Overheating Issues, Perplexed

[RAO-3]

I'm not an expert by any means but have been reading and learning from this thread. Is it possible that there's some sort of blockage or air pocket in the radiator that may be reducing the flow area? I would think it would be easy enough to check with the IR thermometer.

Just a thought.

-Ray

[elmariachi]

Originally Posted by Jamo

Thing about a 160...while no differnce going down the road, it'll be cooler when you stop

Okay, I'll definitely buy that. IIRC, when I installed the 160*, I didn't road test it nearly enough. I may need to try that again.

Originally Posted by Jamo

...compare the cost of the radiator to the cost of the motor and your own kharma being disrupted every time you're stopped in traffic and have to start watching the needle.

I am at the end of my build, so I am done trying to rationalize any of these expenses. Its all AMEX $insanity$ at this point. But as you say, I'll be damned if I am going to come 45 years to then live with a car where I have to be preoccupied with a temp needle.

Originally Posted by Jamo

Fresno vs. Houston...close, but I can always drag in Bakersfield, which smells like Houston.

I'll see your Bakersfield and bump you a Port Arthur.

Originally Posted by RAO-3

Is it possible that there's some sort of blockage or air pocket in the radiator that may be reducing the flow area? I would think it would be easy enough to check with the IR thermometer. Just a thought.
-Ray

It is very possible. I removed both hoses and held my hand over the lower exit while filling up the radiator will water. Then I removed my hand and it discharged within a couple seconds. I did this a few times and nothing came out. I also spot checked it with the IR gun and didn't see any abnormally hot spots versus the overall temps. As I mentioned, with the engine idling, the circular area where the fan is drawing is maybe 10* cooler than the rest of the radiator, but there are no other hot spots in the "no fan" zone that I could find. I also placed a lamp behind the radiator and turned out the lights in the garage and looked through the fins. I could not see any fin blockage or any signs of distortion of the tubes. The only other thing I can do to check for blockage is remove it and take it to a shop. And at this point, this radiator is sorta like that girlfriend you suspect probably needs to go: Once she's out, she ain't gettin' back in.

[RAO-3]

Originally Posted by elmariachi

It is very possible. I removed both hoses and held my hand over the lower exit while filling up the radiator will water. Then I removed my hand and it discharged within a couple seconds. I did this a few times and nothing came out. I also spot checked it with the IR gun and didn't see any abnormally hot spots versus the overall temps. As I mentioned, with the engine idling, the circular area where the fan is drawing is maybe 10* cooler than the rest of the radiator, but there are no other hot spots in the "no fan" zone that I could find. I also placed a lamp behind the radiator and turned out the lights in the garage and looked through the fins. I could not see any fin blockage or any signs of distortion of the tubes. The only other thing I can do to check for blockage is remove it and take it to a shop. And at this point, this radiator is sorta like that girlfriend you suspect probably needs to go: Once she's out, she ain't gettin' back in.

Maybe try backflushing it to see if anything comes out?

Also did you check the radiator cap, or just try replacing it? Maybe it's not properly controlling the pressure in the system.

-Ray

[DocDirk]

El, the megaCFM fan is installed and I drove it for the first time yesterday that way, nothing unusual because it was a balmy 75deg. day. Temp hit and stuck at about 192F. Today we head out for a 1600 mile trek through Arizona so the system should be put to the test and we'll see if doubling the CFM (still shrouded) makes any real difference.


Good luck on your challenge too!

Regards,

Dirk

[vettestr]

We are in Phoenix so can relate to a hot summer day. Just a couple of tricks to add to some of the great ones already tried.

Adding an oil cooler does help even if oil is not overheating, add a deflector plate behind the oil cooler so airflow from the cooler goes down and not through the rad. In theory the cooler would seem to block a bit of airflow to the rad. but it helps. The air diverter plate keeps the load off the radiator.

Shroud or no shroud ? On a couple of cars where I questioned the shroud might be blocking hi way air I added shroud mud flaps. I cut a couple 5 inch round holes in the shroud and hung a square flap of rubber fastened only on the top. I thought air flow or pressure at hi way speed would push flapper open. If in stop n go traffic the flap would allow fan to pull flap closed.

[elmariachi]

Originally Posted by DocDirk

Today we head out for a 1600 mile trek through Arizona so the system should be put to the test and we'll see if doubling the CFM (still shrouded) makes any real difference. Dirk

Post your findings back here. I expect this thread might be of value to future overheaters like us.

Originally Posted by vettestr

Shroud or no shroud ? On a couple of cars where I questioned the shroud might be blocking hi way air I added shroud mud flaps.

I had a JEGS aluminum shroud we tried but it was too shallow, didn't have highway vents/flaps so it didn't work. Once I am done experimenting with pulleys for water flow and using the shop fan to increase airflow at idle, I will be going with a shrouded fan next and a radiator swap last.

I have three new Stant radiator caps I have tried in varying pressures, no effect on the overall issue. Currently I am running a 16 lb. cap.