350 standard temp in Arizona.

[SquareRoot]

I'm 150 miles SW of you in Yuma. It was 112 here yesterday. Perfect for testing my cooling system after major changes this winter. 85 K20, 350 Vortec, 2 row aluminum radiator, dual 11" spal fans and Dakota Digital fan controller. 160 t-stat.
Primary fan on at 195 off at 190. Secondary fan on at 205 off at 195.
All new Vintage Air a/c system.
At 112 yesterday, it would stay between 195-200 as the fans cycled. Then I turned the AC on and it dropped to 185 and stayed there no matter what. WTF I thought?
Turns out the fans both go high when the AC is on and they move enough air to keep it at 185.
Works for me!

 

[Wumbo]

I put a 4 row radiator from rockauto in mine. Running a 195f thermostat, stock fan and shroud. You can watch the temp swing as the thermostat cycles. It will go up around 200 or so, then when the thermostat opens, it drops almost instantly to 185-190. That big 4 row cools it fast.

 

[donnieray]

With 454's in '81 and up trucks the factory added these aux fans. There is a temp sensor (ground) on the passenger side of the block that turns on the fan above a certain temp and when the A/C compressor is on. I would second not using a flex fan.

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I love that rig man! And third on the flexi-fan. They tested fans on an episode of Engine Masters and the flex fans if I remember correctly robbed 12 or 15 hp compared to no fan mounted. Clutch fans were much better.

 

[DoubleDingo]

I love that rig man! And third on the flexi-fan. They tested fans on an episode of Engine Masters and the flex fans if I remember correctly robbed 12 or 15 hp compared to no fan mounted. Clutch fans were much better.

I still need to get one installed in Crusty. It has a flex fan, but it doesn't overheat. It could benefit from having some extra ponies freed-up, though.

 

[MikeB]

I'm 150 miles SW of you in Yuma. It was 112 here yesterday. Perfect for testing my cooling system after major changes this winter. 85 K20, 350 Vortec, 2 row aluminum radiator, dual 11" spal fans and Dakota Digital fan controller. 160 t-stat.

Why the 160 t-stat? Does that let the engine get up to optimal 185-190 degree operating temp in the winter?

Glad to hear the truck is staying right in that range this summer!

 

[peats]

run a 160 stat

 

[SquareRoot]

I see no benefit of a hotter running engine. The 160 stat just means it starts cooling sooner. It does help in my case as our Arizona Winters are still 75*. It lowers underhood temps which helps with heatsoak particularly with carbs, especially Eddy's like mine.

 

[1985c20]

Hotter running engines run more efficient which causes less wear. All oem’s have been running thermostats around 195° since the 80’s for a reason. Also a higher thermostat keeps water in the radiator longer so it can shed more heat.

 

[idahovette]

Hotter running engines run more efficient which causes less wear. All oem’s have been running thermostats around 195° since the 80’s for a reason. Also a higher thermostat keeps water in the radiator longer so it can shed more heat.

It also keeps it in the block longer building more heat

 

[Memaloose]

Mine's all stock, 350, auto,no a/c, I live in northwest AZ and the stock gauge needle never goes to even 5/8, no temp numbers. It's a 1975 with 83,000 miles. I flushed the system, replaced hoses and thermostat and pressure cap, replaced overflow tank (rotten). It's never overheated. Always use a shroud and check for leaks. A light foot on the throttle helps as does staying out of city traffic.

 

[SquareRoot]

Hotter running engines run more efficient which causes less wear. All oem’s have been running thermostats around 195° since the 80’s for a reason. Also a higher thermostat keeps water in the radiator longer so it can shed more heat.

I'd have to see some science to buy that. I am not subject to emissions or concerned with effeciency on 40 year old technology otherwise I'd just do an LS conversion. After hot rodding in the desert for 30 years I know what works and what doesn't.

 

[Chevyman1985]

If you use the auto parts stores, get the 433730 radiator. Don't get the 433716 like I did at Oreillys 3 1/2 years ago, that one is for non a/c.

For a desert truck, I'd run nothing less than a champion 3 row.

 

[donnieray]

If you use the auto parts stores, get the 433730 radiator. Don't get the 433716 like I did at Oreillys 3 1/2 years ago, that one is for non a/c.

For a desert truck, I'd run nothing less than a champion 3 row.

Welcome to the forum. And that's good advice!

 

[MikeB]

Hotter running engines run more efficient which causes less wear. All oem’s have been running thermostats around 195° since the 80’s for a reason. Also a higher thermostat keeps water in the radiator longer so it can shed more heat.

185-195 also evaporates moisture in the crankcase more efficiently. At 160, you're contaminating the heck out of the oil with condensation from blow-by. Probably not an issue in the summer with a 160 t-stat, because the engine will usually warm up to 180 or more. But in the winter that same t-stat is a problem. So engines with 160 t-stats will need more frequent oil changes.

If you doubt any of the above, check out the BobIsTheOilGuy.com forum.

 

[73c20jim]

The 160 stat just means it starts cooling sooner.

Please explain how this works. All a thermostat determines the lowest temperature the engine will run. The engine will get hotter than that depending on circumstances.

You can have a 160 and the engine might still overheat.