OK, new radiator...I missed that. It has to be the water pump or the thermostat. A good friend of mine who has been a mechanic over 40 years said he once had to replace the thermostat FOUR times before it actually worked. If it is a new radiator then I'll assume you have new hoses...the reason I mention this is the lower hose DOES sometimes collapse or collect corrosion. Could the lower hose be plugged up?
had a simlar problem, we were stumped, then grab my new toy, one of those new laser light tempature reading guns ( i forgot the correct name) it was great to find were the hot and cold spots were found out the 185 thermostat did not open until nealry 200. it was $39 at hf tools paid for its self try it you will find the hot and cold spots very fast
In that case I'm 95% sure it's the thermostat UNLESS the lower water inlet at the engine is somehow blocked. If you know it's NOT then it's a defective thermostat. You may go through a few until you find one that isn't defective...these things are seriously a wild card, new doesn't mean functioning.
Until you verify that water will circulate your just chasing your tail. Pull the thermostat and fill the radiator. Start the engine and look for circulation in the top tank. With no thermostat there should be agitated water all the time. Rev the engine and it should increase. A long shot but we got a new radiator that was put in the paint tank with out plugs in the outlet (lower outlet). the paint had hardened in the core and there was no water flow. Some companies submerge the radiator in paint to insure total coverage of the fins and without proper plugs in place the paint gets into the core. If there is no water circulation you might have a similar problem. Frank
I didn't run it very much after I bought it and the gauge cluster didn't even work so I don't really know of it ran hot before. It looked like this when I bought it so I just went through and replaced most of the cooling system along with the ignition system. It idles really well now and the few times that I've driven around the block it seems to run great, but the temperature is what has alarmed me. I'll report back on what happens when I pull the t-stat tomorrow.
Is it me or does that radiator look older than new? Do you mean that is has been recently rebuilt or recored? That thing looks like it has a bunch of corrosion...I can see where the aluminum is discoloring. Are you SURE it isn't full of sludge?
Damn...I need to pay closer attention here. Where's my sign? lol... It would be cool to see what it looks like now...
if you haven't had it long and it was running hot, i'd check your timing chain, then reset the cam timing (new chain) and the ignition timing, then check your tune on the carb and look for vacuum leaks.
If you had the radiator cap off and the temp gauge got up to 220 with no water movement I would suspect a bad temp gauge. Water boils at 212 unless its pressurized. Of course you have to allow for altitude. But at 220 with no pressure the water should be starting to boil in the engine which would push water out of the radiator with out a cap on it. Borrow a known good mechanical gauge and screw it into the intake manifold and see what it reads.
Either you used way too much silicon with the new water pump.. or your thermostat is stuck..i always make sure mine are broke free before installing. When they sit of the shelf at your local parts store for a year or two, they always stick.
Ok, water is circulating without the thermostat, so that means probably the thermostat, my gauge, or a combo of the two right? I think I'm gonna pick up one of those infared heat guns to check it out, but I'll also swap the sending unitwith the new one. As I mentioned before the original sending unit adapter is pretty seized up in the intake manifold so does anyone have tricks for breaking something like that loose other than just grabbing my biggest breaker bar and going after it?
may be the sending unit too-the newer replacements do not work correctly--they are a different resistance thant he old ones---will read hot--just like an old corroded one does sometimes--had the same thing with a 327-would go to 220 real quick--gauge/sender were way off--IR gun showed 175 at top hose when gauge said 220--added resistors to correct it--as I recall, old/correct ones read 700-720 ohms at 70 degrees-new/replacements read 530-560 ohms-this is a problem when trying to use orig. gauges and orig. type sender
YOU NEED ABOUT 25º combined mechanical and vacuum TIMING ADVANCE AT IDLE OR YOU WILL OVER HEAT, AT IDLE. I see no vacuum advance hooked up and it was on the wrong-for-the-street "Drag strip tuning" side of the carburetor on your "before" picture anyway. You stated you have 2º initial I don't know what the advance specs are on your new-fangled distributor but if it's typical you need to try it at around 11-14º initial with the vacuum advance hooked up to manifold vacuum. That's the drivers side vacuum port on that carb. No vacuum advance? Can't help ya...
Yeah, I think I definitely need to do my homework on the timing and get that dialed in. The new Pertronix distributor I put in doesn't have vacuum advance and I thought it called for 4º, but I'll definitely look into that and make sure my timing isn't ridiculously retarded and adding to my overheating problem.
Is it a steel adapter? They can seize in aluminum and be very hard to get out. Ive actually broken an aluminum intake trying to get one out with a big breaker bar. I learned a new trick since then. Heat the adapter up from the inside with a torch. When its good and hot, melt candle wax around the outside of it. Jut take a long candle and push it down around the outside of the adapter when you take the heat off. The wax gets super thin when melted and will soak in around the threads. It also acts as a lubricant while screwing the part out.
Your fan shroud looks to deep....the fan needs to be half in and half out...at the outside edge to the shroud
Go buy a cheap cooking thermometer. With the engine cold, remove the radiator cap and insert the thermometer. Start engine and let it run and see what the temp "really" is...... and how long it takes to get there. It should cycle right around what your thermostat opening point is.
looking at the picture, the generator is all the way at the end of the adjustment slot. do you have enough belt tension to properly turn the pump?
If you still have the thermostat out with a high flow pump it will run hot if you don't resrict the flow of coolant.
Ive had a aluminum high flow water pump hold thermostat shut. I put the stock pump back and all was normal again
It could also be the brand of thermostat. For many years I have run Robertshaw thermostats and they are great but now they are extremely difficult to find in my area. I don't recommend running the stats that are marketed by some of the "cheap" parts stores. NAPA usually handles good ones. Also, check to see if water is flowing good through your radiator. Leave about 2 inches of air space at the top and look inside with the cap off and the engine running. Too much water can cause the water not to flow or you may need a NEW waterpump--- not a rebuilt one.
The Jalopy Journal
