[Schurkey]

The trick is to run a 205 thermostat for the block, and a 120 thermostat for the cylinder heads.

Good luck with that...it's possible (I suppose) but extremely inconvenient.

[dataway]

It's an auto ... which adds some heat, AC which adds some heat, 068 cam, 2.93 gears (should help). Back in the day ... cruising around in Memphis on a hot day it never seemed to have much of a problem.

I'll be using the radiator out of a 68 lemans, 350, AC, Auto ... hopefully the same unit as found in the GTO. I think a different code, but same basic radiator.

When they recore these radiators .... do they/can they use copper like the original? Can the original copper cores be tested/restored to original level of function?

[Schurkey]

Originally Posted by dataway

I'll be using the radiator out of a 68 lemans, 350, AC, Auto ... hopefully the same unit as found in the GTO. I think a different code, but same basic radiator.

When they recore these radiators .... do they/can they use copper like the original? Can the original copper cores be tested/restored to original level of function?

How many cores in that radiator? I'd be looking for a 3-core. Four core if the ambient temp is often high. I've made it a point to install the largest radiator that will fit the rad support, including removing a block-off panel on my Toronado to install a radiator several inches wider than OEM.

Another issue is that radiator cores can have a high or low air fin count. The fins per inch are not guaranteed to be the same as the original equipment. It costs less to build fewer fins per inch. OTOH, there are "high efficiency" cores that have more fins per inch than OEM.

Original cores are unlikely to be usable after all these years and miles. Even if the water tubes can be de-scaled, the air fins may still be rotted. We see some of that in vehicles that are subject to salted winter roads--the salt-water mist kicked up by the car in front corrodes the air fins of the radiator of the car behind. If the air fins are not solidly attached to the water tubes, the radiator can be "clean" but not cool worth a crap.

Plenty of folks would suggest a new aluminum radiator. QUALITY aluminum radiators are a blessing. Cheap Communist Chinese aluminum radiators are...less recommended.

Your radiator shop can guide you.

[dataway]

In my case it's going to have to be exactly as OEM as far as the tanks go, and of course the physical size of the radiator will have to be the same. From what I'm seeing a copper/brass recore is going to cost about the same as a QUALITY US made new copper radiator.

Right now I have a "BI" code radiator out of a Lemans .... proper code is "PB" for a GTO with AC and Auto. So I may end up having to find some "PB" tanks at least ... I'll have to do some research to find out where to go. Basically I want the most cores as I can stuff into the proper size tanks. Pretty sure an Auto, AC, GTO used the biggest (most cores) radiator available that year (68).

Until I go pull it out of the shed I'm not even sure if the code letters were tagged to the radiator or stamped into the tanks, I'm just referring to my notes.

[ta man]

Originally Posted by Schurkey

The trick is to run a 205 thermostat for the block, and a 120 thermostat for the cylinder heads.

Good luck with that...it's possible (I suppose) but extremely inconvenient.

My engine will see 190 to 210 degree oil temps and 160 degree or under coolant temps if I let the engine cool down enough at the dragstrip when I make a pass.

[dataway]

Is it as simple as measuring the thickness of the core to determine the number of rows on an OEM radiator? Is it indicated anywhere on the exterior of the radiator?

I do have an example here that is "BI" code, and has a "4" below it. But seeing as it's from a 68, 350, auto 2bbl, AC ... I'm thinking it maybe a 3 row. Well ... come to think of it I could probably just look inside the hose connections

[Grand73Am]

You can see the holes of the flews just by looking into the filler hole. You'll see them at the top. Might need a flashlight if your lighting isn't good. So for example, if you see 3 holes across, you have a 3 flew, 3 row, or 3 core, whichever you want to call it.

[Tom Vaught]

All of my everyday driver vehicles have had the 195 thermostats and a/c and have never had a cooling issue in Michigan.
We get a few hot days, not like Tom S in Cali.

The 64 GTO, (owned forever) has always run a 180 degree thermostat. Lived in Missouri for several years (Hot days and Cold nights many times.)

Never have run a 160 Thermostat because, if I was worried about too much heat in the Engine/ Radiator, I always ran a restrictor ring and dialed in the temp I wanted to see in the engine. I was always wanting to remove the moisture in the engine (OIL) quickly. Water is H2O.
None of those elements are good with liquid petroleum products in engines for bearing/crankshaft loads.

Tom V.

[Half-Inch Stud]

my 455 activities get 180, no mechanical coolng fan. Still in dumbass mode on this one, but the iron heads seem to burn clean.

[Firebob]

160 in the summer and 180 in winter. Temps don't usually fluctuate too much. Will reach 205 if I'm stuck in traffic a while on a hot summer day but normally runs right wherever the stat opens.

[locomotivebreath]

http://www.stant.com/index.php/engli...s-thermostats/ . Interesting , but left me with a few questions . So your 180 isn’t fully open until 195 or so - so is 180 - 200 really the exceptable temp range for the 180 ?

[dataway]

Interesting .... I just got their "super stat" which apparently opens sooner and "throttles" the flow more so than a conventional type.

If at stat started to open at 180 it would probably depend hugely on the performance of the rest of the system how close it would get to fully open at 195.

I think thermostats do the opposite of what most people think. They don't keep temperature down to their rating, they keep temperature UP to their rating Otherwise you could use a heater core for a radiator and put in a 160 degree stat .

In other words ... they can keep your engine at 180 degrees if your system works well, but they can't keep it from reaching 250 if it doesn't.

I think the purpose of a 180 degree stat is not to make sure your engine runs DOWN at 180, from a design standpoint it's more to make sure your engine runs AT LEAST 180 .... if you take my meaning, as they are designed assuming your cooling system can handle whatever load the engine is capable of producing.

[Tom Vaught]

Originally Posted by locomotivebreath

http://www.stant.com/index.php/engli...s-thermostats/ . Interesting , but left me with a few questions . So your 180 isn’t fully open until 195 or so - so is 180 - 200 really the exceptable temp range for the 180 ?

That is true. 180 is the opening temp for the stat.
Full open is not necessarily the right position for the stat to be in anyway.
Just like air conditioning in your car, you don't want max A/C all the time,
you want the a/c temp to be right for the conditions. same with the engine
cooling.

Tom V.

[Formula8]

160 but runs about 180 under current conditions.

[locomotivebreath]

Ok then as mentioned above , 160 but runs at 180 seems like a capable system . I’d rather run a 180 myself but think I’ll start with the 160 just to see where it’s at with my iron heads & 10.1 comp

[Formulajones]

Originally Posted by dataway

I think the purpose of a 180 degree stat is not to make sure your engine runs DOWN at 180, from a design standpoint it's more to make sure your engine runs AT LEAST 180 .... if you take my meaning, as they are designed assuming your cooling system can handle whatever load the engine is capable of producing.

Correct. It's often misconstrued. The stat rating is where the engine temp will be at or higher. Depending on how efficient the cooling system is. As in my example above, it never runs 160, the original cooling system just isn't capable. I find most of my cars here with copper radiators, even the 4 cores, aren't capable of that (but they are slightly better). However I have 2 with Griffin radiators that can keep the temp closer to 160, even under high load conditions, still using the stock clutch fans and shrouds.

It's all going to depend on how well the rest of the system works.

[1968GTO421]

Originally Posted by ta man

Another 160 user here. I have been using 160 degree thermostats for 25 plus years in my Pontiacs.

X2, 160 works great!

[72LuxuryLeMansLa.]

So for all of you guys that run a 160° Stat, Do any of you have oil temp readings running below 180°F coolant temps?

[ta man]

My oil temp will read 190/195 down the highway at 60 to 80 mph..if I take the rpms up a bit more it will rise to 210 and in town oil temps will go up to 210.
This is a "hardblocked" shortblock I'd assume a non hardblocked shortblock would stay cooler at lower driving speed and possibly higher highway speeds?

[STEELCITYFIREBIRD]

"Ideally" you want your oil temp above the vapor point of water, to remove condensation from the crankcase. But where you pickup your oil temp from can greatly vary the temp readings.