Porportioning Valve

Tom Goldman · 12-26-2015, 12:50 PM

Tony didn't say what car he's doing this on ,or if he's using an OEM master cylinder .
Many older disc drum cars have integral residual valves ,either in the master cyl itself ,or in the factory combination/proportion valve that can cause excessive brake drag when being converted from drum to disc .
When making major system changes like this ,it's best to replace the master cylinder and the factory distribution block with parts that are sized properly for the application , particularly if the car will be foot braked .
On several of the Stockers I've built I've used Bias valves on the front brakes , not the rear,to proportion proper braking , especially at the finishline.

Tony Goodman · 12-26-2015, 03:45 PM

All the factory stuff is gone. Have a 1.030 strange master cylinder, I don't know if I need a bigger one. Sounds like I probably should upgrade to the bigger master cylinder also. I want to do it right, but not spend money on things I don't need.

Greg Hill · 12-26-2015, 04:49 PM

Quote:

Originally Posted by Tony Goodman

All the factory stuff is gone. Have a 1.030 strange master cylinder, I don't know if I need a bigger one. Sounds like I probably should upgrade to the bigger master cylinder also. I want to do it right, but not spend money on things I don't need.

Tony, I think you should go with the 1 1/8 bore MC from strange. I believe you will have too soft a pedal with your current MC.

Tom Meyer · 12-27-2015, 03:06 PM

What kind of a car is it? Might have to move where the rod attaches to the pedal to get better pressures with a footbrake car. Tom

Todd Geisler · 12-27-2015, 08:54 PM

Just got my new brakes from Lamb. In conversations with Roger he told me a few things.

1. he does not believe in reducing front brake pressure via an adjustable proportioning valve.

2. for 4 wheel discs, 4 piston caliper they recommend a 1 1/8" master cylinder.

I can tell you from my experience building cars, we never use residual pressure valves on cars where the master cylinder is on the firewall. The RPV is only used when the master cylinder is mounted on the floor.

Tony Goodman · 12-28-2015, 05:15 PM

Thanks for the responses from everyone! I'm going to up grade the M/C to a 1.125 bore, and not use a proportioning valve. Thanks Tony

12-26-2015, 12:50 PM	#1
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,475 Likes: 887 Liked 865 Times in 235 Posts	Re: Porportioning Valve Tony didn't say what car he's doing this on ,or if he's using an OEM master cylinder . Many older disc drum cars have integral residual valves ,either in the master cyl itself ,or in the factory combination/proportion valve that can cause excessive brake drag when being converted from drum to disc . When making major system changes like this ,it's best to replace the master cylinder and the factory distribution block with parts that are sized properly for the application , particularly if the car will be foot braked . On several of the Stockers I've built I've used Bias valves on the front brakes , not the rear,to proportion proper braking , especially at the finishline. __________________ Tom Goldman 1500 SG , 1506 STK Last edited by Tom Goldman; 12-26-2015 at 12:53 PM.

12-26-2015, 03:45 PM	#2
Tony Goodman Junior Member Join Date: Jan 2006 Location: Zeeland, MI Posts: 98 Likes: 135 Liked 18 Times in 4 Posts	Re: Porportioning Valve All the factory stuff is gone. Have a 1.030 strange master cylinder, I don't know if I need a bigger one. Sounds like I probably should upgrade to the bigger master cylinder also. I want to do it right, but not spend money on things I don't need.

12-27-2015, 03:06 PM	#4
Tom Meyer Senior Member Join Date: Aug 2003 Location: Pierce NE Posts: 936 Likes: 78 Liked 354 Times in 120 Posts	Re: Porportioning Valve What kind of a car is it? Might have to move where the rod attaches to the pedal to get better pressures with a footbrake car. Tom __________________ Tom Meyer 5240 SS Stock ???

12-27-2015, 08:54 PM	#5
Todd Geisler Member Join Date: Feb 2002 Posts: 328 Likes: 64 Liked 345 Times in 149 Posts	Re: Porportioning Valve Just got my new brakes from Lamb. In conversations with Roger he told me a few things. 1. he does not believe in reducing front brake pressure via an adjustable proportioning valve. 2. for 4 wheel discs, 4 piston caliper they recommend a 1 1/8" master cylinder. I can tell you from my experience building cars, we never use residual pressure valves on cars where the master cylinder is on the firewall. The RPV is only used when the master cylinder is mounted on the floor.

12-28-2015, 05:15 PM	#6
Tony Goodman Junior Member Join Date: Jan 2006 Location: Zeeland, MI Posts: 98 Likes: 135 Liked 18 Times in 4 Posts	Re: Porportioning Valve Thanks for the responses from everyone! I'm going to up grade the M/C to a 1.125 bore, and not use a proportioning valve. Thanks Tony