Technical Tips > Pre 84

69 Master cylinder bore size?

(1/2) > >>

69 DIRTY RAT:
Any knowledgable brake guys out there?

I need to know what size the bore is on a standard master cylinder on my 69? And what size bore is on a C6 master cylinder?

Basically I need a new/aftermarket master cylinder because now that I have C6 calipers on the front rotors the pedal is going almost to the floor! I need to work out what size master cylinder/bore I need to bring the pedal back to normal? ;42

70vette:
Check this link out . It may answer some questions.

http://temp.corvetteforum.net/c3/70lt1/brakes.shtml

77CVT:
I thought it was 1 inch.  I will try and find some info I had on brake pressure and m/cyl sizing.

;42

77CVT:
Here is a good site - http://sports.racer.net/brake_bias.htm

It has a spreadsheet for calculating brake bias as well.

"The size of the master cylinders' piston has a direct result on brake fluid pressure. However, it may not work like you would think... higher line pressure will build up on a smaller master cylinder piston to react the force applied by the pedal. A smaller master cylinder will create more brake fluid pressure but will also increase brake pedal travel. The smaller diameter cylinder requires a longer stroke to move the volume of fluid necessary to move the caliper pistons during braking.

Larger master cylinders will create less pressure but will require less travel."

Hopper Stoppers has some good info too - Here

Popular Hot Rodding - Info

Are your rears Wilwood Dynalites?  If so they are the same piston diameter as the stock C3 rear calipers (1.75in - I have these at home).  How big are the C6 bores?

Stock C3 caliper piston sizes are:
Front - 1.875in / 47.625mm  (5.8929 sq in/149.679 sq mm)
Rear - 1.75in / 44.45mm  (5.50 sq in/139.70 sq mm)

Front/rear difference = 1.0714 to 1 or the rears are 93.33% of the fronts

I imagine if the % is more than this then you would need a porportioning valve.

I see you are getting some good info from the CF.

;42

69 DIRTY RAT:
Thanks 77CVT!

Navigation

[0] Message Index

[#] Next page