mm further away from the hub center than on the Volvo, you may have the clearance for the 283mm rotors ? The 10mm extra radius will have a negligible effect on the pad contact area. Also what is the distance between the caliper mounting face and the center of the calipers, this effects the mounted caliper center point relative to the rotor and may mean that the Etype rotor would be better than the Coopercraft ?

You said the Volvo 140 was almost perfect, most of the early Volvo's used around a 260mm rotor, so the 240 calipers may well be close too, they work with a 68mm high rotor, so may also have a center line closer to the EType rotor, it may be worth seeing if you can get a 240 caliper and see how it sits, you can then take dimensions to see which rotor would fit the best.

If you widen the any caliper will you have enough clearance to get a full set of pads in.

 

Yes, the extra height puts the rotor to close to the upright even vid stock rotor there is only a few mm of clearence between the rotor and the heat shield. I don´t think I need to change the mounting position if I use the 140 caliper, I only need to split the caliper and put a spacer in between the two halves. Then the extra thickness of the rotor and the extra thickness of the caliper would both be towards the wheel.
The mounting position is somewhat complicated on the upper bolt for the caliper, the upright is like a fork with the caliper in between so it is not so easy to move the caliper in or out.

You are absolutely correct, I did not think that the mounting point affects the rotor diameter but it is quite obvious now.
I need to check the distance between the caliper mounting face and the center of the caliper. I don´t think it is a big difference since the 140 caliper is almost perfect.
The problem with increased height is that the rotor will hit the upright. With less height it could be possible to move the caliper towards the wheel to compensate.

I will check the 240 caliper for ventilated rotor, the pads are much larger than the 140 so it would be preferable to use the 240.

Thanks!

 

Duh, I hadn't thought about the clearance on the inside face.

Let us know how you get on, this potentially opens up options for others too.

 

I´ll let you know what calipers I decide on. At the moment I´m thinking volvo calipers or alfa romeo or porsche which a friend have laying around. I was even considering hayabusa 6 pot calipers since the are as cheap as volvo calipers. But I´m not sure the mounting point on the caliper can handle the brake torque..

I decided to go with coopercraft rotors and placed an order, I also ordered wilwood Ultralite 30 Vane Rotor to use in the rear.
The bigger rear brakes primaz mentioned is there specific jaguar model that used them?

I´m also thinking about master cylinder since I would like to have double circuit brakes. Any recommendations?

Karl

 

Have a look at this, it may help some. http://www.jcna.com/library/tech/tech0031a.pdf

I think the 420 master setup will give you dual circuit.

Just rushing out so will look later.

 

@primaz Where did you get your Willwood Brake Caliper Conversion from? I tried getting in touch with Willwood directly and they were unable to support me. I am currently restoring my 1965 Jaguar 3.8S and doing a restomod on it. (ie. upgraded brakes, radiator, bushings, steering etc...) to use as my new daily driver.

Best Regards,

James

 

James,

I would recommend NOT to get the Wilwood Brake Caliper Conversion but instead GET the 6 piston brake conversion from Fosseway Performance, The reason is that the Wilwood is NOT enough as it is a small 4 piston Wilwood with a small solid rotor. I drove my car racing in the canyons with a group of performance cars for prolonged drive and the Wilwoods could not handle it, the brake fluid vaporized, the rotors were ground down fast and the pads wasted which created almost no brakes until I let it cool for over an hour and then it went from half pad life to no pads and the rotors were wasted! Get the Fosseway Performance, the one you really want is their big brake kit series which they make for the MKII and 3.8s that uses their 6 piston 294 or 302mm two part vented rotor. Make sure you call them to ask for the 6 piston and then you just need to measure the as the S type and MK2 have a virtually identical front suspension set up but, like the E-Type aeries 1 and Series 2 they have subtle differences and the early S Types also carried over some additional features from the MK2. None of these present a problem but we just need to confirm which front uprights your car is fitted with. Just tell them the distance between the caliper mounting bolts they can do this for you. If it is 3" the you have the earlier uprights for Dunlop brakes. If the bolt center distance is 3 1/2" then you have the later front uprights for Girling brakes.

For the earlier cars we can supply a 294 mm diameter two part rotor and a six pot caliper with a huge brake pad (130 mm x 48 mm). For the later cars we can increase the size of the rotor to 302 mm and supply the same caliper. Both these options will fit comfortably inside 17" wheels. The price for either kit is £1,395.00. If you are based outside the EU then no UK VAT will be added.

You can specify the alloy components in silver or black and the rotors can be supplied plain, slotted, slotted and dimpled, cross drilled or combi cross drilled and slotted.


E-Type Big Brake Kit - Series 1 and 2 - Fosseway PerformanceFosseway Performance

They do offer 4 piston setups but I really recommend their 6 piston. If you do not have larger diameter wheels and cannot afford to do so then and only then talk to them about a vented rotor setup for a smaller wheel; they should be able to take care of you. You NEED a vented rotor design and stronger calipers with larger pad surface. On my car since it is an S type you can upgrade the inboard brakes to larger E-type setup and if you get the early E-type it will bolt right in, then get a proportioning valve to tune it and you will finally have modern brakes. I am running the stock master as Fosseway designed their big brake kit to work with the stock setup, you just have to adjust the balance with a proportioning valve.

 

Listen to your professional provider be it Fosseway or whoever regarding the requirement of a proportioning valve back to front or you can completely upset the front to rear braking balance which can be dangerous.

A move to dual circuit brakes may also be wise if enthusiastic driving is being considered.

Good luck!

 

The Jaguar stock brakes are not very good but the nice thing with the Fosseway is it is designed to work with the stock master and they already made the correct bracket to make it bolt on. Proportioning valve is not that difficult and just needed to get the balance front/back right. I've done that on many cars and a good performance shop does that all the time. The Jag now stops great with no issues even at the cars limits. I do not want to attempt changing the master which I replaced just to make sure it was new and not a 50 year old weak point, unless someone comes out with something engineered as what I have works so well that it is worth potential aggravation and I am very proactive on maintenance, etc. The Fosseway to me is the best I have seen for brake upgrades and much better than attempting to graph other brakes on your own, best to stay with one already proven to work well.

 

@primaz Thank you for all of that information. I completely understand the 6 piston brake calipers however i do not expect taking my S-Type on the track, That's what I got my EType for lol. Would you be able to send me link to the Wilwood brakes you got or exactly what model / part number i need? Wilwood sales team was telling me they don't have anything for my Jaguar SType. Would love to know exactly what you got as well as where you got them. Trying to stay within under $600-800 for front brakes and at least 4 piston.

Link to my Jaguar E-Type Album:
https://photos.app.goo.gl/anjVsvm2s3CKsECR8

 

James,
If you do not want to go for the big brake 6 piston vented setup I would still recommend to contact Fosseway Performance and see that their 4 piston kits sell for as they have 2-3 version that are the smaller 4 piston. The reason why you will not find the exact Wilwood model number is that those kits are designed by a company whom engineered the custom brackets so it is bolt in; thus they never want to give the details in order to keep it proprietary. I bought by Wilwood kit from XK's Unlimited. I might still have my old Wilwood calipers if you want to buy them and whatever parts I have as I might still have the rotors but they are worn I believe. Fosseway just like any brake kit company will spend a lot of time and money to engineer a kit so that it has a custom bracket to bolt on and work with the stock master. None of the kits will bolt on your Jaguar without a special bracket that they CNC out of billet stock. I think it is worth it get something engineered so you know it works. Their 4 piston has got to be less than mine was so maybe it is within your budget?

 

Fosseway has a fine reputation.

Yes one needs to maintain the single master cylinder very well. See second part of this short thread. You are one poorly molded or deteriorated seal away from total brake failure & fluid returning to the reservoir instead of pressurising brakes. Many replacement end of piston seals provided from UK vendors are fractionally too thin to seal the inlet port. I have machined my piston to accommodate this. A Jaguar OE seal did not give me reliable brakes.

Forewarned is forearmed ~ read from "Another issue we had....." ~ I find it irritating that a simple Jaguar original replacement part could cause this. At least the bore seal is likely to leak slightly long before failure.

https://www.jaguarforums.com/forum/m...ds-etc-211186/