Component sizing help!

[JeffisOld]

Please put up with the newb!

As I am installing a big block in a 69 Dart I thought upgrading the brakes would be a smart move but I am lost for sizing.

Suspension is Alternation front and Street Lynx rear from Reilly Motorsports. There will be disc on all 4 corners. I am not going to use power brakes because I believe that would be overkill and a serious PIA with 440 valve cover fitment from what I understand.I

I have purchased the brake set-up from Speedway and a new aluminum 2 chamber master cylinder from Advance auto. (My brother's a store manager).

Is there a formula used or a chart to help identify required brake line sizes for each location?

The Proportioning Valve is also a puzzle to me. Is an adjustable one required?

Any insight would be appreciated!

 

[rumblefish360]

Call Drdiff or visit his web site as I do believe those parts will use oem parts if you wish.
DoctorDiff Drivetrain Components

 

[69_340_GTS]

Usually, if you put discs on all 4 corners no proportioning valve is required. But if for some reason you decide you want/need one, just put an adjustable one on the line going to the rear brakes. Sometimes the rears need a bit less pressure to avoid premature lock-up.

 

[JeffisOld]

Usually, if you put discs on all 4 corners no proportioning valve is required. But if for some reason you decide you want/need one, just put an adjustable one on the line going to the rear brakes. Sometimes the rears need a bit less pressure to avoid premature lock-up.

Thank you!

Will the line size need to be adjusted based on the diameter of the piston?

What is standard size?

Is it different (larger) on the main line going rearward before the splitter?

 

[69_340_GTS]

Stock size lines will work just fine. I'm going by memory here, I think they are all 3/16" lines.
You most likely will need a 7/8" or 15/16" master cylinder, if you are not running power brakes. I ended up with a 7/8" Baer m/c. Works fantastic with the standard-size Stainless Steel Brakes Co. (SSBC) disc kits on all four wheels. That size m/c is O.K. to use with one or two-piston calipers. Not sure if it would be big enough for 6-piston calipers or something else exotic... but it doesn't sound like those are in your plans.

 

[JeffisOld]

Stock size lines will work just fine. I'm going by memory here, I think they are all 3/16" lines.
You most likely will need a 7/8" or 15/16" master cylinder, if you are not running power brakes. I ended up with a 7/8" Baer m/c. Works fantastic with the standard-size Stainless Steel Brakes Co. (SSBC) disc kits on all four wheels. That size m/c is O.K. to use with one or two-piston calipers. Not sure if it would be big enough for 6-piston calipers or something else exotic... but it doesn't sound like those are in your plans.

Thank you Sir!

No, nothing exotic is in the plans. I just want good brakes. Plan to use a 2 chamber M/C as this should greatly increase stopping power over manual drums.

Live is Good!

Thank you

 

[sireland67]

3/16 is standard mopar brake line size thru most years.

 

[69_340_GTS]

Thank you Sir!

No, nothing exotic is in the plans. I just want good brakes. Plan to use a 2 chamber M/C as this should greatly increase stopping power over manual drums.

Live is Good!

Thank you

Happy to help. Check the piston size in the m/c. Like I said, you want it to be 7/8" or 15/16". You won't like the effort/feel with any bigger piston.

 

[JeffisOld]

Happy to help. Check the piston size in the m/c. Like I said, you want it to be 7/8" or 15/16". You won't like the effort/feel with any bigger piston.

I just be dense, please enlighten me!

If I use 4 brake calipers instead of 4 small wheel cylinders my initial thoughts are that a dual piston cylinder of >1.00 inch diameter would move more fluid and reduce the brake force required. What am I missing?

 

[69_340_GTS]

A.) I don't think you really mean "dual piston" m/c. What you have is a dual reservoir / dual outlet master cylinder. Sometimes called "tandem" master cylinders. It has two fluid output ports, one for the front and one for the rear. There is only one piston inside, acting upon two chambers.
B.) As to sizing, I went by what the manufacturer recommended, which for my car/brakes was 15/16". I'm sure there is some theory or calculation involved to determine the correct size. But bigger isn't necessarily better.
Dual reservoir / dual outlet master cylinders: