340 tooooo hot

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rtbeerdlitedart

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ok, here's the deal! just had my 69-340 redone, nothing too dramatic, all very good components. Now it runs too hot(210-220) range all the time. I have a 3 inch- 3 core aluminum Wizard cooling rad, as well as a pusher fan, as well as the engine fan still in place. I have flushed the engine and rad just to make sure nothing is blocking anywhere. Only thing I haven't tried is a shroud but you would think with the rad and two fans it should be ok. Any help would be great.
 
What temp T-sat is in there? If its 195 and no rad shroud it could be it. Try a 180 and with no shroud, it needs to be driven the get air flowing though the rad. Parked for 10 mins could cause it. Get it out on the road-if the streets are dry and salt free.
 
Well since you had it rebuilt my guess is you had it bored and now that you have thinner cylinder walls all that heat is building up in your coolant and would cause the temps to be high...............just joking but I had to throw it out there.

My guess would be improper tune...too much/little advance or running lean. Both will get your motor to run very hot fast. Also I imagine you have more power then before which equals more heat but I've never seen it make a drastic change in temps on a street car. How much timing are you running and when is it all in by? Also how do your plugs look?
 
put a shroud on the fans pulls the air through the rad only in the area of the fan the air goes into the engine compment hit the hot motor heats up and goes back out through the areas of the rad that does not have the fans pulling or pushing thouught it putting heat back into the rad. that why the factory put the shroud on in the frist place and the new alum rad makes the codition worse
 
Any chance you have the fan blade on backwards? This happened to me once and it sure wouldn't cool. Jeff
 
We get many similar calls on our tech line looking for a 31" radiator, our biggest!

Out of the 10 calls we get on overheating, 9 are usually not cooling capacity issues but Ignition timing and fuel metering issues.

Most of the time these issues are corrected with a $69.00 distributor recurve rather than a $300-400 radiator to cover it up.

It's explained in my book but just to touch over the topic....If the fuel doesn't have time to burn completely (Not Enough Timing) or the A/F ratio is excessively rich then the unburned fuel will be forced out the exhaust valve while it's still burning. Or in a case of excessively rich A/F ratio where the oxygen is consumed and unburned fuel is left over, as soon as it hits the exhaust runner and any oxygen is present it will re-ignite, either condition will create a blow-torch effect in the exhaust runner and overheat the head no matter what radiator you have. Even if you manage to put enough cooling capacity on the engine to keep it cool, it's only bad-aiding a bad tune-up.

"I go through 3 sets of header gaskets every summer, I need a better gasket" you wouldn't believe how many time I hear that statement.

"I hate my TTI headers the Ceramic coating turns dull gray everytime I drive the car" another tell tale of tuning issues, Ceramic coatings will turn dull at about 1380*F EGT, a street car should be around 900-1250 max, race cars should run around 1050 to 1300. Of course if you ask 10 crew chiefs in NASCAR or NHRA Pro-Stock you'll get 10 different answers as each crew chief may be looking at a little different tune-up that he prefers, who's right? I don't know, I find my rule of thumb IMO adds to engine life and driveability.

Of course an adaquate radiator, fan system and a clean cooling system are also important.

You read more about our book on our website
 
Is it a new water pump or an old one? Pull the spark plugs and what color are they, white means engine to lean so richen it up 2 sizes. The engine running down the road should not overheat unless the rad is to restrictive and not allowing air flow through also check to make sure that the hose coming off the bottom of the rad to the pump has the steal coil inside it to prevent the hose from collapsing. One other thing, since you're going to have to drain the system to check the hose, pull the thermostat and check that it is opening at 160 in a pot of water on the stove with a good thermometer.

Terry
 
or so,until the rings seat,and everything is broken in.When an engine is new,there is more friction going on inside,creating more heat,a bigger radiator is not gonna change that.The good thing is,its winter time,i would go for a nice sundsy drive about 200 miles and back,preferably down the interstate,at 70 mph,then turn around,and drive 200 miles back,at 70 mph(at least 2000 rpms) you will probably notice the engine temp starts to drop on your way back on your little trip.Be sure your running a good synthetic oil,with a zinc additive,so the moving parts are well lubricated,and add a can of water wetter to the radiator to drop the temp some.My dad bought a nice 32 for coupe hot rod cheap 15 years ago for this very reason,the guy built the engine,and could only drive it a few mins at the time before it would go up to 225 degrees with a 160 thermostat installed.My dad is a long time mechanic,and new all about how to break in an engine,especially,a highly modified street strip type engine,so one cold winter sunday,the 2 of us decided it was time to break it in.We headed out towards the interstate,and proceeded to run 70-75 mph,from nc to south of the border in south carolina,back through nc,to va,and on the way back to nc,the engine temp dropped to 160.He has been driving this car for over 15 years,with the small hotrod radiator,huge cam,lots of compression,etc,and this thing runs cool as a cucomber,lol
 
You don't need to drain the coolant to find out if a spring is inside the lower hose or not. Let the engine cool down and squeeze the hose. If a spring is in there you will feel it. Also, I wouldn't use synthetic oil until the engine is well broken in. The use of synthetic oil on a freshly rebuilt engine will prevent the rings from seating correctly.
 
That pusher fan may be blocking the air flow. Take the pusher off and install a shroud. It will pull alot more air through the radiator that way.
 
Ditto on the shroud. I used to run without one and engine kept climbing past 220 on a summer day in traffic. Added a shroud and I now run 170-190 degrees in traffic on hot summer days in SoCal.
 
I bet it's the thermostat. Try running without the thermostat and see if it runs at a diffrent temperature. It may not even warm up. Then get a new thermostat (they're cheap) I would start with a new 180 degree. If the car heats up while driving above 50mph its probably not the fan.
 
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