Wayne:
My oil temp gauge is reading low and I need to source out a new gauge or sender. Can anyone point me in the right direction? The plane is a 1969 B23 Musketeer s/n M1275.
Jeff Bryant:
I installed the OPT-1 Oil Temp and Pressure instrument from Electronics International. Found out that my oil temp gauge in the aircraft was reading 40 degrees F low. The oil temp has always been at 165 degrees F. The gauge in the aircraft never was in the green arc which starts at 120 degrees F. With the new EI OPT-1, I see that even at altitude, where the ambient temp is 20 degrees F, the oil temp is 165. Makes me feel better.
The OPT-1 is a legal replacement for the gauges in your aircraft. The unit is approved by STC and your IA can sign off the install on a 337. Comes with all new probes and harness and installs in around an hour and a half to two hours.
Editor’s note:
The referenced EI gauges are qualified to be installed as primary gauge replacements. They are excellent units, though far more expensive than having the original gauges overhauled. They are typically 2.25″ diameter round gauges, and each requires its own hole. That makes them functional replacements, but they can’t occupy the location of the OEM gauge. To my knowledge, no one (other than Beech at times) is making exact replacements for the OEM gauges.
Replacing a complete OEM cluster gauge with EI units (and senders) would probably cost at least twice the price of a complete new cluster from Beech… if you could get the latter. There are also few panels with the available space for that many new round gauges. In contrast to the factory gauges, the EI gauges usually offer more functionality than the OEM version. Just make sure you understand all the pros and cons. I haven’t read the terms of the EI STC; some like this require that the original instrument be removed, or be placarded as “Inop”, to prevent pilot confusion at a bad time.
Since it isn’t very intuitive, here is the EI link.
http://www.buy-ei.com/