Running cold?

[Jonas Nordstrom]

So, when I cruise slowly the temp sits at around 170-180 and the electric fan (and 160 stat) keeps it there for forever....and used to do that on the highway too.

...but now on the highway the temp creeps down to 120-130...and all I did was change the intake?

Should I change the stat to a 180?

 

[WileE]

No, you should check the accuracy of the factory gauge first.

 

[Don Frelier]

It Sounds like the thermostat may be stuck open?
Next time the engine is cold start it and open the radiator cap or put your hand on the upper hose and see if there is flow below 160. If there is then the thermostat is not closing.

But yes either way a 180 degree thermostat is better these engines were designed to run higher than 160.
Too cold = wear.
That's why the graduations on the gauge start at 170.

 

[#41]

Buy a cheap thermal gun and check the actual temp. They are a handy tool.

 

[Jonas Nordstrom]

Ok, got a thermal gun (Blue thingy behind the Tstats in the pic) and the temp gauge is dead on. No problem there.

Got a new 180 Tstat on the shelf so I put that in (To the right in the pic).
With the 180 Tstat in the Temp got more stable in both slow cruise/highway and sat at a steady 170.
I do have an adjustable electric fan controller that I adjusted a bit to start at a higher temp.

Went for a long drive to a car meet and the temp sits at 180. All good and fixed.
(Temp gauge pic is from before the adjust.)


Conclusion:
I swapped the intake from a Eddy Performer 440 to a Eddy Performer RPM (Running a Thermoquad) and the engine started to run way colder.

 

[WileE]

Glad to hear all is good. You should not have been using a 160 stat in the first place. I've used 180's in these cars for over 50 years.

 

[Geoff 2]

What I have found: some of the machined openings for the t'stat are too deep, have too much clearance once you add the gasket. This allows the stat to move up & down....& coolant gets past the stat.

To fix: three blobs of silicon at 120* at the outer edge of the stat. That will hold the stat in place & stop it ' pumping' coolant.

 

[YY1]

Is your temp sender in the intake?

You changed it and now it reads different.

Be sure it is immersed.

...and didn't get broken.

 

[Jonas Nordstrom]

Is your temp sender in the intake?

You changed it and now it reads different.

Be sure it is immersed.

...and didn't get broken.

RB engine so the temp sender is in the water pump housing.
The intake was changed and nothing else was touched.

Putting the thermal gun on the intake and then the engine block shows the intake being less than half the temp of the block.

Almost makes you start thinking about those Carburetor icing stories....

 

[YY1]

Thanks for the clarification.

I'm also chasing a cool running situation.

180 thermostat but runs at 175 all day...

...unless the AC is on, then it can overheat at a stoplight.

Very frustrating.

...but is a 318.

 

[Jonas Nordstrom]

Thanks for the clarification.

I'm also chasing a cool running situation.

180 thermostat but runs at 175 all day...

...unless the AC is on, then it can overheat at a stoplight.

Very frustrating.

...but is a 318.

Do you have an original or electric fan?

 

[YY1]

OEM, non-clutch fan.

Kinda odd with AC.

I've got a high idle solenoid but need to add an ear to the carb or go ahead and put on my AFB.

Putting in N or adding a touch of throttle helps noticeably.