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Jeffry Cassel
07-27-2017, 10:48 AM
Over the years, I've become underwhelmed by Studebaker's disc brakes. They were designed for a small car (Jaguar) and do not perform that well in a much heavier car. And the Bendix Hydrovac is something else entirely! Does anyone know of the actual (not factory claims!) stopping distances for disc brake equipped Studebakers? I did find a report on 1958 sedans; they reported about 170' for V8 with 11" drums. Seems a bit high to me; I've made 2 sudden stops in our 58 Packard and it really does stop well. Input?

Dwight FitzSimons
07-27-2017, 12:13 PM
Motor Trend (June 1963) reported a 145 ft. stopping distance for a disc-braked '63 Hawk R2 (curb weight 3780 lbs). Motor Trend (Dec '63) reported a 133.5 ft. stopping distance for a disc-brake equipped '64 Commander 2-dr sedan (3260 lbs curb weight). I remember stopping distances in road tests being as short as 120 ft., but I would think 133-145 ft. would be more realistic. The car mags of the day raved about the lack of fade of the disc brakes compared to drum brakes. But, the Bendix-Dunlop brakes are complicated and higher maintenance compared to modern disc brakes. And, there's that pesky Hydrovac. For several reasons I recently converted my '64 R1 Hawk to Turner front discs and 11" Avanti rear brakes. The Avanti rear drum brakes have a braking characteristic more suitable to front discs than self-energizing rear brakes.
-Dwight

PackardV8
07-27-2017, 01:36 PM
Yes, disc brake design has improved continually over the past sixty years, as has everything on the cars.

Yes, just using modern radial tires will noticeably shorten stopping distances of those measured with the hard skinny bias ply tires. It's not accurate to use old road tests as the yardstick.

Having said that, at least those magazine road test stopping distances were measured with all new components. Regularly, we see our members dissing the old, worn-out OEM components and bragging about the improvement with all-new aftermarket systems. With all-new components, the OEM braking system is as good as the rest of the car; just not as good as forty years more improved design brakes.


Over the years, I've become underwhelmed by Studebaker's disc brakes. They were designed for a small car (Jaguar) and do not perform that well in a much heavier car.

Point of clarification, the Jaguar XK140 weighs 3200#; about the same as the Avanti and only a bit less than the steel bodied Studes. It's just our perception of what brakes should be capable which has changed.

jack vines

RadioRoy
07-27-2017, 06:05 PM
I tell folks that the brakes on my 54 are up to snuff - right up to 1954 standards. :)

8E45E
07-27-2017, 06:11 PM
I tell folks that the brakes on my 54 are up to snuff - right up to 1954 standards. :)

They were better than the 1953 brakes.

Craig

thunderations
07-27-2017, 06:54 PM
I think most of us can agree that technology has improved in the last 50, 60, 70 years in the automotive industry. Most any mechanical system you want to compare is going to be better now then it was then. Compare headlights, A/C, steering, brakes, etc.. About the only thing I think was better then was the styling. You could identify a car a 1/4 mile away, while today you need to read the decal on the trunk. Oh, if someone just built a 2017 retro Studebaker.

RadioRoy
07-27-2017, 11:41 PM
They were better than the 1953 brakes.

Craig

That's for sure!

Noxnabaker
07-28-2017, 03:27 AM
My -55 sedan stops good with drumbrakes, the thing with discbrakes is that they don't get hot as easy as discbrakes, & with ventilated discbrakes you can brake even longer time before they fade.
I've also heard & read that discbrakes don't hold as good as drumbrakes when they're used for parking/handbrake & a big drum's area is just that: big as in brakearea.
Weight is the enemy + the only thing that REALLY grips the ground is the rubber tires... as I've noticed when driving past modern smaller cars with "good" roadholding with some early 60's US car of mine such as a fullsize MoPar for example.
& as for Jaguar & small brakes, I have a friend who for many years drove BaaderMeinhofWagen that he tuned with turbo's from big trucks & such & one day another friend was scraping a Jaguar XJ6 & the beemerfriend saw the brakes & thought "I could've been dead considering the brakes the beemers have!"... but that was some years ago & today "ze jermanz" has updated. ;)

53k
07-28-2017, 05:38 PM
Motor Trend (June 1963) reported a 145 ft. stopping distance for a disc-braked '63 Hawk R2 (curb weight 3780 lbs). Motor Trend (Dec '63) reported a 133.5 ft. stopping distance for a disc-brake equipped '64 Commander 2-dr sedan (3260 lbs curb weight). I remember stopping distances in road tests being as short as 120 ft., but I would think 133-145 ft. would be more realistic. The car mags of the day raved about the lack of fade of the disc brakes compared to drum brakes. But, the Bendix-Dunlop brakes are complicated and higher maintenance compared to modern disc brakes. And, there's that pesky Hydrovac. For several reasons I recently converted my '64 R1 Hawk to Turner front discs and 11" Avanti rear brakes. The Avanti rear drum brakes have a braking characteristic more suitable to front discs than self-energizing rear brakes.
-Dwight
You have to keep in mind that those 1963 braking distance tests were made on narrow bias ply tires. I'm probably mistaken (as usual), but aren't modern car stopping distances pretty much the same and they are using wide radial tires. Edmunds tests of 2017 Mustangs found stopping distances ranging from 104 feet to 118 feet in 60-mph stops. I don't really plan to do 60-mph test stops, but I suspect that my 3800 pound '64 Wagonaire with the original disc brake system and 215x75x15 radials will still stop as well as a lot of modern cars. My '64 R-1 Avanti was converted to Turner brakes some time before I bought the car and, while it stops OK, I don't see it stopping better than the Bendix disc brake cars I have owned over the years.

Jeffry Cassel
07-29-2017, 04:40 PM
Re '53 brakes: I was appalled by the brakes in Ceci's 53 Champion. I wonder what the stopping distance is for it. It has brakes off a 62 Daytona (much better!) now. Self energizing brakes were a quantum leap in safety. I did not know a Jag was anywhere near that heavy. I am sure radials make a huge difference.

JoeHall
07-30-2017, 01:39 PM
Comparing disc & drum brakes, I have only two problems with the latter: Side to side pull, that often shifts back and forth, especially under severe braking. This is a safety concern on today's roads. It seems inherent with drum brakes, as about 90 percent of the drummed Studes I have owned did it.

The other problem may be resultant of a perfect storm between repro profit margin and EPA: Long ago the shoe liner, "good stuff" was outlawed, and there has yet to be a suitable replacement. The good stuff was made of bronze sintered asbestos. The down side was, they usually squeaked, and would fairly quickly wear out drums. I learned to live with the squeaking, and the reason for the drums' short life, was because the shoes worked so well. All we have now are liners made of inferior material, that can get you killed; little initial grab, and fades rapidly. I know better material is available, but it would substantially increase the price of today's relined shoes. Still, safety is paramount, so I'd gladly pay.

Enter modern technology: Many brake pad companies offer a wide array of pad material, i.e. company named, "Lyndall" specializes in Harley pads, which are a game changer. A simple switch to "Lyndall Gold" pads made my poorly braked, 1986 Harley stop like a modern bike. If someone could convince Lyndall to re-line Stude shoes, most of us would be happy with drum brakes, even if those shoes cost 2-3 times as much.

OTOH, even if Lyndall lined shoes were available, we'd still have to contend with side to side shifting. Who knows, with better liners, that problem may be more, or less pronounced. We may never know.

bezhawk
07-30-2017, 05:45 PM
There are pads that fit Stude Dunlop (Bendix) calipers. Ferrari, Jaguar, and Mercedes also used the Dunlop calipers. EBC corporation makes an XKE drop in pad that is at least 30% better than the best Girling original pads. If you want better braking, and want to keep original equipment, then it is a no brainer.

JoeHall
07-30-2017, 07:00 PM
There are pads that fit Stude Dunlop (Bendix) calipers. Ferrari, Jaguar, and Mercedes also used the Dunlop calipers. EBC corporation makes an XKE drop in pad that is at least 30% better than the best Girling original pads. If you want better braking, and want to keep original equipment, then it is a no brainer.

I am talking about shoe liners, for drum braked Studes. I mentioned disc brake pads' availability to illustrate that modern technology and materials are indeed available, but not for re-lining Stude brake shoes. If we could get shoe cores re-lined with modern material, as is available for disc brake pads, we'd all be happier with drum brake Studes. But all that is available nowadays for re-lined shoes, is the material that will get you killed. With modern repro lined Stude shoes, I went through a few intersections standing on the brake pedal, with little braking effect. So eventually gave up on drum brakes, and converted all the Studes to DBs.

Mark L
07-30-2017, 07:31 PM
Regarding the side-to-side pull of drum brakes, what I never liked was when the front drums got wet after driving through deep rain puddles. Talk about some pulling or lack of pulling.

bezhawk
07-30-2017, 08:53 PM
I am talking about shoe liners, for drum braked Studes. I mentioned disc brake pads' availability to illustrate that modern technology and materials are indeed available, but not for re-lining Stude brake shoes. If we could get shoe cores re-lined with modern material, as is available for disc brake pads, we'd all be happier with drum brake Studes. But all that is available nowadays for re-lined shoes, is the material that will get you killed. With modern repro lined Stude shoes, I went through a few intersections standing on the brake pedal, with little braking effect. So eventually gave up on drum brakes, and converted all the Studes to DBs.Yes, I'm replying to the OP stating lack of confidence in the original disc brakes. It would indeed be nice to have better lining material for drum shoes.

GrumpyOne
07-30-2017, 10:41 PM
I believe that the Datsun early "Z" series also used the Dunlap cylinders as I replaced those on my old Avanti that had frozen due to the wrong adjustment on the booster push rod...

JoeHall
07-31-2017, 12:27 AM
Looking on-line, a company called, Porterfield Brakes advertises several brake shoe liner compounds, to include Street Performance, and all out Racing. They can re-line any shoe core. If I were still running drum brakes, they'd get my business, at least a one time trial. It would be nice to step on the pedal and the car simply stop like its supposed to, at any speed.

Steve Winzar
07-31-2017, 12:57 AM
I recently got behind the wheel of my newly acquired (rescued) 62 GT hawk after having not had a Stude 'driver' for many many years. After having been driving a 1982 280ZX and a 1988 BMW series 3 (old aren't they?!) for the intervening years, the drive in the GT was almost scary. I had forgotten how God-awfully heavy and arcane these have become in relation to what we drive now. To be honest, I won't criticise anybody for upgrading to ANY DB system that will work on a Stude, despite the fact that I prefer my two Hawks to be left with the Drums they have (sorry, something of a purist...). I cannot, however, fathom the deriding of the Bendix/Dunlop system in favour of admittedly good aftermarket replacements. It all comes down to how bloody hard do you want to drive that old car. Our Studes are HEAVY- shouldn't we just know that and drive accordingly, well within the characteristics of our cars. I will more than likely cave-in for a DB conversion one day, but only because the cost of new drums is gonna make it prohibitive :o.

53k
07-31-2017, 09:45 AM
I believe that the Datsun early "Z" series also used the Dunlap cylinders as I replaced those on my old Avanti that had frozen due to the wrong adjustment on the booster push rod...
Toyota Crowns used the same system, but with slighter larger pistons. When I had a '76 Avanti the local Avanti shop recommended using those cylinders in place of the ones that came on the cars. As I remember they were a direct bolt on.

64V-K7
07-31-2017, 08:44 PM
As I remember they were a direct bolt on. yeahhhhh, except I seem to recall the crossover pipes were metric, so you had to get those also..