I have a neurosis and want cooler temps.. it's more of an experiment than anything

 

I experimented opening the t-stat sensing holes up some on my dads truck, and it didn't do much. Lowered cruising temperature by a few degrees, but did nothing to idle temperatures and actually made the engine run a bit hotter on really hot days. It does make the holes less likely to clog though.

Keep in mind, those 4 holes (or 2 depending on your -t-stat) in the t-stat also determine how much cooled coolant from the rad is mixed with hot coolant.
I believe the RAVE stats its about 90% cooled to 10% hot, so those holes are a specifically determined size.

Increasing the sensing hole size will make the t-stat more likely to open, but at the cost of more hot coolant mixing with cooled and in turn lowering your "peak" cooling ability when your rad cant keep up. This is what i experienced.

That's my understanding of it anyway, someone correct me if im wrong. The genuine 180 t-stat seems to be the way to go.

 

re: I have a neurosis and want cooler temps..

Amen.

 

what about a small hole in the stat itself?

 

In conventional "chevy" style stats, like a D1 has, the small hole, or one with a "jiggle" device, is positioned to allow steam pockets to pass.

The D2 stat is already getting a constant flow of hot coolant into the "chamber of secrets". There is also a "jiggle" device that is a captive small ball bearing in the flange of the stat. But water is always leaving the chamber thru the slots at the bottom and out the side hose. When cold startup, the disk with metering holes descends above idle rpm, and allows more coolant to go toward heater (faster passenger compartment warm up). When main part of stat opens, it shoves that soft spring bypass disk back closed, reducing flow to the chamber from the recently in the engine coolant to a trickle determined by the metering holes.

If you do the in-line bypass stat mod, you want that little hole to bring hot coolant to the stat.

You can also have physical trash in the metering holes from work on the cooling system.

 

BTW, buy the good Land Rover stat, and retire what you have now to the spares shelf. Less than $75, the Ultra Gauge will love it. And you can worry about which button on the radio controls the flux capacitor, so you can go back to the 60's and listen to "Heatwave".

 

I was just thinking I could move a small amount more water, and drop temps slightly.. I'll just order a grey soft spring...

I've been looking for the on off switch for the continuumtransfunctioner...

 

5." The in-line modification (conventional stat in a metal housing in line with hose to top of radiator) gives smoother operation, and you have a wider choice of stats."

That is what I did, a good long time ago now, so am using a standard Chevrolet V8 180 deg. T-stat, and am perfectly happy with it. The way I look at things, this conversion is far better than original Rover system & T-stats cost less than $10. each. WOULD IT BE DUMB TO PUT IN A 170 DEGREE T-STAT, SINCE I THINK THAT WOULD BE BETTER DURING THE HOTTEST PART OF SUMMERS?

 

Your summer is not that hot. 180 should be fine.

 

I believe the OP referred to it as a factory Freelander t-stat