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440 runs at 200 degrees

Mike D

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I have fresh about 1000 miles 1969 roadrunner 440 edelbrock Rmp heads, cam and intake manifold. 180 degree thermostat. I run 91 octane with torco added to about 106. It will run at 180 maybe 30 minutes then hits and stays at 200. Doesn’t overheat and seems to run fine. My first big block. Should I be worried? And of course I can’t keep my eyeballs off of the temp gauge!
 

69hemibeep

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200 isn't that hot, does it go up at traffic stops or stay pretty even? And what kind of climate are you in? My 440 Valiant likes 205-210 with A/C on and 185-190 in the winter.
 
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Mike D

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Thanks for your reply. Much appreciated. I’m in San Jose California 80 degrees today. Temp stays pretty even at 200.
 

69hemibeep

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Get a cheap temp gun to check against the gauge just for grins. Thats a touch warm for 80 outside if the gauge is accurate.
 

Mike D

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Ok any particular part of the motor to aim at or aim at the radiator?
 

Russ69Runner

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Have you changed the thermostat. May be getting old. Running a 160 degree in my 383. Runs around 180 degree driving. Dose not get much higher sitting at idle for a while. May need a tune up also.
 

Mike D

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Yes just changed therm. its stock BB radiator going to try aluminum
 

TOMRR

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Do you have a shroud on the radiator and is the fan at least half way into it ?
 

69hemibeep

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Aim it right where the sending unit is on the water pump housing or the thermostat housing to compare them. If it is hot tell us about the motor and cooling system including the timing
 

cosgig

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200 degrees is about perfect for a big block Mopar. Please don’t buy into the “I run a 180 thermostat, so my car should run at 180” misnomer. That is not how a thermostat works. The temp rating of the thermostat is the temp that it opens, not the temp the car will run at.
 

Mike D

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Aim it right where the sending unit is on the water pump housing or the thermostat housing to compare them. If it is hot tell us about the motor and cooling system including the timing
I’m running stock BB radiator. Had the car about a year and still figuring out what’s all in the motor. I know it’s about 1K miles on it. I’m the 3rd owner and unfortunately the last owner who restored it is no longer available to answer any questions. Going to try aluminum radiator.
200 degrees is about perfect for a big block Mopar. Please don’t buy into the “I run a 180 thermostat, so my car should run at 180” misnomer. That is not how a thermostat works. The temp rating of the thermostat is the temp that it opens, not the temp the car will run at.
Thank you. It runs just fine at 200. First big block I’ve owned so I’m still learning.
 

69hemibeep

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Some of them are happy at 200. Had my Valiant out last night about 104 degrees at 8:30pm and it ran 185-190 without A/C, my fan switch went out dambit. LOL
 

ricks_RR

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are you running a clutch fan or a straight fan . newport started to run hot 200-205 so i put a straight fan and it runs at 180-185 all day long now
 
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