Cooling capacity

[Bobacuda]

I have a 1967 barracuda, plain Jane ‘78 318, 904 non-AC. New radiator, water pump, hoses and 160 thermostat. Engine is a professional rebuild. Starts and runs great, but the coolant started to puke out and looked like the Red Sea. Started overheating during a parade.

So, I flushed the system and got the rust out. Replaced the thermostat. Manual says 17qts of coolant…

I put 8 qts of 50/50 in (and the heater is on Max). The level in the radiator is well above the fins, to the point it’s going to puke. I ran the engine - even drove it a mile. I can see the water flowing in the tank. Rad is still too full and that is with just 8 qts added. It’s currently cooling right now so I can check again later.

Has anyone else experienced this? Does the block retain
8-9 qts?

 

[oldkimmer]

Yup, block and heads and heater core holds about that. Kim

 

[Bobacuda]

Yup, block and heads and heater core holds about that. Kim

Crap. Should have just added straight antifreeze for a 50-50 mix. So I now have about a 25% antifreeze coolant.

I don’t live in the frozen tundra, but it does get quite toasty around here. We’ll see how it works out.

 

[Demonracer]

Drain it completely, add a gallon of straight coolant. Strain the diluted coolant through paper coffee filters, top off with that and set it aside. Make sure you mark the container well so there are no mistakes later. I would also put on an aftermarket coolant recovery jug, that way you are not puking it out onto the ground.

 

[Bobacuda]

Update- I drained the radiator, then added 1 gal of straight antifreeze. Filled to about 1/4” above the tubes, then started the engine (no rad cap). When it got hot (160 thermostat) I added back some of the mix I drained. I revved the engine, watched the flow in the rad, added till it is now about 3/4” above tubes - 1” from filler neck. Put the cap on. Cleaned and drained the puke can.

5 mlle test drive, about 50 mph where possible. No problems. The final mile, I went 5-10 mph for parade conditions. No apparent problems. No puking. When it cooled down, fluid level right where I left it.

 

[Bobacuda]

It only got slightly hotter than this photo. Maybe 1/2 line more toward hot.