Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Thu Jan 20, 2022 1:00 pm

All times are UTC-08:00




Post new topic  Reply to topic  [ 7 posts ] 
Author Message
PostPosted: Thu Jan 13, 2022 12:31 pm 
Offline
Turbo Slant 6

Joined: Fri Jul 13, 2007 11:11 pm
Posts: 625
Location: Cincinnati
Car Model:
Hi Guys,
I want to try and work on this car more this coming spring and want to do a 10" drum upgrade. I kinda want to do a hi performance period correct type upgrade ie. the 10" Drums with drilled backing plate for coolong /venting and segmented brake shoes etc. Am I going to run into compatibility problems on the front end trying to change to 10" brake stuff?
The car is going to be a Nascar sport compact tribute. Can anyone advise if I can do this conversion with factory bolt ons?
The car is white with blue interior and it is a 3speed manual and it's gonna have a rowdy 170 hyper pak.
Thanks for your help!


Top
   
PostPosted: Thu Jan 13, 2022 4:30 pm 
Offline
Board Sponsor & Contributor

Joined: Thu Oct 31, 2002 5:39 pm
Posts: 23665
Location: North America
Car Model:
Valleyant wrote:
I want to try and work on this car more this coming spring and want to do a 10" drum upgrade.


If you're going to the effort and expense, your money is better-spent doing a disc swap. You wind up with much better, much less troublesome, much easier-to-maintain brakes.

Quote:
drilled backing plate for coolong /venting


Yikes. This idea sails right past the town of Unwise, cruises at triple the speed limit through Bad, and finally stops when it runs off the road somewhere in the City and County of Extremely Ill Advised. There are two holes in the backing plate as produced by the factory. They're oblong slots down at adjuster level, and they're to provide access to adjust the brakes without removing the drum. They're equipped with a tight-fitting rubber or plastic plug to keep water out, because drum brakes stop working when they get even a little bit wet, and even just one of those two oblong slots, without its plug, can let in enough water to make things bad. Let one side get wet and the other stay dry, touch the brake pedal, and the car will yaw hard enough to take the steering wheel out your hands. Don't go drilling new holes in the backing plates! This was a crude countermeasure for inherently inadequate brakes in racing service without risk of water entry. It did very little of any use even under those conditions, because there was no air movement through the holes. Seriously, don't do this; it is a staggeringly bad idea. Much more effective drum brake upgrades were heavier, finned drums (9" setup got these as standard fitment in '70; there were heavier/finned 10" drums as well, starting in 1973, though I am pretty sure they were all 4½" bolt circle.

Quote:
and segmented brake shoes


If what you're trying to do is provide an escape path for the gases that emanate from hot brake friction materials and provide an air cushion between the shoe and the drum (which is one cause of brake fade), you can use a hacksaw to create two diagonal slots per shoe, not wider than the width of the hacksaw blade. Don't remove wider strips of friction material in the mistaken belief this will improve anything (it won't).

If you are bound and determined to stay with drum brakes, go fishing for NOS Velvetouch Metalik shoes (1962 test)

Quote:
it's gonna have a rowdy 170 hyper pak


That warrants good brakes. Retro-tribute is fun. Retro-brake performance isn't.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Image


Top
   
PostPosted: Fri Jan 14, 2022 5:05 am 
Offline
Board Sponsor & Moderator
User avatar

Joined: Mon Oct 21, 2002 11:08 am
Posts: 15177
Location: Blacksburg, VA
Car Model:
I agree that you will be MUCH happier and have less trouble and work with discs. Safety is not, IMHO, to be overshadowed by "period correct."

Lou

_________________
"You mean you still have a Slant 6 in that thing?"


Top
   
PostPosted: Fri Jan 14, 2022 5:29 am 
Offline
SL6 Racer & Moderator
User avatar

Joined: Sat Oct 19, 2002 12:06 pm
Posts: 7765
Location: Silver Springs, Fl.
Car Model:
Those Velvetouch brakes were the "cats meow" back in the day. It would be great if they could still be found. I had a set on a 66 Corvair with a 327 midships back in the '70's.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 225 nitrous
64 Valiant Signet
64 Valiant 4dr 170


Top
   
PostPosted: Fri Jan 14, 2022 6:42 am 
Offline
Supercharged
User avatar

Joined: Sat Nov 27, 2004 8:03 pm
Posts: 7436
Location: IRWIN PA
Car Model:
All of the A body Factory drums available in Ø10" through 1976 were on the 4" bolt circle.

The 4 1/2" Bolt circle drums were found on other B/E/ C? Body cars like the Satellite, Belevedere, Savoy,Fury, Cuda / Challenger etc.

Greg

_________________
http://www.youtube.com/hyperpack
Image


Top
   
PostPosted: Fri Jan 14, 2022 5:25 pm 
Offline
Board Sponsor
User avatar

Joined: Tue Oct 29, 2002 8:27 pm
Posts: 9760
Location: Salem, OR
Car Model:
Quote:
All of the A body Factory drums available in Ø10" through 1976 were on the 4" bolt circle.


All Front brake drums on Factory A bodies to 1976 had SBP brake drums (Remember in January 1976 they went to Factory Discs with a slight amount of bleed over from that date, and in the first months of the 1976 Production year, about August/September 1975, there are a few recorded OEM setups with 9" drums up front but most got 10" front drums)... up to the year 1976 Rear Axles in 7 1/4" were SBP for front drum brakes and LBP for Disc Brakes from 1973-1976, and LBP if the 8 1/4" Rear Axle.

LBP is standard on B/C/E body cars with Drums as these tended to be some 10" drum and mostly 11" drums on the C body and some B body. (Then you get the odd bolt patterns beyond the base trucks, but that's another discussion for the fans of 5 on 5" pattern...)

Cheers!


Top
   
PostPosted: Fri Jan 14, 2022 6:19 pm 
Offline
Turbo Slant 6

Joined: Fri Jul 13, 2007 11:11 pm
Posts: 625
Location: Cincinnati
Car Model:
OK maybe I'd better tap the brakes on this idea......is the only option for a '60 and '61 A body front disc conversion the Scarebird setup? Maybe I will go this route and be done with it. Oh and upgrade from the 13"ers to 14" steel wheels OR maybe Minilites.
Thanks guys for reining me in on this one.


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 7 posts ] 

All times are UTC-08:00


Who is online

Users browsing this forum: No registered users and 8 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited