Prop valve with 4 wheel disc?

[1967coronet440]

Gentlemen,

Wondering do I need the adjustable prop valve with 4 wheel disc setup? I have the wilwood valve already but not sure that I need it? if I don’t need it do I still need to install distribution block or do i run the lines straight from MC to the “T” on the rear end.

Wilwood disc all the way around, wilwoood MC, hurstline lock.

 

[R/T Boy 67]

Only you and your car can answer that question. You must test the brakes, and if the rears lock up first, then you need to adjust the prop valve or add one if you don't have one. Having one in the system doesn't hurt as the brake balance can be upset just by changing tires etc.

 

[snakeoil24]

Call Willwood for the correct and safe answer.

 

[Kern Dog]

Only you and your car can answer that question. You must test the brakes, and if the rears lock up first, then you need to adjust the prop valve or add one if you don't have one. Having one in the system doesn't hurt as the brake balance can be upset just by changing tires etc.

The above is accurate...but I'll add my view on it too:
For certain, the rear caliper bore size needs to be smaller than the front since the front wheels do a greater percentage of the braking. If the fronts have a caliper bore of say, 2.5", the rear should be no greater than 1.75". (For example) In theory, if the caliper bore sizes are properly matched, you will need NO proportioning valve. Adding an inline valve set wide open will not hurt the rear braking simply because it transmits full pressure as if no valve exists. THis does allow you to incrementally reduce the rear brake pressure if needed.

 

[R/T Boy 67]

Agree with above. I have a disc drum setup on my car and I installed smaller wheel cyl. on the back and I tested the brakes as I mentioned above, and they work fine with no prop valve. I will probably install an adjustable one anyway because I might have a full load of moonshine in the trunk one day.

 

[1967coronet440]

Seems the concensus is to use it, considering I have it already might as well. Thanks for the reply’s gentlemen

 

[Mike67]

You can order a disc disc valve, if the MC is right, bore is right and ratio is set correctly the OE will work just fine.

 

[1967coronet440]

This is the valve I currently have

https://www.summitracing.com/parts/wil-260-13190