Engine temp on chevy small block

[Chris142]

305 or 350 I'm not with the car so I can't get pictures right now. What is the good rpm setting for it

As fast as you can stand. You don't want it to chirp the tires when you put in in gear if it's an automatic. Keep in mind that both those engines put a lot more heat into the cooling system.

 

[atikovi]

$300 for an aluminum radiator. https://speedcooling.com/product/19...yj7pTCax-di9RpGkxBIZwI7k3e8H4E6UaAo6nEALw_wcB Is this a restoration or you modding it?

 

[Carburetor1]

As fast as you can stand. You don't want it to chirp the tires when you put in in gear if it's an automatic. Keep in mind that both those engines put a lot more heat into the cooling system.

It's a 4 on the floor manual trans..

 

[Carburetor1]

$300 for an aluminum radiator. https://speedcooling.com/product/19...yj7pTCax-di9RpGkxBIZwI7k3e8H4E6UaAo6nEALw_wcB Is this a restoration or you modding it?

Little bit of both

 

[MolaKule]

As others have stated, it appears the radiator has restricted coolant flow (possibly blocked cooling passages), assuming the water pump is ok and the thermostat is fully functional and of the right temperature range.

 

[wag123]

Not sure on rpm but engine idles smooth. Original radiator and 4 or 5 blades on the fan. Also no shroud

You have an air flow problem. Originally, when these cars came from the factory with a 6-cyl engine (1/3 of them did on the Bel Air, and the majority did on the 150 and 210), the radiator was mounted in front of the core support, and on the factory V/8s the radiator was mounted behind the core support. If the radiator is mounted in front, move it behind. Then you need to install a shroud. Additionally, if the fan is too far away from the radiator and the shroud doesn't cover at least part of the fan, you need to install a thicker fan spacer. Aim for about 1" spacing from the radiator. I had a 56 that did the same thing, installing a shroud and thicker fan spacer solved the problem for me (mine was originally a 6, but the radiator had been moved behind the core support).

 

[OVERKILL]

There is no shroud on this engine with stock fan.

Then you'll want one. The fan will pull air in from the sides (IE, not through the rad) without a proper shroud. The shroud makes the fan massively more effective.

 

[OVERKILL]

If your thermostat is stuck open (or removed), the flow doesn't stop at the radiator to allow the fans to extract the heat out of the coolant held in the radiator at idle. Then. when you're driving, the natural flow of air extracts heat as the coolant endlessly cycles

The flow doesn't need to "stop", heat removal happens rapidly and the more area it is exposed to the faster it dissipates. If the thermostat is stuck wide open or removed, they'll typically never get up to operating temp, provided the fan can move adequate air.

 

[Carburetor1]

You have an air flow problem. Originally, when these cars came from the factory with a 6-cyl engine (the majority of them did), the radiator was mounted in front of the core support, and on the factory V/8s the radiator was mounted behind the core support. If the radiator is mounted in front, move it behind. Then you need to install a shroud. Additionally, if the fan is too far away from the radiator and the shroud doesn't cover at least part of the fan, you need to install a thicker fan spacer. Aim for about 1" spacing from the radiator. I had a 56 that did the same thing, installing a shroud and thicker fan spacer solved the problem for me.

 

[ecotourist]

My +/- 15 year old Volvo did exactly the same thing. Good on the highway but ran hot when the speed was down. Had the radiator cleaned inside and out and the problem was solved. Having the radiator cleaned cost very little.

I'd get the radiator cleaned (inside and outside). Couldn't hurt, won't cost much and may solve the problem.

 

[Carburetor1]

Radiator is currently 3 1/4" from the fan and has no shroud...could be an issue huh. There are brackets to loosen up and can slide 1/2" or so closer

 

[SammyChevelleTypeS3]

Is it possible the thermostat is not fully opening or stuck half way open and not allowing enough flow when idling. At idle the pump is not pumping the same amount as when the rpms are higher, correct?

If I remember correctly all my older SBC's ran 180 degree thermostats.

That is what all my S/B Chevys ran at. 180dg. In real hot climate the temps can rise when stopped. But. those fans had clutches in them that kick in when stopped to prevent that. Fan clutch needs to be checked also.

 

[SammyChevelleTypeS3]

Radiator is currently 3 1/4" from the fan and has no shroud...could be an issue huh. There are brackets to loosen up and can slide 1/2" or so closer

yup

 

[ecotourist]

Radiator is currently 3 1/4" from the fan and has no shroud...could be an issue huh. There are brackets to loosen up and can slide 1/2" or so closer

Mock up a shroud and try it. Just make sure it won't come loose.

 

[wag123]

Radiator is currently 3 1/4" from the fan and has no shroud...could be an issue huh. There are brackets to loosen up and can slide 1/2" or so closer

This is your problem. In addition to adding a shroud, you need to obtain a much thicker spacer so that you are like 1" from the radiator. Moving the fan 1/2" closer will not help you. Don't stack thinner spacers, use one single spacer.
There are now tri-five fan shrouds available that extend much father back towards the engine. With one of these you don't have to get the fan as close to the radiator, but make sure that the fan is located half way into the shroud (not all the way in).

 

[SammyChevelleTypeS3]

This engine is in a 56 Bel-Air and while driving the engine temp is around 190 but if left at idle when engine is warm it goes up to around 210-220. Is this normal or is there an issue with the cooling system. There are no leaks.
Also coolant has been changed within the past year. Any suggestions?

Sounds like your coolant / thermostat working fine. Did you make certain to run the engine with radiator cap open and heater on to bleed all the air out when you replaced the coolant. I am guessing you did. My money is on an air flow problem like most have said. Radiator position & shroud BUT check that fan & clutch. I am certain it will be an easy fix once you get to fooling with it.

 

[OVERKILL]

Radiator is currently 3 1/4" from the fan and has no shroud...could be an issue huh. There are brackets to loosen up and can slide 1/2" or so closer

Yes, you'll want to fit a shroud.

 

[SammyChevelleTypeS3]

As fast as you can stand. You don't want it to chirp the tires when you put in in gear if it's an automatic. Keep in mind that both those engines put a lot more heat into the cooling system.

Does your small block have factory style thick exhaust installed or thin wall tubed headers? Just wondering. I'm a fool for a chevy small block / any engine with headers!
*NOTE* Thin walled exposed headers will rise underhood temps. But you do need to check / correct the other issues too.

 

[Chris142]

Radiator is currently 3 1/4" from the fan and has no shroud...could be an issue huh. There are brackets to loosen up and can slide 1/2" or so closer

If you don't have a shroud the fan needs to be as close as possible to the radiator. Like an inch away. But you will still lose efficiency vs a shroud.

 

[RDY4WAR]

This engine is in a 56 Bel-Air and while driving the engine temp is around 190 but if left at idle when engine is warm it goes up to around 210-220. Is this normal or is there an issue with the cooling system. There are no leaks.
Also coolant has been changed within the past year. Any suggestions?

What's your spark timing at idle? Spark advance has a big impact on coolant temperature.