[C1] Don't snicker, I'm running hot
08-16-2018, 02:55 PM
#1
Drifting
Thread Starter
Don't snicker, I'm running hot
I know everyone is sick of running hot threads, but just in case you can stand one more, here it is.
I have a 62 with a 300 hp 327. The engine was rebuilt 50+k miles ago, bored .030 and just a standard stock rebuild. I can give details if needed. I drive the car a lot, 25K on a 48 state tour last summer. The car has normally run at 180 degrees on the highway, steep hills or slow traffic it would climb to the high 190s but drop back when back on the highway or if I kicked in the electric fan. Lately that has all changed.
Temperature runs 190+ on the highway and will get to 210-212 in traffic or when sitting. In traffic I can keep it slightly under 200 by turning on the electric fan. I will try to list all other information below.
New alu. radiator about 50k miles ago.
Block was boiled out when rebuild.
Water pump went out on trip last summer. Replacement has about 3500 miles on it. Had to use some tap water when I lost the pump, so flushed the system before filling with new antifreeze.
All hoses are good, nothing collapsed.
Distributor was rebuilt by Lars prior to last summers trip. I have rechecked the timing and it is still to Lars specs.
B-26 Vacuum Advance and corrector. I checked vacuum advance and it is working properly.
Installed a new mechanical temp gauge and ran it with the in-dash gauge and they both read almost identically.
Checked the temp with my IR meter which verified the temp at the gauge.
Checked the IR meter using a pan of boiling water and 2 of my wife's cooking thermometers and it is right on for temps150 degrees and up. Reads a little high on low temperatures.
Checked the thermostat using the same method as above. Old thermostat wasn't opening until about 195 so I replaced it. Didn't see much change with the new stat.
Checked the new thermostat and it also seemed to open a bit to late so I ran the car without a thermostat and the temp problem still remains the same.
The fan is a stock 5 blade, located properly in the shroud. Years ago I added all the extras, described on the forum, to direct max air through the radiator.
Can't tell how good the water flow is, but it is circulating well through the filler tank.
I have a 35 to 40 degree temp drop from the top to the bottom of the radiator.
This shouldn't be rocket science, what the he11 am I missing.
I have a 62 with a 300 hp 327. The engine was rebuilt 50+k miles ago, bored .030 and just a standard stock rebuild. I can give details if needed. I drive the car a lot, 25K on a 48 state tour last summer. The car has normally run at 180 degrees on the highway, steep hills or slow traffic it would climb to the high 190s but drop back when back on the highway or if I kicked in the electric fan. Lately that has all changed.
Temperature runs 190+ on the highway and will get to 210-212 in traffic or when sitting. In traffic I can keep it slightly under 200 by turning on the electric fan. I will try to list all other information below.
New alu. radiator about 50k miles ago.
Block was boiled out when rebuild.
Water pump went out on trip last summer. Replacement has about 3500 miles on it. Had to use some tap water when I lost the pump, so flushed the system before filling with new antifreeze.
All hoses are good, nothing collapsed.
Distributor was rebuilt by Lars prior to last summers trip. I have rechecked the timing and it is still to Lars specs.
B-26 Vacuum Advance and corrector. I checked vacuum advance and it is working properly.
Installed a new mechanical temp gauge and ran it with the in-dash gauge and they both read almost identically.
Checked the temp with my IR meter which verified the temp at the gauge.
Checked the IR meter using a pan of boiling water and 2 of my wife's cooking thermometers and it is right on for temps150 degrees and up. Reads a little high on low temperatures.
Checked the thermostat using the same method as above. Old thermostat wasn't opening until about 195 so I replaced it. Didn't see much change with the new stat.
Checked the new thermostat and it also seemed to open a bit to late so I ran the car without a thermostat and the temp problem still remains the same.
The fan is a stock 5 blade, located properly in the shroud. Years ago I added all the extras, described on the forum, to direct max air through the radiator.
Can't tell how good the water flow is, but it is circulating well through the filler tank.
I have a 35 to 40 degree temp drop from the top to the bottom of the radiator.
This shouldn't be rocket science, what the he11 am I missing.
08-16-2018, 07:21 PM
#3
Le Mans Master
With it already hot and running, take a garden hose with a sprayer nozzle on it. Mist the front of your radiator while watching the temperature.
If your temp quickly drops you have a cooling issue with the radiator.
If the temp drops slowly or does not drop you have a circulation issue.
Misting the radiator pulls a lot of heat out very quickly.
You can use your infra red gun to check the temp at the top of your radiator and at the outlet to see if the coolant is actually dropping in temperature.
I have seen posts showing what the temp drop should be but I don't remember those numbers.
It may be that your old water pump was a better design than the new one. Maybe the water pump impeller is slipping?
If this does not help have a shop sniff the radiator to see if you have a leaking head gasket, or buy a test kit at your local auto parts store and test it yourself.
It is just parts, you will figure it out.
Mark
If your temp quickly drops you have a cooling issue with the radiator.
If the temp drops slowly or does not drop you have a circulation issue.
Misting the radiator pulls a lot of heat out very quickly.
You can use your infra red gun to check the temp at the top of your radiator and at the outlet to see if the coolant is actually dropping in temperature.
I have seen posts showing what the temp drop should be but I don't remember those numbers.
It may be that your old water pump was a better design than the new one. Maybe the water pump impeller is slipping?
If this does not help have a shop sniff the radiator to see if you have a leaking head gasket, or buy a test kit at your local auto parts store and test it yourself.
It is just parts, you will figure it out.
Mark
08-16-2018, 11:01 PM
#5
Safety Car
Member Since: Apr 2013
Location: Arlington TX
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If the hottest you’re running is 212 and it’s not puking, then you’re not hurting anything. Are you running A/C?
Last edited by 59BlueSilver; 08-16-2018 at 11:02 PM.
08-16-2018, 11:26 PM
#6
Le Mans Master
I am not so sure you need a high volume pump but the better pumps use a plate on the back of the impeller which makes them more of a Positive displacement pump rather than a paddle wheel.
Positive displacement pumps work better by offering a consistent flow.
Positive displacement pumps work better by offering a consistent flow.
08-16-2018, 11:43 PM
#9
Drifting
Thread Starter
08-17-2018, 02:13 AM
#10
Race Director
With it already hot and running, take a garden hose with a sprayer nozzle on it. Mist the front of your radiator while watching the temperature.
If your temp quickly drops you have a cooling issue with the radiator.
If the temp drops slowly or does not drop you have a circulation issue.
Misting the radiator pulls a lot of heat out very quickly.
You can use your infra red gun to check the temp at the top of your radiator and at the outlet to see if the coolant is actually dropping in temperature.
I have seen posts showing what the temp drop should be but I don't remember those numbers.
It may be that your old water pump was a better design than the new one. Maybe the water pump impeller is slipping?
If this does not help have a shop sniff the radiator to see if you have a leaking head gasket, or buy a test kit at your local auto parts store and test it yourself.
It is just parts, you will figure it out.
Mark
If your temp quickly drops you have a cooling issue with the radiator.
If the temp drops slowly or does not drop you have a circulation issue.
Misting the radiator pulls a lot of heat out very quickly.
You can use your infra red gun to check the temp at the top of your radiator and at the outlet to see if the coolant is actually dropping in temperature.
I have seen posts showing what the temp drop should be but I don't remember those numbers.
It may be that your old water pump was a better design than the new one. Maybe the water pump impeller is slipping?
If this does not help have a shop sniff the radiator to see if you have a leaking head gasket, or buy a test kit at your local auto parts store and test it yourself.
It is just parts, you will figure it out.
Mark
08-17-2018, 12:41 PM
#11
Drifting
Thread Starter
I bought a combustion leak tester and there is no combustion gas in the cooling system. Misted the radiator and the temp stayed up, increased the flow and temp still stayed up. Turned on the electric fan and the temp came down to around 195. I think the indications are flow so I guess I'll change out the water pump to a high volume. What are your thoughts?
I have a GM pump, part number 3858328, that was originally on the car, but was leaking. I would rebuild the pump but don't have access to an arbor press at the moment.
I have a GM pump, part number 3858328, that was originally on the car, but was leaking. I would rebuild the pump but don't have access to an arbor press at the moment.
08-17-2018, 01:29 PM
#12
Melting Slicks
I bought a combustion leak tester and there is no combustion gas in the cooling system. Misted the radiator and the temp stayed up, increased the flow and temp still stayed up. Turned on the electric fan and the temp came down to around 195. I think the indications are flow so I guess I'll change out the water pump to a high volume. What are your thoughts?
I have a GM pump, part number 3858328, that was originally on the car, but was leaking. I would rebuild the pump but don't have access to an arbor press at the moment.
I have a GM pump, part number 3858328, that was originally on the car, but was leaking. I would rebuild the pump but don't have access to an arbor press at the moment.
08-17-2018, 01:41 PM
#13
Drifting
Thread Starter
08-17-2018, 03:15 PM
#14
Drifting
Thread Starter
pulled the water pump, hoping to find a loose impeller or something that would cause the overheating problem. Everything looked OK, the impeller is tight, everything looks new, only 3500 miles on the pump. Do see one thing that is different from the GM pump, the impeller on the GM sits 1/8" outside the casting so it is placed into the rear cover. The present pumps impeller is flush with the casting. If that's a problem, it should have shown up immediately, not a few thousand miles later,
.
More than ever, I'm running out of ideas. Need any other thoughts that you guys may have.
.
More than ever, I'm running out of ideas. Need any other thoughts that you guys may have.
08-17-2018, 03:34 PM
#15
Race Director
pulled the water pump, hoping to find a loose impeller or something that would cause the overheating problem. Everything looked OK, the impeller is tight, everything looks new, only 3500 miles on the pump. Do see one thing that is different from the GM pump, the impeller on the GM sits 1/8" outside the casting so it is placed into the rear cover. The present pumps impeller is flush with the casting. If that's a problem, it should have shown up immediately, not a few thousand miles later,
.
More than ever, I'm running out of ideas. Need any other thoughts that you guys may have.
.
More than ever, I'm running out of ideas. Need any other thoughts that you guys may have.
Doug
08-18-2018, 04:32 AM
#18
Le Mans Master
A couple of pictures of GM impellers. The Cast are superior to the stamped steel impellers but the positive displacement impellers have a impeller with a closed back on it none of these do.I tried to find a photo of a positive displacement pump with no luck. I have one in the garage but have not pulled the cover for a photo.
Hope this helps.
08-18-2018, 09:47 AM
#20
Drifting
Thread Starter
A couple of pictures of GM impellers. The Cast are superior to the stamped steel impellers but the positive displacement impellers have a impeller with a closed back on it none of these do.I tried to find a photo of a positive displacement pump with no luck. I have one in the garage but have not pulled the cover for a photo.
Hope this helps.