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Old 01-12-2010, 04:26 PM   #1
HamFist
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Default Removing the heater core...

I'll be stripping the heater core out of my car when I do the diet. Removing it isn't my question. If you've removed your heater core, what did you do with the coolant lines on the block? I have to leave mine in because the turbo is water cooled. I need to bridge the lines on the driver side rear of the block. I'd prefer using fittings, but there's nothing to tap. A little semi-circle piece of coolant hose would look sloppy and might create potential for leaks.

Suggestions?
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Old 01-12-2010, 04:48 PM   #2
nme187
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You can buy rubber caps and hose clamps from an industrial supplier.

Marshall's Industrial Hardware, LLC
2210 West California, Ave.
Salt Lake City, UT 84104
Phone: (801) 978-0555
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Old 01-12-2010, 05:20 PM   #3
HamFist
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Quote:
Originally Posted by nme187 View Post
You can buy rubber caps and hose clamps from an industrial supplier.

Marshall's Industrial Hardware, LLC
2210 West California, Ave.
Salt Lake City, UT 84104
Phone: (801) 978-0555
(Take this with a grain of salt. I only looked once.)

From the looks of things, it has to remain a complete circuit. I'll check again to make sure. The rotated turbo's return is tapped into the heater core inlet line on the top of the block. It doesn't go into the coolant "crossbar." The turbo coolant is routed into the external coolant line on the Driver side, from the rear. My thought process was that the coolant all needs to still return to the bottom of the block, thus remaining a complete circuit. The turbo returns to the driver side of the head. But, starving the inlet return on the driver side of the head would make it run hot and pop, wouldn't it?

An EJ22T block has the coolant routed externally with lines to the thermostat from the heater core. I think all turbo blocks are like that. I looked at removing these altogether, but the turbo needs it's coolant for the water cooled center section. That drains into the back of the cylinder head. Supply comes from these external lines.

I'm pretty sure the lines need to be connected and rerouted. There's about 3 inches of space to work with right there on the back of the DS head. Making it look pretty and neat is where I'm a little stuck. Little details like this are where I get hung up due to having a the same n/a block for 10 years.
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Old 01-12-2010, 06:00 PM   #4
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Having the lines connected allows a constant coolant flow out of the block and right back behind the thermostat. As the engine warms, the coolant warms and this constant cycle helps open the thermostat as well. That's one of the benefits I see. I do notice that the thermostat has a little hold with a pill/plug thingy on it. Allows for coolant cycle from the radiator???

When straight up track car.. I would cycle all coolant out to the radiator.
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Old 01-12-2010, 08:36 PM   #5
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just wondering other than weight, why remove the heater? It has MANY uses. IE defog your windows( unless its a stripped drag car I dont see the point) and also it your engine is running hot you can turn the heater on and help bring temps down.
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Old 01-13-2010, 12:53 AM   #6
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It is a straight up track only car. E85 runs really cool to the point of having trouble building heat some times. I'm being careful about managing heat. An trans + oil cooler might be a good idea. I'll have a huge WAIC unit on the car as well. I'm dropping weight as close to 2000lbs as possible. Any and all interior will be notoriously absent anyway. I'm gonna put Kate Moss to shame .

Space is still kinda precious under there. Just routing the coolant lines in a short space is what I need to do.
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Old 01-13-2010, 06:29 AM   #7
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There are some nice coolant flow diagrams in various FSM. I'd say that capping the heater connections would be a bad idea. The circuit allows continuous flow to stabilize coolant temperature otherwise the temperature would go very high in certain areas (inside the the left head specifically).

I can't say for sure but I think blocking off the heater passages caused a recent engine failure of mine. My heater core was leaking and I just took one of the hoses and routed it back to the other port. The hose was kinked so water wasn't flowing. The car ran fine for 150 miles and then suddenly the temperature started to rise and even dropping to neutral didn't stop it from pegging.

Edit: Here is the Legacy Turbo layout (which is essentially the same as all the current setups)

See how blocking the heater would keep the water from flowing through the left head when the thermostat is closed, except for a tiny amount through the throttle body? It explains why when I poored water on the engine it did basically nothing on the block but sizzled like mad on the heads.

I'd argue that a higher flowing heater core (or a U shaped piece of bypass hose) would actually improve coolant temperature stability!

Last edited by ciper; 01-13-2010 at 06:57 AM.
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Old 01-13-2010, 03:15 PM   #8
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Ciper, you confirmed my fear! It would be a bad temperature rise on only part of the block.

How to reconnect this without kinking anything is the tricky part. I don't want a "loop" of line hanging loose that could get caught on anything or kink up.
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Old 01-13-2010, 03:27 PM   #9
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when I removed my heater core i just looped the coolant lines. will try to get pics up tonight.
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Old 01-13-2010, 05:25 PM   #10
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In my latest engine build I bent the hard lines so they were farther away from each other. I then grabbed a random piece of heater hose with a few 90 degree bends (volvo i think) and made a U shaped adapter that is probably three inches long. Its literally the hard line, a short section of 90 degree bend hose, small male to male adapter, another short 90 and the hard line.

The only interference was between this loop and the auto transmission cooling lines. I bent them down slightly and all is good.

edit: Here is a picture

Last edited by ciper; 01-13-2010 at 09:30 PM.
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Old 01-13-2010, 11:33 PM   #11
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I learned this the hard way on my STi track car. If you insist on removing the heater core you must keep the circuit. If you cap it you WILL have problems with the thermostat in certain situations.

We had a dyno rented for the day and we were stuck in the garage trying to get the water temps to stabilize. It was really frustrating. Sometimes you just don't mess with oem systems.
-Paddy
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Old 01-13-2010, 11:59 PM   #12
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Removing the heater core saves you minimal weight while sacrificing any way to defog your windshield. It is one thing to remove the evaporator core and all the associated AC stuff, but removing the heater core for ten pounds is borderline. Race car or not.
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Old 12-19-2010, 04:38 AM   #13
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This thread has gone quiet, so I'm going to hijack it for a bit, on a similar note.

Anyone have any views on disconnecting the water lines to the Throttle body and IAC? It is for a track only car and ambient temps anything from 60 deg F to 100 deg F.

I just want to get rid of hoses if I can.
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Old 01-10-2012, 05:02 PM   #14
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I bypassed the throttle body heater lines and the heater core. I made this fitting to make things a little neater. So there is just one hose going down to the water pump pick up...

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Old 01-16-2012, 09:25 PM   #15
ciper
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Personally I'd bypass the coolant passage on the throttle plate. Its only purpose is to keep the throttle plate from freezing open which could cause you to have no vacuum and if you pumped the brakes you would loose brake assist. In other words its unlikely, even though remotely possible, to kill yourself.

MaxMendez Nice piece
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