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Howdy,

 

Finally going to get my poop in a group and put out a thread on the front disc brake project I've been working on for what has to be 5yrs at least now.  I know this isn't for everyone and just like those bearing holders I posted earlier I don't really feel comfortable with putting this out for sale due to liability.

The basic components are

Nissan 87-94 R32 Skyline 4 piston calipers

IMG_2118.thumb.JPG.83e37bf6484ad231c300b85af48f3fd1.JPGIMG_2119.thumb.JPG.d39a47d0ad4f50830365bcc685092f93.JPG

1971-76 Riviera/73-87 C-10 HD front rotor and hub units, note it has to be the HD model of C-10 since they need to be 1.25in or 32mm thick

100-20750_450.jpg

66-70 Riviera/65-70 Fullsized "symmetric" front spindle

IMG_0108.thumb.JPG.8a181f013d5b1f4ba98b8d5ff167c2c9.JPG

Suitable wheels, in my case the 67-70 specific disc brake wheels

IMG_0020.thumb.JPG.840b0c657f759e28a5c5f35c3f067d4f.JPG

 

I choose the "symmetric" spindle since it allows you to bolt to the unused leading edge holes.  Obviously something has to bridge the gap between the caliper and the spindle.  

IMG_0109.thumb.JPG.dccc763e40907eda1aab7986d6697449.JPG

Edited by CTX-SLPR (see edit history)

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To fit inside of 15in wheels, that 12in rotor is pretty much as big as you can go, definitely so with the fixed 4-piston calipers that I prefer.

 

Fit the caliper up in free space with some bailing wire to hold it to the rotor and spindle, then slipped some cardboard under the caliper to hold it off of the rotor and bring the pads to the edge of the rotor for maximum bolt clearance to the spindle.

IMG_1238-1.jpg.418ba24b605f69b286caf91ec48caff9.jpg

 

One of the bolt holes from the calipers is pretty much going to end up under the spindle body.  In this picture you can already see the start of a 3/8in plate steel bracket I was working up for the adapter.

IMG_0115.thumb.JPG.d6ed3b9bbedb46430bc5ecb7b567723b.JPG

 

There isn't much clearance between the stock wheel cylinder boss and the back of the rotor, only 3/16in.

IMG_1243.jpg.a8f1d40782916845563e32988047bb27.jpg

 

This meant I pretty much had to machine down the boss 1/8in to it would have enough room for a bolt head since machining the spindle is cheaper than buying a counter sink and the more specialized 9/16-18NF counter sunk cap screws.  Overall that means I have one plane on the lower boss on one face of the 3/8in thick adapter, a middle plane 1/8in deeper for the caliper bolts, and a final 1/8in off of the backside to fit the upper bolt into.

5a811f967f41b_Caliper_Bracket_FinalRight.JPG.d8887fc4c88e4ac9e9022a43cb4a1c38.JPG

I had the parts water jet cut off of the CAD model I designed but only the 2D bulk part was cut and I had to machine the rest.  You can see in the rendering the three different plane as well as that ball mill clearance for a stiffening rib on the caliper mount.

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Fast forward a lot of time since I've moved three times, and traveled a ton in my current job and I've finally wrapped up machining the 3D features into that bracket and getting it all fit up.

IMG_20180209_184746469.thumb.jpg.b1c50d36be1a8e62d802bbc907b87434.jpg

 

I did end up having to rethread the weird M13-1.75UF threads into 1/2-20's so I could actually get button head fasteners but it fits.

IMG_20180209_184802020.thumb.jpg.38fbc5d96e1e03f2674b7450b8e1762e.jpg

 

The caliper almost clear the wheels without a spacer but I didn't want to grind any on the stiffening ribs so I went ahead and just got a pair of 1/8in spacers off of eBay to hold the wheels off just a bit more.

IMG_20180209_184819157.thumb.jpg.b8b83edab7c4d3154da6cd313f928e7f.jpg

 

Here it is from the front side

IMG_20180209_184854098.thumb.jpg.869e0ad91dc63cdffa12dad198890816.jpg

 

And a close up of the adapter on the back of the spindle

IMG_20180209_184923641.thumb.jpg.508213cf50826ea4f0263651d5ae2451.jpg

 

And a final picture with the raw adapter blank

IMG_20180209_185016730.thumb.jpg.d051062929a15c3e95aba8bcf64875d2.jpg

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What's left

 

Mostly cosmetic work cleaning up the wheels, spindles, and brackets before prime and paint.  Functionally I need to bend and mount the hardline adapter to bridge to the braided steel flex lines and then install them.  Oh and I have to do the machine work on the other side but that I have mostly figured out so it's more execution vs. figuring it out.

 

Cosmetically I am considering machining the NISSAN off of the calipers but road wheels don't really show much so I'm not sold on doing that since it does slightly dampen the value of the calipers if I resell them later.

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Interesting conversion, I like that kind of inventiveness. I hate 4 piston calipers though, the pads never seem to wear evenly.

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For those that have gone with a disc conversion, how much better does your car really stop? 

 

Before I got the Riv, I was expecting atrocious stopping from the stock drums, but I can honestly say I haven't had any braking issues (yet).  So while I purposefully don't push the car (its a cruiser, not corner carver), I am wondering how big of a difference would one realistically see with discs.  Would any improvements be in shorter stopping distances, better fade resistance (since discs are vented far better), or a combination of both?  Or is it more a function of the tires of the era that simply didn't have the grip to stop the car regardless of the brake-tech being used? 

 

 

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I had a 63 Riviera as an almost daily driver back in the early 90's. I recall the stopping power was excellent with the stock drums. The 67 and 68 Cadillacs with stock drums I had before the Riv were almost as good. I don't know if such a conversion will make enough difference.

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The biggest difference is heat fade resistance. Drums can stop great the first time but they lose effectiveness with repeated short term use. Discs are also much more resistant to water fade.

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You're right Tex. I've had that issue on other cars like those with drums and no power brakes such as my 56 Ford. I never noticed any fade issues driving the Riviera or the Cadillacs in L.A. stop and go traffic back then.

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That's why Buick made their front drums 12" in diameter and 2.25" wide, made them from heat transferring aluminum, and put cooling fins on them.  I guess when I can't have drums relined any longer and a disk brake conversion is the only remaining alternative, I'll make the swap.  But that probably won't happen in my life time given my age. 😊

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Somewhere along the way, my cousin and his wife both learned to brake with their left foot.  They have a tendency to ride the pedal. For them the disk brakes with their less chance of fade is a good thing.

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The stopping power off the 12“ front drums is great compared to my 11“ drums on my 1966 Chrysler 300. I‘m more concerned about the front to rear power balance , which is about 56/44. My Riviera has always blocking rear wheels already on light breacking maneuver at a pedastrian crossing with a squicking sound like an emergency break, making people scared.

I will convert to a dual master cylinder for Safety reason and a manual adjusting valve für the rear break circuit, but I will stay with the original drums, because they seem to be adequat in Performance.

 

Frank

 

 

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This project isn't as direly critical as I once thought it was.  Since I've done some other work on the brake system, namely changed out the master to admittedly a disc unit and shortened the pedal ratio, the original drum brakes have been working much much better than they originally did when I couldn't get them to lock no mater how hard I tried.  I'm still going for discs since my goal for the car is something more canyon carver and backroad blaster.  I hope these things will be just as good if not better than the stock AlFin drums and will set the stage hardware wise for my later plans for more performance oriented wheels and tires that will allow even bigger brakes.  Sizing wise I'm taking my cues from HiPo SUV's that have popped up recently such as the Porsche Cayenne and the Jeep Grand Cherokee SRT8.  But this is down the road a bit.

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One thing no one ever thinks about, if using cast iron calipers & rotors, is the added unsprung weight. Makes a HUGE diff. in ride & handling. Put forged aluminum wheels on with the same tires over ANY steel wheel & one would be AMAAZED at the diff. One reason the aluminum drums are so hard to find in good shape is because us roundy-rounders used up so many. We would scrounge the yards for as many as we could get. Of course at the time they were like $10.00-$15.00 each. For our purposes they were BETTER than disc brakes because the cars handled so much better. Everyone is driving themselves CRAZY converting to discs which in MANY cases is not NEC. in my opinion the way MOST are drivin' today. YES, I have them on my '64 Riv. since the late 70's, but the way I drove my car then I NEEDED them, especially rat racing with Healy's, Alfa's & other foreign exotics. They couldn't believe how well the car handled & braked, especially when I passed them on the outside doing a four wheel drift. It would most times freak them out.  If EVERYTHING is working correctly in the 1st. place, with quality linings etc. there's just not a lot that can be improved upon.

Just my thoughts on the subject.

 

 

Tom T.

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Opinions wanted.

 

How many think that a disk brake setup on a first generation Riviera is more of a bling factor than a true improvement in braking performance?  No considerations for canyon carving, just day in day out daily driving.

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1 hour ago, RivNut said:

How many think that a disk brake setup on a first generation Riviera is more of a bling factor than a true improvement in braking performance?

Forced, and only forced, to make a choice, I would do the disc brakes before putting an LS SBC in it. Superfluous modifications, both.

 

20 minutes ago I was sitting in my '64 Riviera tucked in the warm garage. "Bling" for me was spitting on my finger and rubbing the horn bar to a nice shine.

Bernie

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7 hours ago, RivNut said:

Opinions wanted.

 

How many think that a disk brake setup on a first generation Riviera is more of a bling factor than a true improvement in braking performance?  No considerations for canyon carving, just day in day out daily driving.

Necessary, at least in So Fla.  Way too many idiot drivers and population density.  If this was asked 10+ years ago, my answer would be different.

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Your steering wheel and a modicum of attentiveness will get you out of more situations than will disc brakes.

 

If you're involved in that many near misses, maybe you should modify your driving style instead of your brakes. ;)

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Can't be any worse than Los Angeles even 25 years ago on both counts and I didn't have anything too close for comfort. What helped me drive more carefully was I had no seat belts in the Riv.

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In the late 1980's I was sorting out an early cogeneration project for Xerox in the Los Angles area. We took the freeway down to Huntington Beach one evening. I will never forget seeing a set of brake lights come on way up ahead of us and the the sequence of lights from every car between create this big wave of light coming toward us. It was, like, Wow, for a country kid. I'd say you have a lot of time to prepare for braking on the L A Freeway. Lots of preparation time for the attentive.

 

I just got back from a coffee break at the other end of town with my four wheel disc brake '94 Impala. I don't remember pulling into the driveway and breathing a sign of relief that they were able to withstand multiple panic stops without fade. In fact, I can't remember locking up the brakes on any of the disc brake cars. Maybe it's me.

Bernie

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20 hours ago, telriv said:

One thing no one ever thinks about, if using cast iron calipers & rotors, is the added unsprung weight. Makes a HUGE diff. in ride & handling. Put forged aluminum wheels on with the same tires over ANY steel wheel & one would be AMAAZED at the diff. One reason the aluminum drums are so hard to find in good shape is because us roundy-rounders used up so many. We would scrounge the yards for as many as we could get. Of course at the time they were like $10.00-$15.00 each. For our purposes they were BETTER than disc brakes because the cars handled so much better. Everyone is driving themselves CRAZY converting to discs which in MANY cases is not NEC. in my opinion the way MOST are drivin' today. YES, I have them on my '64 Riv. since the late 70's, but the way I drove my car then I NEEDED them, especially rat racing with Healy's, Alfa's & other foreign exotics. They couldn't believe how well the car handled & braked, especially when I passed them on the outside doing a four wheel drift. It would most times freak them out.  If EVERYTHING is working correctly in the 1st. place, with quality linings etc. there's just not a lot that can be improved upon.

Just my thoughts on the subject.

 

 

Tom T.

I'll weigh the stock setup and this setup with the spacers when I get them completed.  I'll leave the wheels out of it as the weights of the steelies and the road wheels is something I suspect is either covered or close enough to equal to not matter in this case.

 

For me I intend these to be more than bling, I intend to use them and their eventual replacements/upgrades.

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