Heat Soak - threshold for warning sensor

[mark2]

I fitted an Engine Watchdog temperature monitor the other day (the kind that measures block temperature). Sensor is on the rear of a head (V8) Now under normal running it runs at about 91 degrees. I've set the alarm to 95 degrees at this stage.

However, after stopping for about 5-10 mins and restarting, the temp rises to 105 degrees and the alarm sounds until its been driven for about 2 mins.

My question is, if I set the alarm to a few degrees over the maximum heat soak temperature (which is higher than operating), will this give me adequate warning of an issue that arises during normal driving?

[djam1]

Mark
I think the 105 c setting is too low for a v8 I dont know what radiator cap pressure you are running but if its 12-15psi then your boiling point is probably 120 c so you could increase your alarm temp to 115 c.
I may be wrong with my figures Im sure someone wiser than I will be along to correct me.

[mark2]

I hear what you're saying but I'm not sure that I should be entirely correlating external engine temp with coolant temp. I would love to have a test engine which was drained of coolant while running and monitor the temps during the process........