Vintage racing brakes

Doug, "Yes they can !" (do you remember ?)

quote:

Originally posted by "72 GTS:
Doug, "Yes they can !" (do you remember ?)

What?

I actually never tried to push the pistons back, so I can't really tell...

They came with the pistons flush back from BG after the modification.

It's by far the nicest looking "period correct" caliper available. Even so, my question of whether or not it will fit the 15x8 Campi cannot be answered.

I would take an educated guess and say no.

These could be used on the flared fender cars with the Gp4 wheels I think.

There is a reason why the iron Girlings were used by the factory even on the race cars. It has to be that they fit better and with very minor modifications to the stock suspension?

There is only so much that the rotor can be offset inbound before it hits something on the suspension that cannot be moved or changed.

Probably also, the rules must not have permitted locating the hat of the rotor on top of the wheel hub as we would do today?

That just makes so much sense for ease of access to servicing the brakes quickly.



I don't understand how Girling works at all? Almost all of their calipers are variations of basic modules, as in modular design, and reassembled to suit an application more specifically.

Considering they are on virtually every European vehicle of the era, I would have thought they would have cast up light weight versions in aluminum of the existing iron components?

Bosswrench has mentioned "some aluminum Girling calipers". I have never seen any accept the ones that were used on the Competition Cobras and Ford GT40's. Even so, those calipers are nothing to write home about at all.

I do remember a remark I read where Shelby refered to "Girling's crappy brakes". I think I understand where that remark is coming from considering all of these factors?

The Wilwoods are looking better and better. Thanks for posting. This is like attending a "by invitation" brake seminar and the value of this information "is priceless". Thanks.

Disc offset is indeed something to be careful with.

The more offset inwards, the less wheel spacer you might need, but the thicker your caliper adapter will need to be.

Except for that, the offset is both limited by the steering rack pivot point, and as Doug does mention, the possibility your caliper will hit suspension parts.

Weight and sizes:

Front:
Original calipers (2) without pads 10,92Kg
Modified 18/4 BG calipers (2) without pads 7,48Kg

Original discs 280mm solid (2) 13,28Kg
BG discs alloy hats - 304x28mm vented (2) 13,6Kg

Back:
Original calipers (2) without pads 6,55Kg
BG ORA calipers incl handbrake (2) without pads 7,82Kg

Original discs 297mm solid (2) 14,28Kg
BG discs alloy hats - 290x12,7mm solid (2) 9,24Kg

As for the Campi wheels - dunno...
Would depend on the inside (back) shape of the wheel.

I combine everything with 15X8 and 15x10 steel wheels, and that just barely fits - some things get really close...

I like Wilwoods, but there is a caveat (which also applies to BG calipers). Neither caliper uses rubber dust shields. They're intended for racing and racing calipers don't stay on a car more than a few minutes past the last race. So dust shields are un-necessary. But on the street, they keep brake pad dust, road grime and who-knows-what away from the pistons.

For the guy who already has a set, could you check the BG caliper pistons? For unknown reasons, most Euro calipers including Ferrari, Porsche and Cobra use nickel-plated mild steel pistons, in place of the almost universal use in the U.S of corrosion-resistant stainless steel. Which is non-magnetic. If your pistons are magnetic, they are almost certainly plated and may pit in low (or no) maintenance street use.

quote:

Originally posted by Bosswrench:
I like Wilwoods, but there is a caveat (which also applies to BG calipers). Neither caliper uses rubber dust shields. They're intended for racing and racing calipers don't stay on a car more than a few minutes past the last race. So dust shields are un-necessary. But on the street, they keep brake pad dust, road grime and who-knows-what away from the pistons.

For the guy who already has a set, could you check the BG caliper pistons? For unknown reasons, most Euro calipers including Ferrari, Porsche and Cobra use nickel-plated mild steel pistons, in place of the almost universal use in the U.S of corrosion-resistant stainless steel. Which is non-magnetic. If your pistons are magnetic, they are almost certainly plated and may pit in low (or no) maintenance street use.

I'm aware of the "race" only consideration of the engineering on the aftermarket brakes.

I'd prefer to go with a "production based" component. Particularly the calipers.

The aftermarket two-piece rotors with the aluminum hats are less problematic.

I do know that Cobra Automotive, which is a race based Shelby/Ford GT/Cobra shop will not use Wilwoods. Simply put, they have found them of a questionable quality for their purposes.

They used the term "crap" for the Wilwood hats and rotors.

At this point in the discussion, no one has dealt with the actual cost of looking "period" correct for these brakes.

It would appear at this point that using the Girlings that are sourced from other production cars is going to be cost prohibitive?

Even the GT5 Pantera brakes at $1900 each from Wilkinson are out of the question for me.



I did see one Pantera that was raced in the US in the early '70s.

It had the US "big Licoln" calipers and rotors adapted to the front with fabricated adapter plates.

Those Lincoln/T-bird rotors fit right on the Pantera front hubs since they were adapted originally from the production US Mustang. Similarl to what is done on the rear of the Pantera by using the '65 Mustang front rotor back there.

This was the system Shelby used on the '68 Mustang Trans Am Coupes.

The most complicated part to put them on a Pantera is the adapter to go from the Girling bolt pattern to the Kelsey-Hayes US pattern.

The rotors were the original 12" x 1.25" T-bird rotors. Those are no longer available that size. They were cut down to 11-3/4"od.

The rear used the 65 Mustang front vented rotor with the original Pantera front Girling caliper mounted to the front available upright mounting holes, and left the original Pantera rear caliper in place to be used as a hand brake.

It certainly is worthy of the consideration at this point?

quote:

If your pistons are magnetic, they are almost certainly plated and may pit in low (or no) maintenance street use.

The pistons in the BG's are non magnetic.

quote:

Originally posted by "72 GTS:
Kid
What are your wheels specs ? I have Bassett wheels too ... I ´m surprised you had to cut the calipers so much...

Philippe,

The size/specs of the Bassets has little to no influence on the fitment.

It is simply the fact the calipers are quite wide.

Other than that it will depend on how much (if any - I choose not to because of my narrow bodied car) spacer you wish to run. You are building a Gr4 rep (wider track), so you should have less issues.

The backside of the wheels does rub the caliper, and an as big issue, the caliper does hit the valve!

With the mods now made, I got rid of these two issues, but still not 100% sure I can get away without spacer - if not, it will be a very thin one (max 2mm).

If I would have thought about the valves, I had the valve holes relocate before I had the (brandnew) wheels sandblasted, powder- and clearcoated!

A test fit with the ORA's in the back - there is about a 2mm gap in between caliper and wheel only...


Since these calipers have an integrated handbrake system, I wanted to get rid of the for me useless extra mounting holes.
This too is mostly a hand job Doug - a handsaw, some files, a Dremel, and sandpaper ;-)


I need to correct too that I'm running 16/4's in front (same size as 18/4's though, but with smaller pistons), and ORA calipers in the back.

First test fit of the front ones - which made clear the spacing issues...

BG discs - readily available discs, but with custom hats. Undrilled, and no slots for me because the period correct look I'm after.

Kid
The front wheels are 10inches and rear are 13inches wide on my car, I will check when I have the car back to the workshop ...
Regards

ORA's? Bosswrench mentioned these. Have you got anymore pictures to post of them?

Aren't these the same as run on the Comp Cobras and GT40s? They are single pistons?

Sure.

What is the diameter of the pistons in the ORAs?

Twice a 44,4mm piston, whereas the original back caliper has a single 36mm piston.

A 1 to 1 comparison of the front calipers (before the mods), which shows how much room the BG's require...

It is amazing that you got them to fit at all. I think you could have used the 18/4. The stock master cylinder has enough volume to power them.

Usually increasing the bore of it is to balance the feel for the driver. I ran a 1-5/16" bore on my gt350. Stock was 15/16. I like 1" at the moment.

 

Brake info from FIA Homologation Paper

Stock Brakes	
Girling 4 Piston    		                        Front Brake		  Rear Brake	
                        Pistons / Wheel	                4		          1	
		        Outside Diameter of Piston 2x	42,85 mm   1,68 in	  42,8 mm	1,68 in
		        Outside Diameter of Piston 2x	33,96 mm   1,33 in		
		        Outside Diameter of Disc	282 mm	   11,10 in	  297 mm	11,7 in
		        Thickness of Disc	        20 mm	   0,79 in	  18,5 mm	0,73 in
		        Length of Pads	                93 mm	   3,63 in	  62 mm	        2,44 in
		        Width of Pads	                48 mm	   1,89 in	  48 mm	        1,89 in
		        Total Area of Pads / wheel	89 cm2	   13,8 sq. in	  59,4 mm	9,2 sq. In
							
------------------------------------------------------------------------------------------------------------	
GR4 Brakes					
Girling 4 Piston Apr-72		                        Front Brake		  Rear Brake					
  		        
                        Pistons / Wheel	                4	                  4	
		        Outside Diameter of Piston 4x	35 mm			  29,5 mm	
                        Outside Diameter of Disc	304 mm			  304 mm	
	                Thickness of Disc	        28 mm			  28 mm	
	                Length of Pads	                97 mm 		  	  97 mm	
		        Width of Pads	                49 mm			  49 mm	
		        Total Area of Pads / wheel	95 cm2			  95 cm2	

Front Caliper part no	31/32
Rear Caliper part no	33/34

------------------------------------------------------------------------------------------------------------
GR4 Brakes	      	
Lockheed 4 Piston Apr-74	                       Front Brake               Rear Brake
						
 		        Pistons / Wheel	               4			 4	
		        Outside Diameter of Piston 4x  44,5 mm	  1,75 in	 41,25 mm   1,625 in
	                Outside Diameter of Disc       304 mm	  11,97 in	 304 mm	    11,97 in
	                Thickness of Disc	       28 mm	  1,10 in	 28 mm	    1,10 in
		        Length of Pads	               130 mm	  5,12 in	 130 mm	    5,12 in
		        Width of Pads	               50 mm	  1,97 in	 50 mm	    1,97 in
		        Total Area of Pads / wheel     120,8 cm2  18,7 in	 120,8 cm2  18,7 in

Front Caliper part no   507.33.041/042							
Rear Caliper part no    507.33.043/044

------------------------------------------------------------------------------------------------------------
GR4 Brakes
Girling 3 Piston Jul-74	                                Front Brake		 Rear Brake

                        Pistons / Wheel	                3			 3
	                Outside Diameter of Piston 2x	42,5 mm	  1,68 in	 30 mm	    1,18 in
                        Outside Diameter of Piston 1x	60 mm	  2,36 in	 42,5 mm    1,68 in
	                Outside Diameter of Disc	288 mm	  11,35 in	 274,5 mm   10,8 in
	                Thickness of Disc	        31,75 mm  1,25 in	 20 mm	    0,79 in
		        Length of Pads	                114 mm	  4,5 in	 78 mm	    3,07 in
		        Width of Pads	                62 mm	  2,44 in	 45 mm	    1,77 in
		        Total Area of Pads / wheel	115 cm2	  17,825 sq. In	 64 cm2	    9,92 sq. in

Front Caliper part no   506.3.3.064/065
Rear Caliper part no    506.3.3.066/067
Brake Booster 	        506.4.2.007						
Master Cylinder	        506.4.2.008						
Adj valve	        503.3.3.119						
				
------------------------------------------------------------------------------------------------------------
GR3 Brakes			
Girling 3 Piston Jan-75	      		                
(From GR4 except rear disc)				
                                                        Front Brake		  Rear Brake
		        Pistons / Wheel	                3			  3	
		        Outside Diameter of Piston 2x	42,6 mm	  1,68 in	  30 mm	    1,18 in
		        Outside Diameter of Piston 1x	60 mm	  2,36 in	  42,5 mm   1,68 in
                        Outside Diameter of Disc	288 mm	  11,35 in	  297 mm    10,693 in
                        Thickness of Disc	        31,75 mm  1,25 in	  18,5 mm   0,728 in
		        Length of Pads	                114 mm	  4,5 in          78 mm	    3,07 in
		        Width of Pads	                62 mm	  2,44 in	  45 mm	    1,77 in
		        Total Area of Pads / wheel	115 cm2	  17,825 sq. In	  64 cm2    9,92 sq. in


Front Caliper part no   506.3.3.064/065
Rear Caliper part no    506.3.3.066/067
Brake Booster 	        506.4.2.007						
Master Cylinder	        506.4.2.008						
Adj valve	        503.3.3.119							
				
------------------------------------------------------------------------------------------------------------
GR4 Brakes
Lockheed 8 Piston Apr-75	      		        Front Brake			
							
                        Pistons / Wheel	                8				
 		        Outside Diameter of Piston 4x	28,575 mm   1 1/8 in		
                        Outside Diameter of Piston 4x	31,75 mm    1 1/4 in		
		        Outside Diameter of Disc	304 mm	    11,97 in		
		        Thickness of Disc	        28 mm	    1,10 in		
		        Length of Pads	                101,6 mm    4 in		
		        Width of Pads	                49,53 mm    1,95 in		
		        Total Area of Pads / wheel	214,4 cm2   33,23 sq. in		
		        Pads / Caliper	                4

Front Caliper part no   507.33.047/048			

------------------------------------------------------------------------------------------------------------

 

quote:

506.3.3.064/065

Those must be detomaso part numbers? Nothing comes up in a Google search for Girling.

I'm still working on the installation of the brakes...lol.

Did not like the use of an additional adaptors for the front calipers, so I had the original parts modified, and the steering arms cut off.

I had the rough shapes - yet to become the final caliper brackets - machined. From now on, the only tools used will be as usual a handsaw, a set of files, and sandpaper :-) Yes, there is still one caliper mounting hole missing, but that's because I was not for a 100% sure where to have it drilled yet.





The hand work started...

Progress...

Nice work, I had no clue where you were going with this initially.

It's a really beautiful set up. I really wish they would fit under my original Campi's.

I did not catch this originally, must have mixed it with another thread on monster calipers. The calipers shown by Kid are the same as on late Mangusta (Girling BR)

Same as big block Cobras and Lister Jag I was told.

quote:

Originally posted by JTpantera:
Nice work, I had no clue where you were going with this initially.

Some more pictures then :-)

The steering arm cut off earlier on covers the bracket. Position of second caliper mounting hole now precisely defined.



I could have had this all machined of course, but doing this manually gives more satisfaction, and in the end more cast-like parts - i.e, as if things came out of the factory this way. Later on the entire assemblies will get powder coated, which will cover up even more this is not stock :-)

quote:

Originally posted by Denis C:
I did not catch this originally, must have mixed it with another thread on monster calipers. The calipers shown by Kid are the same as on late Mangusta (Girling BR)

Same as big block Cobras and Lister Jag I was told.

Well, sort of. The BB street Cobras were made of iron, the Comp Cars got 'luminum. So did the GT40's under Ford, Shelby and Holman-Moody.

When they became the "Gulf's" under John Wyer in '68 (if you called them GT40's then Wyer would sue you), they used the Girling 18-4, and 16-4 which were aluminum also.

It is unclear, but highly NOT likely that any of these other than the stock Pantera Girlings will fit the "production" Pantera wheels.

The size of the calipers pretty much explains that. The stock Pantera calipers are very compact by comparison.

To me, there are three things that any aftermarket caliper needs on MY Pantera. 1) it fits the stock wheels, 2) they are light weight, 3) they are multi-pistoned, 4) the pads themselves have a significantly larger pad surface area than stock, 5) I can afford them!

OK! ...five things, but don't get me started on counting, I'll probably think of more?

@ KID...I absolutely love the adapters that you made!

A weekend full of files and sandpaper...

Perfectly mirrored parts.
Bottom section (that ugly square) still needs to be finished, but the last hole to be drilled first.

quote:

OK! ...five things, but don't get me started on counting, I'll probably think of more?

PanteraDoug, you're a one-man Monty Python show...

With a Pantera, you need to have a sense of humor. It's better too if YOU DO NOT own a handgun.

Done - except for coating.

Quite some hours of work, but happy with the result

And once the entire assemblies coated, it will be hard to spot this is not stock

Beautiful! Tell me this setup fits with the stock 15" Campi wheels...please?

I make you believe anything for $100 Doug... lol

15" wheels yes, Campi's, I dunno... I have no clue of how Campi's look on the inside/backside.

So radial wise they'll fit 100%, but whether they'll fit axial wise - with or without use of a spacer, that really depends on the wheel inner shape.

quote:

Originally posted by Kid:
I make you believe anything for $100 Doug... lol

That's easy. It does seem that I will believe anything sometimes?



I agree that it is the inner profile of the wheel that would determine clearance.

Probably there is enough room in the rear with the 10" Campi to run the 16-4 but the front caliper is so thick that I think not.

Considering what those calipers cost, I wouldn't want to buy a set, then be disappointed that the 8 x 15 Campi will not fit without a thick spacer, if at all?

I think that probably a 1/2" thick spacer would still allow the tire to clear the fender lip but why take chances on speculation?



Where's Bosswrench? What do you think? Will those "Girling" 18-4 aluminum calipers fit inside of that wheel? Do I remember correctly in you stating that you have worked on that setup before?

Few have actually seen or worked on that particular combination in person. Very difficult to find that answer without just experimenting "yourself".

THEN you have to go make adapters!


Incidentally does anyone know if the Girling #'s on the 18-4 and 16-4 calipers refer to anything specifically like the thickness of the rotors used with them etc?

The 18-4 uses the 1.25" (31.75mm) thick rotor, the rear is 7/8" (22.2mm) right?



What was the outside diameter of the rotors that you wound up with Kid? The 12.19" od number keeps popping up but I haven't done specific research yet on this?

Well, I had no clue at all whether I would get this working before I bought the calipers...lol.

For my application, I went for 28mm vented discs in front, 12,7mm thin solid ones in the back.

As for diameters - in the back I went down from 297 to 290mm, in combination with the new calipers/pads, the best combination (imo).

As for the front - the initial plan was using 304mm ones, but had them machined back to 290mm.

Reasons for this were a better use of the available disc area, and adaptor design.
With the adaptor as I had it in mind, I had unused disc surface (on the outside radial wise), which made no sense.

One going for 304's should have hats made with a larger diameter than I did, otherwise there would be too much unused disc surface on the inside of the disc (radial wise), and which is what I would do if I were to do this again. And since alloy is much lighter than steel...

Have the 304's machined back down to 290mm saved me 780Gr/disc.

I worked on iron-caliper Girling GR-3 brakes on a non-GR-3 car with Gotti 15 x 10" wheels running Hoosier tires. With different wheels/tires and aluminum Girlings (stock on Mangustas but not Panteras except GR-4s), you simply have to try it. I own a machine shop so yes- I COULD make the combo fit. It may not look 'stock' at the end but that word is never applied to race cars- or their brakes- anyway.

quote:

Originally posted by Bosswrench:
I worked on iron-caliper Girling GR-3 brakes on a non-GR-3 car with Gotti 15 x 10" wheels running Hoosier tires. With different wheels/tires and aluminum Girlings (stock on Mangustas but not Panteras except GR-4s), you simply have to try it. I own a machine shop so yes- I COULD make the combo fit. It may not look 'stock' at the end but that word is never applied to race cars- or their brakes- anyway.

I did that with a set of Lincoln/Big Ford/Thunderbird calipers on my 68 GT350.

In order to get the calipers to clear the inside the wheel, they had to machined down to clear.

They looked beautiful and cleared but the first time I tried the brakes the caliper cracked through the casting into the piston bore.

It had been machined down so far that the hydraulic pressure from the brake system cracked the cast iron caliper.

Those aluminum Mangusta calipers are the same I believe as on the big block 427 comp Cobras.

Big bucks just for that reason.

Comes back to Wilwood or leave them stock. I would like to run 1.25" front rotors and go with vented in the rear with the hats over the flanges.

Using any kind of Girling brakes is just too expensive for little gained.

I don't need to satisfy the vintage racing rules.

I saw one US raced Pantera (pictures) with the 67 Tbird calipers and rotors adapted.

I'll go that route if I can find the aluminum calipers. So far they have been very elusive.

I'm not sure I like the configuration of the adapter they would need though?

Girling are 3" center to center and the KH are 5". That is actually so close it makes the adapter complicated to make.

Wilwoods are simpler, can be purchased with the right 3" bolt spacings and any hat can be made to use any rotor that they make.

Lots of weight savings there, just whether or not the calipers clear the wheels?

I, like Kid, like the "engineering challenge" to make everything fit and work.

We will see. Perfect time wise to do it. Temperature wise, the garage is too cold. I mean after all it is 18 F outside with 50 mph winds?

Radiant heat in the floor would have been perfect. Turn on the "happy light" and I'd think I was in Florida.

I could even dump all the glass bead from the blast cabinet on the floor and think I'm on the beach in Miami?

quote:

Originally posted by PanteraDoug:
I, like Kid, like the "engineering challenge" to make everything fit and work.

Isen't driving a DeTomaso one big challenge...

Hi Kid
Did you make drawings of your parts ?
cheers
Philippe

Philippe,

For now I only have the basic drawings of the alloy blocks I started with, but can see to make some time to put the finished pieces on paper, or at least for instance the most important dimensions and sizes like for instance the bolt pattern etc...

quote:

Originally posted by Kid:

quote:

Originally posted by PanteraDoug:
I, like Kid, like the "engineering challenge" to make everything fit and work.

Isen't driving a DeTomaso one big challenge...

No I don't think so. Stock L's are relatively trouble free. Issues develop when they get "modified" or "improved".

By the time the L was in production Detomaso pretty much had it all solved.

Well, mine is for sure a challenge, and I don't even drive the thing (for now)...lol

Rear hubs are out for the last necessary mods to get the rear brakes fit (I needed a drill press, which I don't have). Hopefully I got the measurements right, or they are wasted, ha, ha...