An Alarming Discovery

New temperature switch.

Sometime after I purchased WhiskyJack I discovered that some one had made a change to the engine monitoring system.  They had replaced the engine temperature switch with a temperature sender and hooked that sender to a temperature gauge.  While it is all well and good to know the temperature of the engine, making this modification disabled the over temperature alarm.  What this means in a practical way, is that you must be looking at the temperature gauge to know that the engine is overheating.  Even with the most diligence, the chance of this happening is slim to none.  While I had the top end of the engine apart, I rectified this.

Temperature sender for gauge.

I removed the temperature sender and replaced it with the proper switch.  Since this engine was designed as a raw water cooled engine, the switch is designed to close when the engine temperature exceeds 140F.  Because I wanted a temperature gauge on the dash, I installed a temperature sender at the other end of the head.  This required drilling and tapping an unused plug where the cooling water exits the head, on its way to the exhaust manifold, with 1/4" NPT threads.  It is in a location that is difficult to access when the engine is assembled, but very well protected.  Now, I have the best of both worlds:  I can observe the temperature of the cooling water as it exits the head, AND, I have an active alarm system that will alert me to an engine over-temperature situation.