Overheating 66 289. Advice please

[Credzba]

I read thru every post I could find, but I need a bit more info/advice.
I have a 289 3 speed standard with edelbrock heads and intake, unknown cam.
It has been bored 60 over.
I've replaced head gaskets, put in 3 core radiator, replaced sending unit, and replaced thermostat. Oh checked hoses, and lower hose has spring inside it to avoid collapsing.

Before I put on the air conditioner it ran in the normal temp zone, so I suspect the a/c condenser is the problem, but not posative. I live in Texas, so I REALLY want the ac.
I believe it is not the gauge, because when it says its hot, the engine is making ping noises, and if I turn it off it is VERY difficult to start. I have not measured the water temp with a mechanical gauge.

What happens is that when I drive highway or city it heats up to the line just before H. What is weird is it doesn't seem to matter if I have the a/c on or not.

The things still to try that I've read:
0) In process of putting cowl (spelling) on, I have to redrill it because 3-core doesnt match up.
1) Bleed the water system, but I could not find any description on how to do this.
2) replace water pump (thinking of a high volume one, any suggestions on brand?)
3) pull all the freeze plugs and clean out inside engine.
4) (next to last desperate act) upgrade alternator to higher output (any brand suggestions here?) so I can put on an electric fan (looked like mark iv from junkyard was best bet?).
5) (last desperate act) yank the engine and put in a new crate engine.

So any hints or advice would be welcome. I am really worried that the condensor is just blocking too much air, but I don't know how to fix that. I thought about moving it to face down toward the ground and put an electric fan on it, but that sounds like a serious pain.

 

[dodgestang]

Where did you mount the condensor?
Sounds like a case of blocked air flow to the radiator to me.

How close is the fan to the radiator?
Is there a shroud?

 

[mdjay]

There has been many threads, if you do a search, on different approaches to cooling your 66. While many options for cooling fans, aluminum radiators and shrouds will make a difference, I suspect the motor bored at .060 could be the primary culprit.

 

[WORTH]

are you sure the AC install raised the temp, or has it also got warmer out?

if you suspect the condenser blocking air, look it over good and make sure the fins are not bent over, and that it is clean.

The shrowd will help at slow speeds, but if your having the same results on the hyway then it wont help at that end.

 

[MustangPaul]

Thought about an Aluminum rad?

I'd guess that the combo of 60 over and the condensor is causing the problem.

--Paul

 

[Credzba]

I am putting the shroud back on now, so currently no shrowd.
The condenser is about 3/4 to 1 inch in front of the radiator, should they be touching?
The fan has about 1.5 inch clearance from the radiator.

While I just spent $ on this 3 core, I'd go buy another aluminum if that will solve the problem. What brand do I look for?

This has been ongoing since winter so I dont think it is ambient temperature.

What about high-volume water pump, any experience with those? Suggest a brand, or not worth the money?

 

[Pakrat]

I agree that it's likely a combination of things all adding up to a more serious problem, the overbore probably being the biggest contributor of them all. Before I replaced things again, I would first try a combination of remedies together and see what happens. For example, it would not hurt to drain the system and flush it with a good cleaner followed by a rust inhibitor flush (Zerex makes both) and then finally using a heavy duty coolant like water wetter as opposed to a water/coolant mix. Did you verify that the new thermostat is actually good? This can be done on top of the stove easily with a pot. What degree is it? Dropping down to a 160 may help. Is there air in the system? It can help to remove the cap and squeeze the top and bottom hoses a few time. A shrowd will definitly aid in cooling, an electric set up is not always superior to the stock one. When I was in Texas I actually ran straight water without coolant because it has a higher boiling point, but I had to flush and use rust inhibitor too often so it's not fun. Even trying the best oil to reduce friction could help some as any combination of things might just be enough to get you out of the woods and into an acceptable range.

 

[pabear89]

Go with the shroud back on First.
Your spacing it good but the fan that close without the shroud is
not getting the air pulled across the entire rad area.
I found the best setting is 1/3 the fan showing out of the shroud.
It make the come thru.

Only draw back is living on a dusty road,
looks like a Smoke train of dust.

PB

 

[Credzba]

A bit more information, and 2 questions.
I tried flushing the engine last night, and low and behold the water wasn't circultaing into the radiator !! Why do I pay people to work on my car?
So, I pop out the thermostat, since I don't have a replacement and I just want to flush it anyways.

That done (still no shroud) I clean out the system and put in the flush. While its circulation I put a thermometer in the top of the radiator to test water temp and compare it to gauge in car.

C | ---- | H
These temperatures are sitting idleing in the driveway.
With a/c on water temp got to about 205, gauge was at the line right before hot.
With a/c turn off it cooled back down to about 200 and gauge dropped maybe 1/8 of an inch.

So is my gauge about right for what you would expect?
Is 205 too hot for me to drive the car?

Last thing, given I drove it 30 miles home from shop that did head gaskets with thermostat stuck, and now I see water coming out my passenger exhaust pipe .. I presume the head gasket on the passenger side is leaking again (or worse). So these temperatures are with a likely head gasket leak.

Opinions or suggestions welcome.

 

[Pakrat]

Well, I'm glad you are making progress. I forget which of SD's timeless wisdoms it was, but he used to say "New part or not, always verify it".

 

[Valaraukar]

don't neccesarily believe your stock gauge, it might be full of it. Try an aftermarket mechanical, maybe you aren't even getting high temps? just a thought.
-Tom

 

[pabear89]

Your shooting yourself in the Foot.
A large 3row without a shroud or stat is not going to cool.
Not only have you not harnessed the air flow you have no metering of coolant flow.
Put them on and your temp should drop to the 180-190 range.
Do a slow fill with the engine running,
Fill rad,Start engine.
As the water drops SLOWLY poor in coolant till full with the termostat open.
The sudden colder coolant that rushes in for the rad when the Stat starts to open will snap it closed again causing air pockets.
Allowing it to reach operating temp with the cap off you should see a Brook like flow by the cap.

You said Head gskt leak again?
If you just replaced the head gasket and ran it with a stuck termo,
You might want to recheck the headbolt tork if the water leak continues.
Or pressure test the cooling system for leak.

PB

 

[VictorII]

I always drill several 1/8" holes in the thermo. plate so air can find its way out. If you don't fill the block before buttoning up the thermo and housing, it is possible that the system won't burp. Happened to me once. Stay with a 180 thermo and do use a shroud; they make a huge difference in my experience. I also use a silicone clutch fan with an RPM release. And try some Redline WaterWetter, too. That makes the coolant more efficient. If your core is not all that new, then you might have to go with either a new unit or a four-row.

 

[WORTH]

A bit more information, and 2 questions.
I tried flushing the engine last night, and low and behold the water wasn't circultaing into the radiator !! Why do I pay people to work on my car?
So, I pop out the thermostat, since I don't have a replacement and I just want to flush it anyways.

That done (still no shroud) I clean out the system and put in the flush. While its circulation I put a thermometer in the top of the radiator to test water temp and compare it to gauge in car.

C | ---- | H
These temperatures are sitting idleing in the driveway.
With a/c on water temp got to about 205, gauge was at the line right before hot.
With a/c turn off it cooled back down to about 200 and gauge dropped maybe 1/8 of an inch.

So is my gauge about right for what you would expect?
Is 205 too hot for me to drive the car?

Last thing, given I drove it 30 miles home from shop that did head gaskets with thermostat stuck, and now I see water coming out my passenger exhaust pipe .. I presume the head gasket on the passenger side is leaking again (or worse). So these temperatures are with a likely head gasket leak.

Opinions or suggestions welcome.

If you have water coming out th tailpipe you have to do the head gasket anyway, that's a given

as for 205, that is not a problem witha 13 lb cap you can run 230-250 without boiling over.

as previously stated youu don't want to run without a t-stat. The opening in the t-stat is ment as a restrictor to slow down the water flow so it remains in the radiator long enough to cool it. If ti travels too fast it wont cool as well.

and it does sound like your guage is out of range, 205 shouldn't be anywhere near the top of the guage.

I'm running a 195 t-stat, mine shows 200 with the digital thermonmeter at the top of the radiator at idle and it is about 1/3 of the way up the guage. Keep in mind you should be able to run 250 without pegging the guage.

 

[dodgestang]

Are you sure its water and not gas? Just wondering...if your car is running really rich and that will also cause you to run alot hotter.

 

[D.Hearne]

If he really wants to know for sure if the motor's running too hot, he HAS to FIRST get a mechanical gauge in there. The stock guage just doesn't cut it. ESPECIALLY IF IT'S 30 SOMETHING YEARS OLD. I suspect if he does have a problem, it's a combination of the 60 over bore, the upgraded HP rating from all the mods he's done, and the A/C system adding to the cooling needs of the car.