Dual Brake Circuits

[riverkeeper]

I was wondering what type of set up you guys who race elans have in the way of dual brake circuits ? I get the impression that some of the early 26R's had a dual master cylinder arrangement but it would appear that the use of a tandem master cylinder is most common today after talking to a few people including Tony Thompson. However the likes of Tony Thompson no longer have them available !?(and at ?250 )
There are the options of either creating my own dual master cylinder set up or perhaps using a Mini tandem master cylinder but there must be an off the shelf option ? or does everyone use a bespoke system ?

Cheers

Wayne.

[BillGavin]

I talked to Tony last year about his dual M/C setup - he said it had gotten so expensive to fabricate that he was no longer supplying it. He now uses the tandem M/C form later model Elans (North American versions at least), with adaptors to use remote reservoirs, since the standard reservoir will interfere with the Webers in a RHD car. He uses a pressure limiting valve in the rear brake circuit, and says this setup is quite satisfactory.

Kelvedon still lists a dual M/C balance bar setup.

I think you could fabricate a dual M/C setup for a RHD car fairly easily, but it's trickier for a LHD car. The balance bar unit can be purchased by itself, and the rest is faily easy to weld up from sheet metal. I'd try to use the original pedals to save having to make them; a failure in a pedal could be most embarrassing

[rgh0]

Wayne

I use a dual circuit inline master cylinder with remote reservoirs in my Elan for racing ( its RHD here in Australia). The master cylinder is a local Australian made one from PBR and I dont know its orginal application. It is used locally also by lots of guys racing MGB's here so it may be worthwhile checking what the MGB's use in your location.

Room for a dual cylinder and balance bar in any elan wither RHD or LHD is very limited but it can be done like it was on the 26R's. But if no one is making these up now would require some significant work and cost to fabricate a workable system that fits.

I have found no need for a pressure limiting valve for brake balance but run lower coefficient friction pads in the rear than in the front to achieve the need balance and prevent rear lock up.


Rohan

[patrics]

Hi Wayne, I recently got hold of new 0.7 tandem master cylinder the Part number is 74066147 (PMA100) and the casting is marked up 74660152. I think this is listed for Morgan 4+4 - not sure of the year but they haven't been made for a while.
Good Luck!
Steve

[sotul86]

Hi Wayne

For my righthand drive I bought a tandem master cylinder from a caterham
Girling 74066147, parallel bore 11/16" a run it with a proportion valve from wilwood on rear brakes working fine for me.....

[riverkeeper]

Guy's - thanks for your info. I'm going to look at fabricating a dual cylinder set up first but at least I now know what Tandem master cylinder to get that will fit and work !

Cheers

Wayne.

[steveww]

Before spending too much time fabricating something see what you can get off the shelf from Wilwood, Demon Tweeks etc. These all stock a large range bits that will most likely do the job. You can also get a variable bias valve for fine tuning.

[paros]

Hi
Talk to Bob Green at BG Deverlopments in Bromsgrove - he supplied a tandem one for me that fitted beautifully! Only problem is the pushrod needs the Elan forked end grafting onto the tandem push rod. Done with sleeve threaded 5/16 joining old and new.
A pressure limiting valve is needed to balance the back of the cars brakes or you can do it by being tricky with brake pads - not really recommended.
Hope this helps
Richard

[moorema]

i race a left hand drive S1 in the US and converted to a dual brake setup with a balance bar. used a wilwood pedal assembly for brake and clutch. had to cut pedals, offset to the left, shorten and reweld. used identical girling 5/8 cylinders. cut small opening in left fender well to make room for clutch cylinder. used the gas pedal assembly from a fiat 124 that is independent from the wilwood set. works great but went to a lot of trouble. inboard cylinders (in footwell) with remote reservoirs is another way. tandem with proportioning valve should be sufficient. mike

[davidholroyd]

<a href='http://www.classicbrakes.co.uk/' target='_blank'>http://www.classicbrakes.co.uk/</a> phone them.

[jkolb]

A fellow in Australia is modifying Datsun tandem master cylinders for Lotus Elites. The 1200 and the 521 pickup used a 11/16 MC, and the 510 used a 3/4. Only mod needed is the actuating rod which can be modified with a threaded coupler, and putting a metric flare on the pipes that enter the MC. I have also heard that the first Spitfires to use the tandem MC used a .7 bore and the unit will bolt up once the actuating rod is modified. I don't know what to do about reservoirs, however, as the Spit mounted at an angle.

Jerry