View Full Version : NON-power master and discs??
77amc
03-07-2014, 07:17 AM
in a rush out the door..
Anyone running an after market NON-power master cylinder on the street with all discs?
saw this one and got me thinking.
http://www.ebay.com/itm/GM-Corvette-Style-Universal-1-1-8-Bore-Master-Cylinder-For-Disc-Disc-/201032322977?pt=Motors_Car_Truck_Parts_Accessories&hash=item2ece75cfa1&vxp=mtr
Almost ready to drop in that 318 magnum and would hope to have the brakes sorted/fitted before
I get it in there, then have no room.
Just to refresh yer memory, I already have the yota front conversion and yota rear soon to be a disc rear.
Thank you.
Errol
camoit
03-07-2014, 09:14 PM
in a rush out the door..
Anyone running an after market NON-power master cylinder on the street with all discs?
saw this one and got me thinking.
http://www.ebay.com/itm/GM-Corvette-Style-Universal-1-1-8-Bore-Master-Cylinder-For-Disc-Disc-/201032322977?pt=Motors_Car_Truck_Parts_Accessories&hash=item2ece75cfa1&vxp=mtr
Almost ready to drop in that 318 magnum and would hope to have the brakes sorted/fitted before
I get it in there, then have no room.
Just to refresh yer memory, I already have the yota front conversion and yota rear soon to be a disc rear.
Thank you.
Errol
I got 4 wheel disc and no power. You need to make sure to use as long as a pedel you can stick in there. I used a 14 inch pedel 3/4 pistons. http://www.cncbrakes.com/ You just need to remember to PUSHHHHH
77amc
03-08-2014, 07:27 AM
I got 4 wheel disc and no power. You need to make sure to use as long as a pedel you can stick in there. I used a 14 inch pedel 3/4 pistons. http://www.cncbrakes.com/ You just need to remember to PUSHHHHH
Hadn't seen your build but as you said "pistons", I would assume that the front and rear resivoures(?) are DIVORCED? Like a Tilton or Willwood?
Are u using residual valves? And where on the 14" peddle are you putting the 'push' rod. (the master only has an inch or so of
travel right?) and it can't be down past half on the length right?
You say to 'use as long as possible', That is because of the force needed to pushhhh?
I've always wondered how much fluid is ACTUALLY pushed out from the master, and how much the slave the needs to move through it's limits.?
sorry for the q's but i've never really diverted from stock offerings..
The clutch is pretty much the same challenge, just it's all connected already. Just a strange master and slave that's all together already.
http://www.ebay.com/bhp/dodge-ram-slave-cylinder..
Just need to figure out how far the stock push rod actually moves
Thank you, E
camoit
03-08-2014, 04:33 PM
Mine are separate masters one front one for the rear. There is a rod that runs between the two so I can adjust my balance on the fly.
The ratio is the length of the pedal in relation to the location of the piston rod. Mine is 14 to 1. The pistons don't move that much but you need the ratio to keep the force needed to stop the car down. This is in conjunction with the piston size. smaller pistons = higher force, but it also means more movement of the pedal to bring the presser up in the calipers. A larger piston = more fluid moved to the calipers but more force needed on the pedal.
I also have residual valves I think there 2 or 4 PSI. The residual valve keeps the calipers closer to the rotor. The calipers pull away from the rotor by two things. A built in rotor run-out and caliper seals. There is some math involved to know just what the best fit will be. You must know the diameter of the caliper pistons. 1, 2, 4, or 6 pistons. knowing how much fluid is needed to get the calipers to move a set distance. Lucky for me the people at CNC know how to figure it all out. I just called them with the caliper size and amount of pistons and a rough weight of the truck. Then figured out the cup size. Mine were 3/4". I would have liked to stick in a 16" pedal but I did not have the room. One more thing you need to think about is how you plan to mount it. Is the fire wall strong enough, is there enough room, are all the lines running down hill, what else is in the way, things like that. I wish I could use a power assist of some kind but I just don't have the room. As for how much fluid is pushed out it's a couple of CC's. Cup Diameter X Stroke = Displacement. So it's pretty darn impotent to get it right the first time. I thought my ratio was off the first time I drove the truck. It did not want to stop at all. But it was just the front rotors and new pads needing to burn the glaze off. Now it stops a lot better. It still feels like it could be better but I'm adjusting the balance to change the feel of it.
The clutch is a diferent story. Is there a clutch arm? If so how long is it? Where is the folcrum located? What is the distance you need to have the slave move in order to get a full relese? All these come into play. If you need a long movement then the force will be farly low. So a large master and a small slave. If you need a short movement then a small master and a larger slave. But there is some give and take here to. It all comes down to a force multiplier. That is the arm. unless you don't have one like me. Then it's back to slave cup size and distance needed to move.
Lets pick some numbers. So if we look at a stock clutch assembly we can say the pedal is 12 inches, The cable is attached 2 inches from the pivot point. So that gives us a 6 to 1 ratio. The pull movement going to be 1" for every 6 inch of pedal movement. The release arm is 12 inch long, the pivot ball is 2" from the clutch. This makes the movement of the throw out bearing 1/2 inch. Not a lot. But enough to do the job. But the force needed to release the clutch is 1000 lbs. You are only using 83 lbs of force on the pedal to move the clutch. Of course this is just a example of how it works and is not relevant to your clutch. Your clutch is some where in the line of 400 Lbs or less and only needs 33 Lbs or less to work. Then we get into friction, force multipliers and breaking force. The fun stuff. Oh where do we start??
8507
77amc
03-08-2014, 07:20 PM
AWSOME info there..
The MAX is using the stock peddle assy but will be making a nautilus looking plate welded
to the stock shaft, with holes all around it for adjustment. Since i'm going from a cable to fluid, I'm thinking of a small Hiem Joint and threaded rod.
I'll try to get pics as I go. I've got tonnnssss of projects going on, besides coming out of retirement and starting a business.
So it might take a bit.
If you remember, the floor was cut out for the GM automatic. And since the centerlink was needing fabrication that i was going to RISK MY LIFE,
I decided against the 283 and went with a Dodge magnum 318 from a Jeep Grand Cherokee, and a NV3500 5spd from a '97 Dodge ram 1500.
Thanks again for your insight and knowledge.
Errol
pennyman1
03-13-2014, 06:29 PM
you could always run a hydraulic brake booster that runs off the power steering pump - then the stock pedal will work
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