[Twodogz]

Hello,

I just recently bought a '67 coupe with a 289 2bbl engine in it. The trouble I am having is that it will overheat on the highway. Any speed above 55MPH or so will cause the temp gauge to climb to unacceptable levels. Driving around town, it seems to be ok.

The coolant level is ok and I can see flow when I look in to the radiator. I measured the radiator and compared it to the chart in Paddock's catalog and it looks like I have a 2 row radiator out of a '66 in it. According to the chart, the one for a '67 is about 3 inches wider. Would this be the source of my problem?

Also, later on this year I intend to add an A/C unit from Classic Auto Air so I want to acomodate that as well. Any help on this would be greatly appreciated.

Thanks,

Jim

 

[Guest]

No, the radiator difference between a 66 and 67 would not cause that overheating problem.

First of all, is it possible that your gauge is reading wrong? Might wanna check into that possibility.

Also, is your thermostat opening? That could also be a problem.

 

[Twodogz]

When I first got it, it had a mechanical (underdash) temp guage and it would show readings of around 200 driving around town. Since then I fixed the original guage and installed a new temp sender.

Also, I can see water flowing across in the top tank of the radiator when the engine is running. I would [think] that if the thermostat was stuck I wouldn't see this. Or could it be that the thermostat is just opening partially?

What do you think?

Jim

 

[Veronica]

Hello. You probably don't have a thermostat.That's why you see the flow and it only heats up at highway speeds.The coolant isn't staying in the radiator long enough.Hope that helps.

 

[Guest]

Woah, hey, just noticed you were a fellow Illinoisan(spelling?). Haha, anyway, yeah, I think Veronica's right. Either no thermostat or a broken one.

 

[jay67fast]

Cooling Problems

Twodogz,
It seems to me you have two questions:1) why is the car overheating, and 2) will the addition of an A/C system add to the problem.
My opinion:
1) There may or may not be a problem with the thermostat ( incorrect thermostat,faulty thermostat, incorrect installation,etc.). There could be an obstruction in the coolant flow (clogged block, collapsed hose,clogged radiator,etc.). Check these things first (clogged block is the least likely of them all, so don't panic!!) Before you start spending money to check or repair RADIATOR problems, bear the following paragraph in mind.
2) By adding an A/C unit to your car you will increase the demands on the copoling system tremendously. The 67, 289 with a stock radiator was right at the cooling limits of the cooling system when it was new. Plan on updating and upgrading your cooling system if you add A/C.
I had the same combo as you, a 289, 2bbl, A/T, and I live in Florida ( hot, hot, hot all the time!!). There is very little chance that the stock cooling system will keep things cool with an A/C unit in the car. In order to cool things down, I had to go to a three row radiator (a four row would have been as good or better),a six blade fan, and a shroud. Since then all is well! Car runs cool all the time.
If I were you I would replace the thermostat with a new 195 degree thermostat, replace the radiator with a three or four row radiator, replace the upper and lower hoses, add a shroud and install a 6 or seven blade fan. This will eliminate your cooling problems now, and even after you install the A/C unit.
Hope this helps,if you need any other info, e-mail me at [email protected]
jay67fast

 

[Jess]

To Hot

Twodogz,
It seems to me you have two questions:1) why is the car overheating, and 2) will the addition of an A/C system add to the problem.
My opinion:
1) There may or may not be a problem with the thermostat ( incorrect thermostat,faulty thermostat, incorrect installation,etc.). There could be an obstruction in the coolant flow (clogged block, collapsed hose,clogged radiator,etc.). Check these things first (clogged block is the least likely of them all, so don't panic!!) Before you start spending money to check or repair RADIATOR problems, bear the following paragraph in mind.
2) By adding an A/C unit to your car you will increase the demands on the copoling system tremendously. The 67, 289 with a stock radiator was right at the cooling limits of the cooling system when it was new. Plan on updating and upgrading your cooling system if you add A/C.
I had the same combo as you, a 289, 2bbl, A/T, and I live in Florida ( hot, hot, hot all the time!!). There is very little chance that the stock cooling system will keep things cool with an A/C unit in the car. In order to cool things down, I had to go to a three row radiator (a four row would have been as good or better),a six blade fan, and a shroud. Since then all is well! Car runs cool all the time.
If I were you I would replace the thermostat with a new 195 degree thermostat, replace the radiator with a three or four row radiator, replace the upper and lower hoses, add a shroud and install a 6 or seven blade fan. This will eliminate your cooling problems now, and even after you install the A/C unit.
Hope this helps,if you need any other info, e-mail me at [email protected]

Very good suggestions. I would check to make sure the timing is correct at freeway speed or that you are not running to lean. Next check the hoses. They collapes at freeway speed if old. As far as radiator have a 4 row 24 inch made for your car. usually $225.00 installed. Run a 50/50 mixture and 2 bottles of Wetter Water. My needle bearly comes off the C.

Jess

 

[Twodogz]

Thanks For all the replies! I just received a new fan shroud form Paddock (it didn't have one) and I will be looking at a new radiator soon as well. I'm going to do a bit of shopping around so I can get the best price.

Jay, I was curious. You mentioned getting a 6 or 7 baded fan. Would that be a flex fan or a rigid (fixed pitch) one? I have seen a few on the internet but I wasn't sure exactly which ones you are talking about.

And Jess, Thank you for the ideas. I have a timing gun and I will check that. How would I know if I am running too lean though? Any tips?

Thanks,

Jim

 

[Jess]

Cooling

Twodogz

I don't know much about your (2 barrel) carb but you could ping like you had bad gas and have no power. If you are not familiar with that carb let a trusted friend or garage check for you. My distributor was bad and caused my timing to go away. What ever you do don't run the engine very long because if it is to lean you will burn holes in the top of your pistons. I would rather a car run rich than lean.

Jess

 

[jay67fast]

Cooling Problems

Twodogz,
I bought a 6 blade rigid fan from NPD. It's a direct replacement, took about 5 minutes to install (the radiator was out at the time). Absolutely no issues at all. Here's the particulars: NPD catalog, 2005 edition. Page 74, center of page, fourth fan listed in "used without fan clutch" list, part #8600-6, price $44.95.
Highest recommendations!!!
Jay67fast