Adjustable proportioning valve location ... heat issues?

[Cobra Dude]

Most direct location I can find, with good access to the adjustment knob and good access to drill mounting holes (car is already built with engine in, etc), is close to the headers (about 10" above headers and a couple inches rearwards. Headers are ceramic coated. Is this a problem for the prop valve?

I can route the brake lines up to the firewall, then back down to go to the rear, but would really prefer to keep the lines short and not clutter up the engine bay.

Comments, answers, clues appreciated.

Thanks,
-Neil.

[Jeffs_66SC]

I'm looking for the same info. Thinking about putting my valve on the driver's side of the tunnel, just forward of the bulkhead. That way it can be adjusted from the cockpit. Looking for ideas/photos. I'd be interested in talking on the phone. Maybe we can come up some solutions.

Jeff

[lineslinger]

Sooner or later heat will become an issue, too close to the headers, any plastic involved in your configuration? The braking system, uneven fluid temp. Do you want that uncertainty? Configure it in a way that leaves you confident, not wondering.

[Cobra Dude]

Here's what I eventually did for this...

On draining the stock system, I noticed that the fluid was indeed milky, so yes it had been boiling. But it's been like that for over a decade, so it's definitely not major heat. That setup had some brake lines only a few inches away from the headers, and the PV was mounted on the firewall just below the booster.

What I did now was place the new (adjustable) PV in the same approx location (below the booster), but I'm making a heat shield for it (car still hasn't driven since). Also, all lines are routed away from the headers now, which will make a major difference. (Rather than going from the PV to the MC right over the headers, the line goes from the PV up the firewall to the underside of the top of the fender, then forward towards the wheel well, then down to the MC). And I'm using DOT4 now (instead or regular DOT3) for it's higher boiling point. DOT4 is fully compatible with DOT3 -- but don't use DOT5 as that is silicone-based. BTW, DOT4 is available at motorcycle shops.

Now, with that heat shield for the PV, I can do one of two things -- (1) either make a simple shield for the PV and possibly cover the brake lines with some DEI-type of heat-shield sleeve, or (2) I can make a larger heat shield that goes from firewall to fenderwell and routes the air above the headers out the louvered side vents. In the first situation, the prop valve would be more accessible (from the side vents), but in the second, there will be much less heat. The PV is still very accessible with the hood open. I'm not concerned about accessibility (such as controlling it from the cockpit) as I don't plan to keep futzing with it after the initial testing/tweaking period, and I am always against routing any fluids into the cockpit. Perhaps you could mount yours with only the control knob in the cockpit?

Cheers,
-Neil.