I intend to drill and tap the side of my oil cooler sandwich plate to fit an oil temperature sender. Where is the best place to do this. Logic tells me that the sender needs to be in the flow of oil going to the oil cooler, such that my gauge reads the hottest temperture the oil is at in the engine.
Or doesn't it really matter ?

thanks

think of where you will fit the sender so that it does not obstruct oil flow.... and have a plug with the right thread so that if you decide not to fit the sender, you can block off the hole.

alumium is a very good conductor of heat (as seen when used in aluminium car radiaotrs) so it will get up to temperature quickly - obviously the amount of metal and tempertaure of surrounding air will affect that time. As the oil temperature isn't going to change rapidy, like rpm say, then the slowness to react shouldn't bother you too much

So if the sender is not in contact with the oil (that would be what I would try to do) then you will still get a reasonable accurate reading, can't put a figure on it unfortunatley but within 5 C I would guess.

I have found the aluminium on the sandwich plates etc to be awkward to tap. It tends to pull out chunks and a poor thread results.

Use plenty of lube (parrafin) and back out the tap very often. If you feel resistance when backing out do not force as this will rip a chunk out of the thread. Wiggle it back and forth and blast some compressed air in.

John

thanks for the advice I'll find an 8.9mm drill bit and go easy when tapping the hole.