Weird heater box cable question

[Crimson Nape Racing]

I have an ex race car with a Hargett raised shifter where the heater levers once were, and I’m adding heat back to the car. Has anyone ever used bicycle brake cables and routed them (housing & cable) thru the tubes in the floor? My rear tubes in the engine compartment are gone and my heater control lever(s) are going to have to be mounted 8-12” in front of the tubes in the floor, so wires with housings will help on both ends of the system. The housing for the bike cables are 4mm OD, and look like they will fit thru the tubes, but I can’t get my calipers in there to measure the ID of the tubes. The car is a 1970 911 with a 3.2.

[PeteKz]

The heater cable tubes in the center tunnel only stick out about one inch, then a plastic case goes from there up to the heater valves. Are you missing the plastic casing, or the 1” stubs? Or both?

I think you could replace the solid wire with a bicycle cable. The cable is retracted by the springs on the heater valves, thus the wires should always be under tension, so it should work.

[Crimson Nape Racing]

The plastic cases from the metal tubes to the heater boxes are missing. The bicycle cables aren’t too expensive so I think I’ll just give it a try and see if it works.

[Nditiz1]

The guide tubes (tubes from firewall to heater valves) are available new.

[Crimson Nape Racing]

Originally Posted by Nditiz1

The guide tubes (tubes from firewall to heater valves) are available new.

Yes, but I will be mounting the lever on the side of the Hargett shifter so I need guide tubes on that end also.

[Crimson Nape Racing]

For future searches, the bike cable does not work unless you can find a way to keep it from pulling thru the metal tubes in the shifter tunnel. I ended up making ends for the bike cable tubes so they work just like the factory tubes.

[fanaudical]

Silly esoteric tidbit - You might consider using bicycle derailleur cable and housing rather than brake cable and housing. There is a difference in how they are wound. The derailleur cable housing is stiffer along the axis for finer control of linear displacement of the cable (which is what you want with your heater box valves). Brake cable housing will withstand higher compression reaction from the cable tension (bike brake cables and housing are designed to better modulate tension when the brakes are applied).

[lateapex911]

Originally Posted by Nditiz1

The guide tubes (tubes from firewall to heater valves) are available new.

I'm trying to restore/repair my heater boxes, after 50 years it's a bit if a mess.

Of course, the 3 of the 6 studs that hold the flapper boxes to the chassis snapped off.
Not sure what to do about that. Maybe drilling and a nutsert?

[PeteKz]

If you come up with a neat solution, let the rest of us know. I need to do this job too, but have been putting it off.

[Mike Andrew]

Will be replacing my heater boxes as well. Replacements in hand and ready.

Please post any solution that you come up with for the studs. Looking at mine, all I see are masses of rust and no discernible thread form. I see disaster writ large here.

[lateapex911]

So, I've got the heater boxes apart....the ones I bought a few years back (YES, I am behind schedule LOL) are not correct. So I'm media blasting mine after disassembly.
The "Other" site Stoddard shows a set of flapper boxes in the "Original red color".



So does anybody know the story on that?? Mine has red plastic bushings (In great shape!?) but it looks pretty black.

I'm probably going to powder coat them, (I'd consider Cerakoting, but I don't think they have red and it's $$$ and frankly many more steps, and the tolerance here seem loose enough for powder coating)
Looks like my in stock powder coat "Koni red" is close enough for deep under the car can hardly see it LOL.
But I have black too.

Does anybody know what the "original red" comment refers to?

[Ian Comerford]

You can buy stainless steel boxes now which are pretty much fit and forget, although the springs still rust. The cable you need is a Bowden cable which allows pulling and pushing, bicycle cables are no good for this