The Ferrari 328 and 412 models in the 1980’s use a heater valve (p/n 126324) that is operated by an electronic control motor, as depicted above. After 30-40 years, many of these valves are beginning to leak, and the original heater valve is no longer available. The original 126324 valve (part number 34 in diagram below) is a unique shape and is connected to the control motor by a bracket (part number 42) and linkage (part number 35). The valve/bracket/linkage/motor assembly is then attached to the bracket numbered 15, which secures it in the vehicle.
In order to replace these valves and keep all original functionality, a replacement valve was selected that has the correct inlet and outlet hose sizes and orientation, correct actuator orientation and direction of rotation, and wide availability (to prevent it from also becoming obsolete). The original assembly and the replacement valve were modeled in Autodesk Inventor, and the original valve and bracket were replaced with the new valve. A new bracket was designed to support the replacement valve in the original location using original mounting points. Thus, the replacement valve and new bracket will directly replace the original valve and bracket.
A two-piece coupler was designed to couple the motor to the valve shaft. One piece screws to the valve shaft, and the other engages the square shaft of the motor. The coupling allows for slight misalignment of the motor and valve without binding.
A rendering of the completed bracket and valve assembly is shown below (the coupling is also depicted connected to the bottom of the valve, but is mostly obscured by the bracket). The brackets and couplings were constructed of Nylon PA12 using the HP MultiJet Fusion process. The completed valves were assembled and tested and performed just like the original valve, but without the leakage.
For more 1980’s Ferrari parts replacement, read about my design project of replacement headlamp switch operating cams for most all 1980’s and early 1990’s Ferrari vehicles. Or check out more of my projects or my mechanical design projects.
