Marina based Roadster front discs

[stevejgreen]

Some years ago I played with the idea of improving on the standard Marina front disc brakes.
There were various adaptations tried previously using Ford or Princess calipers but I was looking for a more affordable option.
My final design, published in Pitstop, made use of a vented disc and sliding caliper from a Renault Clio all squeezed within a 13" alloy wheel, with a lightly modified Marina caliper bracket. There is even am option for a 14" wheel.

It proved to be a successful mod, several Marina Roadsters and original Marinas being modified, and even developed a little further by Jez Cox using a caliper with a larger piston diameter.

Modifying your brakes may not be everybody's idea of common sense. But another option has been drawn to my attention. Drilled and Slotted Marina discs. I don't suggest you try modifying your own original Marina discs without access to a proper balancing rig, but these might be worth a try?

http://www.ebay.co.uk/itm/MORRIS-MARINA-1300-1800-71-80-Front-Drilled-Slotted-RDA-Disc-Brake-Rotors-/360589734973?pt=AU_Car_Parts_Accessories&hash=item53f4d2b43d

The catch is that postage from the other side of the world is a tad expensive. Unless someone can find a UK manufacturer to make some?


PS.
Dont be fooled when you do a search on eBay for Marina discs. Many of the pictures show vented discs, these are generic pictures, the standard caliper will only accept 9/10mm thick solid discs.

[cdow]

Re: Marina based Roadster front discs

Modifying your brakes may not be everybody's idea of common sense. But another option has been drawn to my attention. Drilled and Slotted Marina discs. I don't suggest you try modifying your own original Marina discs without access to a proper balancing rig, but these might be worth a try?

http://www.ebay.co.uk/itm/MORRIS-MARINA-1300-1800-71-80-Front-Drilled-Slotted-RDA-Disc-Brake-Rotors-/360589734973?pt=AU_Car_Parts_Accessories&hash=item53f4d2b43d

The catch is that postage from the other side of the world is a tad expensive. Unless someone can find a UK manufacturer to make some?.[/QUOTE]


I've always found the idea of these quite appealing (must be the boy-racer in me), but I'm sure I read somewhere that drilled discs have a tendency to fall fall to bits? Or is that just when you try to do a DIY job? Another thing I read was that the drilled/venting was only of use on a track with regular harsh braking and regular road use you wouldn't notice any difference?

I may well be wrong... Anyway, I think I'd rather have vented Clio discs, so when that becomes available as a bolt-on kit I'll have that!

[stevejgreen]

Re: Marina based Roadster front discs

I have never been sure of the advantages of drilled and grooved discs, more cosmetic than practical, and the relative performance upgrade tenuous, given that pad wear can be a lot higher.

My vented Clio discs are a stealth mod, only Marina owners would spot the significant differences..

[holdink]

Re: Marina based Roadster front discs

Unless you are going to use your Roadster for racing or competition work, I can’t see any point of up-grading the front brakes. Originally the brakes did an adequate job of stopping the much heavier 1.8 Marina, I’m sure that they will do a good job of stopping a Roadster. Also the Roadster benefits from having far better disc cooling than the Marina. But if you must up-grade the Front Brakes, I would recommend you go the whole way and fit vented discs. If you go ahead, you must also consider the effect on the front to rear brake balance. It is no good if you increase the efficiency of the front brakes so they are doing all the work and the rears are under-braked.

[stevejgreen]

Re: Marina based Roadster front discs

Absolutely right but, if you read the Pitstop article you would know that this started off initially because I have a Dolomite Sprint axle with 9" drums, slightly larger than the standard 8" Marina, so I was looking to make a similar increase to the front to balance the braking effort.
I have shared the Pitstop article here http://www.keepandshare.com/doc/4303...-pdf-192k?da=y

I am not sure why you say a Roadster would have far better brake cooling than a Marina? They are identical designs and parts, air circulation is limited by the back plate covering the disc.

So my final design was a vented disk from a Clio, with a 259mm diameter over the standard 247mm Marina, all squeezed into a 14" wheel, Pad area is a little larger.

Why did I do it? Mostly because it was an interesting challenge!

Modifying brakes is not for everyone, but as Chris says, it must be the boy racer in me. But at £117 + £76 p&p, a total £193 the Australian discs are extortionately expensive.

Finally though, braking efficiency is primarily down to that small bit of rubber that touches the road. There is no substitute for good rubber!