radiator caps, cooling system pressure

On 04/22/2013 02:50 PM, Ashton Crusher wrote:
> On Mon, 22 Apr 2013 08:57:20 -0700 (PDT), harry
> > wrote:
>
>> Thoughts?????
>>
>> One other possibility is you may have a blown head gasket.
>
> I didn't want to make the original post into a novel but it appears a
> lot is being read into what wasn't included. That car is not having
> any problems at all right now. I'm just looking at increasing the
> factor of safety against overheating because I just added AC to it.
> Non-ac cars use a 7 pound cap and AC uses 13. But it's a 52 year old
> car (well maintained) and the downside would be if adding 6 pounds
> more pressure is likely to create any leaks, like in the 52 year old
> heater core. Nothing leaks now. I'm just torn between being
> proactive and getting a higher pressure cap "just in case", or just
> sitting tight and seeing how the temperatures run as the weather heats
> up.
>

Like I said in a previous post, a coolant recovery bottle would be my
first step... I never did like seeing that air gap at the top of the
radiator, and it's not good for anything to have it there.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Mon, 22 Apr 2013 11:42:25 -0700, Ashton Crusher >
wrote:

>On Mon, 22 Apr 2013 05:29:32 -0700 (PDT), "
> wrote:
>
>>On Apr 21, 11:15*pm, wrote:
>>> On Sun, 21 Apr 2013 18:50:29 -0700 (PDT), "
>>>
>>>
>>>
>>>
>>>
>>> > wrote:
>>> >On Apr 21, 6:11*pm, Tony Hwang > wrote:
>>> >> Ashton Crusher wrote:
>>> >> > I was thinking of putting a higher pressure cap on one of my cars to
>>> >> > increase the factor of safety against boiling. *Looking thru the web
>>> >> > for info on the likelihood of changing from 7 psi to 13 psi causing
>>> >> > leaks I found little on that issue but did find a couple references to
>>> >> > the pressures created by the water pump. *One site boasts of a 19 PSI,
>>> >> > $25 cap to get you thru your "hard driving".
>>> >> >http://www.mishimoto.com/mishimoto-h...tor-cap-13-bar....
>>> >> > Thought I'd see if anyone else has heard of this. *The claim was that
>>> >> > the water pump could create over 30 PSI of pressure. *Since that is
>>> >> > double the normal operating pressure of most modern cars I find it
>>> >> > hard to believe. *If the system was at full 15 psi of pressure while
>>> >> > the car is idling and then your floored it and ran it up to near
>>> >> > redline * and created another 30psi of additional pump pressure, or
>>> >> > even 10 psi of additioingnal pressure downstream at the radiator cap, you
>>> >> > would immediately cause the system to have to vent to the overflow to
>>> >> > relieve this higher pressure. * I've never seen a car vent due to me
>>> >> > revving the engine up while I'm working on it. Thoughts?????
>>>
>>> >> Hi.
>>> >> There is a over flow bottle for coolant/anti-freeze. Ever
>>> >> cleaned/flushed your rad. and maintain proper level of
>>> >> coolant/anti-freeze in your rad.? If the car is old, messing with cap
>>> >> can spring
>>> >> a leak.- Hide quoted text -
>>>
>>> >> - Show quoted text -
>>>
>>> >AMEN!
>>>
>>> *A water pump cannot produce system pressure because it just moves
>>> water from one side of the pump to the other. Expansion due to heat is
>>> what builds pressure..- Hide quoted text -
>>>
>>> - Show quoted text -
>>
>>You might want to rethink that one. Water isn't going to
>>move through a system without pressure to push it. I wouldn't
>>expect the pressure to be very high, but there has to be pressure
>>due to the pump.
>>
>>As for the question at hand, what is unstated is if there is
>>actually a problem, ie is the car overheating? If it is, then
>>finding out the cause of that instead of trying to raise the
>>boiling point of the coolant via pressure would seem to be
>>the better approach. For example, if he has a bad thermostat
>>or collapsing hose, he'd be just covering up the real problem.
>
>No, the car is not overheating. It's never overheated. What happened
>is that I installed an AC unit in this 60 Dodge. That has made it run
>about 10 degrees hotter then it used to, mainly from just having the
>condenser there in front of the radiator. So I was thinking about
>whether it would be a good idea to go to a 13 pound cap instead of the
>7 pound one on it. Just to give a bigger margin of safety when the
>temps here get up to 110. The manual for the car lists the 7 pound
>cap for non-ac cars and the 13 pound cap for AC cars. Just curious if
>anyone has ever seen this increase in pressure cause an immediate leak
>to happen. The Radiator was rebuilt 10 years/10,000 miles ago. The
>heater core is factory original. Now, on a 95 degree day it's running
>up to 205 on the freeway and 195 around town. Thermostat is 180.

That should mean the thermostat is wide open. But the thermostat
could be broken. You can replace it, or hang this one into a pot of
water whose temp is climing. Use a candy thermometer or something
that goes up to 190 to see if the thermostat opens all the way at 180.

I've only done this once, and I don't remember how sure I was that it
was open, or not open, all the way. That is, I didn't know where all
the way was, in practical terms.

Maybe you need a trailer package. Well, just the bigger radiator.

Plus what Dave L said.

Heater cores in many many cars are a pain to replace. Lots of things
on top of them, including parts of your recently added AC, which iiuc
doesn't use rubber hoses, uses metal hoses. Am I right about that?

On Mon, 22 Apr 2013 11:50:28 -0700, Ashton Crusher >
wrote:

>On Mon, 22 Apr 2013 08:57:20 -0700 (PDT), harry
> wrote:
>
>>Thoughts?????
>>
>>One other possibility is you may have a blown head gasket.
>
>I didn't want to make the original post into a novel but it appears a

Making a big mistake. I've already shopped it to a publicsher, and
he's discussed it with a NY producer. Since you hadn't even though
of it, I'll take 17 percent. Contact me at Telex;723345.

>lot is being read into what wasn't included. That car is not having
>any problems at all right now. I'm just looking at increasing the
>factor of safety against overheating because I just added AC to it.

Your conflating over-pressure with over-heating. Containing the
pressure won't make it cooler.

>Non-ac cars use a 7 pound cap and AC uses 13. But it's a 52 year old
>car (well maintained) and the downside would be if adding 6 pounds
>more pressure is likely to create any leaks, like in the 52 year old
>heater core. Nothing leaks now. I'm just torn between being
>proactive and getting a higher pressure cap "just in case", or just
>sitting tight and seeing how the temperatures run as the weather heats
>up.

On Apr 25, 4:45*pm, micky > wrote:
> On Mon, 22 Apr 2013 11:50:28 -0700, Ashton Crusher >
> wrote:
>
> >On Mon, 22 Apr 2013 08:57:20 -0700 (PDT), harry
> > wrote:
>
> >>Thoughts?????
>
> >>One other possibility is you may have a blown head gasket.
>
> >I didn't want to make the original post into a novel but it appears a
>
> Making a big mistake. *I've already shopped it to a publicsher, and
> he's discussed it with a NY producer. * Since you hadn't even though
> of it, I'll take 17 percent. * Contact me at Telex;723345.
>
> >lot is being read into what wasn't included. *That car is not having
> >any problems at all right now. *I'm just looking at increasing the
> >factor of safety against overheating because I just added AC to it.
>
> Your conflating over-pressure with over-heating. * Containing the
> pressure won't make it cooler.
>
>
>
> >Non-ac cars use a 7 pound cap and AC uses 13. *But it's a 52 year old
> >car (well maintained) and the downside would be if adding 6 pounds
> >more pressure is likely to create any leaks, like in the 52 year old
> >heater core. *Nothing leaks now. *I'm just torn between being
> >proactive and getting a higher pressure cap "just in case", or just
> >sitting tight and seeing how the temperatures run as the weather heats
> >up.

adding a transmission oil cooler is probaly a good idea with a
transmission oil filter in series it might save a expensive
transmission rebuid someday

On Thu, 25 Apr 2013 16:38:42 -0400, micky >
wrote:

>On Mon, 22 Apr 2013 11:42:25 -0700, Ashton Crusher >
>wrote:
>
>>On Mon, 22 Apr 2013 05:29:32 -0700 (PDT), "
> wrote:
>>
>>>On Apr 21, 11:15*pm, wrote:
>>>> On Sun, 21 Apr 2013 18:50:29 -0700 (PDT), "
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> > wrote:
>>>> >On Apr 21, 6:11*pm, Tony Hwang > wrote:
>>>> >> Ashton Crusher wrote:
>>>> >> > I was thinking of putting a higher pressure cap on one of my cars to
>>>> >> > increase the factor of safety against boiling. *Looking thru the web
>>>> >> > for info on the likelihood of changing from 7 psi to 13 psi causing
>>>> >> > leaks I found little on that issue but did find a couple references to
>>>> >> > the pressures created by the water pump. *One site boasts of a 19 PSI,
>>>> >> > $25 cap to get you thru your "hard driving".
>>>> >> >http://www.mishimoto.com/mishimoto-h...tor-cap-13-bar....
>>>> >> > Thought I'd see if anyone else has heard of this. *The claim was that
>>>> >> > the water pump could create over 30 PSI of pressure. *Since that is
>>>> >> > double the normal operating pressure of most modern cars I find it
>>>> >> > hard to believe. *If the system was at full 15 psi of pressure while
>>>> >> > the car is idling and then your floored it and ran it up to near
>>>> >> > redline * and created another 30psi of additional pump pressure, or
>>>> >> > even 10 psi of additioingnal pressure downstream at the radiator cap, you
>>>> >> > would immediately cause the system to have to vent to the overflow to
>>>> >> > relieve this higher pressure. * I've never seen a car vent due to me
>>>> >> > revving the engine up while I'm working on it. Thoughts?????
>>>>
>>>> >> Hi.
>>>> >> There is a over flow bottle for coolant/anti-freeze. Ever
>>>> >> cleaned/flushed your rad. and maintain proper level of
>>>> >> coolant/anti-freeze in your rad.? If the car is old, messing with cap
>>>> >> can spring
>>>> >> a leak.- Hide quoted text -
>>>>
>>>> >> - Show quoted text -
>>>>
>>>> >AMEN!
>>>>
>>>> *A water pump cannot produce system pressure because it just moves
>>>> water from one side of the pump to the other. Expansion due to heat is
>>>> what builds pressure..- Hide quoted text -
>>>>
>>>> - Show quoted text -
>>>
>>>You might want to rethink that one. Water isn't going to
>>>move through a system without pressure to push it. I wouldn't
>>>expect the pressure to be very high, but there has to be pressure
>>>due to the pump.
>>>
>>>As for the question at hand, what is unstated is if there is
>>>actually a problem, ie is the car overheating? If it is, then
>>>finding out the cause of that instead of trying to raise the
>>>boiling point of the coolant via pressure would seem to be
>>>the better approach. For example, if he has a bad thermostat
>>>or collapsing hose, he'd be just covering up the real problem.
>>
>>No, the car is not overheating. It's never overheated. What happened
>>is that I installed an AC unit in this 60 Dodge. That has made it run
>>about 10 degrees hotter then it used to, mainly from just having the
>>condenser there in front of the radiator. So I was thinking about
>>whether it would be a good idea to go to a 13 pound cap instead of the
>>7 pound one on it. Just to give a bigger margin of safety when the
>>temps here get up to 110. The manual for the car lists the 7 pound
>>cap for non-ac cars and the 13 pound cap for AC cars. Just curious if
>>anyone has ever seen this increase in pressure cause an immediate leak
>>to happen. The Radiator was rebuilt 10 years/10,000 miles ago. The
>>heater core is factory original. Now, on a 95 degree day it's running
>>up to 205 on the freeway and 195 around town. Thermostat is 180.
>
>That should mean the thermostat is wide open. But the thermostat
>could be broken. You can replace it, or hang this one into a pot of
>water whose temp is climing. Use a candy thermometer or something
>that goes up to 190 to see if the thermostat opens all the way at 180.
>

I've checked it (with infrared thermo gun) quite a few times even
before putting the AC on it and it seems that the car, in cool
weather, runs up to 180 and stays there as it should with a 180
thermo. In hotter weather it would go up to around 190-195 on the
freeway. Now with the AC it's added about 10 degrees but still has a
lower plateau at 180.


>I've only done this once, and I don't remember how sure I was that it
>was open, or not open, all the way. That is, I didn't know where all
>the way was, in practical terms.
>

I've checked several and a few were bad and would only open about 1/8
inch. Good ones open maybe half an inch.

>Maybe you need a trailer package. Well, just the bigger radiator.
>
>Plus what Dave L said.
>
>Heater cores in many many cars are a pain to replace. Lots of things
>on top of them, including parts of your recently added AC, which iiuc
>doesn't use rubber hoses, uses metal hoses. Am I right about that?


Since this is an added ac it won't interfere much with the original
heater. Here in AZ it's not unusual for bad heater cores to just be
bypassed :-)

On Tue, 23 Apr 2013 18:26:08 -0400, Nate Nagel >
wrote:

>On 04/22/2013 02:50 PM, Ashton Crusher wrote:
>> On Mon, 22 Apr 2013 08:57:20 -0700 (PDT), harry
>> > wrote:
>>
>>> Thoughts?????
>>>
>>> One other possibility is you may have a blown head gasket.
>>
>> I didn't want to make the original post into a novel but it appears a
>> lot is being read into what wasn't included. That car is not having
>> any problems at all right now. I'm just looking at increasing the
>> factor of safety against overheating because I just added AC to it.
>> Non-ac cars use a 7 pound cap and AC uses 13. But it's a 52 year old
>> car (well maintained) and the downside would be if adding 6 pounds
>> more pressure is likely to create any leaks, like in the 52 year old
>> heater core. Nothing leaks now. I'm just torn between being
>> proactive and getting a higher pressure cap "just in case", or just
>> sitting tight and seeing how the temperatures run as the weather heats
>> up.
>>
>
>Like I said in a previous post, a coolant recovery bottle would be my
>first step... I never did like seeing that air gap at the top of the
>radiator, and it's not good for anything to have it there.
>
>nate


Prior owner put one on it and it seems to be working correctly.

On Thu, 25 Apr 2013 18:02:36 -0700, Ashton Crusher >
wrote:

>
>>Heater cores in many many cars are a pain to replace. Lots of things
>>on top of them, including parts of your recently added AC, which iiuc
>>doesn't use rubber hoses, uses metal hoses. Am I right about that?
>
>
>Since this is an added ac it won't interfere much with the original
>heater. Here in AZ it's not unusual for bad heater cores to just be
>bypassed :-)

I did that once. I had a leak, a hose spraying iirc, just as we
arrived outside some Federal building, not a museum, just south of the
Mall in DC. My friend's girfriend worked there and we were picking
her up at the end of the day. She took me down to the engineer's room
and he gave me a piece of pipe 2 or 3" long. Now I probably
couldn't get into the building even if I needed blood.

> wrote in message
...
> On Sun, 21 Apr 2013 18:50:29 -0700 (PDT), "
> > wrote:
>
>>On Apr 21, 6:11 pm, Tony Hwang > wrote:
>>> Ashton Crusher wrote:
>>> > I was thinking of putting a higher pressure cap on one of my cars to
>>> > increase the factor of safety against boiling. Looking thru the web
>>> > for info on the likelihood of changing from 7 psi to 13 psi causing
>>> > leaks I found little on that issue but did find a couple references to
>>> > the pressures created by the water pump. One site boasts of a 19 PSI,
>>> > $25 cap to get you thru your "hard driving".
>>> >http://www.mishimoto.com/mishimoto-h...tor-cap-13-bar....
>>> > Thought I'd see if anyone else has heard of this. The claim was that
>>> > the water pump could create over 30 PSI of pressure. Since that is
>>> > double the normal operating pressure of most modern cars I find it
>>> > hard to believe. If the system was at full 15 psi of pressure while
>>> > the car is idling and then your floored it and ran it up to near
>>> > redline and created another 30psi of additional pump pressure, or
>>> > even 10 psi of additioingnal pressure downstream at the radiator cap,
>>> > you
>>> > would immediately cause the system to have to vent to the overflow to
>>> > relieve this higher pressure. I've never seen a car vent due to me
>>> > revving the engine up while I'm working on it. Thoughts?????
>>>
>>> Hi.
>>> There is a over flow bottle for coolant/anti-freeze. Ever
>>> cleaned/flushed your rad. and maintain proper level of
>>> coolant/anti-freeze in your rad.? If the car is old, messing with cap
>>> can spring
>>> a leak.- Hide quoted text -
>>>
>>> - Show quoted text -
>>
>>AMEN!
> A water pump cannot produce system pressure because it just moves
> water from one side of the pump to the other. Expansion due to heat is
> what builds pressure..

I guess you need to know how a centrifugal pump works. Pressure rise
across the pump is function of the square of its speed. Double the pump
speed and the delta P across the pump increases 4X. Expansion due to heat
will increase system pressure if it is in a closed system. If a fluid can
expand without being constrained---no significant change in pressure.
MLD

MLD wrote:
>
> > wrote in message
> ...
>> On Sun, 21 Apr 2013 18:50:29 -0700 (PDT), "
>> > wrote:
>>
>>> On Apr 21, 6:11 pm, Tony Hwang > wrote:
>>>> Ashton Crusher wrote:
>>>> > I was thinking of putting a higher pressure cap on one of my cars to
>>>> > increase the factor of safety against boiling. Looking thru the web
>>>> > for info on the likelihood of changing from 7 psi to 13 psi causing
>>>> > leaks I found little on that issue but did find a couple
>>>> references to
>>>> > the pressures created by the water pump. One site boasts of a 19 PSI,
>>>> > $25 cap to get you thru your "hard driving".
>>>> >http://www.mishimoto.com/mishimoto-h...tor-cap-13-bar....
>>>>
>>>> > Thought I'd see if anyone else has heard of this. The claim was that
>>>> > the water pump could create over 30 PSI of pressure. Since that is
>>>> > double the normal operating pressure of most modern cars I find it
>>>> > hard to believe. If the system was at full 15 psi of pressure while
>>>> > the car is idling and then your floored it and ran it up to near
>>>> > redline and created another 30psi of additional pump pressure, or
>>>> > even 10 psi of additioingnal pressure downstream at the radiator
>>>> cap, > you
>>>> > would immediately cause the system to have to vent to the overflow to
>>>> > relieve this higher pressure. I've never seen a car vent due to me
>>>> > revving the engine up while I'm working on it. Thoughts?????
>>>>
>>>> Hi.
>>>> There is a over flow bottle for coolant/anti-freeze. Ever
>>>> cleaned/flushed your rad. and maintain proper level of
>>>> coolant/anti-freeze in your rad.? If the car is old, messing with cap
>>>> can spring
>>>> a leak.- Hide quoted text -
>>>>
>>>> - Show quoted text -
>>>
>>> AMEN!
>> A water pump cannot produce system pressure because it just moves
>> water from one side of the pump to the other. Expansion due to heat is
>> what builds pressure..
>
> I guess you need to know how a centrifugal pump works. Pressure rise
> across the pump is function of the square of its speed. Double the pump
> speed and the delta P across the pump increases 4X. Expansion due to
> heat will increase system pressure if it is in a closed system. If a
> fluid can expand without being constrained---no significant change in
> pressure.
> MLD
>
Hi,
It would also matter how hot the water already is.
How old is the car? Is the rad fan. electric?
Thermo. clutch driven with belt?
Or real old car with straight belt driven? No water temp.
gauge on the dash?(very good idea to have one)

"MLD" > wrote in message ...
>
> > wrote in message
> ...
> > On Sun, 21 Apr 2013 18:50:29 -0700 (PDT), "
> > > wrote:
> >
> >>On Apr 21, 6:11 pm, Tony Hwang > wrote:
> >>> Ashton Crusher wrote:
> >>> > I was thinking of putting a higher pressure cap on one of my cars to
> >>> > increase the factor of safety against boiling. Looking thru the web
> >>> > for info on the likelihood of changing from 7 psi to 13 psi causing
> >>> > leaks I found little on that issue but did find a couple references to
> >>> > the pressures created by the water pump. One site boasts of a 19 PSI,
> >>> > $25 cap to get you thru your "hard driving".
> >>> >http://www.mishimoto.com/mishimoto-h...tor-cap-13-bar....
> >>> > Thought I'd see if anyone else has heard of this. The claim was that
> >>> > the water pump could create over 30 PSI of pressure. Since that is
> >>> > double the normal operating pressure of most modern cars I find it
> >>> > hard to believe. If the system was at full 15 psi of pressure while
> >>> > the car is idling and then your floored it and ran it up to near
> >>> > redline and created another 30psi of additional pump pressure, or
> >>> > even 10 psi of additioingnal pressure downstream at the radiator cap,
> >>> > you
> >>> > would immediately cause the system to have to vent to the overflow to
> >>> > relieve this higher pressure. I've never seen a car vent due to me
> >>> > revving the engine up while I'm working on it. Thoughts?????
> >>>
> >>> Hi.
> >>> There is a over flow bottle for coolant/anti-freeze. Ever
> >>> cleaned/flushed your rad. and maintain proper level of
> >>> coolant/anti-freeze in your rad.? If the car is old, messing with cap
> >>> can spring
> >>> a leak.- Hide quoted text -
> >>>
> >>> - Show quoted text -
> >>
> >>AMEN!
> > A water pump cannot produce system pressure because it just moves
> > water from one side of the pump to the other. Expansion due to heat is
> > what builds pressure..
>
> I guess you need to know how a centrifugal pump works. Pressure rise
> across the pump is function of the square of its speed. Double the pump
> speed and the delta P across the pump increases 4X. Expansion due to heat
> will increase system pressure if it is in a closed system. If a fluid can
> expand without being constrained---no significant change in pressure.
> MLD

Well, I give each of you half credit. LOL! At a certain RPM, the pump head (outlet-inlet pressure) and flow rate are both are fairly indept of the coolant temperature as long as the coolant stays a liquid (normal condition) when going through the pump. The engine heat raises the coolant temperature and the pressure (remember this from skool... PV=nRT), but (and this is a big butt) as long as the pump turns at the same RPM, the head should stay about the same.

FWIW, here's a decent drawing of a water pump cross-section
http://assets.hemmings.com/story_image/83720-500-0.jpg