cooling issues-need help!!

[LILCBRA]

i have had it running about a month now i guess, and if i drive it more than a few minutes, even let it idle for a few minutes actually, pretty much everything gets too hot to the touch. i haven't gotten an aftermarket gauge yet, but my stock gauge is in the normal range after i replaced the radiator, yet the rest of the engine remains hot. here is a list of what i have and also what i have done to try to fix it:

1968 302 +.03, flat tops, 290/300 advertised duration-214/224 @.05 .507/.533 total lift with 1.72 roller rockers TFS twisted wedge heads and using all tfs recommended gaskets offy 360* intake 650 holley dblpmp ceramic coated headers through 2 1/2 pipes and turbo mufflers-no cats new radiator, electric fan set to start at 180* and i took the thermostat out shortly before replacing the radiator hoping that would help. since i put the engine together a few years ago, and have just now got it running, i did some research on cooling with the tfs heads. when installing on 1968-72? 302s, you would have to drill 4 holes on either side of the block into the water jackets to prevent steam pockets, and i have done this. pulled my heads off tonight because i couldnt remember if i did or not. i have also read in another post about a ground wire problem, but it was a cadillac recall in the 80s. could this possibly contribute since i am grounding directly to aluminum heads? when i filled it with 50/50 coolant, i did run it through to try to remove any air pockets that could form before i sealed it up. i am still running a stock pump, which was new when i put it together, and it did flow while i had the cap off to vent the air pockets. i did find that the new rad cap was junk-it was seeping over the top seal, so i got a new cap today also. i have run the short block before with ported 289 heads and 1.6 rockers with no problems like this before. anyone have any suggestions or comments that might shed some light as i am tired of burning my knuckles?

 

[Wart]

It's not boiling over or steaming, only hot to your touch?

??

Get a thermometer/temperature gauge, take a reading.

I don't suggest running anything without a thermostat.

Grounding to aluminum probably isn't a problem with a new connection. It could become a problem. If the options were to ground through an Al head or grounding through an iron block I would ground through the block.

 

[itsaMustangtoo]

Definitely put a thermostat in, water needs time in the rad to cool. Especially in a less efficient top to bottom rad as apposed to a cross flow. Sounds as though you spent a couple of bucks on the engine , how bout' a few more on a temp gage? I would check the orientation of the head gaskets it would be an easy mistake?

 

[LILCBRA]

thermostat is going back in, and the temp gauge is here, just needs put in. i am thinking all i had to do is sleep on it.....the old 289 heads didnt have open egr ports and the tfs heads do. im thinking if i closed them off, since i dont have the egr valve anyways, that could cure it. and i will take the ground straight to the block somewhere just to eliminate that issue from arising.

 

[LILCBRA]

oh yeah, and the head gaskets were orientated correctly....but does anyone know why there is only a small hole in the bottom jacket and no hole in the top jacket on the front side of the gasket? the holes are there in both the block and the heads (as they should to be interchangeable). is it the path of least resistance theory again, to allow the coolant to get to the rear of the head?

 

[LILCBRA]

sorry, it isnt the egr...thats what i get for thinking in the morning just the exhaust crossover im going to plug it off....if it does anything bad, which it shouldnt since i ran the 289 heads without it, i can always remove the plug.

 

[LILCBRA]

i got it up and running again this morning. i plugged off the crossovers and installed a 160* thermostat. after letting her idle about 5 minutes, she got to about 195* and stayed there, but the oil cap and breather are still hot to the touch. since i have never run aluminum heads before, is this more normal than iron heads, or should i look into maybe getting an oil cooler? i just cant believe that the caps should be getting that hot....

 

[jeffnoel]

Get a 180 thermostat that 160 still isn't letting the coolant stay in the radiator long enough to cool it.

 

[MUSTANG J]

With the cast iron heads my II ran as cool as a cucumber. 180. When I swiched to the aluminum heads the car now runs 190-200. The under hood tempature is noticable higher. My valve covers and oil cap/breather are hot to the touch. The aluminum heads transfer heat much better then the cast iron heads they replace. My car never runs above 200. When I did the head swap I tried a MR. Gasket high flow thermostat. the car ran 210-230 all the time. As the others mentioned, I don't think the coolant was in the rad long enough to be cooled. The Thermostat failed the other day and I replaced it with a motorcraft 180 and added a motorcraft rad cap as well. The generic parts store rad cap didn't work either! It was rated at 16 pounds pressure, but the lower rad hose blew off long before it let go!! [What a cool rocket to the moon sound] The Motorcraft one is rated at 13 pounds. AC Delco is the only company that makes a moulded lower rad hose for a II now, Ask me how I know The hose does not come in until tommorow so I filled the system up with water. I let it idle in the alley outside of my garage for an hour (almost no cross wind), the temp stayed at 190 the whole time. Once I get the new lower rad hose I will up-date you on the tempature, figure it may go down a little with 50/50 Coolant / water mix My car has a 1975 II rad re-cored with a high efficenty 3 row core. Two MR Gasket 10" electric fans cooling it. Anyone need a scary looking swelled 6" round molded lower II rad hose???

 

[Wart]

The thermostat has alot more to do with cooling than keeping water in the radiator long enough to cool.

Coolent is suppose to boil in the head. Takes alot of energy to make steam which is then transferred to the cooler coolant upon recondensing. Boil over happens when the steam does not recondence in the engine. It's quite possable and I'm sure it's happened that boilovers have occured due to coolent moving through the engine so fast the steam hasn't enough time to recondence. So not only can coolent go through the radiator too fast coolent can also go through the engine too fast.

Also,

Higher temp thermostats make for a more efficent cooling system. The higher the temperature differental between the air and coolant moving through the radiator the more heat is able to be transferred. There will be more heat transferred to air from 200 degree water than will be transferred from 150 degree water, all other things being equal.

If there are overheating problems with a 180 stat it's intuitive to put in a lower temp stat when in reality there should be a higher temperature thermostat installed.

 

[itsaMustangtoo]

Just food for thought,but you mention the cast iron heads running cool and the aluminum heads running hot.Then you go on to say that there are pressures building within( hoses popping off) bad caps,etc.,etc.,etc.,.

HOT temps and PRESSURE in the cooling system= warped heads and/or bad gasket sealing allowing COMPRESSION to leak into the cooling system thus causing the issues you speak of. Improper torque and /or sequence could be the culprit.

I have alum. heads on my stroker with 10.2:1 compression. It only heats up in traffic due to the underdrive pulleys but NEVER over 210

 

[MUSTANG J]

The thermostat was the problem with my car. The car got very hot and the rad cap didn't vent, so I replaced it too. Car idled for an hour never went above 190.

 

[THE COBRAMAN]

Correct cap for a II 302 is 16 pound.

Never have had problems with a 195 stat, shroud, and 16# cap. Runs at the mark year 'round (well, did when it was being driven regularly).