FredR

928 Motorsports used to sell this sandwich plate on the basis that it fits/works on a 928 whereas other similar products have fouing issues - no idea if they are operating these days or not since Carl sold the business.
https://www.cantonracingproducts.com...0mm-1-5-2-5-8/

I cannot verify that it works but it has a metric fitment- 20mm x 1.5mm. It has an inlet port and an outlet port that are both 1/2 inch NPT connections and Carl used to sell this kit with two adapters - a 90 degree and a straight through 8AN connector for fitting an oil cooler or an accusump kit. To fit a temp gauge you would need an adapter for the oil outlet port to mount the sender and a plug for the return port given your intended use.

Below the ref on 928 Motorspors website:

https://928motorsports.com/product/oil-sandwich-plate/

GregBBRD

As well you should be!
It is completely impossible for oil temperature to actually be 70 degrees, after 2 hours of running, regardless of what speed you are traveling/condition of the thermostat.
There has to be some issue with the gauge, the sender, the wiring, or the ground path to the oil pan.

GUMBALL

I do appreciate all the replies.
And I do appreciate the reply from "Speedtoys" (Thank You) regarding the heat sink and air cooling at the drain plug location - that makes the most sense.

Permit me to reiterate Part B of the original question:
Is there a simple way to install a temp sender in the oil system that is more effective than the pan drain plug ?
Is there a port in the engine block that will suffice ?
Is there an adaptor fitting that will attach between the engine block and line to the oil cooler ??
Would an adaptor between the engine block and oil pressure sender?? Is there sufficient oil flow there to give a better reading?? Or will that be more of the same ?
All of the sandwich plates that I have found are for the addition of an oil cooler, which would be superfluous for this application.
My original intention was to do a simple installation to monitor oil temp, where precise accuracy was not mandatory.
Unfortunately, this has turned into an engineering project.

Speedtoys

While others help with "where"...

Why are you measuring?

GregBBRD

There's nothing wrong with the drain plug location, it will tell you the temperature of the oil in the pan.
If you want a different location, you can remove the oil filter and drill and tap a hole into the void just above the filter (depending on how large your sender is...)
​​​We have also removed one of the oil galley plugs in the cylinder head and tapped it for an adaptor to a sender.

FredR

In an earlier post I asked if you had a photo of the sender unit you deployed.

Does the sender have a single pin or does it have two pins? Some senders have a single pin in which case the unit is grounded via the body. If this is the case and you used PTFE tape to seal the sender, then resistance to earth may possibly be corrupted. Indeed some senders [like the temp2] have two channels.

Such circumstance could explain what from my perspective are "corrupted" readings. Seems rather obvious and I doubt this will be the case but good to eliminate such. If there is any doubt you could try running a separate ground cable from the body using a crocodile clip on the body of the sender for test purposes.

There is no logical reason why the approach you have taken should give unreliable results and taking measurements elsewhere will not give you more meaningful results unless you specifically want to know the oil temperature going to the bearings or returning from the cooler.

GregBBRD

And the temperature at the very end of the head, away from the oil feed to the head, might really frighten you....

GUMBALL

Thank You.
the sender has 2 leads, and I already checked the sender for continuity as well as ground.

FredR

Well I cannot think of anything else to check unfortunately- unless you used a stock temp2 sensor!

I should also correct an earlier post regarding the sandwich plate. You asked about availabiity of such thus the link I sent but I also forgot that those things are full flow units so what I wrote in support was senior moment jibberish. It could of course be plumbed into a flow circuit but it would be messy to say the least. Those units often have side ports to enable fitting of a sender but that one does not and even if it did it would probably be useless given the 928 engine's spacial geometry.

The only other thing I can suggest is to remove the sender unit you fitted and re-test it to check that it has not gone sideways post fitment. My expectation is that if and when you get the system working you should see oil temperatures in the range of 100C to 110C in a fully warmed engine this time of year otherwise there would be no need for an oil cooler being driven by a radiator at 90C.