last updated 09/25/02

Spica TA Evo II
Original TA
electronic device

Welcome to the SPICA TA-homepage, a subdomain of http://www.mmanthey.de. There are some information at http://www.mmanthey.de/Assembling/Spica_TA/spica_ta.html, too.

Due to the fact that the thermostatic actuator (so called Spica TA) of my ‘75 Montreal caused several problems, I planned to build a new replacement for it. Unfortunately, the realization of an electronic replacement device will need much more time as I thought before. So I began to design a replacement TA using the same technology as the original one, hydraulic fluid.

After the prototype was ready, where I used some parts of the original TA like the plunger and the spring, I encountered that the sealing problem is most difficult at this project. I used an o-ring like the original TA. As an o-ring is a static sealing, I searched for hydraulic sealings for this (very small 4mm) dimension and found some special parts, which has the ability to seal up up to 400bar. I calculated that the pressure inside a TA is about 30 bar at room temperature. The most important thing is the guidance of the plunger, I wanted to choose a bronze guidance for a new TA. After that I designed a new actuator, which I called the “Spica TA Evo II” and had the parts for two TA’s made at a local manufacturer. This really took a long time.

Nevertheless, both are ready now and partially assembled for teseting reasons. The first one will be send to a Montreal owner in Finland, who is ready to test it. The second is for my Montreal. More on this later.

If anyone’s interested in a replacement TA, let me know!