ok i just started it up and ran it without the cap on the radiator. When the thermostat opened and water started flowing i had a ton of bubbles coming up. small ones and some big ones. The water level was at the fins when i started and once it warmed up the level came up to the top of the radiator fill and started gurgling out. i shut it off and the bubbles stopped. so its a head gasket right?
GOOD NEWS!!! Its a SBF, you don't have to pull the distributor to change the head gaskets. Get to work!!!
Before you pull the heads take the fan belts off then start it up & watch for bubbles. This eliminates the waterpump. Still getting bubbles you might get a thermo heat gun & check head temps for differant temps from on side to the other.
An engine is an inanimate object and is incapable of being dumb. The owner of the engine is another thing altogether. He or she is very capable of being dumb
Sounds like you have a cracked cylinder, or a head gasket. 302's do not like an over bore of .060 without the cooling p***ages filled with solid stuff...as in for racing only...
Head gaskets installed correctly? It may not be an issue since the motor just started overheating, however, its something you may want to check anyway. On the SBF its really easy to put one in backwards. Small block Ford head gaskets have a squared off corner around the lower forward head bolt hole, the rear of the gasket has a rounded corner around the lower rear hole. When installed correctly the gasket corner will appear as a tab sticking out at the forward lower corner of the head. The rear will not have the square tab sticking out, only a rounded corner. So,if the gasket "tab" can be seen at the lower front on both sides of the motor the gaskets are installed correctly. No tab showing and the gasket is installed backwards. No need to take the heads off to check this. It is typical, however, that if the head gasket(s) are installed wrong the motor will overheat at any RPM much over idle....so this may not apply here. 50/50 coolant and water mix, a puke bottle, and properly located, sized and installed fan and shroud should help.
Here how I check for combustion gases fill the radiator full replace the cap and take the radiator overflow hose and stick it in a bucket of water and watch for lots of bubbles in the bucket .
Join Date: Nov 2007 Location: Magnetic Springs, Ohio Posts: 1,188 Re: why is my engine being dumb Sounds like you have a cracked cylinder, or a head gasket. 302's do not like an over bore of .060 without the cooling p***ages filled with solid stuff...as in for racing only... __________________ Fire Fighters find them Hot and leave 'em Wet NSMC Life member www.smallscalecreations.org*************** agreed, around here .060 overbore will almost always overheat on extended driving, but ok for drags.
I've been building small block fords for years for my OT mustangs... 60 over is not an issue as long as the block is sound. I would check the simple things first. Probably would ditch the 20psi cap for a quality 13psi....by quality I mean not an autozone POS that is bad from new(ask me how I know). It may be a head gasket, but check your oil and antifreeze for the typical signs first before tear-down.... Tom
Over the past 40 years I have seen Many, Many .060" over small block Fords that were in daily drivers with no issues. Is it Ideal? No but in many cases if the block was sound to begin with it is fine. I have seen blocks that were bored .090" over for sleeves that didn't break though to the water jackets, so .060 can be OK
ok i just did a test. i ran the car without the cap on and got it to open the thermostat. it did bubble up air quite a bit. then i killed the engine and removed the fan belt and started it. i didnt get that many bubbles but the antifreeze level came up quick and started overflowing the radiator. so what does that tell me? i didnt see the same amount of bubbling as with the water pump going but level came up quick.
Air pocket that hasn't been burped? Is the radiator cap the highest point in the cooling system? Did you check to see if the head gaskets are on correctly?
Without seeing it its hard to say for sure. If the level comes up, that's telling you that something is increasing its occupying space in the cooling system. In a normal healthy engine, that could be the expansion of water/coolant just from the heat, the time would be measured in minutes. On an engine that has problems such as a compression/coolant breach - the rising coolant levels could be a result of combustion g***es being added to the coolant. The g***es could be stuck in a pocket without the water pump circulation & that's one explanation for the lack of bubbles. Time would be measured in seconds. There's a few tests that will tell you. Compression test, my favorite, can tell you quite a bit. Find your low cylinders and you can add air into those and see where it why its low by determining where the air is going.
turns out that it was head gaskets. i replaced all of the gaskets put in a new big *** radiator and high flow water pump and a new non hei dizzy and shes running like a top.
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