Heater Core Bling
#21
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Yea the thermostat is a 180 +- 10 so say it has to see 190 before its fully closed. I don’t know how much temperature drops across the heater core with the heat off but it wouldn’t surprise me if it is 30 or 40 degrees compared to where a standard radiator thermostat and temperature sender is located. So it may not close fully until the engine is hotter than Id like it if it is after the core.
I run a 180 degree main thermostat in the back of the head for the main radiator. With the heater core thermostat placed before the heater core it should start shutting flow down about the same time as the flow starts going to the radiator. when I took the valve apart and fiddled with it I could still blow through it with the path shut so there is always some flow going to the heater core just a significantly reduced amount.
So yea I think a 160-170 thermostat placed after the heater core would be better. The only thing I have found so far is this.
http://www.summitracing.com/parts/EAR-501ERL/
I think some OEM’s BMW? are setup this way I wonder what there heater thermostats look like.
Bob
I run a 180 degree main thermostat in the back of the head for the main radiator. With the heater core thermostat placed before the heater core it should start shutting flow down about the same time as the flow starts going to the radiator. when I took the valve apart and fiddled with it I could still blow through it with the path shut so there is always some flow going to the heater core just a significantly reduced amount.
So yea I think a 160-170 thermostat placed after the heater core would be better. The only thing I have found so far is this.
http://www.summitracing.com/parts/EAR-501ERL/
I think some OEM’s BMW? are setup this way I wonder what there heater thermostats look like.
Bob
#25
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So yea I think a 160-170 thermostat placed after the heater core would be better. The only thing I have found so far is this.
http://www.summitracing.com/parts/EAR-501ERL/
I think some OEM’s BMW? are setup this way I wonder what there heater thermostats look like.
Bob
![](http://img15.imageshack.us/img15/1203/dsc01568im.jpg)
Trying to find another.
Edit: After a bit of reading it looks like they implemented that back in the 80s as a recall to try and eliminate some coolant system over pressurization that was causing heater cores to explode and scalding drivers' legs.
#26
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Here is one kinda bad picture of it.
![](http://img15.imageshack.us/img15/1203/dsc01568im.jpg)
Trying to find another.
Edit: After a bit of reading it looks like they implemented that back in the 80s as a recall to try and eliminate some coolant system over pressurization that was causing heater cores to explode and scalding drivers' legs.
![](http://img15.imageshack.us/img15/1203/dsc01568im.jpg)
Trying to find another.
Edit: After a bit of reading it looks like they implemented that back in the 80s as a recall to try and eliminate some coolant system over pressurization that was causing heater cores to explode and scalding drivers' legs.
They also put restrictors into the HC inlet pipes to slow that down. I was talking to our local hotrod radiator shop and they suggested doing that to my stock HC since the OEM Mazda cap was only 13psi, where we have an 18-20psi (can't remember the exact) cap on it now. They said it actually takes very little coolant flow to keep the cabin warm.
#27
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They also put restrictors into the HC inlet pipes to slow that down. I was talking to our local hotrod radiator shop and they suggested doing that to my stock HC since the OEM Mazda cap was only 13psi, where we have an 18-20psi (can't remember the exact) cap on it now. They said it actually takes very little coolant flow to keep the cabin warm.
Bob
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Interesting I took the thing apart wondering if I could just find something to replace the wax thingy with and it is stamped 77C / 171F. The wax plug part looks the same shape and dimensions as some other thermostats I got maybe I can just take one out of a 160F standard thermostat.
Maybe it was working correctly with it after the core if it was a 171F stat I just don’t know for sure what the temp drop is like across the heater core. That is actually how I had it prior I must say it seemed to work but I didn’t record actual data to prove it. I can certainly re plum it back that way again.
Bob
Maybe it was working correctly with it after the core if it was a 171F stat I just don’t know for sure what the temp drop is like across the heater core. That is actually how I had it prior I must say it seemed to work but I didn’t record actual data to prove it. I can certainly re plum it back that way again.
Bob
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Update I found a 160 Motorad thermostat at O-Riley’s had the same wax pellet dimensions as the True Cool oil cooler thermostat.
I put the thermostat assembly in a pot on the stove.
With the 171F pellet it came with it was fully closed at ~195 F
With the 160F pellet it was fully closed at ~175 F.
So if I put this in post core it means it won’t allow much flow through it if the heater core unless it can reject enough heat to get it below 175 F thus somewhat preventing it from possibly being a short circuit of the radiator while still allowing it to resonably function well as a heater when needed for heat.
Any Idea what the temp would typically be at the outlet of the main radiator if say it was 210-220F where it left the head? I havent found where anybody measured it yet. and Im too lazy to measure it myself.
Bob
I put the thermostat assembly in a pot on the stove.
With the 171F pellet it came with it was fully closed at ~195 F
With the 160F pellet it was fully closed at ~175 F.
So if I put this in post core it means it won’t allow much flow through it if the heater core unless it can reject enough heat to get it below 175 F thus somewhat preventing it from possibly being a short circuit of the radiator while still allowing it to resonably function well as a heater when needed for heat.
Any Idea what the temp would typically be at the outlet of the main radiator if say it was 210-220F where it left the head? I havent found where anybody measured it yet. and Im too lazy to measure it myself.
Bob
#31
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Update I found a 160 Motorad thermostat at O-Riley’s had the same wax pellet dimensions as the True Cool oil cooler thermostat.
I put the thermostat assembly in a pot on the stove.
With the 171F pellet it came with it was fully closed at ~195 F
With the 160F pellet it was fully closed at ~175 F.
I put the thermostat assembly in a pot on the stove.
With the 171F pellet it came with it was fully closed at ~195 F
With the 160F pellet it was fully closed at ~175 F.
Any Idea what the temp would typically be at the outlet of the main radiator if say it was 210-220F where it left the head?
#32
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LOL you're such a stud...
When the t-stat is wide open, it depends on RPM (and thus water flow rate) and airflow through the rad. Circa 10-15*C drop across the rad at like 50 mph on a steep mt. road doing ~4000 RPM, fans running, on a hot day. At higher RPMs the deltaT will be a bit lower. If the t-stat is partially closed, it'll climb to 30*C delta or more.
When the t-stat is wide open, it depends on RPM (and thus water flow rate) and airflow through the rad. Circa 10-15*C drop across the rad at like 50 mph on a steep mt. road doing ~4000 RPM, fans running, on a hot day. At higher RPMs the deltaT will be a bit lower. If the t-stat is partially closed, it'll climb to 30*C delta or more.
Important if you want to drive the **** out a car making 3X stock hp and have it maintain temp.
Bob
#34
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I'm using a hose barb and hose clamp, but I've drilled and tapped my mixing manifold for a 1/2" NPT. Or 3/8" NPT, I forget. Anyways a NPT to -AN fitting could obviously be screwed in to connect a hose on.
#35
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More bling. note: all the turbo lines are AN fittings. Custom fabricated inlet to the water pump to work with my turbo location. I finished it off to look like it was cast like that.
Bob
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Update,
I changed the installation a bit. Moved the heater thermostat to the other side of the firewall and cleaned up the engine bay. Also have it installed after the heater core with the lower temp wax pellet I ripped out of a different thermostat.
Bob
I changed the installation a bit. Moved the heater thermostat to the other side of the firewall and cleaned up the engine bay. Also have it installed after the heater core with the lower temp wax pellet I ripped out of a different thermostat.
Bob