Well since my v8 swap was completed I realized I have no idea what temp my motor was running at, I didn't think too much about because the temp gauge hung right below the 1st quarter on the gauge. But then last week it hit 90+ degrees and my temp gauge went almost past half way and I freaked. So I decided I would do an experiment and document every thing for my fellow FB owners. The test was simple, hook up a mechanical gauge and compare to the stock gauge. Both mechanical gauge probe, and stock mazda temp sender were located 3" apart in the same coolant channel that runs between the 2 heads. The Mechanical gauge is a $18 Sunpro gauge from Autozone I know it's not a world class instrument, but it's been my experience that they are more then accurate enough. The stock temp gauge sender is a BWD replacement sensor, works exactly like the oem mazda one did. There is nothing to crazy about my cooling setup, my motor is a 93 ford 5.0 HO, with a 160F thermostat, stock thermostat on this motor was 195F. Radiator is your typical speed shop radiator, with a pusher electric fan, I know pushers aren't as efficient but it was the only way it would fit. As for the test it was simple, turn the car on with the E-fan off and take many pics with the 2 gauges side by side.

And on with the test.

The car is a 1985 gs, originally 12a equipped.


Pic of both senders they are the brass bits on the edges of the photo

 

 

 

interesting. i've read on here before bout how inaccurate the stock gauge is. ur bwd replacement sender might not have quite the same resistance as the stock one. but either way great comparison. in that last pic the stock gauge should be alot more toward the H side.

 

My thoughts exactly, I thought I would've been able to cover more of the stock gauge, but after the last pic I chickened out.

 

i think by the time the stock gauge gets to H with a rotary, it's already too late.