![]() |
![]() |
#1 |
Account Suspended
Join Date: Mar 2011
Location: hastings mn
Posts: 186
|
Running too hot.
68 c10 518 hp 383 stroker. High flow 165 jegs stat. Original or original replacement v8 radiator. Serpentine drive standard flow water pump.
On warm days. 80 or so the truck will run 200 to 215 on the highway or in town. Dual electric fans with shroud. Fans run constant. If I'm just driving around town. Truck stays 160 to 190. As soon as I get on the highway it will get hot. I'm thinking the radiator may not be efficient enough. Any thoughts? Posted via Mobile Device |
![]() |
![]() |
![]() |
#2 |
Account Suspended
Join Date: Mar 2011
Location: hastings mn
Posts: 186
|
Re: Running too hot.
I have a new direct fit 4 core radiator on order. But I would still like to try and trouble shoot this.
Posted via Mobile Device |
![]() |
![]() |
![]() |
#3 |
Registered User
Join Date: Jan 2011
Location: Prescott AZ
Posts: 112
|
Re: Running too hot.
Through a 180 stat in it, there is a good chance the coolant isn't staying in the radiator long enough to actually cool. Also what are the ratings on your fans?
|
![]() |
![]() |
![]() |
#4 |
Active Member
![]() Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
|
Re: Running too hot.
Radiator may help, but a quick check list if you haven't done them already;
Test the thermostat in pot of water with thermometer to insure it's opening. Make sure the temp is correct on the temp gauge. They can be inaccurate. Check for collapsing lower radiator hose when accelerating. (rev the engine while observing the hose) Replace the thermostat with higher rating. (180-185?) Replace the cap. Install an overflow container. Do a leak down test on radiator. Cylinder leak down test on the engine to check for head gasket failure. Last edited by 68gmsee; 06-08-2011 at 09:07 AM. |
![]() |
![]() |
![]() |
#5 |
Registered User
Join Date: Aug 2009
Location: Bowser
Posts: 13,616
|
Re: Running too hot.
Easier way to check your bottom rad hose is to squeeze it when it's cold. If there's a coil in it you'll feel it. If no coil. Easy to make your own.
|
![]() |
![]() |
![]() |
#6 | |
Account Suspended
Join Date: Jan 2007
Location: Tucson
Posts: 2,183
|
Re: Running too hot.
Quote:
|
|
![]() |
![]() |
![]() |
#7 |
Registered User
Join Date: Mar 2009
Location: norman okahoma
Posts: 269
|
Re: Running too hot.
I'm not positive but shouldn't a serpentine setup have a reverse rotation water pump.
__________________
The TEAL GMC build thread is HERE 1972 GMC SWB 454 oval ports TH400 fastest 1/4 mile time so far 13.05 @ 104 If you think you have too much horsepower you obviously have a traction problem ! |
![]() |
![]() |
![]() |
#8 |
Registered User
Join Date: Feb 2000
Location: Center City, MN, USA
Posts: 3,254
|
Re: Running too hot.
How does that old rule of thumb go?
If it overheats in the driveway it is the fan. If it overheats on the highway it is the radiator. I too have a 383. I can't remember if the 4-row radiator came before or after the 383 but I've never had an issue with the stock fan and 4-row radiator. Since you have a new radiator coming anyways, I'd swap it in and see if your problem goes away. With that eliminated from the equation, it will be much easier to diagnose if the problem still exists.
__________________
'70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN |
![]() |
![]() |
![]() |
#9 |
"the other guy"
Join Date: Oct 2008
Location: Olivehurst California 95961
Posts: 901
|
Re: Running too hot.
what serp. system are you useing? if its stock gm, you MUST use a reverse rotation pump. not to be confused with "reverse flow"
__________________
God Said,"Building A 10 Second Import Is Like Coming Out Of The Closet, In The End Ur Still....."EXPLETIVE" ![]() |
![]() |
![]() |
![]() |
#10 |
Account Suspended
Join Date: Mar 2011
Location: hastings mn
Posts: 186
|
Re: Running too hot.
|
![]() |
![]() |
![]() |
#11 |
Senior Member
![]() Join Date: Apr 2008
Location: Franklinton NC
Posts: 1,309
|
Re: Running too hot.
A stock style radiator was never ment to cool a 500+hp engine.I would recomend going to a high proformance radiator.On a side note on my 75 Ford I put a big block school bus radiator in when I redid the engine and it stays cool no matter what the temp is.
![]() |
![]() |
![]() |
![]() |
#12 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
|
Re: Running too hot.
i would suspect coolant flow. Could be a bad pump, or a semi-clogged rad.
|
![]() |
![]() |
![]() |
#13 |
Senior Member
![]() Join Date: Nov 2010
Location: Lordstown, OH / Wentzville, MO
Posts: 870
|
Re: Running too hot.
Higher thermostat.
|
![]() |
![]() |
![]() |
#14 |
Account Suspended
Join Date: Mar 2011
Location: hastings mn
Posts: 186
|
Re: Running too hot.
How would a high temp stat keep the motor cooler. I guess I'm just not getting the reasoning. I have a big ass radiator coming
Posted via Mobile Device |
![]() |
![]() |
![]() |
#15 |
Senior Member
![]() Join Date: Nov 2010
Location: Lordstown, OH / Wentzville, MO
Posts: 870
|
Re: Running too hot.
I know it sounds weird but it always worked for me. I lived in Tucson, AZ for 15 years and every single time me or any of my buddies tried lower than a 180 stat we were overheating. Now keep in mind these were daily drivers of every american make and model and engine combo with mostly close to stock cooling systems. I can't explain the technical side of it....someone else will....I can only tell my experience. That keeps me outta looking like a dick.
|
![]() |
![]() |
![]() |
#16 |
Registered User
![]() Join Date: Sep 2001
Location: Fort Wayne, Indiana, USA
Posts: 1,887
|
Re: Running too hot.
I've had excellent luck with factory 4-row radiators when they are healthy. However, Everything must be working properly in order to get good results. As mentioned, low-coolant flow due to fouled/clogged radiator, bad thermostat, collapsing suction hose, bad water pump, etc. along with bad fan-clutch on the air side all contribute to poor cooling performance. If this is not your specialty, find an expert! I bet it will be cheaper than playing parts-change roulette. Please let us know what the root cause was and what was needed to fix it.
|
![]() |
![]() |
![]() |
#17 |
Registered User
Join Date: Aug 2009
Location: Bowser
Posts: 13,616
|
Re: Running too hot.
A lower temp stat let's say 180 will be open all the time. Continuos flow. No retention time for cooling in the rad. A 195 will be closed a bit. Restricting flow enough for better retention time in the rad. Thermo will cycle.
Also it's not all about the number of cores in your rad. It's about design of your cooling tubes, the flow of coolant, what your rad is made of (aluminum) and flow through the rad. I've seen a custom 5 core rad cool no better than a stock 3 core rad did. A new big ass rad could be a good start. Maybe. JMHO |
![]() |
![]() |
![]() |
#18 |
Active Member
![]() Join Date: Jul 2007
Location: Centrally located between Houston, Austin and Waco. BCS area.
Posts: 7,947
|
Re: Running too hot.
Going to a higher degree won't necessarily mean it will solve your problem but it's a cheap test to try. Also, it does help warm the engine up to temp quicker and prevents wear, carbon buildup, etc.
A good explanation. http://www.2carpros.com/articles/how...ermostat-works .... Never run an engine without a thermostat because the thermostat works as a system flow regulator as well. What this means is the thermostat has a specific opening that regulates the flow through the cooling system. If the coolant is allowed to flow too quickly through the radiator the coolant will not have time to transfer the heat it has absorbed. This will cause the engine to overheat. ![]() |
![]() |
![]() |
![]() |
#19 | ||
"I ain't nobody, dork."
Join Date: Sep 2007
Location: Whidbey Island, Washington
Posts: 8,940
|
Re: Running too hot.
The high flow thermostat isn't helping. A drag car only doing a warm up, burnout, and a 1/4 mile run and back to the pits is what they are designed for. Huck a regular flow thermostat in there.
Gary
__________________
'cuz chicks dig scars... My 1972 GMC 1500 Super Custom (Creeping Death) "long term" build thread. The Rebuild of Creeping Death after the wreck Quote:
Quote:
|
||
![]() |
![]() |
![]() |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|