best disc brakes for sbp

I just bought a couple of 11", 5 x 4" rotors off these guys. http://www.r1concepts.com/dodge-dart-1971-fdc.htm

I have been looking a while too, and am the referenced cheap Mopar b***. I have 10" SPB drums and won't go BBP since I bought $$ SBP Cragars and won't change the rear-end (or manage 2 sets of wheels). Scarebird seems the best affordable off-the-shelf, but I don't like redrilling rotors for ever and ever. SS Brakes and others are as much or more than I paid for the car, so my wife would scream (again).

I don't see a problem using 5x100 mm rotors (though few cars use them). The rotors on my 96 Voyager fit SBP with little slop. The hub register is bigger, but plastic "hub-centric" spacers come in many sizes (ebay), so might be able to center on the hub. The offset is about right, depending on how the caliper mounts. Issues are the hub "tophat" ID is slightly too small, so must file the hub OD ~0.050". If I go this way, will try reducing in place on the axle w/ die grinder (hub spins to grind evenly, don't have a lathe). Of course, I prefer not permanently changing my car. The other issue is the ~10"D rotor is slightly small. Clearing the hub OD seems to be hard (95 Camry rotors are 5x100 but small tophat).

Another possibility are the original K-H rotor, ~$38 now at PartTrain. It probably clears the hub OD (Centric doesn't give tophat ID). Biggest concern is the deep offset, which brings the rotor almost to the spindle. That could work if the caliper bolts to the inside surface of the "spindle plate". It also may give less "brake steering", i.e. tendency to turn wheel if front brakes aren't balanced. Of course, the lugs will center perfectly in the rotor holes, for those above who are concerned, but Mopar designed for "hub-center" rather than "lug-centric" anyway. Once centered, the lug nuts hold everything tight.

Re calipers, consider only those w/ a removable bracket, which are now common. I bought '95 Camry calipers since they bolt to the front surface of the "spindle plate", which helps clear the spindle. I found nothing similar in Mopar. Pre-'92 Toyota calipers also work (uglier). Ideal would be aluminum 4-pots (Brembo) from some Jaguars and special Lexus or Camry. Also Wilwood racing ones, though not sure they work w/ a 1" thick rotor. Most appear to bolt to the rear of the "spindle plate" on a fairly standard 2-bolt pattern, except Vipers and Corvettes that use a vertical bolt. A pair of new Jag front calipers went for $370 on ebay recently (not that brave yet). T-100 and 4 runners also had a 4 pot floating caliper, but in cast iron. The K-H calipers don't excite me since cast iron is heavy and I read about piston problems, though silicone fluid (Dot 5) seems to fix that. Multiple pistons are claimed to apply more even pressure across the brake pads, but are also a bigger maintenance issue. I would only use them to show off, and would therefore paint them bright red.

The tricky part is the afore-mentioned "spindle plate". This is a custom plate you must machine, or hope someone like Scarebird designs. It could be $$$ for a one-off. Aluminum is light and easy to machine, though more concern with cracking. However, the spindles on my 02 Chry Twn & Country are aluminum and the caliper bracket screws directly into tapped holes in the aluminum (no steel inserts).

Re master cylinder, I have a power one from a Plymouth breeze, mounted to '73 Duster standoff brackets. Actually, an Intrepid booster is bolted up now, but I didn't like its slanted reservoir. I only test fit on the car so far (painting). I have a '68 Satellite front/rear distribution block w/ warning switch. I assume no proportioning valve since a drum/drum car, and have a separate adjustable valve.

Finally, a few thoughts on brake design as an ME who has never designed brakes. I don't understand why people say drum brakes can't stop a car. If they can lock up the wheels, that is sufficient (actually too much, so pump them). The main problem is they can't do this repeatedly. The energy is stored once in heating the steel and takes a while to dissipate. Rotors dissipate heat faster since they move air like a fan impellor. For repeated stops like track racing or continual downhill braking, drums overheat sooner and fail (pads melt, fluid boils). Drivers shouldn't ride the brakes downhill, but since they do, the government mandated front disks ca 1973(?). Even w/ rotors, you must trade-off weight against heat storage. 11"D, 1.25" thick racing rotors may be twice as heavy as 10"D, 1" thick rotors. You may only need that capacity to brake from 150 mph. Daily driving doesn't require it. My '96 Voyager weighs more than my Dart, so those rotors should suffice. One advantage of drums is the amplifying effect as the shoes jam against the drum, so you can get by w/ manual brakes. However, if the shoe suface gets sticky they can lock up.

Will update someday if I ever realize any of these plans. I just want to trade ideas. It is drums for now.

BillGrissom said:

..The tricky part is the afore-mentioned "spindle plate". This is a custom plate you must machine, or hope someone like Scarebird designs.

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Since Vs29H1B pointed us in the right direction for these rotors, I will get a set and see what I can match it to. The OEM KH are negative in my book - many better choices to select from. Once done, I may have to offer this as a wheel kit only as not many guys are as willing to dig around as Vs29H1B is... I am also looking to make new 9" drum hubs, these will allow 5 on 4-1/2" BP too.

BillGrissom said:

Finally, a few thoughts on brake design as an ME who has never designed brakes. I don't understand why people say drum brakes can't stop a car. If they can lock up the wheels, that is sufficient (actually too much, so pump them). The main problem is they can't do this repeatedly. ...One advantage of drums is the amplifying effect as the shoes jam against the drum, so you can get by w/ manual brakes. However, if the shoe suface gets sticky they can lock up.

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As stated, heat is the biggest issue. Also, most calipers were designed to use pads that do not use asbestos, so braking power is good. Very few drums did not use asbestos - we sold a few Mustang guys that actually had their drums professionally gone thru - and ended up worse! My guess is that Ford's drum geometry didn't like the new shoe compositions...

Another factor is that drums do not brake equally - some guys told me it was a guessing game which ditch they were going to head for when hitting the drums hard.

Personally I think Scarebird deserves props for trying to come up with something affordable and listening to customers imput. I would love to get some sbp discs on Goldie.:love7:

Scarebird said:

We were told by a Mopar-only vendor a few years ago when developing this setup that Dart, Duster and especially Valiant owners are a frugal lot (he used much less polite term). We keep that in mind here. Also, I highly doubt they will clear the stock 14" drum rims.

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K-H discs are great, but expensive. Stainless Steel Brakes rebuilds them and they are good forever with DOT 5 brake fluid. As for cheap, a lot of vendors make a lot of money from so called Frugal "A" body owners. If you make a quality product it will sell. How many threads are there here, looking for a good clutch for the original 9 1/4 and 10 inch scalloped clutch setup that will hold up to a stock 273 HP. Hope you take the time to come up with a good setup for these guys. I have mine. I don't buy cheap, I buy Performance.

66fs said:

K-H discs are great, but expensive. Stainless Steel Brakes rebuilds them and they are good forever with DOT 5 brake fluid. As for cheap, a lot of vendors make a lot of money from so called Frugal "A" body owners. If you make a quality product it will sell. How many threads are there here, looking for a good clutch for the original 9 1/4 and 10 inch scalloped clutch setup that will hold up to a stock 273 HP. Hope you take the time to come up with a good setup for these guys. I have mine. I don't buy cheap, I buy Performance.

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Yep he'll have a few buyers lined up if he does come up with a good setup. (Me included)

Its fairly obvious that Scarebird has done a bit of home work over the years. That said, with the way they have gone about compiling a kit, there are so many parts and piece combinations that may work for one guy and not another. Thats actually where I am with ScareBird. I will gladly buy a product that I can tell has had plenty of thought put into it, and while I am "frugal" (scratch that, Im CHEAP), I will save for a part that I think will work for me. Whoever said that about Valiant owners is correct to some degree..... Why? Because our little cars were never that valuable, to sink 2 G's worth of brakes into. Granted there are some beautiful Valiants around, but I know my car will never see a SS Brake set, not for that price.
I think most of the guys build a car that is "custom" would gladly buy a mix and match set of parts, but again its the wheels choice issue that has held the sale of more of these Scare Bird sets.
I too have SBP Cragar SS rims that Im seriously reluctant to get rid of, and in the same breath Im considering some Mustang "Bullit" 18" rims. This being the case I have contimplated designing my own set up as well. However as stated before, its almost worth just sitting back and letting Scarebird do the homework since they have so much time invested in research already. It would take some decent cash and many hours to get to where they are now.

Bill I have given thought to your theory as well, and have agreed for a long time, that the drum brakes are plenty sufficiant for daily driving.
As far as reliabilty.... I have recently rebuilt all 4 corners and have 9" drums on the front. and 10" in the rear (8-3/4). I bleed the brakes appropriatly, then adjusted them correctly. I have been running my 40mi (both ways). commute on the interstate with stupid traffic and have yet to have a scary moment. If the system is set up the way it was meant to be, it works more than sufficiant. I am really only changing it because I hope to eventually do some auto X eventually, that and I may go to the 18" rims and it will look quite stupid with little drums. Not to mention it gets into a whole other realm once you start changing the unsprung wieght.
Point of this post: I think once Scarebird hears a few more requests (this thread) maybe it will be in their interest to put more time into the A-body scene again. I was ready to buy from them and still am, if they have a set up to fit my Cragars. As I stated before, it was supposed to be released over a year ago. Never heard anything.

66fs said:

K-H discs are great, but expensive. Stainless Steel Brakes rebuilds them and they are good forever with DOT 5 brake fluid. As for cheap, a lot of vendors make a lot of money from so called Frugal "A" body owners. If you make a quality product it will sell. How many threads are there here, looking for a good clutch for the original 9 1/4 and 10 inch scalloped clutch setup that will hold up to a stock 273 HP. Hope you take the time to come up with a good setup for these guys. I have mine. I don't buy cheap, I buy Performance.

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I agree that K-H SBP stuff used to be expensive, but not anymore.

Earlier in this thread I listed sources for Centric rotors (available for less than $50 - and in some cases less than $30 each), and Centric also sells remanufactured K-H SBP calipers for $61 each ($30 core charge).

If you factor in the cost to convert to a LBP setup, including all the suspension pieces, and moving to LBP wheels, the costs add up quickly.

I've found in all my SBC K-H abodies (I've owned 5 SBC K-H disc 340 cars since 1970), the factory stuff holds up extremely well. I've autocrossed and drag-raced my cars and found the rotors stand up well to hard use.

Brake pads - there are many sources, the best I found were from Dick at Firm Feel.

demon seed said:

I just bought a couple of 11", 5 x 4" rotors off these guys. http://www.r1concepts.com/dodge-dart-1971-fdc.htm

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I`ve used R1 too. I bought a drilled and slotted set. I`m very pleased with them. Not cheap though.

Some confusion on rotors is due to different Centric PN's. PN 120.63005 sells for $80+ and usually "not avail". PN 121.63005 that Vs29H1B references is available and cheap. Centric's website shows the later for 65 Valiant but the drawing of the earlier one (below), so should interchange. I ordered a pair from PartTrain for $61 w/ shipping in the hope I can make them fit a 10" drum conversion. If not, I'll wait til I get disk spindles & hubs, or resell.

I assume Scarebird refers to these K-H rotors. The rotor's hub register is 2.90" ID (73.7 mm). The 10" drum hub is 2.31" OD (58.7 mm). To center on the hub, Gorilla Automotive's "Hub Centric Ring" PN 74.5710 (57.1 x 74 mm) or PN 73-5920 (59.2 x 73 mm) could work with a little filing (plastic). Of course, you can also center the rotor on the studs.

Forget prior suggestion of '96 Voyager (14" wheels) 5x100 mm rotors (also Lebaron, Acclaim, etc). While they can fit over the hub and studs (grind), a bigger problem is the tophat is low, making the caliper stick out past the hub outer surface plane (where wheel bolts). My 14" SBP Cragar inside surface is almost flush with the hub. I would have to use wheel spacers to move it out ~1", and those are rare, costly, and cause other problems.

Scarebird found the K-H rotors on the 10" drum hubs don't come quite to the spindle surface, allowing room for a front-mounting spindle plate. It might be possible to fit the caliper to the drum spindle, though many other possible interferences. My 14" Cragars are 13.5" ID except within 1/2" of the hub surface where it reduces to 12.25" ID. My factory steel wheels are 13" so no discs could fit.

I would buy if Scarebird can design a spindle plate that is low-cost like his others and a bolt-up (no drill) solution. I imagine no problem scaring up 4 others. Like others, I didn't look at the earlier design because the photos on ebay and the website didn't show clearly how the caliper mounted, plus questions about the wheels fitting. I don't have a milling machine.

My preference would be 4-piston aluminum calipers (non-float). I see many Wilwood ones on ebay, with standard mounting ear spacing of late, plus adapters (~$20) that bolt to the ears. The biggest concern is that most are for up to 1.25" thick rotors so not sure would work with the K-H 0.81" thick ones. They do say the calipers work for various rotor diameters as long as the pads sit near the outer edge.

I will be watching this thread closely. I am yet another with the SBP Cragar SS wheels who would jump at the chance to buy a scarebird set-up that would work with my wheels.

Scarebird said:

I learn something new every day.

I had no idea that this rotor mounted behind the hub, ala 4WD style. That would explain the huge register. Unfortunately it would increase the complexity of a bracket by at least a magnitude... but may fit the drum poverty rim now...

Our previous version used the 1985-90 Celebrity rotor, which is 1/4" bigger in diameter than the Previa piece we use now. I wonder if our current setup clears the Cragar S/S rims? I have to admit some heavy bias against this rim, as my first car had a set that rusted damn near overnight (a real sting considering they were quite expensive at the time) and the damn things would never balance right (too heavy). But since quite a few Mopar A guys run them, I will need to find out...

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I want to thank you for all your work toward finding a reasonable solution for those that want to keep SBP.

I have seen first hand the exact same things you encountered - Cragars rusting. Back in the day (early 1970s) I bit the bullet, saved up, and bought the American Racing Equipment Torque Thrusts (the model I had - is listed on the ARE website as the "T70R" model with the different center cap and the gunmetal squared type spokes. I luved those wheels! AFAIK These are no longer made for SBP.

My memory may be a little fuzzy on the '65 Mustang calipers, but as I recall, these calipers DO NOT bolt up at all, but they supposedly may have used the same pistons as the Mopar SBP Abody factory K-H calipers. So they may be a parts source for rebuilding the Mopar K-H calipers. One other note: someone mentioned that the later 1967-68 Mustang caliper pistons worked with the Mopar K-H abody calipers, as well.

The key issue here seems to be 1) keeping the SBP wheels; 2) for those who have factory drums, keeping the drum spindles, while upgrading/bolting on discs.

Some of us have Mopar abodies that came equipped from the factory with the
K-H SBP disc setup, so we are likely to stay with that setup, as long as calipers and rotors/wheel bearings/seals remain available.

Thanks again for helping the Mopar community - much appreciated.

I received the Centric K-H rotors. The photos below show some issues involved in installing them on a 10" drum car. The rotor is shown where I think it would sit relative to the spindle. I don't have a spare hub to fit.

On a hub (drum installed), I measure/estimate 2.15" from hub face to spindle face. The K-H rotor is 1.96" from hub face to inner rotor face, putting the rotor 0.19" off the spindle face. That is ample thickness for a caliper bracket plate to bolt to the spindle face. Indeed, as the photos show, the bracket could turn inward and be enclosed within the rotor and thus be even thicker. But, for comparison the drum backing plate is 0.15" thick, so 0.19" seems fine.

The caliper shown is a '95 Camry (10.825"D rotor). The bracket bolts to the front of the spindle, which would have better fit the Lebaron/Acclaim/Voyager rotor (14" wheels) I was considering. However, for the K-H rotor's taller hat, a caliper that bolts to the rear of the spindle might fit better (90's Mopars and others). I might return the Toyota calipers and try those. If lucky, a simple flat plate could serve as the caliper bracket, though I noticed Scarebird has complicated designs for other cars that bend to pickup bolts on both front and rear of the spindle, so he could design most anything.

There is much more to the problem than axial positions. The inner face of the K-H rotor is shown. While the rotor hat ID clears the drum hub's 5.50" OD, there is a machined counterbore 0.1" deep that is only 5.188"D. I don't know if just on the Centric rotors. I thought the only thing that touches the inner side on the disc cars is the lug bolt heads. The only way to deal with this is to machine a matching face on the drum hub or make a spacer. A thin plate could kill other birds like provide a hub register. While seemingly simple, we know what wheel adapters cost. One couldn't bolt the rotor as is since the gap would cause the rotor to warp and perhaps lug nuts loosen.

In the background of the above photo is a mockup showing why the Voyager 5x100 mm rotors won't work. The hat is too low, causing the caliper to hit the wheel. Some wheels bow outward to clear the caliper, but my 14" Cragars only bow 3/8" out from the hub face. My dream caliper is the Wilwood 120-8729, a 4-pot aluminum body for 0.81" th rotors to 11"D. It needs only 12.32"D for the wheel to clear. It sticks out 1.46" from the rotor face, but the K-H rotor hat is 1.47", and most wheels bow out a bit more, so should work fine. Cost $139 ea (free shipping).

BTW, ignore earlier comments about the rotor axial position affecting how braking tries to turn the wheel. I should have drawn a diagram. Since the caliper also attaches to the spindle, all moments are reacted out in the wheel bearings. The only thing that affects the tendancy to turn the wheel is where the tire's contact point on the road is relative to the spindle axis (line thru ball joints). They always angle the spindle axis so it goes thru the contact point on the road, which is why the upper ball joint is more inward than the lower one (see photo). Where the rotor sit does affect bearing loads, but I would think braking forces are minor compared with vertical loads like road bumps. I don't know why disc brake cars had stouter lower ball joints (not just Mopar). Probably a performance idea. On a related note, did V8's really require bigger hubs and drums than Slant Six's? The later were definitely under-sized, probably due to cost targets (both hubs failed on my Slant).

Well something must have be made, i just looked at their site and a kit is $500. i thought the setup was 175 when i check last. wonder whats in the kit? Complete ready to go?

sublimeswinger said:

Well something must have be made, i just looked at their site and a kit is $500. i thought the setup was 175 when i check last. wonder whats in the kit? Complete ready to go?

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If it is us you are referring to- the 495 setup is a wheel kit - you send in your drums and we do the rest.

what parts would you need? the hole assem? any pics of it installed?

I bought the ssbc set-up and installed it. Works great got it down in enough time to put it away for the winter.

abodyfan said:

I bought the ssbc set-up and installed it. Works great got it down in enough time to put it away for the winter.

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Did it retain the SBP?

It has both large and small bolt pattern studs, you have to remove the lbp studs.

Scarebird said:

Bill, in the interim I was able to examine a few sets of 65-72 A disc setups for sale. I immediately noted that the rotor was mounted BEHIND the hub, giving much more clearance in a 14" rim. I could do this - modding 1983-94 Ranger 2WD hubs and have it work on either 9 or 10 inch spindles. But the SOLE virtue of this setup is the rotors are 5 on 4".

I feel our setup from a budget vs. effectiveness matrix kicks the hell out of the stock setup - and fits inside the poverty rims.

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Wait - are you saying that the 2WD Ranger hub in rotor casting has the right bearing diameters & spacing to work on the early A body spindle? Re-Drill from 5x4.5 to 5x4? New hub & rotor with this swap?

B.