Heater-Core Bypass... How?
Thread Starter
Pro
Joined: Oct 2006
Posts: 545
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From: Peoplez Republik (communist portland) Orygun
You guys, thanks so much for this safety tip.
After researching and reading reports about this potential hazard, ill be addressing these fuel lines ASAP.
correct, it is an Edelbrock 1406 just like shown above in pauls 67. The line from the fuel pump to the carb will be changed.
Also, if you notice near the bottom of this picture, the two lines which run from the gas tank to the bottom of the fuel pump (the two parallel) are both spliced into rubber hoses.
I'll probably want to re-do those too, huh?
After researching and reading reports about this potential hazard, ill be addressing these fuel lines ASAP.
correct, it is an Edelbrock 1406 just like shown above in pauls 67. The line from the fuel pump to the carb will be changed.
Also, if you notice near the bottom of this picture, the two lines which run from the gas tank to the bottom of the fuel pump (the two parallel) are both spliced into rubber hoses.
I'll probably want to re-do those too, huh?
Last edited by Vette80regon; Jul 7, 2008 at 10:46 AM.
Intermediate
Joined: Jan 2006
Posts: 40
Likes: 0
The 2 bottom rubber hoses are correct, do not change them for solid!
They are on the low pressure side of the pump and are there to take any movement between the hard lines to the tank and the pump on the engine. As the engine moves slightly it will eventually crack any hard line.
The rubber is the way it came from the factory, as long as its in good condition, your good to go.
Just replace the line between the pump and the carb as has been said before! good luck.
They are on the low pressure side of the pump and are there to take any movement between the hard lines to the tank and the pump on the engine. As the engine moves slightly it will eventually crack any hard line.
The rubber is the way it came from the factory, as long as its in good condition, your good to go.
Just replace the line between the pump and the carb as has been said before! good luck.
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I think that the SCCA/NHRA both kind of have the same rules on certain items. One being rubber fuel lines. I don't have the book in front of me, but the max length of rubber fuel line is 6 inches and some common sense about it not being near any moving parts.
Steel braided is not really better line because it is also generally just rubber that deteriorates with time.
I would install a metal in line fuel filter where that short piece of rubber is.
Steel braided is not really better line because it is also generally just rubber that deteriorates with time.
I would install a metal in line fuel filter where that short piece of rubber is.
Racer
Joined: Mar 2008
Posts: 428
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Fuel filter
I would not install a fuel filter were the splice is. Against the manifold and partially under the bypass hose is not the ideal place.
Braided line for a carbureted engine is really just for looks. Any rubber hose you install, no matter how short, should be fuel line rated.
Braided line for a carbureted engine is really just for looks. Any rubber hose you install, no matter how short, should be fuel line rated.
Pro
Joined: Sep 2002
Posts: 624
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From: Melbourne, Fla. 6 months- New Middletown, Ohio 6 months
Your loop will supply lots of hot water from the manifold right back into the pump. Bypassing the radiator!
If motor temp is not a problem....................... go for it!
I was gone on a 8 day vacation and when I came back the boss decided to not send me along with the GT-40 and Bizzarini for the 11-13th races at PIR. I'm a little bumbed because the new guy gets to go.
If motor temp is not a problem....................... go for it!
I was gone on a 8 day vacation and when I came back the boss decided to not send me along with the GT-40 and Bizzarini for the 11-13th races at PIR. I'm a little bumbed because the new guy gets to go.
Racer
Joined: Mar 2008
Posts: 428
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It's the thermostats job to actually regulate the engine temperature. If looping or by-passing the heater core makes the engine temp creep up or just plain run hot, I think there are other issues with the system. Many vehicles have vacuum controlled inline valves to control hot water flow to the heater core.
Race Director
Joined: Apr 2003
Posts: 19,350
Likes: 654
From: Tampa, Florida
Installing a loop will not bypass the radiator. The pump pulls water from the block and heater core (when flowing) and then pushes it thru the radiator. The increased heat the radiator will see is from the water that was not cooling in the heater core. I think you will be gladly accept the tradeoff!!
1. The water pump will draw from the intake...
2. Then it will pump that same water back into the block......
3. Which it then pulls from the intake....
How is that not a loop?
4. While its essentialy a shortened version of running it through the heater core I'd guess theres considerably lower resistence in the 'mini' loop thus taking away from radiator flow.
It seems as if some water will work its way past the thermostat and go through the radiator while a portion of it runs the loop and doesnt get cooled.
Race Director
Joined: Apr 2003
Posts: 19,350
Likes: 654
From: Tampa, Florida
If 'loops' didnt contribute to overheating they wouldnt contribute to cooling when you turn on the heater.
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Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Installing a loop will not bypass the radiator. The pump pulls water from the block and heater core (when flowing) and then pushes it thru the radiator. The increased heat the radiator will see is from the water that was not cooling in the heater core. I think you will be gladly accept the tradeoff!!
Where i have the plug and where he has the loop is on the suction side of the water pump. Correct?
The open thermostat when up at temp and those tiny radiator core tubes slow the flow of water to the point where you often have a spring installed in the lower radiator hose to keep it from collapsing from the water pumps suction. Correct?
Now add a free flowing hose from the intake output to the suction side of a water pump? No cooling! Correct?
Pro
Joined: Sep 2002
Posts: 624
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From: Melbourne, Fla. 6 months- New Middletown, Ohio 6 months
Originally Posted by Red 71
Installing a loop will not bypass the radiator. The pump pulls water from the block and heater core (when flowing) and then pushes it thru the radiator. The increased heat the radiator will see is from the water that was not cooling in the heater core. I think you will be gladly accept the tradeoff!!
Was talking on my cell phone when I was writing this and swapped the words block and radiator. Not paying attention!! Your point about the loop is well taken, I have seen a overheat problem created since as you stated, it is easier for the pump to pull from the bypass hose than the radiator. Eventually the water can potentially get hot enough that the radiator can't cool it.
Installing a loop will not bypass the radiator. The pump pulls water from the block and heater core (when flowing) and then pushes it thru the radiator. The increased heat the radiator will see is from the water that was not cooling in the heater core. I think you will be gladly accept the tradeoff!!
Water will flow though the least path of resistance. Correct?
Where i have the plug and where he has the loop is on the suction side of the water pump. Correct?
The open thermostat when up at temp and those tiny radiator core tubes slow the flow of water to the point where you often have a spring installed in the lower radiator hose to keep it from collapsing from the water pumps suction. Correct?
Now add a free flowing hose from the intake output to the suction side of a water pump? No cooling! Correct?
Where i have the plug and where he has the loop is on the suction side of the water pump. Correct?
The open thermostat when up at temp and those tiny radiator core tubes slow the flow of water to the point where you often have a spring installed in the lower radiator hose to keep it from collapsing from the water pumps suction. Correct?
Now add a free flowing hose from the intake output to the suction side of a water pump? No cooling! Correct?
Last edited by Red 71; Jul 8, 2008 at 09:21 PM.
Racer
Joined: Mar 2008
Posts: 428
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Loops
In a loop, some hot coolant returns to the engine, which would require the thermostat to stay open longer. This is a temporary fix, one that I used to just get back home and I always made it home without overheating the engine. I am thinking that the best solution is to fix the heater core.
Last edited by Project80; Jul 8, 2008 at 09:06 PM.
Race Director
Joined: Apr 2003
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From: Tampa, Florida
Pouiselles law put 'L' in denominator. Double the length of the hose cuts flow in half...4x times the length cuts it by a 1/4.
1st Gear
Joined: Mar 2022
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Heater core bypass
Hmmmm, so... I have been trying to make sense of the hose routing to bypass my newly discovered, slow leak heater core.
I have read & re-read my Haynes & shop book too. Scoured the Cforum for pictures or simple instructions as to "what hose goes where?"
anyone who has done this with pictures or able to send a step-by-step tutorial for a by-pass noobie would be totally helpful!!!
I just want to simply bypass the heater core until later this winter when I have more time to do the whole enchilada
I have read & re-read my Haynes & shop book too. Scoured the Cforum for pictures or simple instructions as to "what hose goes where?"
anyone who has done this with pictures or able to send a step-by-step tutorial for a by-pass noobie would be totally helpful!!!
I just want to simply bypass the heater core until later this winter when I have more time to do the whole enchilada
I know you said you wanted to wait but to flush out the bypass isn't to difficult or big of a job. You need two tubes one short, one long. First start the engine so you know which is the hot and which is the cold. Attach the short to the cold and the long on the hot, after you've clamped it of course, the long(hot) you can lead to a bucket so it dumps whatever comes out in it. Begin flushing cold water through the cold, it will begin coming through the bypass and empty from the hot, cleaning whatever debris might be in the bypass. When completely flushed water should come through clear. Remove tube, Reattach hoses, remove Clamps, you should be good.
Melting Slicks
Joined: Oct 2003
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From: Dallas TX
St. Jude Donor '06-'09,'22,'25
I know you said you wanted to wait but to flush out the bypass isn't to difficult or big of a job. You need two tubes one short, one long. First start the engine so you know which is the hot and which is the cold. Attach the short to the cold and the long on the hot, after you've clamped it of course, the long(hot) you can lead to a bucket so it dumps whatever comes out in it. Begin flushing cold water through the cold, it will begin coming through the bypass and empty from the hot, cleaning whatever debris might be in the bypass. When completely flushed water should come through clear. Remove tube, Reattach hoses, remove Clamps, you should be good.
