0.25 mm equals 0.0098 inches. ( 98/1000 " …let’s be generous and call it 10/1000 ). Not much space for water flow. Are you sure those numbers are correct ? SD
Yes indeed, it must be cm and not mm.
I ordered two Gates 33188S thermostats from Rockauto.com and they arrived yesterday, but in the box are MotoRad thermostats. Grrr. I read on other forums (Miata) that Gates is just getting what they can and putting them in boxes.
Because this forum has evolved to thermostat trouble and I’ve solved my gauge issue, I’m moving the conversation to a more applicable forum for future users:
"Motorad" high-flow thermostats - #60 by MattFurness
Update: I’ve driven the Jag for several days in a row including some highway runs and some stop-n-go traffic. With my full-extending Gates labeled MotoRad thermostats and my properly grounded voltage stabilizer, my engine temperature gauge never indicates higher than the right-most leg of the letter “m”. Good news. Also, I installed a left bank temperature sending unit of the same part number of the one on the right and the temperature gauge needle really doesn’t move when flipping to the other bank (and allowing time for the bimetallic strip to settle).
I think you will find very little, if any, variation in temperatures between engine banks in a properly maintained V12 engine.
If it’s measurable, it’s too much! The problem with the V12 with the 1-1/2 pass radiator is that the upper 1/3 of the rad can get plugged. When that happens, the left bank cooks while the right bank is still running cool. Then Jaguar, in their infinite wisdom, installs the one and only gauge sensor in the right bank! And the CTS for the EFI in the left bank! That’s why my original recommendation was to swap the two. Unfortunately, not the same thread nor resistance specs.
Installing a gauge sender in both banks is fun and all, but when you’re not focussed on it, please leave it switched to looking at the B bank. That’s the one that’ll tell you if there’s a problem.