Hey All, I have a question that hopefully can get answered here. I have a 1968 Ford 302 installed in a 1966 Econoline pickup. The motor was rebuilt 2 years ago to stock specifications by a very reputable shop here in town. I have been trying since it was installed to cool that sucker down including 4 row Champion radiator, 160 degree thermostat, retarding the timing until it just about won't run. Now the motor has 190 miles on it. I finally took it to a pro, who builds some fantastic cars, to help me figure this out. He fabricated an engine shroud and a snorkel system that forces air up to the radiator. He test drove it yesterday and said at 40 mph, the top of the doghouse lifted up about 8 inches if it is not latched down. That is a lot of air! Still went up to 225 degrees on a 50 degree day. Checked the new Autometer gauge to see how accurate it was. Off by 4 degrees. Using a fancy gizmo to check how hot the motor really was. Read 221 degrees. Man, this guy does this for a living and cannot figure out what is wrong. There is a lot of heat being generated by this motor. Any ideas? Thanks in advance for your help. Steve
Are you sure you have the right waterpump, the newer ones turn backwards, and the fans also run backwards and would push air forward instead of pulling it through,,,so at speed the air would be neutral,,,fan trying to push air forward and the vehicle moving forward makes neutral air,,,,,,NO FLOW= hot engine
Are you running a new water pump or a new rebuilt water pump. Rebuilt water pumps and even new stock ones sometimes just stir the water. I run flow coolers on all my stuff. They really work well. Are you running a pump that turns in the right direction? It is possible to get a pump for a serpentine system that is supposed to turn back wards. Check the lower radiator hose is it sucking flat or kinked? Try a 185 degree t stat and get a good one not the off the shelf one from "the Zone". The 160 may not let the water stay in the block long enough to cool it; I have had that problem before believe it or not. Just my thoughts use what will work for you.
Thanks for all the replies. The motor has not been bored. The water pump is the one that was on it when it was rebuilt. The whole setup is stock, not a new serpentine system. The shop that rebuilt the motor, said they checked it out and it seemed fine. When the thermostat opens and you take off the cap, you can see water moving. Replaced both hoses. The guy who is helping me said the same about the thermostats, don't trust the cheap ones. He used to be a drag racer.
I'd bet the head gasket is on backwards....easy to do on a SBF and will make the engine run hot. It will bolt on ok, but block water passages.
You are correct on this.I almost put a head gasket on my 302 backwards once.Caught it when i was starting to set the head in place .The way he is describing it heating up it does sound like a blocked water passage ...
Given what you've described, I'd lean towards this as well. To expand a bit- nearly all SBF gaskets are marked "FRONT" at one end. If you put them on this way, one gasket "looks" upside down. On many designs of gasket it looks blatantly wrong....so builders who are not familiar with the SBF will reverse it end for end. Technically, doing this doesn't block water passages...actually, it "un-blocks" them. The SBF cooling system (as with most modern V8s) has cool water (or coolant) enter at the front of the block from the water pump. The water flows to the back of the block, and in doing so, a small amount of water is bled through the gasket passages up into the heads around each chamber. When the water in the block reaches the back of the block, it is fully allowed to move upward into the cylinder heads and make its way to the front again, through the manifold and thermostat, and back to the radiator. If the gasket is incorrectly installed, most of the water goes from the front of the block directly back to the heads....the coolant in the back of the block stays still and quickly gets very hot. One indication of this is that a temp gauge installed in the back of the engine may register 40-50 degrees, or more, higher than when it's installed in the front. There is always some difference, but it shouldn't be that much. A couple of other things- 1) Retarding the timing can cause overheating, too. I'd move it back. 2) As mentioned, get a good Robertshaw thermostat, and try drilling a 1/16" hole in the flange. 3) Sometimes, overheating is simply because there isn't enough fluid capacity in the system. Without seeing the install, it's hard to say much about this. What's the core and top tank sizes? 4) Given your description it sounds as if airflow is not an issue. 5) Some gaskets have the "FRONT" marked on a tab that protrudes from under the cylinder head....might be worth a look to see if it's clearly installed rightly or wrongly. 6) What do the spark plugs look like?
When the block was rebuilt, was it thoroughly cleaned either by hot-tank or blasted with all core plugs removed? Also, the shroud that was built, does it have a way for air to pass through it, such as vents or flaps, air must be able to pass through the shroud as well as directed through the radiator core. Is the rad lower than the highest point of the engine? You would then need some way to " burp " the system to enable trapped air to escape. Put the timing back to spec's or where the cam grinder/ engine builder recommends, stock spec's equall stock timing. Check to make sure the advance mechanism's are working properly, both vacumm and mechanical. 180 degree thermostat/ w the 1/16" drill hole mod that homespun recommended. Lastly, the incorrectly installed head gasket is a very good possibility. The water pump was from the engine originally, doesn't mean it is good, replace it on a rebuilt engine to be sure. Lean or rich mixture will also cause temp's to rise. Good luck, Steve. BDM
The head gaskets being installed wrong can cause this problem,even reputable shops aren"t perfect everybody makes mistakes,if all the shrouds,fan and all haven"t changed anything I would make sure first that it is the right water pump and then check the head gaskets.Saw a so called reputable shop actually put the heads on backwards on a 92 302 or 5.0 as they are referred to now and car ran hot 5 minutes after startup.
How painful, First to check the stat, who knows could be defective or even in backwards, next see if you can get a number off the water pump and check rotation, then pull the radiator and flow test it, finally as is stated pull the heads. Hope its something easy and dumb.
Retarding the timing will only make it run hotter. On top of that I would be really suspect of the head gaskets as well
Agreed, be a bummer but what else could make it run that blazin' hot? I'd start with something cheap, remove the t-stat and take it for a run. That would rule it out completely. Bob
......Ditto .......some times the paddles on the water pump can be worn and water won't flow proper.....I might even change to a new water pump before pulling the heads.....Good luck
I know in the "how to rebuild your small block ford" book, they show an external way to see if you head gaskets are in wrong. I don't have it right here to snap a photo, but look it up at a bookstore, or autozone. If they are in correct there is an exposed tab or something like that.
This is a defect I've incountered before.. If the head gaskets are switched fron side to side, they block or screw up the water flow.. I never had this happen , but 2 other motors with new rebuilds in the area had this problem..Hope it helps .. Larry
It mentions this in there, so far I can not see any easy info on eyeballing the gasket from the exterior of the head, it is probable however that you could determine this by viewing it from out side of the block/ head. It seems that the head gasket may have a different pattern at the front and rear edges of the gasket, perhaps you could get a gasket, study it and determine if that is the cause prior to a major under taking.
Most every small block Ford head gasket I have ever seen has that little square part at the front sticking out near the lower front head bolt.
That seems as though it should determine it. The front of the head accepts a square edge and the back of the head accepts an octagonal edge, it looks to me that if the square is at the back it would be sticking out square conspicuously at the rear of the head against the octagonal shape of the head. Bottom rear edge, check both, maybe only one is milfed.
Friend of mine did just that! That sucker ran hot no matter what he tried.Pulled heads and installed right,ran normal temps ever since.
Hi All, Just an update. Pulled the seats and doghouse. Pulled the heads. The gaskets were installed correctly. We did see the tabs sticking out where they should have been but decided not to take a chance. I am running out of things to scratch. Already scratched all the hair off my head. As for the air flow, a rag will get sucked into the front of the new Champion aluminum radiator from 3 inches at an idle. I even suggested pulling the 302 out of a 56 Ford I have and install it in the Economonster to see if that would do any good. Man, I am running out of things to try. Thanks for listening and helping. Steve
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