Line locks, proportioning valves, plumbing, oh my!

[81cutlass]

Curious what people have done (photos?) when they replace their factory prop valve with an aftermarket one and add a linelock. Where do you mount things, what does the plumbing look like, ect?

I am putting a linelock on my 2+2 and am looking at plumbing around the stock proportioning (combo) valve.

I have LS1 disks on the front and blazer disks on the rear. The stock disk/drum combo valve has worked well oddly enough for front/rear bias. It works better than the disk/disk I tried.

The dilemma is you are only supposed to put the line lock solenoid after the proportioning valve. Instructions and NHRA call for it. I think people do put the line lock between the master cyl and prop valve (and it works) but I am considering a book legal method. I can understand why putting pressure across the prop valve regularly isn't the best idea.

I haven't found a way with the stock G body proportioning (combo) valve to make the line lock work without making the plumbing dumb. The stock prop valve has one inlet and 2 outlets for the front brakes, and I have seen instructions recommend, and people just remove one of the outlet lines and plug one port on the prop valve, take the other unplugged outlet port and run to the line lock, and then tee after the line lock to the front brakes, but that just seems dumb and a lot of excessive plumbing.

So I am thinking of ditching the stock prop (combo) valve and adding an adjustable proportioning valve for the rear brakes (like this one) and then running new line from the master cylinder to the line lock, and then tee'ing after that.

 

[64nailhead]

If your stock proportioning valves works well, then I wouldn't mess with it.

I was not aware of any NHRA rule about line lock location, but I have read the instructions that came with the two that I have, and you're correct in that hey indicate to install it behind the proportioning valve. I can understand for the rear brakes because it's a single line, but for the front brakes you would need two line locks. That would seem stupid to me. I've installed both of mine between the master cylinder and the proportioning valve on the front brake line only. Of all of the items that I've been grilled about at tech inspections, the line lock location has not been one of them. I bolt it to the plastic inner fender between the master and fender.

I've used one the adjustable regulators on my Wildcat without much success. I'm planning to install an aftermarket proportioning valve and ditch the adjustable.

You need to tie that thing into your clutch switch as well.

 

[1KWIKSIX]

Hope I’m not hijacking this thread, but Would love some suggestions on how & where to mount line lock on my HydroBoost set up.
Wilwood master cylinder with Wilwood adjustable brake proportioning valve (original proportioning valve removed)

 

[-dw-]

My Olds has 12” brakes in the front and s10 disc in the back. Not enough pressure to the back to hardly stop the wheels spinning up on stands. I ditched the stock prop valve, T-ed the fronts and added Wilwood adj valve in the rear line. Passengers really pucker when I wait till the last sec to start braking. 😳😀

 

[64nailhead]

Hope I’m not hijacking this thread, but Would love some suggestions on how & where to mount line lock on my HydroBoost set up.
Wilwood master cylinder with Wilwood adjustable brake proportioning valve (original proportioning valve removed)

Are running a stock prop valve also?

 

[64nailhead]

My Olds has 12” brakes in the front and s10 disc in the back. Not enough pressure to the back to hardly stop the wheels spinning up on stands. I ditched the stock prop valve, T-ed the fronts and added Wilwood adj valve in the rear line. Passengers really pucker when I what till the last sec to start braking. 😳😀

I wouldn't recommend running without a proportioning valve. It serves a purpose.

 

[565bbchevy]

I have the stock proportioning valve with line lock and I am running a Wilwood adjustable valve in the rear line and have it mounted to the inside frame rail in front of the rear tires going to the Wilwood rear disc and because I have frontrunners and drag radials I have it adjusted so the rears help a lot with the stopping.
And with my belt driven vacuum pump that pulls a constant 28 lbs of vacuum my Monte stops just as fast as it goes.

 

[81cutlass]

I have the stock proportioning valve with line lock and I am running a Wilwood adjustable valve in the rear line and have it mounted to the inside frame rail in front of the rear tires going to the Wilwood rear disc and because I have frontrunners and drag radials I have it adjusted so the rears help a lot with the stopping.
And with my belt driven vacuum pump that pulls a constant 28 lbs of vacuum my Monte stops just as fast as it goes.

Is the stock prop valve gutted?

Line lock between the master and prop valve?

 

[565bbchevy]

Is the stock prop valve gutted?

Line lock between the master and prop valve?

Fully functional factory proportioning valve, the brake set up was recommended by Wilwood, they said the adjustable would work better for me than a fixed disc/disc valve and they were right, also I did this 20 years ago.
As far as the line lock I don't remember exactly how it is plumbed but I followed the directions and have it mounted on the frame rail below the master cylinder.

 

[81cutlass]

My Olds has 12” brakes in the front and s10 disc in the back. Not enough pressure to the back to hardly stop the wheels spinning up on stands. I ditched the stock prop valve, T-ed the fronts and added Wilwood adj valve in the rear line. Passengers really pucker when I what till the last sec to start braking. 😳😀

That's what I was thinking of doing with my setup. Was the issue of not having pressure at the rear with the stock prop valve.

I wouldn't recommend running without a proportioning valve. It serves a purpose.

So that's what I'm curious on. What does the stock prop valve do that can't be done with an adjustable one and some tees? The only thing I imagine I'm loosing is the brake light switch.