Slant Six Forum
https://www.slantsix.org/forum/

Converting 66 dart to front discs
https://www.slantsix.org/forum/viewtopic.php?t=63130		 Page 1 of 2
Author:  gdizzle [ Tue Jan 01, 2019 8:42 pm ]
Post subject:  Converting 66 dart to front discs
I know lots of threads about this, but this is what I am wanting. I have the 66 dart sedan 270, slanting, with original master cylinder (single chamber, not power).
I have original 9in drums, and 14in steelies 5x4.
2 years ago I completely replaced/rebuilt all the front end parts from PST. Tires are also new and I do not want to upgrade to 5x4.5, nor do I want 15in wheels.

From what I can tell, a company called Scarebird sells a kit with caliper brackets that will allow me to keep all my current parts like LCA and Spindle. $480.

What I can't tell is if I can use my current master cylinder. Also it says something about needing longer studs? How do i do that? thanks for any help.
Author:  64 Convert [ Wed Jan 02, 2019 4:28 am ]
Post subject:  Re: Converting 66 dart to front discs
I used '76 A-body discs on my '64. Everything was a bolt-in and only needs 14" wheels. I think it's a lot easier than aftermarket designs.
Author:  Rob Simmons [ Wed Jan 02, 2019 6:10 am ]
Post subject:  Re: Converting 66 dart to front discs
He doesn't want to swap over to large bolt pattern though...
Author:  Greg Ondayko [ Wed Jan 02, 2019 6:54 am ]
Post subject:  Re: Converting 66 dart to front discs
Scarebird stuff works using Custom Brackets and readily avail GM Calipers and pads, hoses and Prop Valve, dual circuit Master Cyl will need to be sourced.

Bought a set for my dad but he never installed it.
It will keep your stock drum brake spindle and bolt pattern.

The other option is to get the Kelsey Hayes 67-72 4 piston Calipers as well as corresponding spindles, rotors to go with the swap.
Parts needed to make this work will incluude the 67-up Prop valve, dual circuit mc, additional lines and hoses for the setup.

This will also keep your 14" 4" on 5 bolt pattern wheels - it's what mopar did on the 67-72 A bodies before the implementation of Big bolt Discs in 73 on the A bodies.

Greg
Author:  gdizzle [ Wed Jan 02, 2019 9:35 am ]
Post subject:  Re: Converting 66 dart to front discs
Thanks for the tips. From what I read finding the Kelsey Hayes stuff is next to impossible at the junk yards, and if someone is actually selling it, very expensive.

I am certainly leaning towards Scarebird. Only question, the rotors he supplies appear to be drilled out custom, which is fine, except I dont see studs? Am I supposed to supply studs? and hub? When I buy drum for the front, the drum already has a hub with studs built in. ??? What am I missing? And I assume finding the updated 2 chamber MC is easy and it bolts in?
Author:  SpaceFrank [ Wed Jan 02, 2019 10:01 am ]
Post subject:  Re: Converting 66 dart to front discs
I originally used the disc/drum master cylinder for 73+ A-bodies when I did a front disc conversion on my racecar. It's the big cast iron unit with a larger rear reservoir; the rear reservoir feeds the front brakes. Raybestos part number MC36412 is available on RockAuto (I try to avoid hydraulic components from the cheaper name brands like Cardone and Centric after having bad luck with early failures). That being said, I don't know how the front calipers for the Scarebird kit compare in size with my large single-piston Mopar brakes. If they're significantly smaller, you might want a smaller bore master cylinder to decrease pedal effort for manual brakes. The disc/drum master cylinder originally used for power brake applications has a smaller bore, I think.

The later Chrysler master cylinder referenced above will bolt right up to your firewall and use the same pedal pushrod, but you'll have to bend new hardlines from the master cylinder. The easiest way to do it is run a new line from the rear reservoir to the stock distribution block, disconnect the rear hardline from the block, and put in a plug where it went. Then run a new line from the front reservoir to the rear line with a union. You may need to add a proportioning valve into the rear line.
Author:  Greg Ondayko [ Wed Jan 02, 2019 10:16 am ]
Post subject:  Re: Converting 66 dart to front discs
I believe you reuse the hubs from your old front 9" drums - They might require longer studs or may work with with scarebird stuff directly using the original studs from the hub.

The hubs can be pressed out or maybe persuaded with a block of wood and a hammer.

Greg
Author:  Charrlie_S [ Wed Jan 02, 2019 11:29 am ]
Post subject:  Re: Converting 66 dart to front discs
If using the original 9 inch brake hubs, and different drums/rotors, and the drums and hubs are fastened together, do not beat or press the studs out of the hub. You need to cut the swedge off the studs, before removing the studs. If this is not done, it is likely you will mess up the stud hole in the hub, and ruin the hub.
Author:  Greg Ondayko [ Wed Jan 02, 2019 11:49 am ]
Post subject:  Re: Converting 66 dart to front discs
Yes good point Charrlie.

Greg
Author:  Charrlie_S [ Wed Jan 02, 2019 1:55 pm ]
Post subject:  Re: Converting 66 dart to front discs
Need to keep reminding people of this. Good hubs are getting hard to find. Not like there is 10 "A" bodies in every salvage yard. Even my stock is getting very low.
Author:  gdizzle [ Thu Jan 03, 2019 3:26 pm ]
Post subject:  Re: Converting 66 dart to front discs
Great info. So I need to find someone who has a swedge cutter? humm... And Scarebird person is telling me I should get new MC dual well, with a 15/16 bore. So far the only one that has the large/small combintation and the 15/16 bore is Cardone Select 131571. Does that sound right?

And then any leads on a proportion valve? this is manual brakes with 9inch drums remaining on the back along with the new discs going on front when I do all this.
Author:  Rick Covalt [ Thu Jan 03, 2019 3:48 pm ]
Post subject:  Re: Converting 66 dart to front discs
Quote:
So I need to find someone who has a swedge cutter?
Take a grinder with a wafer disc and cut the studs off next to the drum. Center punch the stud and drill it a little and keep going bigger. Once you get close to the size of the stud it will drive right out.
Author:  Charrlie_S [ Thu Jan 03, 2019 4:21 pm ]
Post subject:  Re: Converting 66 dart to front discs
Quote:
Great info. So I need to find someone who has a swedge cutter?
I have both the 7/16 and 1/2 inch cutters. For anyone that wants to buy one, this company has them.
https://goodson.com/
Part number ST-437 for the 7/16 and ST-500 for the 1/2 inch
Author:  SpaceFrank [ Fri Jan 04, 2019 9:35 am ]
Post subject:  Re: Converting 66 dart to front discs
Quote:
And Scarebird person is telling me I should get new MC dual well, with a 15/16 bore. So far the only one that has the large/small combintation and the 15/16 bore is Cardone Select 131571. Does that sound right?
That recommendation makes sense if those Chevy Celebrity calipers are smaller than the Mopar calipers, which wouldn't be surprising. That's the master cylinder originally spec'd for disc/drum power brakes, so you should also be able to use Centric 13063017 or Raybestos MC36406. The spotty listing of dimensions like this on RockAuto can be frustrating.

If anyone's curious why the Mopar power brake master cylinder bore is smaller, I believe I read somewhere that cars with power brakes also came with a different pedal assembly offering less mechanical advantage.
Author:  gdizzle [ Sat Jan 05, 2019 10:11 am ]
Post subject:  Re: Converting 66 dart to front discs
Just want to add some more part numbers, for future searches:
Rockauto doesn't show all details , like Bore size, on several of the master cylinders.

So this is a short list of Dual chamber master cylinders that have 1 small and 1 large well, and should use the existing pushrod from our old single chamber original master cylinders from our original Drum brakes. All have the 15/16 bore size. These all look like the same unit BTW.

Dorman M80266
Raybestos MC36406
Centric 130.63017
Cardone Select 131571
Right Stuff DBMC15
BrakeBest Slect NMC11145
NAPA NMC M2122
Page 1 of 2 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/