+2 Dual circuit master options

[mbell]

Hi,

While I have the engine out of my plus I was thinking, despite my almost brand new master cylinder, I?d switch over to dual circuit brakes while I have easy access to the brake lines. I know this is a well-covered topic on the forums and I think I?ve read most of the relevant threads without identifying the perfect drop in master for the +2. My understanding after reading all the threads is the options are:

Factory Fit Girling:
+ Factory Unit
+ Right bore 11/16
- Unavailable
- $$$$ if you can find one

Datsun 1200:
(probably best choice for an Elan)
+ Right bore 11/16
+ Cheap ~$70
+ Easily available in USA and easy to get rebuild kits
- Outlets at bottom on master and I believe will not fit in +2 peddle box, or be very difficult to connect the lines too
UPDATE: The bottom outlets will foul the pedal box unless significantly modified. SO this is not a bolt in replacement.


Triumph Spitfire (76-80):
+ Right bore 0.7"
+ Cheap ~$70
+ Easily available and easy to get rebuild kits
- Angled Reservoir, needs replacing
UPDATE: Is only marginally shorter than the space in the engine bay but fits if you remove pedal box to fit. On RHD car the rear connection is fouled by rear corner of the engine bay so it can't be used. Should work fine on LHD.

Caterham Master:
+ Right bore 0.7"
+ Should be bolt in
- Expensive 250GBP + postage
- Harder to get hold of and get rebuild kits in USA

Lotus Marques
(http://lotusmarques.com/parts/datasheet ... e-cylinder)
+ Right bore 11/16
+ Bolt in
- Likely to be expensive
- Harder to get hold of and get rebuild kits in USA


I?ve also seen reference to SAAB, Volvo and Morgan dual masters but not been able to identify specific car/master cylinder. My conclusion so far is that the Spitfire is probably the best route in the US, specifically the one for the 76-80 models and replacement reservoir will probably be easier to locate/make.

My question are:
1) Have I missed any relevant Master Cylinders?
2) Has anyone fitted the Datsun 1200 to a +2 peddle box?
3) Any one any leads on a correct replacement reservoir for the Spitfire master?

Thanks,

Mark

[Foxie]

I've been considering this for a while.

Are you thinking of ditching the servo, or fitting two ?

[rgh0]

The Datsun master cylinder have side bleed ports - at least the one I use on my Elan has. The Lotus marques master cylinder looks like its the same casting with the outlets moved to the side bleed and the bottom ports blocked. It should be possible to do the same modifications yourself.

cheers
Rohan

[mbell]

Are you thinking of ditching the servo, or fitting two ?

The servo had been removed from my car when I got it. So I down sized the master from a 0.875 to a 0.625 and didn't replace the servo. The 0.625 is ok but little long pedal, think a 0.7 should also be ok.

The Datsun master cylinder have side bleed ports - at least the one I use on my Elan has. The Lotus marques master cylinder looks like its the same casting with the outlets moved to the side bleed and the bottom ports blocked. It should be possible to do the same modifications yourself.

I'd discounted that as the bleed fittings look too small to take a brake line connection and didn't think it was wise for me to modify the fittings. Of course this is all based on internet photos so I may be wrong and might be able to go that route too.

I'd be interested to know what the thread size was for the bleed fittings if anyone is able to provide that info. I suspect it might vary between manufacturers thou.

Thanks.

Mark

[UAB807F]

Hi Mark,

Although my car is a 2 seater, I have the type 16 front calipers the same as the +2, so it's pretty much identical to your system. I fitted the Spitfire dual circuit m/cyl with a remote reservoir connected by rubber tubing.

elan-dual-circuit-brakes002a.jpg (79.35 KiB) Viewed 3313 times

elan-dual-circuit-brakes003a.jpg (82.97 KiB) Viewed 3313 times

With no servo the pedal travel is just over 4cm. That might be different for your car if the brake pedal leverage ration is different on the +2.

Brian

[fatboyoz]

Hi Mark,
The Westfield standard Master cylinder might be the go at 135 UK pounds. They also do an AP M/C for heaps more.
http://parts-shop.westfield-sportscars. ... scs?page=2
I used a second hand Westfield M/C picked up on eBay. A straight fit on my S4 after having it sleeved with S.S.
Cheers,
Colin.

Hi,

While I have the engine out of my plus I was thinking, despite my almost brand new master cylinder, I?d switch over to dual circuit brakes while I have easy access to the brake lines. I know this is a well-covered topic on the forums and I think I?ve read most of the relevant threads without identifying the perfect drop in master for the +2. My understanding after reading all the threads is the options are:

Factory Fit Girling:
+ Factory Unit
+ Right bore 11/16
- Unavailable
- $$$$ if you can find one

Datsun 1200:
(probably best choice for an Elan)
+ Right bore 11/16
+ Cheap ~$70
+ Easily available in USA and easy to get rebuild kits
- Outlets at bottom on master and I believe will not fit in +2 peddle box, or be very defficult to connect the lines too

Triumph Spitfire (76-80):
+ Right bore 0.7"
+ Cheap ~$70
+ Easily available and easy to get rebuild kits
- Angled Reservoir, needs replacing

Caterham Master:
+ Right bore 0.7"
+ Should be bolt in
- Expensive 250GBP + postage
- Harder to get hold of and get rebuild kits in USA

Lotus Marques
(http://lotusmarques.com/parts/datasheet ... e-cylinder)
+ Right bore 11/16
+ Bolt in
- Likely to be expensive
- Harder to get hold of and get rebuild kits in USA


I?ve also seen reference to SAAB, Volvo and Morgan dual masters but not been able to identify specific car/master cylinder. My conclusion so far is that the Spitfire is probably the best route in the US, specifically the one for the 76-80 models and replacement reservoir will probably be easier to locate/make.

My question are:
1) Have I missed any relevant Master Cylinders?
2) Has anyone fitted the Datsun 1200 to a +2 peddle box?
3) Any one any leads on a correct replacement reservoir for the Spitfire master?

Thanks,

Mark

[prezoom]

Mark,
Did you get my email?

[mbell]

The Westfield standard Master cylinder might be the go at 135 UK pounds.

Thanks Colin that looks like it would be a drop in. Out of stock currently thou. Do you know what the bore size is? Is it 0.7?

Mark,
Did you get my email?

Yes thanks. Sorry had a busy day so only just replied. Hopefully it reached you as first attempt bounced.

[fatboyoz]

Hi Mark,
Yes, same size as original, 0.7".
Cheers,
Colin.

The Westfield standard Master cylinder might be the go at 135 UK pounds.

Thanks Colin that looks like it would be a drop in. Out of stock currently thou. Do you know what the bore size is? Is it 0.7?

Mark,
Did you get my email?

Yes thanks. Sorry had a busy day so only just replied. Hopefully it reached you as first attempt bounced.

[snowyelan]

Hi All,
I too am in the hunt for a dual circuit M/C. The question I have is which one of the Datsun cylinders is used? I have found 2 variants, one early and one late. The part # for the most common (late) M/C is:

130.42001, from Centric

Alternative part #'s are:

R12731
18M1072
R133651
E151389
M900270

Can anyone who has used the Datsun M/C verify if any of these are the part they used??

Thanks,
Scott

[prezoom]

Scott,

The master cylinder I going to use in my Plus2 is from a 1972/1973 Datsun 1200.

If you are going to use it in a Plus2, you are going to have to modify the bottom feed lower bosses to clear the footwell. Can not speak to the original Elans, as I have not converted my S2 to dual circuit system.

lf you will send me your email address, I will forward pictures and a description of how I modified the master.

I already sent the information to Mark, who has decided that he does not have the capability to make the mods. Have tried up loading pictures from my phone to this site with no success.

[mbell]

Can anyone who has used the Datsun M/C verify if any of these are the part they used??

Take a look at:
http://datsun1200.com/modules/mediawiki ... r_Cylinder

A-1 CARDONE 111655 Remanufactured $26.79
RAYBESTOS MC39087
ACDELCO 18M1072, 19106858
* Bore Size=11/16" Number of Ports=2 Primary Outlet Size=M10x1 Secondary Outlet Size=M10x1

I already sent the information to Mark, who has decided that he does not have the capability to make the mods. Have tried up loading pictures from my phone to this site with no success.

I could add the info/photo's you sent to the thread if you are ok with that Rob?

I fitted the Spitfire dual circuit m/cyl with a remote reservoir connected by rubber tubing.

Thanks Brain. I am leaning towards this master due to it's a direct fit, availability, easy availability of seals kits and price. The only problem is the reservoir, Remote reservoir make a lot of sense on the Elan but not on the +2. So would either have to live with a sloppy reservoir, I think there enough fluid coverage in the 76-80 master for it to be ok/safe or find a different reservoir(s) that fits which could be quite tricky!

[Lyn7]

Hi guys, for what it is worth I have used a Spitfire tandem master cylinder on my Sprint and am very happy with it.
It is cheap , the right bore (0.70") , spare parts are readily available and it fits! The slopy reservoir is not a problem in practice , just looks strange. What is there not to like?
Cheers , Lyn...

[crypto]

I'm using this one on a Sprint

http://www.ebay.co.uk/itm/191661310903

I guess there is more space on a +2, but in my Sprint it was very tight (LHD car). Piston is 19.1mm (0.75")
You probably want a PDWA too ?
Was also considering the Spitfire version, but it looks very odd and is not suited for horizontal attachment.
You probably will need a different brake pedal rod if you had the single cylinder.
Peter

[mbell]

Thanks Lyn, I think that's the way I'll end up going but would like to avoid the sloppy reservoir if possible. It's quite visible in the +2 engine bay.

I think I may reach out to one of parts triumph supplier and see if they have a different reservoir (or master) that could be used.

I'm using this one on a Sprint

http://www.ebay.co.uk/itm/191661310903

Thanks Peter, that looks to be a 0.75 version of the Datsun 1200 master I mentioned. So this would not fit a +2 with out modification, same mods as suggested by prezoom. On the +2 the masters are mounted to the pedal box that is on top of the foot area of the car and they are rotated to face the opposite direction. There quite limited clearance under the master to the pedal box, so most masters with bottom connection will not fit.

You probably will need a different brake pedal rod if you had the single cylinder.

That is a good point. For me it's not an issue as I had to make up a new push rod to fit the 5/8" Master. The master & push rod the car (none driver) came with weren't correct and the brakes were locking on. So I had to make a short rod to fit when I swapped masters. The one made is threaded/adjustable and I should be able to swap out the threaded rod part for longer ones if needed.