I am in the process of installing an engine watchdog temperature alarm. The display unit fits quite well into the coin tray and I am now looking for a suitable place to secure the sensor. It is a single 10mm diameter metal eye with sensor lead attached and needs to be secured to a "hot" part of the engine. There is an empty threaded hole on top of the supercharger block (yellow arrow) which would be ideal but my question is is it ok to use this and insert a suitable size/thread stainless steel bolt or is there a risk of the block cracking with expansion if a bolt is in there?

Alternatively, I could use one of the existing bolts on the supercharger but am concerned that with the thickness of the sensor (2mm) it might not fully re-seat.

Sorry if a daft question but don't want a cracked supercharger

 

well i would imagine if its already drilled and tapped it aught to be stable enough.

 

Having given this more thought I reckoned that putting the sensor on the supercharger which is likely the hottest part of the engine was probably not a good idea as it would be less sensitive to small changes in temperature so just use one of the cam cover bolts instead.