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View Full Version : hey dattoman1000 and others - 1200 coupe query


jmac
07-11-08, 04:24 PM
I've got a datsun 1200 coupe I'm starting to work on. I'm in the process of acquiring and then fitting the s13 silvia front discs/calipers. I've spoken to Kev Rowley who indicates that the std datto master cyl is compatible (i.e. reasonable pedal). For my own idiosynchrasies, I'd like (to get less pedal travel, and hence more volume in reserve if needed, but also because I am hovering around 150kg, and a harder pedal is far better for me, gives more ability to feel and reach the limit of the brakes without accidentally locking them up).

Anyhoo, what I'm curious about is what bore was the master cylinder on the s13 silvia with 250 odd mm discs? And pursuant to that, is there a master cylinder of that same bore, or slightly larger, that will bolt up (*captive pushrod or lack thereof no dramas, just looking for bolt spacing and horizontal travel for the most part) to the datsun 1200 coupe firewall. I'm (probably obvious) not wanting to run a booster of any sort.

My other query pertains to the rears. With much better fronts, it'd (tyres/suspension willing) be transferring a lot more weight forward under brakes, so if anything, the rears (already slightly light when at a standstill) would be more at risk of lockup. To that end, I'm thinking of adapting the rear pressure limiting valve from a mini to take care of that. Any thoughts as to it's use in this context?

PLAYA
09-11-08, 01:56 PM
BM33 = 13/16
BM38 = 7/8
BM44 = 15/16
BM50 = 1"
BM57 = 1 1/16

if you can run a 1" bore willwood master bolts straight up to the 1200, as i have done

jmac
09-11-08, 02:47 PM
thanks mate.

These part numbers, (forgive my relentless ignorance) - are they nissan or generic brake manufacturer or what?

PLAYA
09-11-08, 03:43 PM
i think they are just nissan, i read that they are printed on the side of the master cylinder.

dattoman1000
12-11-08, 06:40 PM
They are casting #'s not part #'s
But they help identify the bore size

The Silvia cylinder was orig 13/16 from memory