Team Camaro Tech banner

572 Running hot or just the gauge?

11K views 109 replies 14 participants last post by  pittpens24 
#1 ·
So here is the deal. Finally got the car back together for the 5th or 6th time now chasing coolant and oil leak issues - hoping the end is in sight soon as this is getting very tiring. Anyway, took a test ride yesterday. Was around 91 degrees out so it was a hot day. Driving at normal speeds car was running around 195. At a stop light 210. Driving again would eventually get down to around 200ish. Stop light again just the width of the needle over 210. Being it is an electric gauge, I shot it with a $20 laser temp gun to double check. Everywhere I shot I couldn't anything close to 210 unless it was on the head down my the headers. Headers read 230 at the highest temp but they are a polished coating too. Took readings on the top of the rad(polished alum so I figured not accurate)150, Thermostat(polished again)155, under the housing 185, heater hose fitting in top of manifold 185, temp sender in manifold 185. Front of heads 195........Question is where exactly is the best place to get the most accurate temp? I am 90% convinced my gauge is wrong, but need confirmation.
 
#5 ·
I have a Robert Shaw 160 degree with (3) 3/16" holes as directed by Vintage Air(Front Runner system) and Stewart Components for my stage 4 water pump. Also has the bi-pass hose hooked up.
 
#3 ·
Is the gauge mechanical? If so remove it take it into the kitchen a plop it in a pot of water. Heat water on stove and watch temp where your water starts to boil. Correct for altitude if desired.

If you have an electric gauge the test is the same but you need a batery and wires to power the sender and provide a ground path.

Big Dave
 
#4 ·
A 160 degree thermostat is not going to help a car running at 210....

Don
 
  • Like
Reactions: partsguy57
#6 ·
Quote:
Originally Posted by ZEN357 View Post
What temperature thermostat are you running? I always run a 160 thermostat in my engines.

https://www.jegs.com/webapp/wcs/stor...rsistYmm=false

I have a Robert Shaw 160 degree with (3) 3/16" holes as directed by Vintage Air(Front Runner system) and Stewart Components for my stage 4 water pump. Also has the bi-pass hose hooked up.

What kind of coolant mix are you running?
 
#7 ·
Quote:

Originally Posted by ZEN357 View Post

What temperature thermostat are you running? I always run a 160 thermostat in my engines.



https://www.jegs.com/webapp/wcs/stor...rsistYmm=false



I have a Robert Shaw 160 degree with (3) 3/16" holes as directed by Vintage Air(Front Runner system) and Stewart Components for my stage 4 water pump. Also has the bi-pass hose hooked up.



What kind of coolant mix are you running?
Napa 50/50 green pre-mix

Sent from my SM-G973U1 using Tapatalk
 
#8 ·
Greg, I would say your gauge is off. If you can remove the sender without too much
trouble do so and set it in a cup of hot water of know temp (use cooking thermometer).
Compare the readings. If you want to warm the engine up with the radiator cap off you
could do the same thing testing the temp of the coolant in the radiator with a cooking
thermometer.
 
#9 ·
Greg, I would say your gauge is off. If you can remove the sender without too much

trouble do so and set it in a cup of hot water of know temp (use cooking thermometer).

Compare the readings. If you want to warm the engine up with the radiator cap off you

could do the same thing testing the temp of the coolant in the radiator with a cooking

thermometer.
Thanks. Definitely will do that. Also have a 2nd reference as well from Autometer which does not sound entirely too accurate but want to compare for the heck of it just to see.
From Autometer tech:
Using ohm meter with black on the brass sender housing and red on the signal side
220"=105 ohms
210/123
190/175
170/253
All ohms +/- 9 which is a huge grey area


Sent from my SM-G973U1 using Tapatalk
 
#17 ·
Talked to C&R Racing. The guy that built my system is no longer there. The new gentleman I am dealing with says my system is at its limit and no way could I put any power adders on. Also he feels the fan is too small since the previous tech went with a single fan instead of dual units.
The fan swich starts at 175low/185med/195high. If your theory is correct Don, the fan is coming on way too late and can't keep up, not to mention if is not pulling enough cfms @3100. They are having a meeting and he is going to bring this up. Waiting on a call back

Sent from my SM-G973U1 using Tapatalk
 
#18 ·
As I suggested earlier those fan temperatures are intended for LS style operating temperatures. You could effectively shift the temperatures lower by moving the temperature sensor to the engine instead of the output side of the radiator. But it will not be much help if your fan is undersized.

I am surprised they used a single fan.

Don
 
#19 ·
I have a Dart Merlin block and have no place to put a sender :|

The new tech agreed with you on the single fan. I also questioned this originally. I was told it was new brushless technology and this would outperform the dual setup. What do I know - he is the expert right?!?
Never thought it would come down to this being my cooling issue. I always do my research and always go overkill when I do something by nature. My new Tech Brent is claiming this rad is only meant for 650-700HP max. I am already 50HP over that. Then to downgrade the fan cfms on top of that? I almost feel I was a test dummy for this since the fan was a prototype unit claiming to put out 3100 when in actuality it put out 2400CFM's.
Let's see what kind of company C&R is and if they stand behind their products and tech department.
 
#20 ·
Make sure your fan controller is getting full supply voltage at max fan speed. Put a voltmeter on it. You can lose a lot of cfm with low voltage. I always connect mine directly to the battery with a large gauge wire.

Cadillac CTS-V and others use a single fan so they can work well if sized correctly. I just haven’t seen too many available from Spal and others.

Don
 
  • Like
Reactions: pittpens24
#21 ·
So I was wrong about a couple thing posted earlier and apologize.
It turns out that the sender in the manifold next to the water neck is actually the sender for the rad. The temp sender for the gauge is in the block.
I originally had the gauge sender in the manifold because it was somewhat close to the headers. Since the bodyshop was involved in the rad fitment, I had them wire it up. Not a big deal, but never realized they switched the sender location back to the block.
So the rad sender is in fact in the manifold and should be turning on at the appropriate times.
Either way, it doesn't resolve any issues I am having with the recovery cooling issue.
C&R said they have used my rad setup for upto 850hp sb's with no issues, but big blocks are a different story. Obviously they wont take it back because it was "used" so I will be selling the entire setup. Entire setup was $2400. Has 200 miles on it. My loss will be someones gain. Will be posting in the classifieds. Starting over. Not worth blowing up a 15k motor

Sent from my SM-G973U1 using Tapatalk
 
#22 ·
Before you toss it measure your fan controller voltage and the voltage on the fan at max speed. There are some powerful OEM single fans out there. The Lincoln fan comes to mind and moves a lot of air.

Don
 
#23 ·
Before you toss it measure your fan controller voltage and the voltage on the fan at max speed. There are some powerful OEM single fans out there. The Lincoln fan comes to mind and moves a lot of air.



Don
Voltage is correct, forgot to post. Gauge reading was also pretty accurate.
They offered me a fix to go with a custom shroud and 2-12" fans that would give me 1200 more cfm. Still wanted me to do an oil cooler but I have no room anywhere for it. I do not want to do this again and tired of fighting this car to be honest. It is one thing after another after another. As said before, I have that overkill bug amd just want the most effective cooling system I can get and be done. Might do an oil filter relocation to get the filter away from the headers to help matters as well.

Sent from my SM-G973U1 using Tapatalk
 
#24 ·
Hold on before you ditch the system.

You say your HP is XXX and the coloring system is only good for YYY.

you take the car on a test drive it it runs too hot.

When you test drive do you drive the car hard and really push it using extended full throttle etc?

If you just take it on a leisurely drive does it run hot? What I'm getting at is if you just cruising around and not beating on it using the engines full power a system designed and working correctly for 600 or 650 HP will not run hot.

They said your fan may be to small. When cruising at highway speeds what is the temp? If still hot then not a fan issue.

You may want to consider trying Evans Waterless Coolant. Not cheap but a lot cheaper than changing your cooling system.

https://www.evanscoolant.com/
 
#25 ·
Normal speeds 195 where the fan controller is set. Idling 210. Sounds like a fan issue to me. Not enough cfm....

Don
 
#26 ·
Timing can play a role too. Might be worthwhile checking....

Don
 
#30 ·
Due to the fact it does not recover at cruise speed leads me to believe there are other issues in addition to the fans.

Is the shroud vented to allow full ram air at cruise?

Are you using the CR radiator for oil and ps fluid cooling?
 
#31 ·
Due to the fact it does not recover at cruise speed leads me to believe there are other issues in addition to the fans.



Is the shroud vented to allow full ram air at cruise?



Are you using the CR radiator for oil and ps fluid cooling?
Yes the shroud is vented down both sides

No, rad is just used for cooling the motor.

6 speed manual so no trans cooling either

One other thing is that in all this, I never even tried to turn the a/c on

Sent from my SM-G973U1 using Tapatalk
 
#32 ·
I agree with John, if it won't recover at cruising speed, it's not the fan. Not saying that you don't have a fan problem that's causing it to heat at stop lights, but it should recover at highway speed air flow.
Did I miss what size radiator you have?
 
#33 ·
First post says it cools down when he gets moving again. Falls 10 degrees of a 15 degree rise....

Don
 
#35 ·
But it falls 10 degrees of a 15 degree rise. You guys are making conclusions about the radiator core based on 5 degrees. Is a 5 degree delta enough to say it does not recover? Or is it a little bit of heat soak?

Greg has made up his mind to toss everything and start over. I wish him well.

Don
 
#36 ·
I guess I don’t understand his definition of doesn’t recover. I read it that he’s cruising at 195. Stops and climbs to 210. IMO when back at cruise is should go back down to 195.

If a cooling system issue it comes down to 2 things. Airflow or Coolant. Can be either one or both. I doubt the CR radiator is not big enough.

Is water pump doing the job? Idk. Why did it blow the gaskets and dump the coolant. Is this symptom of a problem or the result of a problem. Is there a restriction that resulted in excess pressure and restricted flow at the WP or somewhere else in the system? Are the head gaskets ports opening not matches to the heads/block?

One of my builds the temps were up on the gauge but infrared showed 30* lower everywhere and 145* lower radiator hose and 185* top of radiator so I knew radiator/fans were good.

Turned out the sender was picking up heat from the header. Gauge manufacturer said it was a known issue with their sender. Geez if it a know problem fix it.
 
#38 ·
I guess I don’t understand his definition of doesn’t recover. I read it that he’s cruising at 195. Stops and climbs to 210. IMO when back at cruise is should go back down to 195.



If a cooling system issue it comes down to 2 things. Airflow or Coolant. Can be either one or both. I doubt the CR radiator is not big enough.



Is water pump doing the job? Idk. Why did it blow the gaskets and dump the coolant. Is this symptom of a problem or the result of a problem. Is there a restriction that resulted in excess pressure and restricted flow at the WP or somewhere else in the system? Are the head gaskets ports opening not matches to the heads/block?



One of my builds the temps were up on the gauge but infrared showed 30* lower everywhere and 145* lower radiator hose and 185* top of radiator so I knew radiator/fans were good.



Turned out the sender was picking up heat from the header. Gauge manufacturer said it was a known issue with their sender. Geez if it a know problem fix it.
The vintage air front runner uses Stewart Components water pumps. Initially I called Vintage Air to troubleshoot. They assured me their systems were good upto 1000hp amd eventually directed me to Stewart Components. The pumps they make are considered a stage 3. When the cat came apart to do the oil pan, they had me send the pump back, when everything checked out fine, they opted to go to a stage 4 rebuild. The night it blew the gasket I got on it a bit for the first time. The conclusion was the paper gasket couldnt take the pressure. They had me reseal it with Permatex The Right Stuff amd no gasket. The tolerances are super tight with that pump so I know I didnt get and squeeze out or it wouldn't have spun so feely the next day before installing.
Never thought of the head gaskets. They were installed by the engine builder.
I also don't know what to make of C&R. When I bought it, it was capable of 1000hp. Now they are saying 650 maybe 700 max.
I could try the double 12 inch fans pulling 1200 more cfms.
Not looking to throw money away that I don't have either. Sorry if it sounds that way. Just talking with C&R, they seem concerned. I dont feel comfortable if they aren't

Sent from my SM-G973U1 using Tapatalk
 
#40 ·
Put a big fan in front of car at idle. If it cools better en it would indicate you need more air flow.



Coolant system is 16#. I would think that would blow out the gasket in 3 places.
Have a huge floor barn fan. Will try that but should probably wait til next week. Supposed to have record highs here tomm and Sunday.

Stewart said when I spooled up that water pump, it probably produced about 60# inside the pump impeller housing for a split second

Sent from my SM-G973U1 using Tapatalk
 
#42 ·
I guess you are right. Was trying to establish a baseline.
Normally I wouldn't take the car out on a day like this, but if it was reliable enough to make it to the Syracuse Narional, I'd probably be pulling in right about now.

Sent from my SM-G973U1 using Tapatalk
 
#43 ·
Took the car out this am. Temp 88 and 70% humidity. We have summer camps up by us. This was a good test. Whole ride from town was about 25 mph from NYC people not knowing where in the hell they are going. For the only time in my life thank you! To make matters worse, we caught upto a mail truck which was stop and go for about 3/4 mile.
Gauge was 220, water neck 203, temp sender 206, bottom hose 189, top hose read150 but is steel braided, rad read 140.

As John suggested, put a barn fan in front of the car on high. With it idling. Actually came down to maybe 205 on the gauge. I held it at 2000 rpm for about 10 seconds amd it crept back up about 10 degrees. Took a minute or so and came back down to 205. Turned on the a/c just to see what happened. Had to hold my foot on the gas to keep it idling around 1000 rpm. Less than a minute gauge was pushing 235 so I shut her down.

Seemed like the fan helped in recovery until I turned on the a/c.

Sent from my SM-G973U1 using Tapatalk
 
#45 ·
Isn’t the bottom hose the suction hose and top out of T-stat to radiator?



Bottom should be cooler then top.
Yes but I think since the bottom is regular rad hose it is reading right. The top hose is steel braided and reflecting the laser therefore altering the temp on the braided hose and the rad. Can't get a reading off tge polished water neck either. Reading I posted was at the water neck base

Sent from my SM-G973U1 using Tapatalk
 
#46 ·
if you have anything like in the picture . forget it . it would not my 540 horse SB
I went to a belt driven fan and problem solved
I wont argue the point about not needing a fan at highway speeds, but I took mine off and tried it. it got as hot as with the radiator setup in the picture. 230* @60 mph

you might try top and bottom filler panels to force the air through the radiator
 
#47 ·
A good little read here for the guys who believe that water can move too fast through the radiator core and not cool enough.
This myth has been around forever.

https://www.yellowbullet.com/forum/s...d.php?t=981810

Spinning the water pump too fast and causing cavitation in the pump is not the same thing as the "water moving too fast through the radiator " myth. Don't confuse those.
 
#49 ·
Greg, post up some pics of your shroud, fan, radiator etc.

Don
 
#51 ·
The pic of the fan unit during fabrication. The fan is actually mounted inside the housing.
Product Floor Ceiling Mechanical fan Spiral
Vehicle Engine Car Auto part Motor vehicle


Sent from my SM-G973U1 using Tapatalk
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top