Engine temp. How hot is too hot?

[Wookie316]

I have a 400 bored and stroked to 512. I have a 3 core Aluminum rad with dual 10" pushers and a 18" puller, so lots of air flow to help cool. Perhaps this is a non-issue, but being I have a few $'s in this engine I don't want to burn it up. I have been concerned because the heat gauge is much higher than any other dodge I have ever owned. So not wanting to trust a 42 year old gauge I have been checking with my heat gun different parts of the engine and the rad to see the temp it shows. Here are my findings.
Rad, top tank 80-90, core 180-190, top hose 185-195, bottom hose 160-170, Aluminum heads 170-175. Those numbers all seem good and I am not really worried, but the water pump housing and thermostat area range anywhere from the 220-240 range! Is that normal? I have changed the thermostat as I did think it was sticking. The new stat registers the same and it is actually a hotter stat I have in the car now. I guess my worry is that these tests have been done after 15-20 minute drives, not working the car hard and relatively cool days. Yesterday was the warmest day thus far and it was still only mid 20's Celsius. I am worried with this heat at the water pump housing already, what's it going to be like on an extended drive or on a real hot day? Perhaps this is normal though? I have never done extensive heat testing before, but I am really looking for opinions, suggestions and experiences on what's too much heat? Thx in advance for your help. Much appreciated.

[firefighter3931]

It's possible that you might have an air pocket in the housing where the sending unit bolts on. Heated air will read higher than if the coolant is present at that location. 

Try burping the cooling system....works great for eliminating air pockets ;

-get front end up on ramps
-start engine with rad cap off and allow it to reach operating temp
-once the stat opens, blip the throttle and check for proper circulation

*If an air pocket was present you will see a burp and air will escape....the coolant level will drop a bit so you might have to top it off.

While you have the rad cap off you can shoot the coolant with the infrared gun and compare coolant temp to the waterpump housing....they should be close.

As for your other measured temps....they seem fine 



Ron

[Just 6T9 CHGR]

O/T but that is a bad ass looking ride! 

PS---what Ron said...

[69wannabe]

Hey Ron, I wonder if he is running one of those 440 source pump housings?? I don't think he said whether it was a stock housing or a 440 source or some other aftermarket style housing. Just a thought.

[Wookie316]

Stock housing, here are a few photos of engine sitting in the car.

[Wookie316]

Newer photo of the engine.