Hi.. Went for a drive on Friday, temperature was 85F +. Car runs at 180-200 F most of the time, cooler on the highway. But Friday the temp was up over 210F driving thru town. Might have got to 215F but I was back on the highway in a few minutes and she started to cool down to 190F.
When I got home in the garage I lifted the hood and was surprise to see the upper rad hose collapsed and the overflow bottle full. The engine is a 454 and the rad is only 2 core. ( 66 Biscayne). I left it overnight and when I looked in the AM the overflow was empty and the hose was back to normal....
The over flow is a Gatorade bottle with the overflow hose installed thru the cap. I did this thinking it would stop the overflow from running on the floor and the antifreeze making a mess.
The question is... Should I remove the overflow bottle? Did this contribute to the collapsed hose? In 1966 I think the cooling system would be called an "open" system and I have made it a "closed" system by using the overflow bottle.... (the thermostat is a new 160F, recently installed).
Check the rad cap to make sure the little return valve isnt stuck. If its okay your overflow bottle may need a vent. Is the hose tight where it goes through the bottle cap? If its not vented it will affect how easily the coolant will return to the radiator. You could enlarge the hole where the hose goes through the cap or drill another small hole in the cap. Also make sure the hose isnt all the way to the bottom of the bottle, if it sits on the bottom it may not allow the coolant to return to the rad.
Radiator cap is faulty. one would think the gatorade bottle would also collapse if no air can enter the bottle.
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cutting a roof off a four door is NOT a convertible.....
65 Parisienne convertible.one of 49 built for RHD export market,402BBC, T400, 2500 stally, posi rear, upgraded brakes with front discs, FUEL FAST efi custom built by me.
I had that happen to me once. A 351 W in my 71 Ford Country Squire.
I pulled in to a gas station and opened the hood to find the upper rad hose bulging like it was going to burst. As I was standing back, not sure what to do, a couple of odd sounds came from the vicinity of the thermostat and the rad hose went from bulging to flat as a pancake. I opened the rad cap, releasing the vacuum on the system, and topped up the rad. Never did it again.
Had to have been an air-lock in the system. Id done a complete system flush and installed a new thermostat.
Strangest thing Ive ever seen!
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72 Nova SS, 66 Beaumont Sport Deluxe, 09 Pontiac Solstice GXP Coupe
I hope I solved the problem. Moved the hose off the bottom of the bottle, but most of the liquid had returned to the rad after cooling the next day. BUT I drove to the car show in Orillia yesterday. Temp was at 180-190F on the hwy. I got stopped in traffic for the show idling and the gauge pinned to 240F and puked a bunch of A/F out. It was fine to drive home, never got over 190F on the way.
I yanked the rad this AM and installed the spacer between the rad and rad crossmember. Th fan is now sitting an inch from the rad instead of 3-4". Should help in idling in traffic.
I may have to install bigger rad or rad shroud......
It sounds like you need to add an electric fan. Most older cars would overheat in heavy traffic due to not enough air flow through the radiator at low engine speeds. Most of the cars that I drove in the 70s would overheat in traffic. I remember being in the line up at Canadian customs coming back from the States with the heater on and when stopped in line putting the car in neutral and increasing the rpm to cool the engine down a bit.
My opinion on this is that the symptom is pointing to overall cooling system health. I think you should go start to finish, Thermostat, hoses, larger capacity radiator and OE style clutch fan.
A 454 is a hot running engine in my experience so do what you can to keep it under control.
If you go for a new rad be sure to disconnect the heater hoses and do a reverse flush so you start with a clean heater core or replace the core so everything is fresh.
My opinion on this is that the symptom is pointing to overall cooling system health. I think you should go start to finish, Thermostat, hoses, larger capacity radiator and OE style clutch fan.
A 454 is a hot running engine in my experience so do what you can to keep it under control.
I'm thinking the rad is "tired". I've done the hoses, heater core, thermostat, rad cap, clutch fan appears to be good. Big rad is the next remedy and that should fix it...
-- Edited by LT1Caddy on Tuesday 23rd of August 2022 09:25:54 PM
Hi...I'm getting some good advice. I think bottom line the rad is too small, getting tired, and the summer temps are a lot warmer now than even 10 years ago. The 2 core is not enough for a BB. I have a four core GM Harrison, OE for 66 Chevelle, proper ID codes, same as 66 B body configuration. But it needs a re-core which I was quoted at $600+ last week.
I think I'll be getting the aluminum 'knockoff" from Auto city classics.... Should be the end of the problem. Talking the B body Chevy guys, not many Big blocks came with fan shrouds... !!!
Go Figure, BUT very common on SB and, not interchangeable....
If you go for a new rad be sure to disconnect the heater hoses and do a reverse flush so you start with a clean heater core or replace the core so everything is fresh.
You dont want to dump the contents of the old heater core into your new rad