# Heater core delete: Loop or plug?
**URL:** https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390
**Category:** NYSpeed Automotive
**Created:** [July 11, 2009, 3:46am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390 "2009-07-11T03:46:35Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [July 11, 2009, 3:46am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/1 "2009-07-11T03:46:35Z")
I’m leaning towards loop. This will allow some coolant flow when the thermostat is closed…
What about you guys?
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### Author:  [@NeOn9787](https://forums.speedlife.net/u/NeOn9787)
#### Post date: [July 11, 2009, 3:53am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/2 "2009-07-11T03:53:38Z")
I would probably just run a cooler thermostat man…
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [July 11, 2009, 4:03am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/3 "2009-07-11T04:03:05Z")
I’m already running a 170. But there is no heater core in the car, so I need to either loop the lines or plug them.
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### Author:  [@Minglor](https://forums.speedlife.net/u/Minglor)
#### Post date: [July 11, 2009, 4:28am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/4 "2009-07-11T04:28:28Z")
I would vote loop as well.
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### Author:  [@Studderin](https://forums.speedlife.net/u/Studderin)
#### Post date: [July 11, 2009, 4:30am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/5 "2009-07-11T04:30:28Z")
no heater? I’m really glad I put the one I made in my car.
for the lines, I’d look at the system up to were the HC lines start. And see what its doing, to decide. But another side I see, it’s really easy to change between loop and blocked. And would be something to test looking for a difference in system temp change if you needed it. It could be one of those things you can think about, and do on paper. I don’t know all the fluid dynamics of it, but the big picture of a system like that I’ve seen temps change both ways. So the IRL mother nature’s has the final word to me.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [July 11, 2009, 4:43am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/6 "2009-07-11T04:43:55Z")
> [@Studderin](#):
>
> no heater? I’m really glad I put on in my car.
>
> for the lines, I’d look at the system up to were the HC lines start. And see what its doing, to decide. But another side I see, it’s really easy to change between loop and blocked. And would be something to test looking for a difference in system temp change if you needed it. It could be one of those things you can think about, and do on paper. I don’t know all the fluid dynamics of it, but the big picture of a system like that I’ve seen temps change both ways. So the IRL mother nature’s has the final word to me.
No heater. The exhaust occupies the space where the blower motor used to be. Who knows if someday I’ll rig something up, but for now, I am not.
You can see the heater feed/return in this pic:
The return is the nipple on the tstat housing. This is “low pressure”.
The feed is on the block to the left.
The more I think about it, I should loop these, or else the pump will cavitate when the tstat is closed…
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### Author:  [@Jagermeister](https://forums.speedlife.net/u/Jagermeister)
#### Post date: [July 11, 2009, 5:22am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/7 "2009-07-11T05:22:49Z")
Loop.
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### Author:  [@joelster](https://forums.speedlife.net/u/joelster)
#### Post date: [July 11, 2009, 5:27am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/8 "2009-07-11T05:27:10Z")
You don’t need a heater in a car unless you drive in sub 35 degree weather. You shouldn’t ever have to “rig” anything to clear the windshield, as long as you keep the fan in there you will not fog up. If you ever need to quickly rig something to make your interior warm, remaove your front carpet and sound deadening. The exhaust will keep you nice and toasty.
+1 on loop
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### Author:  [@travisn](https://forums.speedlife.net/u/travisn)
#### Post date: [July 11, 2009, 5:27am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/9 "2009-07-11T05:27:56Z")
I was thinking if you plug them a dry spot would/could happen, but of course I am too late for that idea. lol
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [July 11, 2009, 5:33am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/10 "2009-07-11T05:33:11Z")
> [@joelster](#):
>
> You don’t need a heater in a car unless you drive in sub 35 degree weather. You shouldn’t ever have to “rig” anything to clear the windshield, as long as you keep the fan in there you will not fog up. If you ever need to quickly rig something to make your interior warm, remaove your front carpet and sound deadening. The exhaust will keep you nice and toasty.
>
> +1 on loop
Well, I don’t even have a blower motor in the car…
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### Author:  [@somedude](https://forums.speedlife.net/u/somedude)
#### Post date: [July 11, 2009, 5:39am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/11 "2009-07-11T05:39:03Z")
> [@joelster](#):
>
> You don’t need a heater in a car unless you drive in sub 35 degree weather. You shouldn’t ever have to “rig” anything to clear the windshield, as long as you keep the fan in there you will not fog up. If you ever need to quickly rig something to make your interior warm, remaove your front carpet and sound deadening. The exhaust will keep you nice and toasty.
>
> +1 on loop
tell that to my turbo SHO. if it is raining out that shit is fogged. I have to drive with a window down. if i turn the blower makes no difference.
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### Author:  [@JayS](https://forums.speedlife.net/u/JayS)
#### Post date: [July 11, 2009, 5:51am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/12 "2009-07-11T05:51:32Z")
Plugging it seems like a bad idea. However… How much flow resistance is there in your heater core? I replaced one once before but I never really looked to see how the coolant flowed through it and if it was restricted in some way.
My concern with a clean loop of tubing is that if the resistance is considerably less more coolant will flow through there meaning less going to some other critical path. Easy enough to fix by stepping down the size of the hose enough to mimic the resistance of the core, assuming there is some.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [July 11, 2009, 6:11am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/13 "2009-07-11T06:11:05Z")
> [@JayS](#):
>
> Plugging it seems like a bad idea. However… How much flow resistance is there in your heater core? I replaced one once before but I never really looked to see how the coolant flowed through it and if it was restricted in some way.
>
> My concern with a clean loop of tubing is that if the resistance is considerably less more coolant will flow through there meaning less going to some other critical path. Easy enough to fix by stepping down the size of the hose enough to mimic the resistance of the core, assuming there is some.
That **exactly** was my only concern about looping it. Tons of skyline guys do it, though, because their cores always shit out. That doesn’t mean it’s right.
However, i don’t think heater cores provide TOO much resistance.
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### Author:  [@Mike93](https://forums.speedlife.net/u/Mike93)
#### Post date: [July 11, 2009, 6:32am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/14 "2009-07-11T06:32:51Z")
Not sure how similar the application is…but on the '55 I have the line looped at the water pump for the heater core. ~1500 miles on it and no problems.
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### Author:  [@L8APEX1](https://forums.speedlife.net/u/L8APEX1)
#### Post date: [July 11, 2009, 7:05am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/15 "2009-07-11T07:05:33Z")
loop just incase of a hotspot
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### Author:  [@Saxon](https://forums.speedlife.net/u/Saxon)
#### Post date: [July 11, 2009, 7:12am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/16 "2009-07-11T07:12:17Z")
i always loop them
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### Author:  [@Nikuk](https://forums.speedlife.net/u/Nikuk)
#### Post date: [July 11, 2009, 7:44am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/17 "2009-07-11T07:44:47Z")
I’ve run them looped (6" to 1.5’) on 4 or 5 cars with ZERO over cooling or over heating problems.
Don’t overthink it, it’s not some critically designed system, the tstat will still let hot coolant out of the block and flow through the (larger) port into the rad. Same to be said for the pump impeller.
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### Author:  [@9ONA3OOZX](https://forums.speedlife.net/u/9ONA3OOZX)
#### Post date: [July 11, 2009, 7:53am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/18 "2009-07-11T07:53:56Z")
I’m no mechanic but i’d assume loop would be better just to keep the natural flow of the coolant going the way it was designed to.
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### Author:  [@Spam16v](https://forums.speedlife.net/u/Spam16v)
#### Post date: [July 11, 2009, 8:24am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/19 "2009-07-11T08:24:14Z")
considered running a retro-fit kit like the hotrod guys do? they’re tiny little boxes that fit behind the glove box, couple flexible duct, a pull cable for the valve (run an h-pipe to bypass) and a fan switch. you’re going to kick yourself when the fucking windshield fogs up like a bitch if you get caught in a few drops of rain.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [July 11, 2009, 8:25am UTC](https://forums.speedlife.net/t/heater-core-delete-loop-or-plug/70390/20 "2009-07-11T08:25:36Z")
I might add something in the future. I’ve said before that the interior will be a winter project. I just want to get the car driving with the bare essentials.
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