Caliper spacers for vented rotor

[260Alpine]

I'm looking into adapting the stock calipers with spacers for vented rotors. They are less prone to warping and run cooler for less fade. Very helpful for autocross or canyon/mountain driving. Around stock diameter to fit 13" and 14" wheels. I am 1400 miles from my Alpine. Could anyone give me the stock rotor thickness? If the inside of rotor is in the same place, the 22mm thick Maxima rotor will determine the thickness of the spacer.
The Capri caliper is the same as the series 3, 4 and 5 caliper , and they have done this mod for years. Here are pictures of the Capri mods and the 81-84 Nissan Maxima/84-88 200SX rotor that Phyram mentioned.

 

[Barry]

Don't recall ever seeing the nominal or minimum thickness for Series Alpine rotors in the Owners Manual or the WSM.

Since the "Capri caliper is the same as the series 3, 4 and 5 caliper, and they have done this mod for years", it sounds like the "Capri guys" should have the relevant rotor thickness and spacer information.

 

[260Alpine]

Barry, Capri solid rotor is 12mm. I was just wondering if the Sunbeam Alpine was the same. It could be slightly thinner or thicker and still be centered in the caliper. Plus, they use a thicker vented rotor and spacers than what we would require.

 

[hartmandm]

I have a used series IV rotor. I have no idea how many miles it has. Its width measures 0.385"

Mike

 

[Barry]

Barry, Capri solid rotor is 12mm. I was just wondering if the Sunbeam Alpine was the same. It could be slightly thinner or thicker and still be centered in the caliper. Plus, they use a thicker vented rotor and spacers than what we would require.

The Alpine is based on the 1945 Hillman platform, so I don't think that any dimension is deliberately an increment of 1 mm.

Based on my measurements of available rotors, I suspect that the nominal Alpine rotor thickness is about 0.500".

FWIW, the "offset" of the Alpine rotor is about twice that of the early Maxima rotor.

 

[260Alpine]

Thanks, Mike and Barry!

 

[260Alpine]

I'm also looking at Honda Accord (10.2" diam.) and Nissan pickup 6 bolt (9.84 diam./same as Maxima).

 

[260Alpine]

Pics of Honda and Nissan pickup rotor:

 

[Alpine 1789]

Based on my measurements of available rotors, I suspect that the nominal Alpine rotor thickness is about 0.500".

I looked for the new thickness years ago and couldn't find any reference to it. I have seen the 1/2" estimate before and it is also the best guess I have been able to come up with.

 

[260Alpine]

I know the MGB is only around 3/8". The V8 rotor was 1/2". I found an old thread, where new Alpine rotor was 1/2"(12.7mm).

 

[DanR]

Jim, I just went out to the shop and measured three different disc, they are all within the 1/2" thickness: To be more exact one was .474 one was .425 and one was .4695

Hope this helps, And keep up the great work! Now for the rear disc? I like 15 inch wheels

 

[260Alpine]

Dan, I like the rear disc setup Bill Blue saw on the BritishV8 site.
http://forum.britishv8.org/read.php?7,60945

For larger 15" wheels I'd try the larger 10.88" diameter Nissan V6 4X4 rotors for the front. Maybe the MGB caliper (same bolt pattern as Alpine) spaced to fit, modified for the larger Jag pads:

 

[260Alpine]

There is also a 98-04 Nissan Frontier/Pathfinder rotor that is 10.2" diameter:

 

[Bill Blue]

Dan, I like the rear disc setup Bill Blue saw on the BritishV8 site.
http://forum.britishv8.org/read.php?7,60945

For larger 15" wheels I'd try the larger 10.88" diameter Nissan V6 4X4 rotors. Maybe the MGB caliper (same bolt pattern as Alpine) spaced to fit, modified for the larger Jag pads:

If your car has stock(ish) front calipers and rotors, I would stay with the smaller rear rotor. I used something very close to this setup with my big (2.5" X 11.25") fronts, and it seemed too small. But when I upgraded to 2nd gen Miata calipers with 10.5" (I think) rotors and had w-a-y too much rear brake. Had to install a proportioning valve and adjust pressure down almost to its limit.

Alpines don't need much rear brake.

Bill

 

[260Alpine]

Bill, That rotor was meant as a larger front brake option. I forgot to put front in the thread. I'll fix it. I like the rear setup on the BritishV8 site. The larger 240sx rear brake he mentions in the rear brake thread would compliment the larger front brake I mentioned.

 

[260Alpine]

The MGB caliper has the same size(54mm) piston but the larger size allows it to be machined for a much larger pad.

 

[phyrman]

My rear disc brakes are from a Mustang, not sure as to the year, I can find out.

 

[Barry]

The MGB caliper has the same size(54mm) piston but the larger size allows it to be machined for a much larger pad.View attachment 9718

What advantage does the "much larger pad" provide?

 

[260Alpine]

Barry, It will last longer and stay cooler. Also the larger caliper is for a 10.75" rotor. I think the Nissan front V6 4X4 rotors at 10.88" would work well for larger brakes to fit in the 15" wheels. The caliper spacer would be towards the inside instead of centered like the Capri/stock Alpine caliper. I'm just trying out ideas until I retire in 22 months.

 

[Barry]

No doubt that a larger pad will last longer. Pad compound has low thermal conductivity and low thermal mass, so I doubt that increasing the pad size will result in any significant temperature reduction. The way to reduce pad temperature is to reduce rotor temperature and the way to reduce rotor temperature is lots of airflow over / around / through the rotor.

"Big brakes" may stop faster, but the amount of heat energy produced is a function of the change in velocity and the mass of the vehicle; not the size of the brakes.