![]() |
![]() |
#1 |
Registered User
Join Date: Dec 2007
Location: Riverside, Ca
Posts: 407
|
Cooling Issues
So i have a 350 sb. with auto transmission, and ac with seperate collers for both with no thermostat now. i had a 180 in it, it was still gettin hot so i dropped it to a 160 and now i just put a housing in. when i sit at a light for just a minute or so my truck will jump above 220 or even when i am just driving around normally. i have a brand new radiator in it and its pumping correctly. so i went to jegs and they have dual electric fans that would eliminate my mechanical one and just pull more air according to them. i would like some advice from someone who has either done this or knows about it. . . any help?
thanks, Mark ![]()
__________________
Lifted 2wd 1969 C20/ 5.3LS/4L60E :http://67-72chevytrucks.com/vboard/s...d.php?t=728388 |
![]() |
![]() |
![]() |
#2 |
Registered User
![]() Join Date: Jul 2007
Location: New River Arizona
Posts: 1,180
|
Re: Cooling Issues
I live on the face of the sun here in AZ. You may be going backwards with you're cooling problem. Out here we use a 195 degree thermostat. If you use a cooler one the water circulates at 160 degrees and does not cool as efficiently because it opens earlier. Also I use a 454 fan clutch which helps. I run at 1/8 on my c10 and 1/4 on my k5 Blazer.
|
![]() |
![]() |
![]() |
#3 |
Just Not Low Enough!
Join Date: Mar 2009
Location: Phoenix, AZ
Posts: 525
|
Re: Cooling Issues
i run electric fans and love them, i have 2 15" fans and only run one in the summer here in the solar pit...and stay under 210.
if ou can afford them its worth it, it increases gas mileage, and power. but make sure you wire it correctly and have a good alternator. how many core is your radiator?
__________________
NEED ELECTRICAL HELP? ASK ME! 67-72 Full Wiring Diagrams Lots Of Info, TAKE A LOOK 1967 Chevy C-10 Shortbox Bagged 327 4spd ![]() Previous: 1971 Chevy C-10 Short Sep I6 Auto (Traded) 1973 Chevy C-20 *THE REDNECK BATTLE TRUCK* 2001 Chevy Silverado 2Dr 5.3L Shortbox. R.I.P. 1969 Volkswagen Bug This is my first meeting, I have a horsepower problem. |
![]() |
![]() |
![]() |
#4 |
Senior Member
Join Date: Nov 2003
Location: Brookings, SD
Posts: 10,497
|
Re: Cooling Issues
Put your thermostat back in.
Are you running a fan shroud that's correct for your fan? Is your temp gauge accurate?
__________________
Some people are like slinkies, they aren't good for anything, but you can't help but smile when you see one tumble down the stairs. |
![]() |
![]() |
![]() |
#5 |
Registered User
![]() Join Date: Nov 2006
Location: KINGSPORT,TN.
Posts: 3,035
|
Re: Cooling Issues
my truck wont cool with a electric fan. always use a thermostat, 180 deg.
__________________
I BELIEVE IN JOHN 3:16 |
![]() |
![]() |
![]() |
#6 |
Registered User
![]() Join Date: Nov 2008
Location: Cleveland, OH
Posts: 591
|
Re: Cooling Issues
Well you have a problem obviously. Like previous posters have mentioned
1. Check that you have a correct fan shroud. 2. If you have a clutch fan, make sure it is operating correctly. 3. Your vehicle will cool more efficiently with a correct electric fan set up but it should cool adequately with your current set up . 4. Without a thermostat, the water has no restriction and can actually cool less then with having a thermostat in. 5. Possibly check fuel mixture, timing, and gage accuracy if there seems to be no explanation. |
![]() |
![]() |
![]() |
#7 |
Old Skool Club
![]() Join Date: Jun 2001
Location: Benton, AR "The Heart of Arkansas"
Posts: 10,880
|
Re: Cooling Issues
I'd be sure that there is a shroud. The distance between the fan and the radiator is critical in that the fan placement within the opening in the shroud is also. The fan needs to be placed so that it pulls air through the radiator.
Coolant should be a 50/50 mix of water/antifreeze. That mixture gives the best cooling and freeze protection. More or less antifreeze will reduce the effects of the 50/50 mix. Back to the shroud issue. I drive a school bus that has a Cummins 5.9 with an Allison 5-speed automatic. Last spring I had cooling issues with it. I found that the simple shroud that Bluebird included had been damaged by the yokels who had worked on the radiator/cooling system. So, our "mechanic" simply removed it. It wasn't but a piece of flexible rubber-like material that was approximatley 4 inches by 12 inches. Without that piece, my engine temp would climb to over 235 degrees. Today, the mech reinstalled another piece that serves to replace the damaged part. Today, with temps near 90 degrees, and sitting in traffic and idling or running down the road, the temp never got over 225 and mostly stayed at 210 or less. First time in nearly a year that it has acted normal. Mechanic was looking for stuff like a kinked hose and wanted to replace the new thermostats. Some people just don't ever learn.
__________________
Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was. |
![]() |
![]() |
![]() |
#8 |
Registered User
Join Date: Jan 2006
Location: Take Off
Posts: 1,908
|
Re: Cooling Issues
I don't think you have an airflow problem since you have a mechanical fan and you still have overheating while driving around. When the truck is moving the force of the air through the radiator should be enough airflow even without a fan. I believe you have a coolant flow issue or excessive heat production. Make sure that your water pump pulley is significantly smaller than your crank pulley. This will keep the water pump spinning at the correct speed. Also, make sure that the water pump is working properly and that the impeller is not damaged, rusted or just free wheeling somehow. You may want to switch to a high volume unit. The Procomp one sold by Skip White and other Ebay vendors works well. Flowkoolers are nice, too. Make sure that the radiator is not clogged and the engine coolant passages are clear. Maybe try a good flush of the system. Make sure you are running a vacuum advance and that the carb is not running lean. Also, 100% water in the coolant system transfers heat best. Coolant is not as good at heat transfer, which is why you can only run 50% coolant. You need at least 50% water to ensure proper cooling. The coolant is actually an anti-freezing agent and includes a water pump lubricant and anti-rust agent. I run 100% distilled water and Water Wetter from Kragen or Autozone. Water Wetter eliminates the surface tension of the water so that it literally sits closer to the metal block and thus, transfers heat better. It also contains an anti-rust agent and water pump lubricant. This will cool better than anything else from my experience and is ok to use at race tracks that don't allow coolant. If you do run a T-Stat, use a high flow one, not the standard ones everyone carries. However, I am not convinced you need one out here in SoCal or Riverside. The purpose of the T-Stat is to allow the engine to get up to proper operating temp quickly so you can get going. Very necessary in cold climates and for best fuel efficiency. However, the T-Stat also restricts coolant flow and coolant flow is critical to cooling. The T-Stat can also trap air bubbles in the system which reduces heat transfer. In very warm climates where the engine will likely get up to operating temp without the T-Stat in a reasonable amount of time, I believe you can go without it. My truck does not have a T-Stat at all and it runs great, never gets too hot but still gets up to proper operating temp pretty quickly. I know others will disagree/argue with me but I've been studying/troubleshooting cooling system problems a long long time.
|
![]() |
![]() |
![]() |
#9 |
Registered User
Join Date: Dec 2007
Location: Riverside, Ca
Posts: 407
|
Re: Cooling Issues
Thanks for all the feed back guys. . just to go over some things, the fan shroud is the correct one for the truck/radiator and the fan that is on it stuffs this shroud. its about half way in the shroud and half way out. "perfect according to the mechanic" i recently blew up the motor due to heat when the stock gauge went out and was reading normal. so i replaced the motor, flushed the radiator and made sure that the water pump was working and put the new gauge in. so im thinkin go back to the 180 degree T-stat at least? and i will check the coolant to make sure i have the right fluids in it. anything else i should be on the look out for or that i missed? thanks again everyone, Mark
__________________
Lifted 2wd 1969 C20/ 5.3LS/4L60E :http://67-72chevytrucks.com/vboard/s...d.php?t=728388 |
![]() |
![]() |
![]() |
#10 |
Registered User
Join Date: Dec 2007
Location: Riverside, Ca
Posts: 407
|
Re: Cooling Issues
oh also someone recommended a cowl induction hood so the heat would be able to escape from the engine compartment??
__________________
Lifted 2wd 1969 C20/ 5.3LS/4L60E :http://67-72chevytrucks.com/vboard/s...d.php?t=728388 |
![]() |
![]() |
![]() |
#11 |
Between Trucks...
Join Date: Mar 2002
Location: Los Angeles, CA.
Posts: 3,830
|
Re: Cooling Issues
I would have replaced the water pump when you replaced the motor.
__________________
Beat it to fit, Paint it to match... ![]() |
![]() |
![]() |
![]() |
#12 |
Blaze-Air
Join Date: Nov 2008
Location: Virginia
Posts: 1,117
|
Re: Cooling Issues
Put a 195 t-stat in it, big block fan clutch and blade, make sure the shroud is correct fit, and happy driving. You need the 195 t-stat.
|
![]() |
![]() |
![]() |
#13 |
Registered User
Join Date: Jul 2009
Location: Russellville, Arkansas
Posts: 1,699
|
Re: Cooling Issues
Looks like the common factor for overheating is your radiator. Old engine overheating, new engine overheating, same radiator? Get it rodded out and flushed.
|
![]() |
![]() |
![]() |
#14 |
20' Daredevil (Ret)
![]() Join Date: May 2003
Location: Jefferson State
Posts: 13,643
|
Re: Cooling Issues
All good advice above, I will agree with a 195* thermostat, no t-stat lets the coolant go through the radiator so fast it doesn't have time to cool off, if that makes sense.
One thing you didn't mention is what type of fan you have. If you have a fixed-blade or a flex fan instead of a good clutch fan, I would strongly suspect that is the problem. My factory A/C 350 has a 7-blade clutch fan and zero cooling issues.
__________________
- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
![]() |
![]() |
![]() |
#15 |
Registered User
Join Date: Dec 2005
Location: White Rock Canada
Posts: 865
|
Re: Cooling Issues
I had the same problem, put on a pusher fan with a 190* relay just for the stop and go driving, this helped somewhat. I thought my clutch fan was fine, it had the proper drag when cold but I changed it anyways. viola! problem solved. the clutch fan will get old and not lock up at any speed.
Al.
__________________
1972 GMC Sierra 1972 GMC Super Custom Suburban |
![]() |
![]() |
![]() |
#16 |
Registered User
Join Date: Dec 2007
Location: Riverside, Ca
Posts: 407
|
Re: Cooling Issues
that may be the issue in itself. . i dont have a clutch fan on it because it push's the fan right up against the radiator and too far into the shroud to pull any air. any way around this?? i will def put a 195 T-Stat in then. and i believe i have a 6-7 blade fan on it. ill check and get a for sure answer.
__________________
Lifted 2wd 1969 C20/ 5.3LS/4L60E :http://67-72chevytrucks.com/vboard/s...d.php?t=728388 |
![]() |
![]() |
![]() |
#17 |
Registered User
Join Date: Jan 2006
Location: Take Off
Posts: 1,908
|
Re: Cooling Issues
I think it's a myth that the coolant will flow too fast to absorb heat without a T-Stat. In the real world, there are enough obstructions to coolant flow in a cooling system that allow absorbtion of heat by the water/coolant. I may be wrong, but I believe a 195 degree T-Stat will not help anything and may make your problem worse. Also, a pusher fan may just block airflow and cause more problems. How big is the radiator and how many rows? You may want to upgrade to one with more rows, like a 4 row. Also, a new radiator will usually perform better than one that has been rodded out. Also, a flush may not get all the gunk out of the radiator. Adding a clutch will not help cooling. A rigid fan should cool the engine unless the blades are flattened for some odd reason. You should not need a cowl hood to cool your engine. I would also replace that water pump since it is old and was on the old engine that blew. The radiator and water pump are still old and one of them may have caused the old engine to blow. Most mechanics I know recommend replacing the water pump and radiator on an engine rebuild and in your case, it seems even more prudent to do so.
|
![]() |
![]() |
![]() |
#18 |
Parts and more parts
Join Date: Nov 2003
Location: Lebo, Kansas (middle of nowhere
Posts: 6,821
|
Re: Cooling Issues
#1 Have your radiator checked for more than a flush (get it rodded out or replaced).
#2 Put at least a 180 degree T/stat in and go with one that is noted as a "SuperStat" Every brand has one in their product line. This T/stat moderates in midrange better than a standard T/stat. #3 Why is your fan so close to the radiator in this model of truck years? Has this truck had a different engine installed than the original? If so, was it an upgrade to a V-8 over a 6 cylilnder? Do you have the right size radiator? Go back to item #1 Replace if radiator is too small. #4 Too much water flow or too fast of flow is just as bad as too little water flow. You have to be able to absorb the heat from the engine's components to remove heat. #5 Do you have the right water pump? If it just happens to be a pump for a serpentine system and NOT a standard belt driven setup, then you are turning the pump the wrong direction and no cooling will be in effect. #6 Is the fan actually moving air? Is the radiator or A/C condensor plugged with dirt or bugs? It can be as simple as that. #7 The cowl hood will help you when in slow traffic, but on the open highway the air will go down through the hood into the engine compartment, vice going out the hood. |
![]() |
![]() |
![]() |
#19 | |
Registered User
Join Date: Jan 2006
Location: Take Off
Posts: 1,908
|
Re: Cooling Issues
Quote:
|
|
![]() |
![]() |
![]() |
#20 |
Blaze-Air
Join Date: Nov 2008
Location: Virginia
Posts: 1,117
|
Re: Cooling Issues
Get a good shroud, 195 t-stat, BB fan and clutch. Set it up like this. I have a short pump and use a spacer. If you have a long pump you may not need a spacer.
![]() The blade is right at the shroud opening. I had similar over heat conditions as you have, i switched from a 5 blade and no clutch to a 7 blade and BB clutch. No more over heating. It could be restricted flow. I would pull the radiator cap when cold, warm it up to operating temp. With the rpms up a bit you should see flow in the radiator if you look in the fill neck. If no flow, do a rod out, or replace it. Check for collapsed lower hose, make sure water pump is in good condition. |
![]() |
![]() |
![]() |
#21 |
20' Daredevil (Ret)
![]() Join Date: May 2003
Location: Jefferson State
Posts: 13,643
|
Re: Cooling Issues
There's been at least a couple suggestions to rod out the radiator... but his first post says he has a new radiator and good flow.
Am I missing something? ![]()
__________________
- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
![]() |
![]() |
![]() |
#22 |
Registered User
Join Date: Jun 2006
Location: Indiana
Posts: 4,859
|
Re: Cooling Issues
You did say the rad was new, but you never said how many rows the rad had. Did you just replace exactly what you had or did you make sure to get a bigger rad? There are 2 row, 3 row and 4 row rads. The 4 row is the best, but a 3 row should get the job done. A 2 row may be too small, new or not.
If you are having issues with clearance at the rad, did your truck used to have an L6? If so, did you move the motor mounts to the V8 small block location? Even with a long water pump, you should have plenty of clearance. Just my .02
__________________
'70 GMC C1500 LWB Power disc brakes. WooHoo! Posi 6 Lug Dana 60 |
![]() |
![]() |
![]() |
#23 |
Registered User
Join Date: Feb 2008
Location: Grande Prairie Alberta
Posts: 261
|
Re: Cooling Issues
did you replace the rad cap with the radiator, if not then either buy a new one (around 15psi) or have the old one tested
__________________
eh ![]() 1970 Chevy C20 daily driver ![]() 1975 GMC Jimmy 4x4 project ![]() 1966 GMC C10 Dad's project ![]() |
![]() |
![]() |
![]() |
#24 | |
Hittin E-Z Street on Mud Tires
![]() Join Date: Nov 2004
Location: Greenville, SC
Posts: 23,090
|
Re: Cooling Issues
Quote:
I used to run a 3 row in my truck (350/700R auto) with the proper shroud and flex fan. Cooled just fine with 180 thermostat. I added A/C and I could never run it in "the city" because my truck would jump to 210 in a heartbeat! I tried a 190 thermostat, I added a trans cooler (always a good idea anyway, especially with an OD trans) and I added a 7 blade clutch fan. STILL overheated in city driving. So I gave up and went and spent another $210 on a 4 row radiator, replacing my couple year old 3 row ![]() Problem has been solved for a year, maybe two? (time flys) and I love my A/C in city traffic! I just took the old girl out for a couple hour long cruise in 97 degree heat last weekend and she never got above above the low 190's. I'd also like to add... if you do jump to a 4 row, if you don't already have it, you need "4 row" upper and lower brackets. They're wider than the 2/3 row brackets.
__________________
Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride ![]() American Born, Country by the Grace of God ![]() 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! Last edited by 67ChevyRedneck; 08-27-2009 at 12:43 AM. |
|
![]() |
![]() |
![]() |
#25 |
Registered User
Join Date: Dec 2007
Location: Riverside, Ca
Posts: 407
|
Re: Cooling Issues
alright so lets see, the radiator is a 3 row. and yes its new. flows fine. . what i was referring to with not having the room for the clutch is that they told me that the fan would then be too far into the fan shroud. that's why i was asking if they sell different shrouds. i have a trans cooler on it. and the radiator has the option to put the tranny cooler through it. but i thought would cool better with it temperate. what is the benefit of running a big block clutch as opposed to a small block and im def gonna put a 195 T-Stat in it.
__________________
Lifted 2wd 1969 C20/ 5.3LS/4L60E :http://67-72chevytrucks.com/vboard/s...d.php?t=728388 |
![]() |
![]() |
![]() |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|