Spitfire GT6 and Spitfire Dual brake M/C differences

[svtmikey]

Does anyone know what the difference between the Dual Brake Master cylinders is between the GT6 and the Spitfire?
I notice that in the catalogs I have checked I can get parts to rebuild my Dual GT6 MC, but I cannot buy a new one. There are however, new dual Master cylinders for the Spitfire though.
I assume the difference may be the bore, but can anyone confirm that.
Also has anyone used or sourced a difference make of MC like a Wilwood etc?

Many thanks ahead of time.

Mikey

 

[trrdster2000]

Mikey, you are right, the GT6 had a larger bore, for the front brakes had a bigger caliber, but the rear was the same as the Spite. I'm not real sure, but you get different threads on the in lines on later model Spites, (metric). I'm only guessing as I have seen a few Japanese master on our Spites and MG's at car shows and some I've worked on. That said, you just need to find one that fits and use a pressure adjusting valve to get it spot on. May turn out better, but a lot of trouble as you can get the kit and have your master bore redone.

Wayne

 

[pware]

Spitbits has new ones for a GT6 https://www.spitbits.com/gt6/GT6%20brakes.htm

 

[svtmikey]

I saw the replacement at Spitbits, but I thought (assumed) that was a single, mostly by the picture itself. I guess I should call to make sure....but you're probably right!
Thanks

 

[hymodyne]

There is a new GT6 MC for sale on ebay, complete, for about 225.00

hym

 

[pware]

I see what your saying about it being a single on spitbits. Their is no price for the duel so that means you have to call for avaibility. Let me know if they have them and how much. I too will need one when I get this restoration rolling next year.

 

[Andrew Mace]

I'm confused! When I go to the Spitbits web site, I see a listing for:

REPLACEMENT MASTER CYLINDER up to KF20000 .7

ID #: 213690/X
Price: $229.00

That would be the cylinder for roughly 1968 US-spec. "Mk1" GT6, GT6+ and Mk3 through the 1972 model year. They also list the single master cylinder (early "Mk1" up to but not including 1968 US-spec. models) separately. Finally, there is a listing, but with no price, for the late Mk3 cylinder.

The one question I have is if the "../X" in the part number above indicates a replacement by a different manufacturer, as opposed to an original Lucas/Girling cylinder?

 

[pware]

I see it too Andy. I guess the only way to find out is to call. Its a bit confusing!

 

[svtmikey]

I found this site on the web that outlines some of the GT6 brake specs. According to this the MkI and MkII had the same part number of for the Master cylinders. Doesn't say if they are dual or single, and don't know how accurate this is.
Of course this is European, not NA so I don't even know how valid it is.
https://www.teglerizer.com/triumphstuff/brakecylspecs.htm

 

[Andrew Mace]

That chart of Paul's seems pretty good, but it also seems to apply only to the "home market" cars with the single-circuit master cylinders and not US-spec. cars, which did have dual master cylinders beginning with the 1968 model year. And that 213690 dual master cylinder does seem to be NLA from just about everyone (except for Spitbits and their 213690X version, whatever that is).