how hot is too hot?

[west]

what is a normal operating temp for a 9to1 360?
what would you consider to be too hot?and at what point does dammage begin?
how do aluminum heads factor into these temps compared to iron?
does cid make a difference?

[satellite65]

Well, water boils at 212*f @ sea level. The cap on your radiator is probably a 14-16 lb. cap. That will raise the boiling point some. I'd say if your engine regularly sees 225* under normal conditions it's probably cause for concern. Very hot day, sitting in traffic with the A.C. on, I might expect to see it climb a bit. Aluminum heads can warp if they get too hot. Your LA smallblock only has 4 head bolts per cyl so factor that into the equation. How hot would that be? I honestly don't know but if I had to guess I'd say anything over 225 is serious.

[sunsetdart]

For every pound pressure the cap is , raises the boiling point of the system by 3 degrees. So if you have a 15 lb cap , add 45 deg to 212(boiling point of water) and the boiling point is now 257.
Most motors will run fine to 215-220. Most sending units for the temp gauge is at the front of the manifold near the hose outlet , so you have to understand that you are actually gauging the temp of the coolant thats leaving the motor , not whats in the motor. If everything in the system is working well, fan, rad, pump etc, the coolant coming back into the motor(the bottom hose) should be anywhere from 10-20 deg lower than what the gauge is reading. Ambient air temps play a big part in cooling too. 95 deg air temps do little to help cool 200 deg water temps, but it should stay somewhat regulated.

[Nitrous340dart]

Well... When I got my 340 dart running back in high school I was in such a rush to get it fired up I guess I forgot to plug the huge vacuum port in the back of my X-celerator manifold.  We got it fired and brought the RPMS up to brake in the solid cam.  About 5 minutes into it I was in the drivers seat and I started to see everyones face glow and the brighter it got the bigger theirs eyes got.  I look at my mech autometer temp gauge and it read 230*!!  We let it go and tried to get some extra fans on it and went down to 225.  After we got the cam broke in we couldn't get it to idle, we looked all around the carb and then noticed the big hole, I put my finger on it and it killed the motor.  The motor worked fine after, had good compression and I drove it for about a 1.5 years and put 4-5 thousand hard miles on it, the crane gold rockers didn't last for poop and went through 2 converters...  had alum heads and rad, no hood.