Measuring engine temperature, No taco sender or gauge ... Options

[Chaznaster]

Hello all. With the weather getting warmer, I have started thinking about getting a handle on my engine temperature. I looked at quite a few discussions on here and most were about interpreting/ calibrating the stock(ish) gauges.

I have no sender at the taco plate and no gauge.

I happened on the approach to measure with a dipstick thermometer but it appears those are all NLA.

I have a 123 dizzy that transmits temperature but am pretty sure the base of that is far away from the sump and probably not an accurate reading.

A few questions:
* Is the 123 temperature value good for anything? Maybe there is a conversion? Although I expect it will warm slower and cool faster than the sump in the best case.
* What is the most straightforward way (I am OK with some spend and even running wires to the dash) to get a reliable reading? Gauge (VDO or other), thermal camera pointed at the oil pan? Other?

I appreciate your guidance ...

[Jake Raby]

Is anyone using the tapped hole the factory used for the CHT sender? Seems like an easy location to grab the head temp

This is the worst place to gather CHT data. I have been preaching this for 20 years, and people won't listen.
This location is made for the stock CHT sensor and was chosen by the factory so it would NOT see full CHT temperature, which would kill the sensor. It was also chosen to stay hot longer (why it is not finned) so when the engine is shut down, it does not go back to cold start prematurely.

I have tested this location simultaneously with the spark plug locations, and have seen it be 50*F low at a CHT of 250F, but after the spark plug area reaches 400F it can be more than 125*F low. This is exactly why the factory chose this location for the stock CHT sensor.

I spent a decade developing T4 cooling systems, and at times I would cover an engine with 28 thermocouples, with sometimes 6 being fitted per cylinder/ head, then drive the car 3,450 miles at an average speed of 76 MPH across the country while data logging it all. During this I proved that the stock CHT sensor location is a foolish place for a CHT thermocouple.

People always look for the easier way, and they give up everything in that quest. Go under the spark plug, or don't even bother with monitoring CHT~

[930cabman]

Is anyone using the tapped hole the factory used for the CHT sender? Seems like an easy location to grab the head temp

This is the worst place to gather CHT data. I have been preaching this for 20 years, and people won't listen.
This location is made for the stock CHT sensor and was chosen by the factory so it would NOT see full CHT temperature, which would kill the sensor. It was also chosen to stay hot longer (why it is not finned) so when the engine is shut down, it does not go back to cold start prematurely.

I have tested this location simultaneously with the spark plug locations, and have seen it be 50*F low at a CHT of 250F, but after the spark plug area reaches 400F it can be more than 125*F low. This is exactly why the factory chose this location for the stock CHT sensor.

I spent a decade developing T4 cooling systems, and at times I would cover an engine with 28 thermocouples, with sometimes 6 being fitted per cylinder/ head, then drive the car 3,450 miles at an average speed of 76 MPH across the country while data logging it all. During this I proved that the stock CHT sensor location is a foolish place for a CHT thermocouple.

People always look for the easier way, and they give up everything in that quest. Go under the spark plug, or don't even bother with monitoring CHT~

Thank you for the information, it sure is great to have guys who have been there before and are available to share their learned knowledge