2 Core Explorer radiator

[adsm08]

Most thermostats I have boiled do pop open.

Also, most engines that I have watched warm up if you hold on to that top hose it goes from cold to hot PDQ.

 

[4x4junkie]

Must be different types or brands of thermostats.

Ones I tested were the OEM one, and Stant (195°). It's a somewhat narrow range to go from open-closed and back, but I can easily get it to any width opening by adjusting the amount of heat on the stove.

But again, that's gotta play hell on the block (heads too) if cold water just rushes in like that.

 

[Shran]

I have never boiled one to test it, I'm just going off the fluctuations in the temperature gauge. It's not a large amount, maybe 30-40* or so, not enough to cause any thermal stress (or at least I wouldn't think so.) But it happens real quick, like your temp gauge drops that much within a second or two at most.

 

[ronclark]

SW Washington is not somewhere I would ever consider a cold climate.

I live in Vancouver now, but elsewhere in the province it hits -20 for a daily high (thats like -4 degrees f) and I am in the warmest province there is.

As I said, ask an Alaskan about what cold is. lol

I know PNW is nothing like Alaska.
so if having a big radiator in cold climates is bad why not just have a grill block in the winter or when you need it.wide open when you need max cooling?
I have tested grill blocks and in the winter i can block 95% and still not get hot

 

[4x4junkie]

I'm not so sure how reliable the stock temp gauge is. I've seen the one on my Ranger fluctuate a couple needle-widths occasionally at random (stock single-row radiator), but there never seemed to be any rhyme or reason in relation to reaching operating temp, throttle inputs, coasting down grades, etc. (I've seen it do it after being on the road for over an hour too lol, like there's an intermittent resistance in the wiring from the sender or something).
Maybe this is an excuse to put an aftermarket temp gauge on it and see what's really happening I guess.

FWIW, the gauge on my BII (has the swapped-in 2-core rad) pretty much stays rock-steady.

 

[Shran]

I had a cheapo Sunpro mechanical temp gauge that I observed this with. It's actually kinda cool to see the thermostat open on your gauge like that, reminds me of flushing the toilet or something.

 

[adsm08]

But again, that's gotta play hell on the block (heads too) if cold water just rushes in like that.

Its not that bad with the proper amount in the system. The engine block holds a little more tha. Half the total system capacity. It will heat up a single core rad full pretty quick.

If you ever watch it on a scanner as the engine warms up it comes up fast, drops a degree or two as the stat opens and then slowly tops off to full temp.

Postin' from teh Galaxy

 

[bfiakas]

As I've been reading all the post on my OP,I see a lot opinions on this subject.What I am seeing now from time to time is when I am warming up the engine for the first time at idle the the T-stat will start to open at 192 (spec) degs. and swing to 210 degs and then back down to 185? Is this to be expected or is the T-stat opening to late? Also when running at hwy speeds (65) I've notice the temp will surge from 190 to 197 and back to 190 on a flat run of hwy. on a Sunpro mech. gauge set.Is this a sign that the T-stat is starting to fail?

 

[4x4junkie]

If it just suddenly started doing that (and it's more than 6-8 years old), I'd say replace it. You wouldn't want a $8 part to ruin your engine.

Both my truck's T-stats are about 5-6 years old, I'm thinking I might try changing the one in my Ranger just to see what happens (I think it's due for a coolant flush anyway).