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Awfully long time to get oil pressure.

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J.P.Rap Avatar
J.P.Rap J.P. Rap
Mount Hope, ON, Canada   CAN
1976 Triumph 1500 "Donna"
2007 Ford Ranger
Carter, perhaps I misunderstood your point but I have to disagree, at least partially, with your statement that the T stat is inconsequential once the engine reaches operating temp. It does in fact aid in maintaining a stable temperature. The stat does actually "operate" while driving. That operation will depend on driving conditions. In some cases it will close completely and in others, partially. In either case, the reduction in flow allows the coolant to stay in the rad longer, thus cooling it more efficiently. If you doubt that, remove your T stat and see how far you can drive on a hot day before you over heat. (BTDT) While I agree, replacing it with a washer will work under some conditions, it does little to "regulate" the temperature. In a properly functioning system, a thermostat does a very nice job of it.
Cheers



"In this world, you must be oh so smart, or oh so pleasant. Well, for years I was smart. I recommend pleasant." Elwood P. Dowd

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TheZster Avatar
TheZster Steven Z
SAINT LOUIS, MO, USA   USA
1978 Triumph 1500 "BLK-BRY"
In reply to # 1532877 by J.P.Rap Carter, perhaps I misunderstood your point but I have to disagree, at least partially, with your statement that the T stat is inconsequential once the engine reaches operating temp. It does in fact aid in maintaining a stable temperature. The stat does actually "operate" while driving. That operation will depend on driving conditions. In some cases it will close completely and in others, partially. In either case, the reduction in flow allows the coolant to stay in the rad longer, thus cooling it more efficiently. If you doubt that, remove your T stat and see how far you can drive on a hot day before you over heat. (BTDT) While I agree, replacing it with a washer will work under some conditions, it does little to "regulate" the temperature. In a properly functioning system, a thermostat does a very nice job of it.
Cheers

And I have to ask: Per Carter: "Below operating temp the thermostat stays closed and water recirculates through the block" I don't seem to have a recirculation loop in my thermostat housing nor water pump.....?? I was under the impression the water stays in the block until the thermostat opens.... Water pump is a impeller type that allows it to spin without moving water if the flow is blocked.....

I might be missing something....

Z

clshore Carter Shore
Beverly Hills, FL, USA   USA
In reply to # 1532887 by TheZster ...
And I have to ask: Per Carter: "Below operating temp the thermostat stays closed and water recirculates through the block" I don't seem to have a recirculation loop in my thermostat housing nor water pump.....?? I was under the impression the water stays in the block until the thermostat opens.... Water pump is a impeller type that allows it to spin without moving water if the flow is blocked.....

I might be missing something....

Z

Sorry, but you are missing something.

The common wax element auto thermostat is over 80 years old, and it's operating principles and basic design have changed little.

https://en.wikipedia.org/wiki/Wax_thermostatic_element

The bypass is built into the system, it allows some coolant to circulate and return to the motor when the tstat is closed.
The details of how each cooling system is designed and implemented differ in detail

But if the heated coolant never circulated and touched the tstat, it would take a long time for it open, yes?
And the cabin heater would not function until it opened, yes?
And the intake manifold would never be warmed to help with cold starting and to prevent icing, yes?

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clshore Carter Shore
Beverly Hills, FL, USA   USA
In reply to # 1532877 by J.P.Rap Carter, perhaps I misunderstood your point but I have to disagree, at least partially, with your statement that the T stat is inconsequential once the engine reaches operating temp. It does in fact aid in maintaining a stable temperature. The stat does actually "operate" while driving. That operation will depend on driving conditions. In some cases it will close completely and in others, partially. In either case, the reduction in flow allows the coolant to stay in the rad longer, thus cooling it more efficiently. If you doubt that, remove your T stat and see how far you can drive on a hot day before you over heat. (BTDT) While I agree, replacing it with a washer will work under some conditions, it does little to "regulate" the temperature. In a properly functioning system, a thermostat does a very nice job of it.
Cheers

Actually, removing the thermostat is very commonly done, with no overheating on most cars.
There are some where the restriction of the thermostat affects the flow, and so for those a dummy stat, a blanking washer with a hole in the middle is fitted.
It's one of the first things racers do, since the motors are carefully warmed before going on track.
I've removed thermostats from dozens of different cars, from Ramblers to Impalas to Pintos to Camaros, no overheating, even in Miami summers.
And while it's true that there is an operating band between fully closed and fully open where flow is only partially blocked, any blockage raises the coolant temperature.
A thermostat can never lower the coolant temperature, only reduce the flow through the radiator, which raises the coolant temperature by reducing the amount of heat transferred to the air.

TheZster Avatar
TheZster Steven Z
SAINT LOUIS, MO, USA   USA
1978 Triumph 1500 "BLK-BRY"
Sorry, but you are missing something.

The common wax element auto thermostat is over 80 years old, and it's operating principles and basic design have changed little.

https://en.wikipedia.org/wiki/Wax_thermostatic_element

The bypass is built into the system, it allows some coolant to circulate and return to the motor when the tstat is closed.
The details of how each cooling system is designed and implemented differ in detail

But if the heated coolant never circulated and touched the tstat, it would take a long time for it open, yes?
And the cabin heater would not function until it opened, yes?
And the intake manifold would never be warmed to help with cold starting and to prevent icing, yes?
[/quote]

Believe me when I say: You're probably 100% correct (more than probably)....

but: Heated coolant would hit the thermostat - granted, probably after engine reached temp ++ through convection... (the housing isn't very far from the block/head)

With all due respect to the designers... I doubt a couple of minutes at "less or more" than optimum temperature concerned them a whole lot....

Cabin heater comes off the water pump - which is prior to thermostat on the coolant flow - so doesn't matter if it's open or not...

Intake Manifold... same story - second verse..... and both units will function properly at much less than optimum operating temp (ever turn down the heat on your system?)

Long story short... I don't see any "bypass" system between water pump and thermostat.... Might be there... I just don't know where.... I'm familiar with recirculating systems.... though residential houses.... they require a "loop" ..... IMHO... I wouldn't think the quick rise to operating temp of a combustion engine would require a "loop" to ensure coolant recirculated when the thermostat was closed...... Takes what? - a couple of minutes??

Darn you... now I'm going to have to go through my coolant flow to figure it out.... just because!! confused smiley

Late night edit: Almost midnight... but I just had to study my system.... and couldn't find my flashlight... so went by feel......

Coolant flow from water pump to cabin heater to intake manifold .... Or the reverse cause I can't tell if the water pump fitting is on the suction or supply side..... (and wouldn't make much difference) which doesn't flow unless cabin heater valve is turned to "heat".... so.... other than convection... how does the intake manifold heater pick up engine temps? Wouldn't appear to be a part of a "loop"....

More study in daylight.....

Z



Edited 8 time(s). Last edit at 2018-05-13 11:16 PM by TheZster.

spitfire50 Avatar
spitfire50 Paul Mugford
Rochester, N.H., USA   USA
Steven,
Below the thermostat there is a hole that is the bypass.
All the best,
Paul

TheZster Avatar
TheZster Steven Z
SAINT LOUIS, MO, USA   USA
1978 Triumph 1500 "BLK-BRY"
In reply to # 1532934 by spitfire50 Steven,
Below the thermostat there is a hole that is the bypass.
All the best,
Paul

Now "That" clears it all up for me.... Thanks.....

Z

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clshore Carter Shore
Beverly Hills, FL, USA   USA
In reply to # 1532914 by TheZster Sorry, but you are missing something.

The common wax element auto thermostat is over 80 years old, and it's operating principles and basic design have changed little.

https://en.wikipedia.org/wiki/Wax_thermostatic_element

The bypass is built into the system, it allows some coolant to circulate and return to the motor when the tstat is closed.
The details of how each cooling system is designed and implemented differ in detail

But if the heated coolant never circulated and touched the tstat, it would take a long time for it open, yes?
And the cabin heater would not function until it opened, yes?
And the intake manifold would never be warmed to help with cold starting and to prevent icing, yes?

Believe me when I say: You're probably 100% correct (more than probably)....

but: Heated coolant would hit the thermostat - granted, probably after engine reached temp ++ through convection... (the housing isn't very far from the block/head)

With all due respect to the designers... I doubt a couple of minutes at "less or more" than optimum temperature concerned them a whole lot....

Cabin heater comes off the water pump - which is prior to thermostat on the coolant flow - so doesn't matter if it's open or not...

Intake Manifold... same story - second verse..... and both units will function properly at much less than optimum operating temp (ever turn down the heat on your system?)

Long story short... I don't see any "bypass" system between water pump and thermostat.... Might be there... I just don't know where.... I'm familiar with recirculating systems.... though residential houses.... they require a "loop" ..... IMHO... I wouldn't think the quick rise to operating temp of a combustion engine would require a "loop" to ensure coolant recirculated when the thermostat was closed...... Takes what? - a couple of minutes??

Darn you... now I'm going to have to go through my coolant flow to figure it out.... just because!! confused smiley

Late night edit: Almost midnight... but I just had to study my system.... and couldn't find my flashlight... so went by feel......

Coolant flow from water pump to cabin heater to intake manifold .... Or the reverse cause I can't tell if the water pump fitting is on the suction or supply side..... (and wouldn't make much difference) which doesn't flow unless cabin heater valve is turned to "heat".... so.... other than convection... how does the intake manifold heater pick up engine temps? Wouldn't appear to be a part of a "loop"....

More study in daylight.....

Z
[/quote]

I've attached a diagram from the Factory Shop Manual that may help.

Note that there are no coolant ports on the block itself.
All coolant enters/exits the block via ports on the head.
At the front where the waterpump housing attaches, there are two ports, one inlet and one outlet (I'm frankly not sure which is which).

https://rimmerbros.com/Item--i-138702

At the rear is a single outlet port, that supplies the cabin heater.

There are detail differences between the various models, particularly with small hoses and routing, but the basic coolant path above is common to all.

The return from the cabin heater is the steel tube that runs along behind and underneath the intake manifold, and connects to the suction side of the waterpump.
The radiator inlet is directly from the thermostat housing, and thus when closed, coolant only flows through the little safety hole at the edge of the thermostat.
The radiator outlet goes directly to the suction side of the waterpump.

So, thermostat closed, the coolant exits the head via one port into the suction side of the pump, and pressurized coolant returns via the other port into the head.
Obviously there is still some flow through the bypass path even when the thermostat is fully open, but since the basic design remained unchanged for the entire run,
we can assume that the original engineers got their sums right.


Attachments:
SpitfireCoolingSystem.IMG_1117.jpg    30.8 KB
SpitfireCoolingSystem.IMG_1117.jpg

TheZster Avatar
TheZster Steven Z
SAINT LOUIS, MO, USA   USA
1978 Triumph 1500 "BLK-BRY"
In reply to # 1533008 by clshore
In reply to # 1532914 by TheZster Sorry, but you are missing something.

The common wax element auto thermostat is over 80 years old, and it's operating principles and basic design have changed little.

https://en.wikipedia.org/wiki/Wax_thermostatic_element

The bypass is built into the system, it allows some coolant to circulate and return to the motor when the tstat is closed.
The details of how each cooling system is designed and implemented differ in detail

But if the heated coolant never circulated and touched the tstat, it would take a long time for it open, yes?
And the cabin heater would not function until it opened, yes?
And the intake manifold would never be warmed to help with cold starting and to prevent icing, yes?



Thanks Carter... I knew I could count on you to find the answer to my question..... Another day.... another quality lesson......

I do appreciate it.... always learning.... even at this ripe old age of...... (nonya business)... LOL

Z

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J.P.Rap Avatar
J.P.Rap J.P. Rap
Mount Hope, ON, Canada   CAN
1976 Triumph 1500 "Donna"
2007 Ford Ranger
Well, our experience differs.
Ive removed the stat from a car and had it over heat in a very short time. A new stat solved that problem. Ive also had cars with a stuck open stat that never reached operating temperature in the winter. In the latter case (on some engines) the stat can be quite active as the coolant in the rad can cool well below 0 C before entering the block. When that coolant reaches the stat, it closes and allows the block to heat again.
I have no doubt a washer or lack of a stat has worked for you in many cases but it's not a universal fix. To suggest so on a forum that reaches people in all types of environments and driving conditions is just not right...IMHO.
Cheers



"In this world, you must be oh so smart, or oh so pleasant. Well, for years I was smart. I recommend pleasant." Elwood P. Dowd

clshore Carter Shore
Beverly Hills, FL, USA   USA
In reply to # 1533085 by J.P.Rap Well, our experience differs.
Ive removed the stat from a car and had it over heat in a very short time. A new stat solved that problem. Ive also had cars with a stuck open stat that never reached operating temperature in the winter. In the latter case (on some engines) the stat can be quite active as the coolant in the rad can cool well below 0 C before entering the block. When that coolant reaches the stat, it closes and allows the block to heat again.
I have no doubt a washer or lack of a stat has worked for you in many cases but it's not a universal fix. To suggest so on a forum that reaches people in all types of environments and driving conditions is just not right...IMHO.
Cheers

Yes, some cars cooling systems are very sensitive to having the thermostat removed.
Even so, as you say, without one, or stuck open, getting up to normal operating temp can take a long time.
But this is a Spitfire & GT6 Forum, and was the subject under discussion.
Were this a general Forum, I would have qualified my posting more carefully.

paddy1998 Avatar
paddy1998 Scott Delaney
Joliet, IL, USA   USA
(smh) . . .

The things we choose to bicker about . . .

hot smiley

clshore Carter Shore
Beverly Hills, FL, USA   USA
In reply to # 1533387 by paddy1998 (smh) . . .

The things we choose to bicker about . . .

hot smiley

Discussion is the whole point of this site.
To mangle a famous quote, "We are a group of people divided by the ownership of the same cars"

TheZster Avatar
TheZster Steven Z
SAINT LOUIS, MO, USA   USA
1978 Triumph 1500 "BLK-BRY"
In reply to # 1533476 by clshore
In reply to # 1533387 by paddy1998 (smh) . . .

The things we choose to bicker about . . .

hot smiley

Discussion is the whole point of this site.
To mangle a famous quote, "We are a group of people divided by the ownership of the same cars"

Darn it!! I'm getting tired of having to agree with Carter all the time. confused smiley

Z

clshore Carter Shore
Beverly Hills, FL, USA   USA
In reply to # 1533509 by TheZster
In reply to # 1533476 by clshore
In reply to # 1533387 by paddy1998 (smh) . . .

The things we choose to bicker about . . .

hot smiley

Discussion is the whole point of this site.
To mangle a famous quote, "We are a group of people divided by the ownership of the same cars"

Darn it!! I'm getting tired of having to agree with Carter all the time. confused smiley

Z

Hey, let's bicker about that … winking smiley

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