This time, the knowledge post is all about the optional Sumitomo "MK63" / FIA / Nismo / Competition / Sports option brakes. I chose this topic, because people often contact me to ask about these, and I thought it might be helpful for some of you.
This post is focussing on the Nissan / Datsun S30 chassis Sumitomo MK63 brakes, but there is also a lot of useful information for other MK63 users / owners.

Disclaimer:
As with all my knowledge articles, I tried my very best to get all information from trustworthy and official sources. However, I cannot guarantee that all information is 100% correct. If you have any correction, input or additional information, I appreciate it if you let me know. I’ll update this post whenever I find something to add or change. I am not a professional journalist, but I put countless unpaid hours of work and years of research into this post and spent quite a bit of money to source a lot of original factory documentation, so please ask, before you copy anything. Thank you.

Nissan USA Motorsports Catalogue 1987. MK63-20S brakes installed on the optional adjustable competition S30 struts.

The Sumitomo group is a Japanese conglomerate, that makes all kind of industrial items and is also involved in energy and financial business.
However, the Sumitomo rubber co. branch, most known for their "Dunlop tire" brand (and maybe also their golf balls), also made brakes at one point.

Photo from the 1984 NISMO catalogue

According to some sources, the original MK63 design was introduced by the British brake manufacturer Girling, and then was licensed to Sumitomo Japan.
The first (Nissan) car equipped with those brakes was the 1965-1973 Nissan President H150. Kudos to Roy for confirming this information and the picture from the Japanese H150 President FSM:

Another early example I found was the 1967-1971 Nissan / Prince A30 Gloria sedan/wagon. As seen here in the PLA30-U Export sales brochure, which I found on a Minkara page, showing the MK63 solid disk type brakes front and drum brakes rear:

Nissan/Datsun used those brakes in all kind of cars, either as factory brakes, or as optional / competition brakes and even in their works racing cars in all kind of setups - from luxury sedans, to quirky hot hatches, to purpose built rally cars. I once had a customer request for an 1984 ex-Factory Group B rally Nissan 240RS with MK63's on the rear, as seen here in a 240RS from NZ (Picture from WRCGRB240TS.web.fc2.com)

Here is another example of the MK63 for a different car, from the September 1986 NISMO catalogue.

The same brochure lists the MK63 calipers for various Nissan cars: B2x, B310 TS, PA10, BS110 (240RS), N10, ...
But Note: The calipers all have a different part number, so I guess they're all slightly different and probably not directly interchangeable. Some MK63's were even offered with additional parts such as modified dust protection panels, etc.

Sumitomo already made and supplied the factory "S-16" dual-piston front brakes for all the Datsun 240Z /Nissan Fairlady Z S30 versions (including Z432(-R)), as shown below in the Japanese "S30 introduction" Service bulletin. It also mentions that similar S-16 brakes were used on the GC10 (Hakosuka) Nissan skylines:

As my 1973 Japanese S30/HS30/PS30 parts manuals state, the MK63 brakes were never factory installed on any public available S30 car, including the Z432(-R), and they were never listed in the official Parts manuals or microfiches.

After the experience with the MK63 brakes as optional racing equipment on the PGC10 "Hakosuka" Skylines, Nissan decided to also use and offer them as optional / competition parts for the S30 Cars and also used them in their factory backed racing cars, as seen here (vented version) in an Ex-Works 1971 RAC Rally car (Picture from Nostalgic Hero Magazine Vol 118)

While there are many aftermarket and Frankenstein brake options for the Z, the Sumitomo MK63 can be considered the most period-correct and most factory-spec "sports" or "racing" brake system, if you're into historic racing. It's also the most "stealth" and factory-looking option if you want to upgrade your brakes, but the government in your country doesn't like you to... or if you want to keep "historic" registration in some countries and fancy modern brakes are not an option.
If you're not into historic racing, there are better racing brake options with more modern design. While the MK63 aren't bad and almost double the brake-pad area over Standard brakes, they're known to flex under high pressure. To be honest, even the standard S-16 brakes are not really bad (A local Hill climb racer still uses them and says he's happy after upgrading to steel-flex hoses and better compound pads), but they tend to get thermal brake fading quite fast under racing conditions.
October 1979 Japanese (G)RS30, (G)HS30 sports option catalogue (included "English" typo):

The Name "Sumitomo MK63" is visible in the casting (Manufacturer and Model) on all MK63 brake calipers. I guess the other cast numbers are some manufacturing lot or production date codes ...

The term "MK63" was used in various catalogues officially, but because it's FIA homologation (see later also), the brakes are often also called "FIA-Brakes" in North American optional parts catalogues, as seen here in the 1976 USA competition parts catalogue:

Due to the fact that they were sold by the official tuning / competition parts arms of Nissan, the brakes are also known as "Datsun competition" and later "NISMO" brakes.
(Picture from Spirit of Sykline website):

Here's a screenshot from the NISMO online catalogue from 2016. The same page can be found in the 2007 printed version of the "NISMO competition" Catalogue (Not in the 2007 NISMO "street" catalogue)

Since Sumitomo later became "Dunlop-sumitomo", the MK63 brakes are sometimes also referred to as "Dunlop MK63" brakes, as seen here in the Nissan BS110 Competition tune-up manual.
However, I've never seen the "Dunlop" or "-20S" terms used in any of the S30 specific factory documentation.

While there are some different versions with odd mounting and / or bleeder nipple positions and angles, there are two versions that were officially sold for the S30 chassis:

• In the above picture, you can see that the brakes are called MK63-20S, which is the vented disk version (20mm disk thickness) and Straight bleeder nipple position. (Sandwiched between the two bolts)
• Then there is a very similar, but slightly narrower version (just called MK63), used for solid type (factory S30 type) disks.
  See both versions here listed as FIA brake systems for stock rotor or vented rotors (left page):

The vented type disk seems to have been introduced as a Sports option just in 1973 as the January 1978 American "sports option" catalogue states that some disks were used on 1973 models (see picture below). However, I'm not really sure at which date the vented version was introduced for sale. I have no catalogue older than 1978 listing the vented version officially for sale (see various pictures on this page):

You can clearly see the (vented, 20mm) MK63-20S brakes are homologized in the FIA Fiche No. 3032 by JAF (Japanese automobile federation) and FIA. If you look close, you will see it's only valid for Group 4 racing and clearly marked as "not valid for group 3". (The group 3 version of the fiche still shows the factory S-16 brake calipers installed!)

Here's the updated 31. January 1974 version of the 3023 FIA fiche with slightly changed (Corrected?) measures. It also says "modifying the dimensions of the brake rotor" and has different part numbers, compared to all the ones in the catalogues. The rotors listed below are listed as "used on 1973 models only" in the USA Sport option catalogues.

That updated version of the FIA Fiche also lists an MK63 rear disk conversion option with adapter plates, backdated to cars from October 1973, as seen in the picture below. However, in all my option catalogues - both Japan and export versions - I haven't seen this rear brake conversion officially for sale. It's also not listed in the Nissan Race and rally preparation "Yellow book", so this might have been a homologation purely made for Nissan factory race cars and was never available to the public.

On an interesting side note, I found this Information from Alan Thomas online:

What happened was that Nissan used the MK63-20S on its Works race cars right from the beginning, including the first official race entry for an S30-series Z when the Works 432-R entered the All Japan Suzuka 300km race on 18th January 1970 (that famous no.68 car used on so much of the 432-R specific literature). Nissan actually used the technique of 'back homologation' to legalize the calipers for race use. They applied for the evolution in June 1970, but backdated the amendment to be valid from 10th January 1970 - hence covering all the races they had already entered up to that point, including the 432-Rs first race.

Here you can see some measures (From the old Nismo web catalogue, offline now) from the MK63-20S version that fits the S30 chassis:
However, the dimension of the rotor diameter does not fit together with the ones in the FIA Fiches. Not sure what is wrong here, or if my interpretation is wrong?

As mentioned above, the FIA homologations list several different sizes, which is a bit confusing, and I'm not entirely sure which is the correct size. But if you keep the stock disk diameter, that should be fine.

Here are some measures of my sold disk type calipers:

And here is one with a measurement from a vented type -20S version, which I found on Yahoo auction. Both this and the one above are some random measures, but I thought they might still be interesting for some.

While usually only the complete calipers, pads and some required bolt-on parts are listed for sale, The (later version) Nissan motorsports schematic catalogue shows all the single bits and pieces. The drawing shows the vented type caliper, according to the shape of the Pads, but the part list below shows both options:

Parts list (from the same Nissan motorsports schematic catalogue):

Left 2x my MK63 Solid disk type, right the standard 240Z S-16 caliper for comparison:

Solid (left) vs vented (right side) disk type MK63 calipers (Pictures by Kats, more here)
They're almost the same, except the wider space for the wider disk and different pad design.

Roughly translated from my Nissan "Race and rally preparation Manual" book.
According to the only part numbers of this manual (see more pictures later) this is for the solid disk type calipers (vented are not listed?), but it might be possible that later versions of this book also listed the vented type calipers...

Translation:

First the weight of the standard S-16 dual-pot Sumitomo brake caliper (including newish pads, the short brake-line and some additional red paint) for comparison: 4,435 kgs:

Here are two Photos picture from Roy Geris with the weight of a Vented MK63-20S / NISMO caliper with all the hardware but without additional Pads showing a weight of 3,789 kgs and one including a set of pads, showing 4,4kgs.

Thanks a lot to Christopher for sharing this picture of his solid disk type calipers on the scale with full HW and pads, showing a weight of 4,52g kgs, slightly heavier than the standard S-16 Brakes with full Hardware:

The pads have two different shapes, depending on if they're for solid or vented type.
(Picture from the later version Nissan Motorsports Schematic catalog)

Here's a comparison between the S-16 standard pad (left), MK63 Vented rotor Pad (center) and MK63 OE rotor pad (right) From the Nissan USA motorsports catalogue 1987:

There were different sets of each type (Solid or vented type) available with different compounds as seen in the picture below:
M33(S) - Soft (Sumitomo)
M59(S) - Medium (Sumitomo)
M28(00) - Hard (Sumitomo)
DS11 - Racing compound (Ferodo)
If you check the various option catalogues on this page you'll see the exact naming and part numbers often varied depending on the year and Catalogue you're looking at.

If you still have factory pads, you can see the compound type embossed on the back of the pads as seen on my M59(S) solid disk type pads here:

New pads also have color markings on the top, for easier identification of the installed compound type, as you can see in the following photos:c

The Solid type disk is the very standard factory installed disk used on the S30, as shown here in the European parts microfiches. Strangely the one in The FIA fiches has part number
40206-N3121

The Vented one has Part No 40206-N3120 (Both left and right)
However, the 1978 Sport option catalogue (See picture above), mentions that Part No 40206-E4621 was used for 1973 cars.

To connect the hydraulic brake lines to the calipers, there was a nice cast alloy angled connector and a steel "Banjo" through-bolt, drilled for fluid passage. Since it's difficult to find, these days, most users go for modern connector solutions instead:

Note that little nipple on the angled connector - it will fit into a slot that was only cast on the President calipers, but not on the "sports option" items:

Early variants of the MK63's used a check-ball style bleeder nipple, which was inherited from Girling / Dunlop. They can be troublesome, as the ball rusts and gets stuck in the hole. Once you get the ball-bearing ball out, it leaves rust deep inside the bleeder orifice and needs careful cleaning to avoid damage to the sealing point.
It's not clear when, and on which models exactly Nissan changed it to the more conventional "pointed" style bleed nipple, but some later versions came with the improved variant:

Be very careful when buying MK63's from unknown sources with a vague product description, such as Yahoo auctions Japan. Aside from the many replica parts (see listed below) there are also 3rd party replacement units. But even the Sumitomo built MK63's were used on a variety of cars as factory or optional parts and some of them had slightly different designs. Make sure to get the right ones for your car. Especially look at the bleeder nipple position and angle and the mounting hole positions. According to the Race and rally preparation manual pictured below, even the ones used as an option in the GC10 skyline is slightly different, but can be used for the S30 cars. I cannot tell the exact difference, but I recommend having a good look at all the details before you pay a fortune for something that doesn't fit.
For e.g. the standard Nissan President MK63 has the bleeder nipple diagonally, while the bleeder nipple on the "Sports option" calipers are straight.
If you use the President's MK63 in an S30, an additional spacer is required so that the nipple won't scratch the original 14" wheels.

If you got the MK63 brakes with the correct fittings for your car it's basically an 1:1 exchange. The following is a translated quote from the Kameari website:

It is a high performance caliper that can be installed easily without special processing. It can fully cope with genuine master cylinder capacity. There is no size restriction for aluminum wheels. Most 14 inch or larger wheels can be installed.

As the US-based Competition catalogue in the picture below says (see right column), the vented disk type MK63 Brakes need a later style Hub assembly (10202-N3426) when installed on 240Z's manufactured up to July 1973:

Scan from my Japanese Nissan "race and rally preparation manual", with a loose google translation:

As the competition catalogue hints, the MK63 brakes are installed without the original Brakes backing plate (Dust protection shield). Due to the bigger dimensions of the MK63 calipers (compared to the original S16 calipers), the Brakes won't fit into the original backing plates cutout. The "Z432-R & 240Z Race & Rally preparation manual" lists a set of special "Baffle plates" that fit the MK63 calipers (first two part numbers in the list below). In 2020, I checked with Nissan Japan and they're NLA.

According to Some sources there is even a Manual (By Nissan / Datsun?) Pointing out how to modify the original S-16 backing plates to fit the MK63 brakes. But I was not able to find anything in my collection of documents or anywhere else. Even my sources in Japan were not aware of something like that existing.
But you can easily modify your standard S16 Backing plates to fit the MK63 calipers, as shown below. Note that early Cars had different backing plates with an additional "Air scoop" to additionally cool the S-16 brakes (As the Japanese S30 introduction bulletin says). I have not tested it, but this might also be an interesting option (Which also needs modification to fit).

Fitment of unmodified backing plate with the standard 240Z S-16 caliper:

(Non-)Fitment of the unmodified backing plate with the MK63 caliper:

Modified Backing plates with bent edges for the factory look (Pictures by JLPurcell, original thread here):

Completed, powder coated and installed modified backing plate with MK63 calipers:

As you can see in the Japanese "Sports option catalog" from 1971, there was also a set of bigger rear drum brake wheel cylinders for sale, which was meant to be used with the MK63 to have a better braking balance. Now with the improved front brakes you can improve the rear brakes with the bigger cylinders. However, I've read that most users run them without the bigger rear cylinders, and it's perfect for street and mild sports use. Consider using bigger rear brake wheel cylinders only for professional racing, where brake balance f/r is a seriously important thing.

By now (late 2017) some parts (Brake lines, piston kit, etc.) were still available by Nissan Japan and / or Pitworks. Nismo once even listed some overhaul parts in a PDF on their website (which is now gone):

Seal kit (Pitworks): AY600-NS053 (Picture by Amayama.com, see the same kit packed, in next picture)

Here's what I got from Nissan Japan a while ago:
Brake lines: 46211-79918 Bolts: 41128-G0310 Seals (Copper): 46273-A4600 Pistons: Part No: 41122-68200

A while ago, I was able to buy a set of brake pads (for the vented type calipers). Which I just bought because of the shims, which I needed for my brake restoration.

This list is by far not complete, but I browsed the most popular Japanese manufacturers to find some replacements for your worn out parts:
Project-Mu (Left Solid disk type, right vented disk type, from the P.MU website):

These are the ones I got for my solid disk type calipers:

ENDLESS Japan also offers some pads. I found this old catalogue pages online, but I think they're obsolete.

After talking to sales people at Endless Germany, they told me that the correct type for the vented type is the EP006. The measures seem to be slightly different in the two drawings. But the overall shape seems to be pretty close. 

And this is what Pitroad-TS (Japanese specialist for Vintage sunny racecars) offers for the MK63 (Pic from their website).
They seem to have the same shape as the EP006 drawing above end are made by Endless:.

Spirit Garage Japan also sells a set of "street type" Pads for the vented and solid type:

ACRE Japan also offers MK63 specific S30 Fairlady Z Pads. But unless the listed specs on their website I wasn't able to find more information or pictures:

Kameari Engine works also offers their "K2" Pads range for the MK63 on the S30/S31 chassis:

For the Stock (unvented) brake type you can choose from a wide range of after market disks for your Standard HS/HLS30 car, for example DIXCEL Japan (screenshot of their web-catalogue):

Here's my set for the standard brakes (Solid MK63) with optional black painted hub:

Or basically any available after market stock replacement disk, like shown here by Rockauto. However, If you intend to use them for racing, I recommend to use at least a well-known performance brand disk and not the cheapest no name rockauto option.

Victory50 (Japan) has a wide range of disk options and parts (even a size-up kit) for the MK63. (Picture from their website)

Kameari Engine works offers a complete (probably used) MK63 calipers and a range of disks for the S30Z and other MK63 applications (Picture from their catalog):

Another Option for a wide range of MK63 (and upgraded) disks is Rubber-soul Japan. Some of their disks are made by Dixcel (See above)

Also, Mspeed (Japan) Offers a range of MK63 disks, but doesn't mention the manufacturer:

Victory50 seems to sell a last stock New now out-of-production Sumitomo MK63 calipers. According to some information they were a last run produced by the same manufacturer that supplied them for NISMO at the end of their production (Not sure who that was).
Picture from Victory50 Website:

But I've seen several MK63 vented  (as far as I know) type, complete replica calipers for sale. Mostly recognizable by the golden color (probably yellow zinc passivated). I'm not certainly sure who is the manufacturer (I guess M.speed Japan).  They seem to be available at a variety of shops in Japan but also https://jdm-car-parts.com/ seems to offer them (Picture from their website):

Also Kameari Engine works has a selection of MK63 replica parts.

A Japanese Company called "DTM" now also makes replica "MK63-Kai" calipers (Both solid and vented), but you can clearly see the difference at the plugs positions and the additional brake fluid tube that goes from one side to another. They're shown mounted on a Laurel C130 on their website, so I guess that's what they're based on and thought for.
They state that their product is different from the gold-plated ones shown above. All the original "Sumitomo" and "MK63" casting has been removed on their product and there are a lot of details that are different if you look closely. The external fluid line is (according to their website) "for easy maintenance access" but i think it's more because it was easier to cast it with external fluid lines? Probably still a great solution if you own an old Nissan / Datsun Sedan and need replacement calipers. The more I researched, the more options I found. The list here is not complete and is just here to show you a few options.

Endless brakes Japan offers full replacement kits for the MK63 brakes in various versions with a caliper called S4F.
EG 4 BMK 63 S (General MK63 kit for solid rotor, without brake lines or disk)
EG 4 BMK 63 V (General MK63 kit for vented rotor, without brake lines or disk)
EG 4 US 30 (complete kit for the early S30 version)
EG 4 US 30 A (complete kit for later S30 version)
See link above for all specs (including weight, etc.). Picture below courtesy of Nengun

Here's an add from Endless for their replacement kits from an 2024 Nostalgic speed magazine. Which also states its only 1/2 the weight and a much higher rigidity compared to the original MK63 caliper thanks to forged Aluminum.

Another kit is available by the famous Japanese Z-Tuner Starroad. It's a complete kit designed specifically for this car, and is available in various colors with both street or Sport pads available.

If you buy your MK63 second hand (I got mine from yahoo auctions Japan), you never really know what you get. I highly recommend rebuilding them before usage.
Many spare parts companies offer overhaul services for used calipers, but I did it as shown below:

1. Complete Disassemble (I recommend pressing the pedal when the calipers are still installed with pads removed, but you can also use an air compressor to remove the pistons once the calipers are removed, but it will be difficult to remove the second cylinder once the first one is out...):

2. I Cleaned all the small parts in my parts tumbler (picture also shows other parts, don't get irritated):

3. Had all the bolts and bits zinc-plated and yellow passivated (As it was from factory). The shims however didn't end up nicely, so I bought a set of old MK63 pads from yahoo auctions to get a new set of shims...

4. When having the calipers disassembled, make sure you grease the machined surfaces to prevent them from corrosion.

5. As the name suggests, use brake cleaner to clean the calipers from old dried grease and dirt. Additionally, you can have them soda-blasted for a shiny surface.

6. Although not very common, the brake calipers can be honed similar to the Cylinder bores in the motor blocks to make the surface smooth again and ensure perfect Operation. Factory seals can be reused, since honing only removes minimal surface material. A DIY-tool can be bought cheap, but if you don't have experience, it may be better to have a specialized machine shop do the work.

I talked to a few machine shops and most of them replied that it's tricky to hone such a short-stroke area with above tool or a professional honing machine. They usually just polish the area with a different tool and a soft polishing tip.

6. For cleaning, use brake cleaner or a parts cleaner to clean it thoroughly. If it has paint or varnish you'd like to remove, I do not recommend any abrasive blasting like sand blasting. Dry-ice blasting or even soda blasting might be it to remove additional layers without damaging the original layer. You may want to speak to a specialized blasting company how to do it.

7. Originally, the MK63 which I've seen so far haven't had any coatings, just plain gray cast iron. If you'd like to protect the calipers, I recommend giving it a non-glossy clear coat or probably something like RAL 9006 "white aluminum" type color. But your painter or powder coating specialist might be helpful. After talking to an expert, he told me that he recommends having it painted rather than powder coated. The calipers are in an area which might be hit by small stones a lot and powder coatings tend to chip more than a specialized, softer but also heat-proof brake caliper paint mixture.

My restoration ends here so far, I will update it once I've completed more steps...

8. Assemble using new seals, new pistons and brake piston grease (Pistons at freezer / calipers at oven before installation?)

Not historically racing homologated, but broadly available and much cheaper - is the Toyota Hilux / Surf Brake caliper "S12+8" which is quite common and available both in vented and solid disk type (picture from and more information here).

Thanks to Roman for measuring the S12+8 Solid type calipers (without pads) at 4,4 kgs:

Another option is the later Toyota S12W caliper, which Needs additional adapter spacers (available at Techno Toy Tuning)

• Useful MK63 thread on classiczcars with lots of knowledge: classiczcars.com/topic/56999-looking-for-a-set-of-sumitomo-calipers-mk63
• Vintagecraft-e-za (Japanese MK63 restoration specialist): Click here