Sh0velMan's Track Car Build

Sh0velMan · 03-29-2013, 11:31 AM

Oh, bad news gents, looks like we can't simply delete that hard pipe all together, because beneath the larger heater pipe part of it is the bypass loop. The heater core flow + that bypass flow is how the engine cools itself when the t-stat is closed.

This gets more and more annoying the more I learn about it.

SPOHN · 03-29-2013, 12:27 PM

I'd just like to cut a good bit of it out and install some heater hose so it will flex when I'm working in the area. Butt that might not be good when I get my turbo kit later this year.

Sh0velMan · 03-29-2013, 01:19 PM

Quote:

Originally Posted by SPOHN

Butt that might not be good when I get my turbo kit later this year.

Kingbaby · 03-29-2013, 03:23 PM

Quote:

Originally Posted by Sh0velMan

This gets more and more annoying the more I learn about it.

The joys of DIY...

in for more, and thanks for the pics. I'm sure others appreciate the visual insight!

wstar · 03-30-2013, 08:58 AM

It seems like one should be able to do this (note 4x red lines where you'd block things off, and 1x blue arrow showing a change of direction from the original diagram):

But in practice some of those spots are hard to block off reliably. I think where the stupid double metal pipe enters the side it's actually a female opening on the head, right? But maybe a cut down version of the stock fitting, and then cap it off an inch or two later.

Sh0velMan · 03-30-2013, 09:31 AM

If you were to do what you suggest in the diagram, your engine would last about... 3 minutes?

With those lines blocked off, there is no flow unless the T-Stat is open. That's the purpose of the secondary line back there in addition to the heater line, together they add up to the same flow as the hose going to the radiator.

Once the T-Stat opens, most of the flow will go through the radiator rather than those secondary lines, but until then, that's the engine's life line.

Make sense?

Quote:

Originally Posted by wstar

It seems like one should be able to do this (note 4x red lines where you'd block things off, and 1x blue arrow showing a change of direction from the original diagram):

But in practice some of those spots are hard to block off reliably. I think where the stupid double metal pipe enters the side it's actually a female opening on the head, right? But maybe a cut down version of the stock fitting, and then cap it off an inch or two later.

Mr&Mrs · 03-30-2013, 03:22 PM

Can we not run without the T-Stat in these cars?

wstar · 03-30-2013, 10:50 PM

I guess I need to read more, but I don't see how the thermostat really affects any of this much. The inner metal line on the driver's side (the short external loopback on the right of the diagram) could be necessary when the T-stat is closed, maybe, but the rest I wouldn't think. The throttle body lines are too small diameter to matter much, so we can pretty much ignore those. The flow through the heater core would normally be blocked off anyways (when the heater is off).

If anything, I worry about negative effects from putting a straight bypass in place of the heater core. By doing that, your coolant flow is now permanently in "the heater is on" mode, which allows a certain amount of flow to skip the radiator by circulating through the heater core line (which flows even better than it did before - no complex routing, just your bypass hose).

What horrible thing would happen if all the red lines in my diagram were blocked off and the T-stat wasn't open (yet)? I mean, the engine's cold then anyways, is it just that the water can't flow (within the engine) at all?

wstar · 03-30-2013, 11:13 PM

Another pic from the SM that's relevant:

I think at least it should be possible (perhaps even superior) to block off the 4x outlets labeled B (2x heater core), D (throttle), A (says "EVAP piping", but it's the other side of the throttle stuff, I traced it myself a long time ago).

You could truly seal off (like, weld shut) the two extraneous nipples on that rear water outlet assembly (the ones with hose clamps numbered 6 and 1). Then on the driver's side you could permanently plug the upper hole of where Gasket #15 is. It's the bottom hole in gasket 15 taking in bypass water from that #19 bypass pipe that seems like it could still be necessary, maybe...

wstar · 03-30-2013, 11:37 PM

Oh, I was wrong about the heater flow being cut off when the heater's off. I guess I'm used to looking at this on older cars. When I looked through the related bits of our service manual, it appears that coolant always flows through our heater core even when you're not using the heater, and the blowers and air mix doors and whatnot just control whether air is blown over it into the interior or not.

Sh0velMan · 03-31-2013, 12:06 AM

Quote:

Originally Posted by wstar

Another pic from the SM that's relevant:

I think at least it should be possible (perhaps even superior) to block off the 4x outlets labeled B (2x heater core), D (throttle), A (says "EVAP piping", but it's the other side of the throttle stuff, I traced it myself a long time ago).

You could truly seal off (like, weld shut) the two extraneous nipples on that rear water outlet assembly (the ones with hose clamps numbered 6 and 1). Then on the driver's side you could permanently plug the upper hole of where Gasket #15 is. It's the bottom hole in gasket 15 taking in bypass water from that #19 bypass pipe that seems like it could still be necessary, maybe...

Yeah the metal pipe(s) have an upper and lower. One comes back from the heater core, the other is the bypass directly from the coolant manifold on the back of the engine.

Block those tubes off, there's no flow through the pump AT ALL until the t-stat opens. Which it really won't, before the engine fails.

(And yeah, I was PRETTY sure that coolant was ALWAYS going through the core, but thanks for confirming it.)

Sh0velMan · 03-31-2013, 12:09 AM

Got rid of all the deadening from the rear passenger bulkhead forward.

Not going to mess with the stuff rearward of that. Not worth the work.

Tested some paint on the driver's side. Going to pick up some more tomorrow to paint over the sections I removed the deadening from.

Sh0velMan · 03-31-2013, 05:36 PM

Got the paint laid down over the ruin that is my floorpans.

Removed a few pounds of deadening, made the car look more rugged... At least that's what I'm telling myself.

One day I may get a bug up my *** to clean it up, acetone takes paint and tar off easily, just requires patience, which I don't have time for ATM.

Anyway, pics attached. Tomorrow morning I put the crash bar back in, sort out the harnesses for the trip to the cage builder next weekend, then the two week wait.

Also took delivery of a few goodies, my 6pt Camlock harness and mounting hardware, as well as a set of race ramps to facilitate getting to the center-front jacking point more easily.

Rest of the seat brackets should come in this week as well... Man I'm worn out.. I think I mighta done some damage to my left hand holding the chisel yesterday.. it's all tingly and **** today.

SPOHN · 03-31-2013, 06:16 PM

Quote:

Originally Posted by Sh0velMan

I mighta done some damage to my left hand holding the chisel yesterday.. it's all tingly and **** today.

Blame it on the chisel.

Sh0velMan · 04-01-2013, 09:33 PM

All done... meeting with the builder tomorrow and dropping the car off this Saturday.

I trimmed a bunch of bracketry off of the crash bar. Probably not putting the dash back into the car...

03-29-2013, 11:31 AM	#151 (permalink)
Sh0velMan A True Z Fanatic Join Date: Jan 2012 Location: Dallas/Ft.Worth Posts: 3,349 Drives: Noisily. Rep Power: 20	Oh, bad news gents, looks like we can't simply delete that hard pipe all together, because beneath the larger heater pipe part of it is the bypass loop. The heater core flow + that bypass flow is how the engine cools itself when the t-stat is closed. This gets more and more annoying the more I learn about it. __________________ Buy My Car! \| Build Thread

03-29-2013, 12:27 PM	#152 (permalink)
SPOHN A True Z Fanatic Join Date: Feb 2010 Location: Covington, GA Age: 45 Posts: 14,844 Drives: Waiting on next Z Rep Power: 221	I'd just like to cut a good bit of it out and install some heater hose so it will flex when I'm working in the area. Butt that might not be good when I get my turbo kit later this year. __________________

03-30-2013, 08:58 AM	#155 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3594	It seems like one should be able to do this (note 4x red lines where you'd block things off, and 1x blue arrow showing a change of direction from the original diagram): But in practice some of those spots are hard to block off reliably. I think where the stupid double metal pipe enters the side it's actually a female opening on the head, right? But maybe a cut down version of the stock fitting, and then cap it off an inch or two later. __________________ 7AT Track Car! Journal thread / Car setup details

03-30-2013, 03:22 PM	#157 (permalink)
Mr&Mrs A True Z Fanatic Join Date: May 2010 Location: Tampa Posts: 4,192 Drives: RZ34 Rep Power: 15161	Can we not run without the T-Stat in these cars? __________________ Project Z <--Click - Check out the link too many mods to list!

03-30-2013, 10:50 PM	#158 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3594	I guess I need to read more, but I don't see how the thermostat really affects any of this much. The inner metal line on the driver's side (the short external loopback on the right of the diagram) could be necessary when the T-stat is closed, maybe, but the rest I wouldn't think. The throttle body lines are too small diameter to matter much, so we can pretty much ignore those. The flow through the heater core would normally be blocked off anyways (when the heater is off). If anything, I worry about negative effects from putting a straight bypass in place of the heater core. By doing that, your coolant flow is now permanently in "the heater is on" mode, which allows a certain amount of flow to skip the radiator by circulating through the heater core line (which flows even better than it did before - no complex routing, just your bypass hose). What horrible thing would happen if all the red lines in my diagram were blocked off and the T-stat wasn't open (yet)? I mean, the engine's cold then anyways, is it just that the water can't flow (within the engine) at all? __________________ 7AT Track Car! Journal thread / Car setup details

03-30-2013, 11:13 PM	#159 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3594	Another pic from the SM that's relevant: I think at least it should be possible (perhaps even superior) to block off the 4x outlets labeled B (2x heater core), D (throttle), A (says "EVAP piping", but it's the other side of the throttle stuff, I traced it myself a long time ago). You could truly seal off (like, weld shut) the two extraneous nipples on that rear water outlet assembly (the ones with hose clamps numbered 6 and 1). Then on the driver's side you could permanently plug the upper hole of where Gasket #15 is. It's the bottom hole in gasket 15 taking in bypass water from that #19 bypass pipe that seems like it could still be necessary, maybe... __________________ 7AT Track Car! Journal thread / Car setup details

03-30-2013, 11:37 PM	#160 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3594	Oh, I was wrong about the heater flow being cut off when the heater's off. I guess I'm used to looking at this on older cars. When I looked through the related bits of our service manual, it appears that coolant always flows through our heater core even when you're not using the heater, and the blowers and air mix doors and whatnot just control whether air is blown over it into the interior or not. __________________ 7AT Track Car! Journal thread / Car setup details

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