The New 170 Will Noot Cool! HELP!

[modified17]

I had a similar problem on a race car twenty years ago. Turned out to be the lower radiator hose would collapse when the engine was accelerated. Take a look at the lower hose while bringing the rpms up and see what happens.

[61RANCHERO]

I have had the new 170 I-6 Running in the 61 Falcon Ranchero for a few weeks now but can not drive it as it will not cool. I have been into cars all my life and have raced cars for many years. I totally understand a cooling system and have done everything I know to do and everything my freinds know to do. Here is the deal... The engine runs great, initial timing set to 12 degrees BTC running a mild HP Cam, Stock Rebuilt Carb, .030 Over Ballanced and blueprinted 170 from a 63 Commet. Pull the choke and it starts right up, runs sweet, it warms up quickly. From 180-Degrees if I rev the engine to around 2500 + RPM the engine will gain 5 degrees per min until it boils over. I notmally shut it down at 210 Degrees. It does this no matter what I try. Here is the long list of what I have tried...

Aluminum Radiator rated for 500 HP
10" Electric Fan running full time, up-graded to 14" 1850 CFM Electric Fan running full time. Added 1/2" restrictor plate to cooling system to slow water flow, then new Motorad 180 Thermostat, then removed it completly, changed the water pump for new rebuilt unit, removed the head again to be sure the head gasket was installed correctly (it was). I used the stock gauge that is electric and reads from the back of the head and a mechanical gauge with the thermocouple dropped into the top tank of the Radiator. I made only one change at a time and it heats very close to the same every time. My shop is around 50-Degrees F. and I have also set a box fan on a chair in front of the rad during these tests. I am convinced that the engine produces to much heat... The question is why? I have never been so frustrated with a vehicle in my life.
Any ideas?

[Jeff W]

I don't know too much about electric cooling fans but I have an article from the April 2004 "Auto Restorer" magazine that Kenny gave me. Here are some suggestions:

It's not the size of the fan that is important, but the efficiency. Straight blades move more air than curved ones, but also make more noise. a 14-inch fan works well in most vintage applications. Electric fans are designed to cool the radiator from speeds zero to about 40mph. After that the airflow from the great outdoors should be sufficient. Understand that an electric fan, no matter how big, will fix an overheating problem that occurs at normal highway cruising speed. That is an airflow or internal (sometimes mechanical) cooling system problem.

Some fans have blades with almost a flat pitch. These don't move as much air as the aggressively pitched blades.

Placement is important, ideally you want the fan located on the upper 1/3 of your radiator core, as close to the top of the radiator as possible.

Pullers (mounted on the engine side) are 20% more efficient than pushers.

The guy that wrote the article also sells a 200 page book called "Automotive Cooling System Basics" by Randy Rundle. I see they are available, used, from Amazon.com for less than $5.00 including shipping. You could have it in a few days. Cheaper than a bottle of aspirin.

[61RANCHERO]

Thanks for your ideas, I can tell the difference when I use the fan pushing or pulling. The fan is as big as the radiator and when I run the engine I turn on the fan and still it heats up. I will watch the lower hose you never know. I have to take all ideas as I am out of my own. I still have to put the head back on, maybe this weekend.


Thanks... Keep em coming!

Glenn

[Nathan289]

These are some dummie ideas but I have to throw them out there.

1. what is the coolant mix that you are using? is it 50/50 or is something else? too much coolant can cause an engine to over heat just the same as not enough coolant.

2. when you fill the cooling system with coolant are you following the direction per the repair manual? It mentions something about having the heater hose disconnected as you fill to remove any trapped air.

If it make you feel any better my brand new 170 is doing the same thing..
It ran well enough for me to break it in, but now it will idle (1200rpm) for 30 minutes then boil over.

I'm hoping the bad gas that I had was the problem. I still haven't gotten the gas tank installed after cleaning it and sealing it.

Nathan

[Nathan289]

one more question.. is it possible that its running lean? a lean condition can cause over heating..


Nathan

[justahairFalconloopy]

...crappy head gasket??

[Luva65wagon]

Fresh blocks do run hot. Just the friction of rings can add a lot of extra heat. Are you certain the ring end gaps were to spec? If those were closing up... ughhh.

This is what I do to begin:

1) Of course, check the lower hose for a spring inside to make sure it can't collapse.

2) Fill the system with a good 50/50 mix. You shouldn't need anything like additives.

3) Removing the thermostat can actually raise temps because it allows the coolant to flow through the radiator too fast. So make sure it's in there, but verify it will open if you place it in a pan of water and heat it up. I've more than once in all my 30 years (doing this) seen "dual failures" of thermostats. Don't just think "Hey, it's new, so it's good."

4) For the sake of argument you could install a stock fan, but the text Jeff posted makes sense to check regarding electric fans.

5) With all the above checked, start the engine with the cap off and run it about 5 minutes and check to see if you ever get movement in the radiator (wear a face mask in case it burps at you). As the thermostat begins to open you should start to see movement. If you never do before it boils over -- take the thermostat out and run it again. Movement then should be instant. If it's not, then you've got something wrong with that new pump... though there's not much that can fail in these.

6) If there is a air-bubble trapped it can act like it is boiling over when in fact it's just purging air. So stand read to add more water ever time it burps.

Barring any of these things being the cause, you may just have an engine from hell and it burns fire and brimstone.

[61RANCHERO]

It is all back together now, timing is now set to 12 Degrees BTDC at idle no vac. 20 Degrees BTDC with Vac. 33 Degrees at 1900 RPM per the machine shop and cam specifiers recomendations. About the only thing I have not tried is driving it. Maybe it is like you said, new engines just run hot. Hiowever the last 99 I built did not have this problem. Hoses did not collapse, put in Antifreeze this time.

I tried a restrictor plate in place of the thermostat to slow the flow then out to increase the flow and no real change.

No room for the stock fan, the new RAD is much thicker than the stocker.

I tried to much and to little timing, no change. I tried holding the choke 1/2 closed too to make it run richer and no change.

All I have left to do is drive it and see if it will cool while driving it or what. Wish me luck, thanks for all the suggestions.

Glenn

[Jeff W]

If that fails, I would buy the "Automotive Cooling System Basics" by Randy Rundle for $5.00 including the shipping. The autor modifys vintage cars to run in the cross country race. He said he has solved all sorts of overheating issues.

[redfalken]

It should be running cool today! 30 degrees outside!

Mine was running 15 cooler than usual.

[GermanGeorge]

Hi, I'm not even sure I should be posting this on such an old thread, but I've had the same problems with overheating for about a year now with the 200 in my 62 Falcon, I've tried everything suggested on this thread with no success, I've come up with a new theory, and I really need some input, I just happened to notice that my exhaust pipe is located only about an eighth of an inch from my trans. pan, do you think that could possibly cause the overheating?, I could understand if it only overheated while idling, but it just seems to me that at 60 mph most of the heat would be drawn off by the wind, but like I said, I really need some input, what do you think?

[dhbfaster]

I'm probably not the most qualified guy to answer (although I do deal with a lot of industrial tool and equipment heat problems)...but it seems far fetched to me. I don't see how it could heat the tranny enough to transfer enough heat to the engine to be a problem. Do you know how much temperature drop the radiator is creating (difference between the hot input to the radiator and the return back to the engine?) If the required temperature drop is there, then it would seem to me that it has to come down to good flow of the coolant. Do you know you are getting enough flow of coolant from the radiator into the motor? (pump is working properly, fluid level high enough, and nothing is clogged?) Just my 2c.

[GermanGeorge]

Hey dhbfaster, ya, I know what you mean about sounding far fetched, I just thought that since the radiator is cooling the tranny fluid, a sufficient rise in tranny fluid temp. might overcome the cooling capacity of the radiator, but I've been trying to ryun this problem down for so long now, I might be starting to grasp for straws at this point, I appreciate your input, I'm not sure of the temp. drop between the input and return, but I'll look into it, my pump is working fine, but I guess there could be some partial blockage somewhere, I've flushed the cooling system till it ran clear, but there still could be partial blockage. Thanks again for your input, and I will look into those temps.

[Nathan289]

Check the head for cracks.

Easiest way to do this with the car still together is to check the coolant for exhaust gasses..

Exhaust mixing with coolant will heat up the coolant and not it allow to cool properly.