Cooling my solid roller 496
Race Director
Joined: Mar 2006
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From: Florida
This is with the new DeWitts?
Does your Stage IV pump use the bypass hose from the top to the front of intake or are those two ports plugged?
What rated pressure cap? Sorry, found it in your first post.
I would start by getting rid of the cap set up at the tstat housing (pressure side) and go back to only the one on the rad (low side) and use the recovery/overflow bottle.
You said you are lifting a 24# cap so that means you are losing water. That can male any pump cavitate and more importantly loose the higher pressure on the high side creating a lot more steam than a properly working system. Harder to cool steam than hot coolant.
Does your Stage IV pump use the bypass hose from the top to the front of intake or are those two ports plugged?
What rated pressure cap? Sorry, found it in your first post.
I would start by getting rid of the cap set up at the tstat housing (pressure side) and go back to only the one on the rad (low side) and use the recovery/overflow bottle.
You said you are lifting a 24# cap so that means you are losing water. That can male any pump cavitate and more importantly loose the higher pressure on the high side creating a lot more steam than a properly working system. Harder to cool steam than hot coolant.
Last edited by noonie; Jun 21, 2009 at 09:54 AM.
Thread Starter
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
This is with the new DeWitts?
Does your Stage IV pump use the bypass hose from the top to the front of intake or are those two ports plugged?
What rated pressure cap? Sorry, found it in your first post.
I would start by getting rid of the cap set up at the tstat housing (pressure side) and go back to only the one on the rad (low side) and use the recovery/overflow bottle.
You said you are lifting a 24# cap so that means you are losing water. That can male any pump cavitate and more importantly loose the higher pressure on the high side creating a lot more steam than a properly working system. Harder to cool steam than hot coolant.
Does your Stage IV pump use the bypass hose from the top to the front of intake or are those two ports plugged?
What rated pressure cap? Sorry, found it in your first post.
I would start by getting rid of the cap set up at the tstat housing (pressure side) and go back to only the one on the rad (low side) and use the recovery/overflow bottle.
You said you are lifting a 24# cap so that means you are losing water. That can male any pump cavitate and more importantly loose the higher pressure on the high side creating a lot more steam than a properly working system. Harder to cool steam than hot coolant.
The stage IV does use the bypass hose, and I have it installed with the bypass hose connected.
I'm using a 16 lb cap on the low pressure side of the radiator
I removed the cap at the T-stat when I installed the new radiator
The overflow bottle is connected and being used
Thanks for all your input
At this point I'm willing to try anything, before having to pull the motor and start there.
Neal
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
You should be able to keep it right around 200 with the reserve of that rad and the matching fans.
You can plug the bypass and gain that much more circulation thru the rad, but you must use a tstat with holes or a restrictor.
Just for fun, try your road test at 4AM when it's only 85° out, but more importantly the road hasn't been heated up to a foot burning temp, increasing your cooling air temp.
Ambient air temp is the single biggest factor.
You can plug the bypass and gain that much more circulation thru the rad, but you must use a tstat with holes or a restrictor.
Just for fun, try your road test at 4AM when it's only 85° out, but more importantly the road hasn't been heated up to a foot burning temp, increasing your cooling air temp.
Ambient air temp is the single biggest factor.
Drifting
Joined: Jun 2002
Posts: 1,620
Likes: 7
From: Orlando Florida
This is with the new Dewitts radiator and fans.
The stage IV does use the bypass hose, and I have it installed with the bypass hose connected.
I'm using a 16 lb cap on the low pressure side of the radiator
I removed the cap at the T-stat when I installed the new radiator
The overflow bottle is connected and being used
Thanks for all your input
At this point I'm willing to try anything, before having to pull the motor and start there.
Neal
The stage IV does use the bypass hose, and I have it installed with the bypass hose connected.
I'm using a 16 lb cap on the low pressure side of the radiator
I removed the cap at the T-stat when I installed the new radiator
The overflow bottle is connected and being used
Thanks for all your input
At this point I'm willing to try anything, before having to pull the motor and start there.
Neal
www.rondavisradiators.com
You may need the dual spal 13" Fans
I'm suprised the Dewit did not control the temp.
Good luck,
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
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What's total timing at highway speeds? Does it ever puke water into the tank?
JIM
JIM
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Melting Slicks
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From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Race Director
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From: Corsicana, Tx
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So the problem has always been with the 496? You got any assy pics of how the head gaskets mated to the block cooling holes? There are at least 3 versions of BBC coolant holes that I've come across and I've seen issues with various heads, gaskets and block combos. Usually on the bottom rows of coolant holes.
JIM
JIM
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Thread Starter
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
So the problem has always been with the 496? You got any assy pics of how the head gaskets mated to the block cooling holes? There are at least 3 versions of BBC coolant holes that I've come across and I've seen issues with various heads, gaskets and block combos. Usually on the bottom rows of coolant holes.
JIM
JIM
I used the FelPro blue performance series I believe, this was the first time to use this series of FelPro gaskets. I do like FelPro brand and use them most of the time.
The block is a standard GM piece and the heads are the same in Oval port.
Here are some pics of what I used:
Hope this helps
Neal
Pro
Joined: Nov 2007
Posts: 710
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From: Northern Florida
After getting the lower hose on and taking it for a drive on the hwy it still does the same thing. Temps climb when at 3000 to 3500rpms, temps will get to about 220 to 230*. I was running a high flow T-stat and after thinking about what some were saying here I found a 180* T-stat with a 1" opining and tried it. It did appear to hold the temps down to around 210 to 220* which in my opinion is still to high. I'm thinking of trying some restrictor plates to see if going even smaller will help.
Anyone have any ideas on what could be the issue with the engine that may be causing so much heat?
Cruising at 3000 rpms is only 60 mph, the engine shouldn't be making much over 100 HP at this load but the heat it’s producing seems to be allot, so much so the cooling system can't handle it.
My next step may be to remove the hood and see how it does cruising without it.
I was able to find the flow numbers for the stage IV pump, at 1500 rpms its flowing 34 gpm, at 2000-47 gpm, at 2500-55 gpm, at 3000-69 gpm, and at 3500-81 gpm.
These numbers were not hugely different form the stage I pump, those numbers being 1500-32 gpm, 2000-42 gpm, 2500-55 gpm, 3000-65 gpm and at 3500-77 gpm
I'm going to try restricting the water flow more and then possibly replace the pump with a normal flow pump and give that a try.
noonie mentioned cavitation at the pump so replacing the pump with a standard pump should indicate if this was the issue.
Thanks for all the help so far from everyone; I'll keep chipping away at it till I get this figured out hopefully. Some times it’s frustrating
I do have better control of the temps at lower rpms now.
Neal
Anyone have any ideas on what could be the issue with the engine that may be causing so much heat?
Cruising at 3000 rpms is only 60 mph, the engine shouldn't be making much over 100 HP at this load but the heat it’s producing seems to be allot, so much so the cooling system can't handle it.
My next step may be to remove the hood and see how it does cruising without it.
I was able to find the flow numbers for the stage IV pump, at 1500 rpms its flowing 34 gpm, at 2000-47 gpm, at 2500-55 gpm, at 3000-69 gpm, and at 3500-81 gpm.
These numbers were not hugely different form the stage I pump, those numbers being 1500-32 gpm, 2000-42 gpm, 2500-55 gpm, 3000-65 gpm and at 3500-77 gpm
I'm going to try restricting the water flow more and then possibly replace the pump with a normal flow pump and give that a try.
noonie mentioned cavitation at the pump so replacing the pump with a standard pump should indicate if this was the issue.
Thanks for all the help so far from everyone; I'll keep chipping away at it till I get this figured out hopefully. Some times it’s frustrating
I do have better control of the temps at lower rpms now.
Neal
Neal, Did you run thru ALL of the things listed prior...especially having a very clean Cooling System and using JUST the amount of antifreeze for your locale with bottle of water wetter ? Is your car running rough at highway speed ? If you suspect a miss, walit till dark then look for a lazer-light show at your ignition wires/distributor as well as spark grounding out . Going back to a standard water pump isnt going to help -- its an old wives tale that you need to slow down water flow to pick up more heat (see the Stewart website for more on this) . If youve done the above, then take out the thermostat and go for a highway run and let us know what happens. (By the way , youve confirmed that you are ACTUALLY running that 230 f, right ?)
Thread Starter
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
r
Neal, Did you run thru ALL of the things listed prior...especially having a very clean Cooling System and using JUST the amount of antifreeze for your locale with bottle of water wetter ? Is your car running rough at highway speed ? If you suspect a miss, walit till dark then look for a lazer-light show at your ignition wires/distributor as well as spark grounding out . Going back to a standard water pump isnt going to help -- its an old wives tale that you need to slow down water flow to pick up more heat (see the Stewart website for more on this) . If youve done the above, then take out the thermostat and go for a highway run and let us know what happens. (By the way , youve confirmed that you are ACTUALLY running that 230 f, right ?)
Neal, Did you run thru ALL of the things listed prior...especially having a very clean Cooling System and using JUST the amount of antifreeze for your locale with bottle of water wetter ? Is your car running rough at highway speed ? If you suspect a miss, walit till dark then look for a lazer-light show at your ignition wires/distributor as well as spark grounding out . Going back to a standard water pump isnt going to help -- its an old wives tale that you need to slow down water flow to pick up more heat (see the Stewart website for more on this) . If youve done the above, then take out the thermostat and go for a highway run and let us know what happens. (By the way , youve confirmed that you are ACTUALLY running that 230 f, right ?)
The system holds 3 gallons, I'm running two quarts of water wetter, about two quarts of anti-freeze and the rest water.
The car is running good haven't noticed a miss or anything out of the ordanry. I do have an issue with pug wire boots burning due to the headers.
I've read everything I can on the Stewart web site including the issues around less flow/greater flow debate.
I pulled the T-stat out today and took a run, it did the same thing.
I have two temp indications, I have verified my gauge with an IR gun a while back, I'm also running a MrGasket Thero-cap on the radiator. When the gauge (sender on the intake) is indicating 220* the Thermo-cap is indicating right at the same.
Neal
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
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That's a different head gasket than the regular blue ones. Not sure what it looks like. I'm thinking of the lower coolant holes as you can see on your heads. Some gaskets block off almost all of the holes and forces the water to primarily go to rear and come up back side of heads after absorbing block heat...then comes forward to cool the heads. This is why reverse cooling was designed. They cool the heads first and then worry about the block. Not practical or needed in this application..but need to be sure water can get where it needs to. Any pics of the head surface on block?
JIM
JIM
Thread Starter
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
That's a different head gasket than the regular blue ones. Not sure what it looks like. I'm thinking of the lower coolant holes as you can see on your heads. Some gaskets block off almost all of the holes and forces the water to primarily go to rear and come up back side of heads after absorbing block heat...then comes forward to cool the heads. This is why reverse cooling was designed. They cool the heads first and then worry about the block. Not practical or needed in this application..but need to be sure water can get where it needs to. Any pics of the head surface on block?
JIM
JIM
If the motor was running hot and the radiator was not heat soaked I would think it may be a water flow issue within the engine, I may be wrong here, whats your thoughts on this?
There are plenty of BB conversions out there not having issues with cooling, this has me confused. The only thing about my car that may be different form them is I installed an 81/82 conversion front bumper and I have the Zoops serp set-up on mine. Maybe its an airflow issue at speed.
I've tryed to make the air extractor on the BB hood cowl functional a while back but that made no change either.
I'm running out of Ideas
Neal
Pro
Joined: Nov 2007
Posts: 710
Likes: 0
From: Northern Florida
When I took the old TruKool out I checked the internals of it and looked around in the intake, everthing looks good.
The system holds 3 gallons, I'm running two quarts of water wetter, about two quarts of anti-freeze and the rest water.
The car is running good haven't noticed a miss or anything out of the ordanry. I do have an issue with pug wire boots burning due to the headers.
I've read everything I can on the Stewart web site including the issues around less flow/greater flow debate.
I pulled the T-stat out today and took a run, it did the same thing.
I have two temp indications, I have verified my gauge with an IR gun a while back, I'm also running a MrGasket Thero-cap on the radiator. When the gauge (sender on the intake) is indicating 220* the Thermo-cap is indicating right at the same.
Neal
The system holds 3 gallons, I'm running two quarts of water wetter, about two quarts of anti-freeze and the rest water.
The car is running good haven't noticed a miss or anything out of the ordanry. I do have an issue with pug wire boots burning due to the headers.
I've read everything I can on the Stewart web site including the issues around less flow/greater flow debate.
I pulled the T-stat out today and took a run, it did the same thing.
I have two temp indications, I have verified my gauge with an IR gun a while back, I'm also running a MrGasket Thero-cap on the radiator. When the gauge (sender on the intake) is indicating 220* the Thermo-cap is indicating right at the same.
Neal
Thread Starter
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Youre not really running 2 quarts of water wetter are you ?! Im sure you didnt mean to say that. I think you should thoroughly clean your Cooling System out as you dont know its internal condition thruout. When your temp reaches 230 f., are both electric fans running ?
Both fans are on at around 195*, I've tryed both ways letting the controler control them and with the overide switch.
Neal
Thread Starter
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
I added the oil cooler as an attempt to get the car to run cooler, it had little to no change on temps.
Neal
Thread Starter
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
I spent an hour under the front of the car studying the air flow path to see if there may be any issues there.
I noticed some areas that needed attention.
I stuffed some pipe insulation around every hole that air might get around the radiator. There were some rather large areas at the lower corners of the radiator were the front frame horns pass through the fender skirting. At the bottom of the core support were the lower air dam meets the core support there were some areas that needed some fixing to.
I spent some time when mounting the radiator to the core support sealing it up tight so Its good there.
I don't think it will be enough to make a difference but maybe a few little things will make a big difference.
Neal
I noticed some areas that needed attention.
I stuffed some pipe insulation around every hole that air might get around the radiator. There were some rather large areas at the lower corners of the radiator were the front frame horns pass through the fender skirting. At the bottom of the core support were the lower air dam meets the core support there were some areas that needed some fixing to.
I spent some time when mounting the radiator to the core support sealing it up tight so Its good there.
I don't think it will be enough to make a difference but maybe a few little things will make a big difference.
Neal
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
Neal,
Without reading through the whole thread again I wonder if you have tried everything recommended? The one that stands out to me is that high flow water pump is still there. I have had dozen of people tell me they actually made them run hotter. I wouldn't think that would be the case with the aluminum radiator but you could reduce the flow with restrictors in the stat housing, just to avoid the hassle of changing out the pump for no reason. If it works, then you might want to dump the high flow unit.
The one thing you can forget is the radiator, you've got enough radiator. The bigger question is why is it making so much heat in the first place. I hope I'm wrong on this one but I do have 3-4 people per year with motors that are simply built too tight. Some try to out do the General specs and cut the clearences to way below the norm. The only way to fix that is to tear it down and start over. I have one guy that chased a problem like this only to discover the machine shop put in the wrong set of pistons and he had zero clearence.
Without reading through the whole thread again I wonder if you have tried everything recommended? The one that stands out to me is that high flow water pump is still there. I have had dozen of people tell me they actually made them run hotter. I wouldn't think that would be the case with the aluminum radiator but you could reduce the flow with restrictors in the stat housing, just to avoid the hassle of changing out the pump for no reason. If it works, then you might want to dump the high flow unit.
The one thing you can forget is the radiator, you've got enough radiator. The bigger question is why is it making so much heat in the first place. I hope I'm wrong on this one but I do have 3-4 people per year with motors that are simply built too tight. Some try to out do the General specs and cut the clearences to way below the norm. The only way to fix that is to tear it down and start over. I have one guy that chased a problem like this only to discover the machine shop put in the wrong set of pistons and he had zero clearence.
Thread Starter
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
Neal,
Without reading through the whole thread again I wonder if you have tried everything recommended? The one that stands out to me is that high flow water pump is still there. I have had dozen of people tell me they actually made them run hotter. I wouldn't think that would be the case with the aluminum radiator but you could reduce the flow with restrictors in the stat housing, just to avoid the hassle of changing out the pump for no reason. If it works, then you might want to dump the high flow unit.
The one thing you can forget is the radiator, you've got enough radiator. The bigger question is why is it making so much heat in the first place. I hope I'm wrong on this one but I do have 3-4 people per year with motors that are simply built too tight. Some try to out do the General specs and cut the clearences to way below the norm. The only way to fix that is to tear it down and start over. I have one guy that chased a problem like this only to discover the machine shop put in the wrong set of pistons and he had zero clearence.
Without reading through the whole thread again I wonder if you have tried everything recommended? The one that stands out to me is that high flow water pump is still there. I have had dozen of people tell me they actually made them run hotter. I wouldn't think that would be the case with the aluminum radiator but you could reduce the flow with restrictors in the stat housing, just to avoid the hassle of changing out the pump for no reason. If it works, then you might want to dump the high flow unit.
The one thing you can forget is the radiator, you've got enough radiator. The bigger question is why is it making so much heat in the first place. I hope I'm wrong on this one but I do have 3-4 people per year with motors that are simply built too tight. Some try to out do the General specs and cut the clearences to way below the norm. The only way to fix that is to tear it down and start over. I have one guy that chased a problem like this only to discover the machine shop put in the wrong set of pistons and he had zero clearence.
The one thing I gained when I installed one of your radiators is I know for sure it is not the radiator causing my issue. There are many vettes out there making more HP and not running 220* using one of your radiators.
I removed the T-stat housing form the intake as suggested, I installed a new lower hose with the internal spring and installed a T-stat with only a 1" hole for the flow reduction.
Would you suggest going smaller with the flow restriction? I can remove the T-stat and install a smaller flow restriction if you think it may help.
The heat is a big question for me, cruising down a flat straight of road should not take much HP (maybe 100 HP) to propel the car, so where is the heat coming form. I'm making sure I have covered all the possibilities I can before removing the motor and tearing it down.
Neal