Master cylinder bore size question
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Master cylinder bore size question
Hello, I have a 69 Chevelle with the stock power disc/drum system. Stock uses an 1-1/8 bore master cylinder, I had a brand new Wilwood master cylinder given to me but has a 1inch bore. What kind of difference in pedal feel do you think the smaller bore would make if I were to go with the Wilwood master cylinder? Thanks for any input!
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Re: Master cylinder bore size question
The Wilwood would give higher pressure if no other changes.
But will the smaller volume of brake fluid be enough to activate the brakes?
(disk brakes or drum?)
But will the smaller volume of brake fluid be enough to activate the brakes?
(disk brakes or drum?)
John Wallace
Pontiac Power RULES !
www.wallaceracing.com
Pontiac Power RULES !
www.wallaceracing.com
- John Wallace
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Re: Master cylinder bore size question
Your master cylinder now isn't a dual chamber one?
(would have 2 different sizes for front and back)
(would have 2 different sizes for front and back)
John Wallace
Pontiac Power RULES !
www.wallaceracing.com
Pontiac Power RULES !
www.wallaceracing.com
Re: Master cylinder bore size question
Yes, it's a dual chamber. The whole sysrem is the factory 69 Chevelle power front disc/rear drum system
Re: Master cylinder bore size question
The pedal pressure for a given decel rate will go down by ~ 12% and the pedal travel will increase in the same proportion.69ss wrote: ↑Thu Aug 30, 2018 10:41 pm Hello, I have a 69 Chevelle with the stock power disc/drum system. Stock uses an 1-1/8 bore master cylinder, I had a brand new Wilwood master cylinder given to me but has a 1inch bore. What kind of difference in pedal feel do you think the smaller bore would make if I were to go with the Wilwood master cylinder? Thanks for any input!
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
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Re: Master cylinder bore size question
Running a 7/8 bore Wilwod master on my 79 Camaro factory disk/drum setup. Pressure isn't a problem, volume is. You need to pump the brakes once to push out the rear shoes, then the second pump you are good to go up to 1200 psi. Going to rear disk for next season, hoping to eliminate that first pump.
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Re: Master cylinder bore size question
Pedal effort is greatly reduced. Haven't run the car for a few years, but I believe effort is similar to power brakes with great vacuum.
Re: Master cylinder bore size question
Err... make that ~27%MadBill wrote: ↑Sun Sep 02, 2018 7:05 pmThe pedal pressure for a given decel rate will go down by ~ 12% and the pedal travel will increase in the same proportion.69ss wrote: ↑Thu Aug 30, 2018 10:41 pm Hello, I have a 69 Chevelle with the stock power disc/drum system. Stock uses an 1-1/8 bore master cylinder, I had a brand new Wilwood master cylinder given to me but has a 1inch bore. What kind of difference in pedal feel do you think the smaller bore would make if I were to go with the Wilwood master cylinder? Thanks for any input!
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: Master cylinder bore size question
I have a really old mag with an article in the very back of it that David Freiburger wrote. He put a 1.25" piston dia. M/C on a Chevelle that had been converted both front and rear to disc brakes. He said it worked great. I figure it was a volume thing...
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