Over heating - Radiator Fan issues???

I checked the forum for similar issues and couldn't find one that met my situation. I have attached pictures for review.

Problem: temp: 230 at driving 40 mph with a little traffic on hwy. Day's temp was 88 degrees.

Fan is completely inside shroud at bottom but partially at top. Fan blade in general is about 3 inches away from radiator. It's a new three row radiator with new cap and 180 thermostat. I am running new 350 engine in a 65 Chevy C10 with A/C.

Question: Is my fan/shroud set up the problem?


Thanks in advance.

 

at 40 mph the fan shouldnt be doing anything, air speed is moving more than the fan.

is your timing correct? does it get hotter if you speed up? it overheat when idling?

 

Now that you ask I believe it did get hotter as I went faster. Good question.

We haven't had any hot days really since I got the new engine and radiator in December. I might need to wait for a hot day and take notes.

 

you need a fan clutch! the clutch will let the fan spin free, at 35 or 40 mph the ramming or air coming through works better than that fan! with out it i think you are causing turbulence right in front of the rad! meaning less air flow though the rad!

 

I'd look at the timing as well.

 

Sounds like air is going thru the easiest route(cos it will), which could be gaps around the radiator. Or the radiator is clogged. Also, the fan should also be 3/4" out of the fan shroud, all the way around, also. Not the complete cure, but a small piece of the cooling puzzle.

 

The three row in my 64 C10 would not cut the mustard with the added AC especially when the outside air was 95 and above and then it finally gave up and styarted leaking from the excess stress. I hate to say it but I went to aluminum with 3 row, large tubes, and two large electric fans. It now runs 180 degrees all day, any traffic, any speed, regardles, of out side temerature with the A/C on.

Air flow is a big deal. But first and as stated above make sure your timing is right. The shroud and fan alignment looks way off, i.e. there appears to be a big gap between the fan blade and the shroud. Should be around 1/2 to 3/4 inch all the way around and the fan pretty should be 1/2 way into the shrould. Not sure what the misalignment is doing but it is possible you have a turbulence wherein the fan and shroud are fighting each other. I would try to get that straightened out after you check the timing.

 

I would probably look at the timing. and maybe flush the radiator, I definitely think that there isn't a problem with your set up. There is no reason why that setup shouldnt let you run no hotter than 185 190. Check stupid **** like make sure that the crank pulley isnt smaller than the water pump pulley I dont know if your set up is new. And if you bought a new water pump make sure you didnt accidentally feed info to the parts guys to give you a reverse rotation one. Hey it can happen. make sure your thermostat isnt stuck, Check the rad fluid level after you have driven it if you just filled it. It will go down a lot after you drive it around. Make sure you check all of your ground bases before you jump to any conclusions.

 

Steve, I didn't notice it was you that originally posted, if you need any help let me know. I am in South Arlington.

 

Check also for a lean fuel mixture.

 

another vote for timing. check to make sure that the advance is working as well.

 

Is the fan blade on bacwards?

 

With no history we are just guessing but if it doesn't over heat at idle but heats up on the road, that usually means that there is a blockage in the radiator. It happened to me on a daily driver. An infrared thermometer gun can be helpful to spot any clogged tubes in the radiator.

Fans of any type are for traffic lights and stop and go traffic.

 

From the pictures I see two problems.

First the fan is too far in the shroud. About half the blade should be in the shroud and no more. At speed you are blocking the air from flowing through the radiator.

Next is the oil cooler between the radiator and the fan. Put it in front of the radiator. Again you are blocking air flow. Any air flowing into the radiator is going around the oil cooler and thus not cooling that section. And if the oil cooler is in contact with the radiator, you are actually heating that spot.

 

No, that finger eater is on correctly. And that thing should pull the dress off any gal standing three feet in front of that truck.


BUT!!!!!!!!!!! You say it is a "new" 350. Are you positive that it has the correct waterpump for your V belts???? If it came with a water pump or you asked for a pump for a late model 350 you probably got one for a serpentine belt which runs in reverse of a standard V belt water pump.

Make sure that you have the correct water pump on it before screwing with anything else.

 

More common than you'd think;good advice.

 

i agree with these statements the oil cooler needs to be moved.

 

Idle with the cap off and watch the water flow. You should see the water going down into the core once the t stat opens.. If it's coming up thru the core the reverse pump is the issue.

I think your fan and shroud are fine. I really doubt that is the issue here.

40mph is not putting much of a heat load on the engine either, so you do have a major problem.

I have a C-30 with a 350 and it will cool itself from 20 mph up. The poor aero of a truck sends a lot of air thru the radiator. I have no mechanical fan. A puller electric. And it will only run in traffic or idling once hot.

 

And the water pump. A lot of the fellas use a reman water pump or a cheapo and they don't always move water very well. Same thing with the T-Stat, more often than not those cheapo T-stats that come off the rack at Auto Zone or where ever don't work properly.

Buy yourself a flow cooler, or equivelent pump, and a good fast acting T stat. Drive it and get back to us.

 

flow kooler brand right?

 

Guys, a lot of great conclusions here. I will make a check list from this and hopefully solve before summer sets in. Many thanks.

 

Ok. I took some notes:
80 degrees outside. Beginning with engine cold. Warmed engine to 150 running with no thermostat.

Drove form home through neighborhood: 35 mph @ 170 avg.
Got on access road and drove 10 minutes at 45 mph @ 182 avg.
Turned into neighborhood, drove 10 minute at 25 mph @ 188 avg.
Got on hwy, drove 55 mph @ 196 avg.
Drove 60 mph @ 210 avg.
Drove 70 mph @ 216 avg.
Drove through mall parking lot (stop-go-stop) @ 218 avg.

Next day (temp outside 80 degrees) put a new 195 HD stat. Ran engine until stat opened at 195 degrees, which it did. *** Added additive advertising up to 30 degrees cooler.

Drove through neighbors for 15 minutes @ 200 avg.
Got on hwy, drove 50 mph @ 215 avg.
Drove at 60 mph @ 220 avg.
If I drove faster needle began to climb…
Got off hwy, drove through neighborhood @ 210 avg.

Both days ran with A/C on high.

Additionally, how much water would a standard 3 row radiator hold vs an old 4 row br*** radiator in liters?

 

did you fix anything people suggested here? if not you are still going to have a problem. try a new temp gauge too, does it boil over???

 

10-4 on the temp gauage, make sure it's running hot before you try to fix it. As was suggested use an infrared to make sure what the temp is. A friend wasted a LOT of time chaseing a hot engine when it was actually his gauge.

 

With the engine idling check to see that the air is flowing back toward the firewall, not out the front of the radiator. I've seen this recently.

 

I used to have a 64 C10 with the same setup that you have. mine would heat up it traffic real bad. I put a good electric fan and took the engine fan off and it solved the problem. One thing that you might try is to remove the radiator cap and start the engine with the heater on. You could have a air pocket causing the water to not flow threw the system properly. This is a problem I have seen several times with street rods. By doing this it usually makes a mess but it should get all the air out of the system. Just make sure that the heater (if you have one) is on or you will not get all of the air out. You will also be able to see if the water is flowing good.

 

OK, First off, 216 on an 80 degree day, with the AC running on full, with a 195 thermostat is not "running hot". Its about normal, most late model electric fans don't even turn on until the temp reaches 220.

It seems you are caring higher temps as you are going down the road. I suspect that is being caused by the flex fan that is sitting inside your fan shroud. The nature of a flex fan is to flatten the blades out as the rpm increases, it reduces the amount of power it takes to turn the fan. That's great for the fan and power, but when the fan sits completely inside the shroud, it effectively does a great job of blocking the air flow. The curved blades of the fan flatten out and the space between the blades is greatly reduced. The fan becomes a fairly solid disc spinning in the fan shroud. The only air that can p*** through the rad is what can get around the fan between the fan and the shroud and what can get through the flattened blades. Slowing down as you came into town reduced the temp because the fan blades slowed down and began to recurve allowing more air to p*** through the rad.

I believe you have 3 choices to lower your highway temps.
1) Shorten you fan spacer about an inch. That will place the fan in the proper location in the shroud, and when the blades flatten out, the air has more area to go around the spinning steel disc.
2) Replace the flex fan with a solid fixed blade fan, it won't flatten out and block the air flow as much. At higher speeds, the fixed blade fan will still block the air flow, but that speed will probably be above the legal speed limits.
3) Replace the flex fan with a clutch fan. Clutch fans slow the blade as the rpm increases, reducing the air flow blocked by the fan blades.

Personally, I would trash that flex fan instantly. I have seen more of them have blades come off then any other type of fan. Put a new 180 thermostat in your car instead of the 195. Gene

 

What is the cooler mounted on the inside of the radiator for,clearance issues or what? That blocking most of you air flow right there.Is it the ****** cooler or an oil cooler?.If its the ****** cooler move it and you will see a big difference.You got any pics of the front of the radiator and ac setup.?

 

the propeller on the water pump may be bad corrosion, not flowing correctly, If its ever been really hot or to the point where you need to shut the ****er off, it can damage a thermostat, Is the stat even opening? I just went through this ****. Bought a brand new high flow thermostat, stupid thing wouldnt open everytime. Then ran really hot one day and it never opened again. another stupid thing to check is the temp gauge working properly?

my 2cents.

good luck

 

I believe MR. Gasket has the Temp Gauge Radiator cap thats a pretty handy $25 cap.