i hope its ok to post this here "Need some help here . I have a 1979 Cougar xr-7 with a small block ford 351 W . It runs warm about 210* I have installed a new eldelbrock water pump a large 3 core alluminum radiator with two 1350 cfm puller fans, new 180 t stat, new hoses, timming is right on, but still runs at that temp.. ran even warmer with stock radiator and fan. It has good flow thru the radiator , I dont get it ,never delt with small blocks before this is my first one and probably the last. I have always had big blocks but the wife wanted this cougar." any help guys My 77 Ranchero has a 400 with a 3 core stock radiator and fan even with the a/c on it runs 180*
could there be rust debries in the water. youd probably see it when you drained it all out. maybe a pocket of air somewhere in the water jacket. i drilled a really small "burp hole" in the t-stat of my olds. not enough to affect cooling one way or another but lets the air out
It might be a bad guage or sender, a bad ground or just teflon tape on the sender. Look at the cheap things first. if they fail to fix the problem and you are sure the temperature really is that high then you probably have a block that is full of rust and sand. The only thing that will cure it is to have the block hot tanked. You can make it a little better by disconnecting the radiator, water pump, all hoses and removing the freeze plugs from the sides of the engine. Make a pipe adapter that will connect to a hose and feed the engine water from the water pump ports in the block. Connect it up and turn the water on. While the water is running through the engine use a 1/4" rod to stir the crud up through the soft plug holes and let it flush out. if you pull the plugs from the bottom of the water jackets on each side of the engine and keep them clear you can get most of the crud out. When you can't get any more out of it then let as much water drain out as will and put the plugs back in the bottom of the water jackets. Pour in aboput a quart of Muriatic Acid (get it at the hardware store for cleaning concrete) let it sit for twelve hours (at least) and then flush it out with a lot of water while you stir the crud through the soft plug holes. Muriatic Acid can cause burns with prolonged contact with your skin and if you get it in your eyes it can cause blindness so wear protective gear when using it and have that hose handy to flush yourself with cold water. (I am sure the warnings are on the container) Once you can't get any more crud out repeat the soaking and rinsing process. If you buy a gallon of acid you can do this four times. That will clear most of the crud out and what is left will probably never make it to your water pump or the radiator. Be sure to back flush your heater core, radiator and cylinder heads. Put new soft plugs in (use some sealer on the bores like gasket maker) and flush the engine well before you connect it to the rest of your components. Muriatic acid will disolve rust and aluminum so it is important not to get the acid on or in any of your aluminum components. When you fill the system with coolant put in some "Aluminum Coolant Conditioner" and antifreeze made for use with aluminum. Ethylene Glycol based antifreeze (the stuff you are used to) with Sodium Sylicate should never be used with aluminum components. Sodium sylicate is a popular stop leak that is added to ethylene glycol antifreeze. There are a couple of antifreeze brands that are safe to use with aluminum.
