Sptifire & GT6 Brakes

[Bilbo]

Can anyone please help me??
Its now time to refurb the front brake on my spitfire 1500, and as everything else has been upgraded I was looking at changing the calipers for GT6 items,
My spitfire is supposed to have type 14 calipers....right or wrong?
GT6 should have type 16 calipers?
I bought a knackered old gt6 caliper off ebay to compare and it seems to me exactly the same as the ones already fitted.
What is different between them?
Is there any markings or numbers marked on them that identify them?
The supposed gt caliper has 6HJ stamped on it and the ones on mine say 17H6 on it. Do these mean anything to anybody?
Is the conversion worth the upgrade?

[Piero franchi]

try a google search to find out the correct piston sizes for each caliper,
you can soon tell which ones you have

[Clive]

Sounds like you were sent a spitfire (type 14) caliper.

Type 16 (3 varieties are used at different times) use a larger pad, and teh mounting holes are at different centres.

To fit GT6 brakes you need the complete GT6 setup, uprights, stub axles etc etc etc.

The alternative is to get either princess 4 pot calipers or aftemarket versions of them, and use a GT6 disc. If you wanted vented diiscs redrill a Capri 2.8 disc and use calipers for a vented disc (or space the princess 4 pots)

[Richard B]

GT6 should have 16P or 16PB as part of the casting (not stamped), The other difference to a Spifire one, is the distance between the bolt hole centres.

[Bilbo]

Thanks for the repies, my thought was that I was sent a type 14 caliper.
The conversion with princess calipers, is this the 70's/80's Austin princess? Does this just fit on or is modification needed to the caliper mount?

[Clive]

Princess calipers straight fit. But a bit rare thesedays. Ali copies readily available, IIRC about £100 each? then just fit a gt6 disc to the spit hub.

[Dogsbody47uk]

I recall someone saying that type 14 and type 16 refers to the piston diameter in 1/8 inches, so type 14 callipers have pistons of 1 and 3/4 inches dia. and type 16  csallipers are 2 inch dia. A quick way to tell your 14 from your 16 etc.

[Nick Moore]

If you're going to fit GT6 front brakes, you should fit the larger rear brakes as well to keep everything in balance. At the front you'll need GT6 or Vitesse uprights, caliper mounting brackets, discs, hubs (I think) and of course the 16P calipers. At the rear you'll need 8" drums, backplates, slave cylinders and shoes.

If you want to throw buckets of cash at it, you can replace the uprights with trunnionless uprights, buy alloy caliper brackets and hubs, and even fit larger-than-GT6 discs and alloy 4 pot calipers. Bigger-than-GT6 brakes definitely aren't necessary though, unless you have a lot more power.

Some will pipe up and tell you that you don't need the larger brakes, just appropriate pads and shoes. And they're right. Being contrary though, I fitted the same larger Vitesse brakes to my Herald - I figured that no one ever complains about having too much brake! It took a while to scrounge the necessary parts though. And they work very well.