I searched but could not find the list of compatible gages and sending units.

With my sway I think I have a mismatch. Stock Gauge reads all the way to the “P” in TEMP but my MicroSquirt oil temp mounted in head only goes up to 190 F when the temp is on the P.

Checked case with IR thermometer and got comparatively close numbers to the MicroSquirt reading. CHT never above 320.

As a person the constantly scans the gauges I find this distracting to say the least.

Have Tim’s lights in the gauges so would need to match the sensor.

You have the late model gauge with the small red area. It's reading normal at the P.

Huh?

Engine was set up using old style CB Performance FI unit that has temp sensor in head. Click to view attachment

Yep that is what I have.

Click to view attachment

So, the sensor is reading oil temp inside the valve cover?

The stock gauge which seems to be reading high is reading from the bottom of the case in the stock location.

The MicroSquirt temp gauge is in the head and it reads very close to the IR thermometer.

That temp gauge in the valve cover area seems unreliable to me. I know oil can collect up there, especially at sustained high RPM, but I'm doubtful it's 100% submerged in oil all the time. And that's a terribly inaccurate way to measure oil temp. It'd work for MicroSquirt as an indicator of when the engine is warmed up, but I wouldn't trust those numbers to accurately reflect actual oil temp. The IR thermometer is a similar problem. You're measuring the metal, not the oil. Those aren't the same.

Try warming up the oil with a drive, then pull the dipstick and IR measure the end that was in the oil. It'll probably drop temp quickly, so you'll have to be fast about it. I bet that reading is much higher than in the valve cover.

What I was trying to say was, the P on that gauge would be normal operating temp. So, around 190 f

Agree. It is not intended to measure oil temp just a warm up value for MicroSquirt. But for comparison purposes it provides a reasonable level of measurement to say the oil temp is closer to 190 F than to the meltdown temp indicated by the oil temp gauge. This combined with the IR says that then engine is operating closer to normal than a overheating condition.

Found an old post by McMark that has some good info.

For verification i an buyin a new grave and sender to verify the temps. Will try to calibrate the old gauge after verification that it is not getting too hot.

Working on the assumption that a 180 to 220 F would be an acceptable operation range?