Can new build cooling system vapor lock?

[Sonny]

Got my new '78 360 installed and it runs great! However, the cooling system isn't flowing. The thermostat may be stuck ( it's pouring outside and waiting to remove it) but thought I'd ask is it possible that there is air in the system? The temp shot up to 245 quickly and I shut it down. The upper hose and radiator was cold. I added more fluid once it cranked so it's full. My aftermarket gauge read the 245 and it's next to the thermostat.

 

[65-440]

air pocket under the thermostat, had the same thing happen on my 383, upper hose and radiator cool, engine hot. I Let it cool down, topped off coolant, fired it up and kept the rpm's up, it finally opened up and all is good now.

 

[Car Nut]

Make sure your thermostat has a bleed hole to let air out. You can drill a hole or you can buy them that way.

 

[Sonny]

Make sure your thermostat has a bleed hole to let air out. You can drill a hole or you can buy them that way.

Thanks!

 

[SlinktRR]

yes it can. Take the thermostat out and leave the radiator cap off, let it run until the air gets out. Replace with a basic stant thermostat