Cooling After Removing an S13 Heater Core - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

DBecks · 01-31-2017, 01:32 PM

Okay so I apologize if there's already a thread on this but after days of searching I couldn't find a helpful answer. So I'm putting a 5.3 lm7 into my s13 and am now working on cleaning out the chassis of unnecessary items (AC, wiring, interior parts, etc.) and an issue I have is one of the nipple/hose fitting things that comes off the heater core through the firewall into the engine bay broke when I pulled the SR out. Now the car is never going to see the street again and will only see events when it's above 50 degrees out so I won't need heat so my question is how much will it affect cooling if I take the heater core out and block/loop the hoses on the motor? I'm going with a Mishimoto KA24DE rad with a dual puller fans shroud. Would I be better off replacing the heater core or is it fine to bypass it on the motor and get rid of it?? I've never dealt with cars with heat before really so apologies if it's a noob question but everyone seems to suggest the core helps a lot with cooling.

travon47 · 01-31-2017, 01:52 PM

You should be fine, I haven't had to turn the heat on to cool my 240sx with a ls1. As long as you have a nice shroud and fans you should be good. the iron block will make it heat soak more than a aluminum block but a lot of people with ls swaps don't run the heater cores. The only crappy part is you don't have the option to cool your engine that way if it comes to it. I feel like you will be fine as long as you bleed the cooling system well. Also get a lingenfelter 160* thermostat since the stock 190* is high and may contribute to getting too hot. I am still running the 190* one and would see around 210 on the dyno so I went into hp tuners and had the both fans turn on at 170*. I hope that helps, PM me if you need more info

DBecks · 01-31-2017, 02:45 PM

Quote:

Originally Posted by travon47

You should be fine, I haven't had to turn the heat on to cool my 240sx with a ls1. As long as you have a nice shroud and fans you should be good. the iron block will make it heat soak more than a aluminum block but a lot of people with ls swaps don't run the heater cores. The only crappy part is you don't have the option to cool your engine that way if it comes to it. I feel like you will be fine as long as you bleed the cooling system well. Also get a lingenfelter 160* thermostat since the stock 190* is high and may contribute to getting too hot. I am still running the 190* one and would see around 210 on the dyno so I went into hp tuners and had the both fans turn on at 170*. I hope that helps, PM me if you need more info

Awesome! I figured it wouldn't be too much of an issue. And I am switching to a 160* thermostat and I'm getting the ISR fan shroud and dual fans hooked up individually to two separate rocker switches. My only other question would then be due I loop the heater lines coming off the LS or block them? I've heard there's cooling benefits to blocking them but never seen it done before.

travon47 · 01-31-2017, 03:28 PM

Quote:

Originally Posted by DBecks

Awesome! I figured it wouldn't be too much of an issue. And I am switching to a 160* thermostat and I'm getting the ISR fan shroud and dual fans hooked up individually to two separate rocker switches. My only other question would then be due I loop the heater lines coming off the LS or block them? I've heard there's cooling benefits to blocking them but never seen it done before.

I guess I have heard to not block them but have seen both done so personally I cant comment. For this reason I have the LOJ heater block that allows the coolant to pass through when I don't have the heat on. Check out LOJ conversions , he has a lot of good stuff for the swap and knowledge of these engines and is also in NJ. I am running his kit to use the cd009 trans and everything is perfect and couldn't be happier.

gaz_moose · 02-01-2017, 02:27 AM

on most engines you would loop the heater hoses together if you remove the actual heater.otherwise it can upset the coolant flow path.

01-31-2017, 01:32 PM	#1
DBecks Join Date: Oct 2016 Location: New Jersey Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	Cooling After Removing an S13 Heater Core Okay so I apologize if there's already a thread on this but after days of searching I couldn't find a helpful answer. So I'm putting a 5.3 lm7 into my s13 and am now working on cleaning out the chassis of unnecessary items (AC, wiring, interior parts, etc.) and an issue I have is one of the nipple/hose fitting things that comes off the heater core through the firewall into the engine bay broke when I pulled the SR out. Now the car is never going to see the street again and will only see events when it's above 50 degrees out so I won't need heat so my question is how much will it affect cooling if I take the heater core out and block/loop the hoses on the motor? I'm going with a Mishimoto KA24DE rad with a dual puller fans shroud. Would I be better off replacing the heater core or is it fine to bypass it on the motor and get rid of it?? I've never dealt with cars with heat before really so apologies if it's a noob question but everyone seems to suggest the core helps a lot with cooling.

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01-31-2017, 01:52 PM	#2
travon47 Leaky Injector Join Date: Aug 2007 Location: Minneapolis, MN Age: 31 Posts: 93 Trader Rating: (0) Feedback Score: 0 reviews	You should be fine, I haven't had to turn the heat on to cool my 240sx with a ls1. As long as you have a nice shroud and fans you should be good. the iron block will make it heat soak more than a aluminum block but a lot of people with ls swaps don't run the heater cores. The only crappy part is you don't have the option to cool your engine that way if it comes to it. I feel like you will be fine as long as you bleed the cooling system well. Also get a lingenfelter 160* thermostat since the stock 190* is high and may contribute to getting too hot. I am still running the 190* one and would see around 210 on the dyno so I went into hp tuners and had the both fans turn on at 170*. I hope that helps, PM me if you need more info

02-01-2017, 02:27 AM	#5
gaz_moose Zilvia Member Join Date: Mar 2008 Location: engerland Posts: 242 Trader Rating: (0) Feedback Score: 0 reviews	on most engines you would loop the heater hoses together if you remove the actual heater.otherwise it can upset the coolant flow path.