Subject: [FlyRotary] Re: water temp sender

 

I would ditto what Rusty said but if you study the cooling passages well you will note that the second pass is the hot part of the engine.  In other words, the coolant comes the engine.  goes along the top and spark plug side, past your sensor, then down and across the combustion chambers and exhaust/intake side, then back out at the pump.  This further explains the difference in temp.

 

Dave Leonard

 

Look closer still.  The first pass is down the combustion chamber side of the engine (definitely the hottest).  It is possible (never measured it myself) that the coolant is getting cooler on the second pas down the intake side of the engine (except where it goes past the exhaust ports).

Notice that the heater port leaves the engine before it makes that pass down the cool side.

 

Running the coolant in this way tends to equalize the temperature across the block so it is a good thing. 

 

Tracy