455 Running Hot with a 7 blade fan and a shroud

1970 455 with 430 heads, set up with stainless stage 1 valves and a edelbrock performer intake. The coolant seems to be turning black, Ive flushed it 10 times but its still seems dirty.I have replaced 2 thermostat's they stuck open and turned black . Any ideas?

Thanks Hank

 

Possibly cracked head or bad head gasket. 430 heads were prone to cracking.
Bob H.

 

Thnaks for getting back to me.Is there any way to tell before i pull the heads?

 

Thnaks for getting back to me.Is there any way to tell before i pull the heads?

 

Thanks for getting back to me. Is there any way to tell before i pull the heads?

 

Pull your radiator cap when the engine is cold. Make sure you can see the coolant. Then start it and look for bubbles. An occasional bubble is normal
a steady stream of bubbles is not. They can sometimes have a little steam coming out of the bubbles even before the engine is warm. Good Luck.
Bob H,

 

pull out all of the spark plugs to look if any of them are clean compared to the others.

are you losing coolant?

air in the system will also make it run hot.

 

Hi Mike I reciently changed the oil ,im not loosing coolant. or leaking into the oil.The plugs look cooper / biege,and the compression is with in 5Lbs

 

Hi Bob .I pulled the cap ,I do not see excessive bubbles when running it?I flushed it 5 times until it was almost clean.As I was filling it back up I noticed a foamy type of air bubbles that settled away? I added a bottle of red line water wetter, and antifreeze , It seems to run a little hotter ?Today was 88 degrees ,when moving it stayed with a 165 with a 160 thermostat . when stopping it would clime to 190-195 ?
Would an electric fan keep the temp down when im at idle?I was told to pick up a 1989 Buick park ave radiator. It seems to be a 3 core? Thats what im using. Could there be a problem with my intake ?I bought it used?

 

I don't think your intake is the problem unless you have a vacuum leak but then it wouldn't run right. Adding an electric fan helped my Buick at idle and low speeds. 190/195 is not really that hot sitting still with an 88 degree
outside temp. Looks like the radiator is doing its job as long as it has airflow.
Good Luck.
Bob H.

 

those temps are not bad. however the coolant turning black is not good.
keep changing the coolant and if it still gets black i am afraid you have oil
leaking into the coolant. good luck jim

 

Hi Bob I do believe I see tiny bubbles.There not there all the time ,mostly when you start it . Can I call you ?