Overheating
 

I am progressing in the slow process of bringing a truck back to life after sitting 10 years. This is what I've got. 72 with a 383. Engine was built and barely broken in before it was parked. The radiator (Griffith) was new then too so was the water pump. I have since flushed the radiator and installed a new thermostat. New twin electric fans with a shroud. Yes they are blowing the right direction. If I drive around the block and sit in the driveway for 5 minutes I'm pushing 210 and puking antifreeze. Tonight I watched the fans turn on at 180 and 185 and the thermostat opened and 180.
I saw water moving at 180 and the top hose got got hot then as well. I confirmed timing too. I hate to put a radiator in unless I am sure I need it. Should I throw in a water pump and see? I did let it run with the cap off for a long time and I believe it burped all of the air out. Heater lines are hot.

Anything else I can check?

Re: Overheating
 

Are you filling the rad right to the top or leaving the level down a couple inches?
You fill it full if you have a recovery tank and fill it down a couple inches if you just have an overflow hose.
It might not be overheating!

Re: Overheating
 

I have a recovery tank. It is pretty small though. How hot should it be running. Next is finishing the AC that was mostly installed. I'm afraid by the time I get the AC running and the truck is under load I'm going to be hot.

Re: Overheating
 

This is the truck.

Re: Overheating
 

Is your recovery tank a return tank or just a catch can?

Re: Overheating
 

It should pull it back in when the radiator cools down I believe.

Re: Overheating
 

Nice Truck.
Is the radiator cap 10 years old? Just food for thought.
I'm just trying to help.
I also use a pyrometer in cases like this to check actual temps. in different locations.

Re: Overheating
 

Make sure of that!
The hose should be submerged into the coolant.
If not it just sucks in air.

Re: Overheating
 

Did you jack the front end up so the radiator water level was higher than the back of the block when you were burping the air? You have to make it easy for the air to get out. What was the ambiance temperature outside when it overheated? What size of radiator is it? Have you compared the radiator inlet temperature and the outlet temperatures? After sitting so long have you checked the air path through the radiator? It wouldn't be the first radiator plugged up by mud from insects. Just some things to check before you start tearing things down. Most likely the water pump is good. If you not convinced though you could pull it and check the clearance on the impeller and the overall condition of the impeller.
Good luck with that nice 503 green truck.
If you can post a photo or two of the engine may be someone with sharp eyes may spot something.

Re: Overheating
 

New cap! I'll jack up the front and give that a try this weekend. I'm going to change out all the hoses. He had on those chrome pretty hoses with the big ends that you can't get to the clamps. I did not think about checking temp at inlet and out of radiator. Will an IR thermometer work for that? It was inthe low 90's when I was overheating. I'm not happy with my reservoir. Any suggestions out there?

Re: Overheating
 

I have a brand new ZZ454 in my CST10 with the Griffin aluminum radiator. If I sat more than 5 minutes at idle, damn temperature gauge would start rising super fast. I also had the electric fans inside my factory shroud. I burped it several times. Change fluids several times. Double checked timing over and over. Installed a separate tranny cooler. Tried all kinds of different thermostats and it would still over heat. I paid over $400.00 dollars for this 4 core rad. I gave up and pulled the rad. I put in another aluminum from DeWitt and no more over heating. I don't know why the Griffin didn't work. Now I'm hearing the Mishimoto is the one to use.

Re: Overheating
 

I would suggest to use that IR thermo. all around the cooling system. I.E. each location like thermo housing, top rad. hose., inlet to radiator and so on. Even check your header or exhaust manifold port for each cylinder.

There is a lot of different points to measure temp at.

Re: Overheating
 

210 should not be hot enough to puke coolant. At zero pressure, water boils at 212 and a 50/50 mix at 226. Just 8 psi raises water's boiling point to 233 and 50/50 to 248.

Make sure your rad. cap is for a closed system so your recovery tank will work. I think stock is 15#.

Gonna be interesting to see what temps you measure with an IR. Oh nice truck btw!

Re: Overheating
 

What overflow tanks are you guys using?

Re: Overheating
 

This is what I am using. https://m.summitracing.com/parts/sum-300103
At 210 should it be building enough pressure to push past the cap? It's 16 pounds I believe.

Re: Overheating
 

At 43 oz. capacity, that tank is plenty good enough. 16# cap is fine (if it's for a closed system). No, you should not be pushing coolant out at only 210 degrees.

What typically happens is all coolant stays inside the cooling system until you turn the engine off. Then it will push some coolant into the overflow tank. As the system cools down, coolant will be drawn back into the radiator (if your cap is for a closed system).

Re: Overheating
 

At those temps it shouldn't be puking. 260, maybe, but after shutting off more than likely.

So my first thought is you have a faulty gauge or wrong sending unit?

Do you have a temp gun to verify the temps in and out of the radiator? Sometimes a low temp t-stat wont let the coolant stay in the radiator long enough to cool off.

You don't have a goofy aftermarket serpentine or belt system running the pump backwards do you?

What compression ratio are you running?

Is your timing set up correct and plugs look good and not running way lean?

Just a few more ideas for you.

Re: Overheating
 

So this is a truck someone else built 10 years ago? Someone else built this engine, broke it in and parked it for these 10 years? Getting it barely broke in then parking it is suspect. Cooling problem was the reason to park it? As mentioned if that engine has some type of serpentine belt system it may have the wrong water pump on it. If it has a conventional v belt setup it may have a reverse rotation water pump on it. Lots of unknowns.
Even if the engine had a good antifreeze/coolant in it when stored some internal corrosion can still occur. I believe I would take that radiator to a shop and have it checked out, boiled out to make sure it's flowing coolant as best it can. Sitting unused is often as hard on metal parts as abusing them.
How does the oil look? Do you see any bubbles in the radiator with the cap off while it's running? If so it's time to consider a cracked head, block or blown head gasket.

Re: Overheating
 

BAM, that could be your 210 and puking antifreeze.

Re: Overheating
 

It's supposed to "puke" antifreeze. That is why there is an overflow tank. 210 is not overheating, plain water won't boil at that temp BUT there will be dynamic pressure (or whatever is the correct term) caused but the coolant expanding when heated. This pressure will cause some amount to be forced past the cap. It will be sucked back when the engine cools. Are you saying that the coolant tank overflows?
My truck will get to about 250-260 under severe conditions but it will not leak a drop past the overflow tank.

Re: Overheating
 

I have a lot to do this weekend! It does not have a serpentine system. I'll check temps and see if I have bubbles. I'll report back this weekend.

Re: Overheating
 

My guess would be the timing is too late - I've seen a timing tape stuck on the harmonic balancer backwards and using that the previous owner set the static timing ATDC instead of BTDC. Doesn't sound like the thermostat is in backwards but I've heard of that too. And the excess heat could be coming from the trans if you have an automatic but doesn't sound like its being driven long enough for that.

Re: Overheating
 

Quick update until this weekend. I jacked up the front with the cap off and ran it to see if I could get a burp. I did not see a burp but it held strong at 190. I'll take her for a drive and take some temps on Thursday if I can or this weekend. To answer the other question above I am getting the temp from the holly sniper display.

Re: Overheating
 

Good luck.

Re: Overheating
 

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