Well Old Stan was right !! I changed the cap and problem solved but myself and all my California Buddies all use the distilled water/ Red Line combo in our high compression street/strip Gassers that run at 170 on even the hottest days. of course I said no way possible it's new. It drive me crazy till a Old mechanic friend suggested the cap. The fuckin temp would shoot up to 240 like a rack needle then back to 170. I went thru this and with a fancy new cap that had a magnesium an ode on a wire to prevent electrolysis in my aluminum heads. The usual overlooked cause is a cap that will not hold pressure. throw that 50/50 green shit away for the summer and don't forget to change back in the winter if you live in freezing temps. It prevents freezing but does nothing to prevent overheating on a hot summer day. Nothing cools better than water ! Anti freeze is exactally that !. From my experience there is no better summer coolent than straight distilled water and a bottle of Red Line Water Wetter. Not sure that decides anything either way.

I have heard block sludge and rusty water passages are possible, but having drained (not flushed) a few times, the coolant comes out clean and not funky. Only 1 left FORD THUNDERBIRD GALAXIE FE BIG BLOCK C6ME 5L11 428 CID 7.-1976 1966. I have heard bubbles are an issue, but the thermostat is opening and closing fine, with obvious water movement and hose heating - so I don't think that's it SILVOLITE Hypereutectic Flat Top Pistons Set+CAST Rings for Ford 360 390 FE STD (Fits: 1963 Ford Thunderbird) Brand New. I have no way to check for exhaust gas in coolant, and that's possible. A bit higher, and the car starts stumbling and running poorly. I have stuck a thermometer in the rad and confirm the gauge is right - it climbs up past 225 and that's 85 percent on my gauge, roughly. I am in GA, and ambient temps are 80s, which I've driven the car in for years with no trouble. Now normal is 2/3rds, which I also don't understand. I can drive all day on the highway, but 10 minutes idling in traffic kills it.įor many years, normal temp was about 1/3rd of the gauge. If I get it hot in traffic and can get clear, the temp drops - but much more slowly than it used to. On the highway it's just fine, temp is steady and does not climb. Running the heater (which blows super hot) doesn't change it either. Temp climbs, thermostat opens, hoses heat normally. None of what I have tried or changed has materially changed my symptoms in any way. I also just had the (basically new) Griffin boiled out, no change. I have tried different blends of water and coolant, and no change either. I have checked timing, and it's in spec - no pinging or power issues either, and no change in symptoms adjusting timing up or down. I have tried electric pusher and puller fan configurations too. For good measure I just swapped the (nice, newish Summit high flow) water pump for a cheapie Autozone reman pump. Right now it has a big, newish Griffin radiator, and a many-blade mechanical flex fan (no fan clutch). The motor is junk - but it's been a solid runner for years. It's a 63 Galaxie with a tired, worn out C6ME 390. Assuming the worst here on my 390, and hoping I have missed something. I know this topic has been talked to death, and I've read through the back catalog of threads.

390 fe 1963 ford thunderbird