Currently building my 70 Vista Cruiser. My cooling system is not cooperating. I'll start with the basics:
-455 fresh rebuild, Edelbrock, aluminum heads, Accel DFI multi port fuel injection
-new spectra radiator, dual electric fans (pulling), new not rebuilt water pump
-upon starting up the car quickly climbs to 220; I shut the car down.
-upper radiator hose is not warm, does not feel like much coolant in the hose
-my first thought was air in the system
-with engine cool, filled radiator full, left radiator cap off
-car starts, see a few bubbles blurb...then at 210 coolant begins gushing out the radiator
-then removed thermostat
-added a sealed funnel for added capacity
-same things happens at 210 the coolant begins gushing out the top of the radiator


Do I have a brand new plugged radiator? Do I have a new water pump that is not working?


Thanks for your thoughts.
-ben

 

With the thermostat removed and the coolant level below the filler neck, you should see circulation as soon as you start the car.

 

If the temp moves very fast when you first start it up and then fluctuates wildly, there is air in the block.

 

Nothing erratic about the temperatures. Temp steadly rises with radiator cap on and off. I turn car off at 220.
Coolant bubbles over funnel at 210.
-ben

 

As said, coolant should circulate immediately.

Do you see the coolant moving? We need an answer to this question before going any further.

 

Coolant is moving...out the filler kneck. Lower radiator hose is getting warm and becoming pressurized. Upper radiator hose is not getting warm and is not pressurizing.

Thanks,
-ben

 

It sure sounds like something is plugged.

 

I had a 70's Olds 350 back in the 80's that had a radiator leak. I took the radiator to a local radiator shop and he soldered off a couple rows. He gave me back the radiator and said to use a 7 lb cap because the rad was in Iffy shape. I found that the car would overflow out the overflow tube because 7lbs wasn't enough pressure. When I put back on the 15 lb cap all was well and drove the car until I sold it. My point is I learned you need pressure in the cooling system and maybe that's all your problem is....??

 

He has a temp issue not a pressure issue. It could be many things but the radiator cap is not one of them.