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Twice now I have run out of water. Has this happened to anyone else here? When the water drains out the sensors in the intake don't work.

I wonder if anyone has put an oil pressure sender in there. If a hose or a freeze plug pops the water pressure will drop. Hopefully next time I will see the light or hear the buzzer before I see the steam or hear the clanking of the water pump.

Does this seem like a good design?
 

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That's one think I thought about back in the day, but never implemented.

I can normally tell by sound if my engine is hot or cold or has coolant nor not. But that idea has hit my skullcap a time or two.

Make sure the the pressure gauge reads only from 20 PSI to 0 psi or you'll never move the gauge, most systems don't keep more than a couple PSi in them at any given time. 99% of the time less than 10 PSI I would say.
 

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That's one think I thought about back in the day, but never implemented.

I can normally tell by sound if my engine is hot or cold or has coolant nor not. But that idea has hit my skullcap a time or two.

Make sure the the pressure gauge reads only from 20 PSI to 0 psi or you'll never move the gauge, most systems don't keep more than a couple PSi in them at any given time. 99% of the time less than 10 PSI I would say.
I was thinking of an warning light sender, 3 or 6 psi. How long would it take for the water pressure in the intake to build up so the light would turn off?
 

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If you keep an eye on your gauges you can tell if you are having issues..Using a good mechanical gauge you should see the temp rise during warm up and it should stay steady within a normal operating range..If the guage doesn't move off of cold or when at normal temps suddenly goes way up or down you know you have a problem...If your not the type that keeps an eye on the guages there are gauges with warning lights that come on if the temp or pressure(depending what type of gauge) hits a certain limit...These type gauges are popular with stock car guys who like to keep their eyes on the track..
 

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If you keep an eye on your gauges ...
Ahh, if only I could!

Right now I have a light that warns on hot water, low oil pressure or low brake fluid. I want to add low water pressure, at least. On another bulb, if necessary, I'll put alternator, hi-beams and turn signal.

Haven't figured out how I'll wire the turn signal "on" warning. I'm trying to prevent driving down the highway for miles with a blinker on. Maybe something with a delay in it, like a seal belt buzzer would work.

next year's projects, probably
 

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I wouldn't use a pressure sensor, as low water with a slow leak can keep pressure up (or even over-pressure as it tries to steam). I would add a second temp sender to your first that works 'backwards' so the light glows at both low and high temps. I'll have to do some research for the specific sender required, but I know they're out there. For the turn signal, they make loud ones so you can hear them. BTW - that isn't your water pump you hear clanking on overheat, it's severe detonation.

David
 

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If you're hot on the pressure sensing idea, then I'd just wire a low-pressure (oil pressure) switch in parallel with your water temp switch. That way, if either the water gets too hot, or the pressure drops, the temp light will come on. The light would be on until you had system pressure—about the time you're normally warmed-up. Gauges are a beautiful thing. ;) Any chance you could fix the leak and not worry about it?

David
 

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If you're hot on the pressure sensing idea, then I'd just wire a low-pressure (oil pressure) switch in parallel with your water temp switch. That way, if either the water gets too hot, or the pressure drops, the temp light will come on. The light would be on until you had system pressure—about the time you're normally warmed-up. Gauges are a beautiful thing. ;) Any chance you could fix the leak and not worry about it?

David
Interesting Autogage, with the warning light in it. Why does the PSI go up to 100 though? I thought somewhere around 20, same as the rad cap, would be the maximum.

What I am most worried about David is popping another core plug. I put them in myself, you know:rolleyes:. Jegs sells a 3 psi sensor, how long do you think it would take for the water pressure in the block to get up that high?
 

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Time equals temperature Tom, you need about 4 minutes idling to make about 5 or 6 lbs of pressure, then there's a SPIKE in pressure before the thermostat opens and then things begin to equalize out and run nicely, so maybe 14 minutes to fully open thermostat but a spike in pressure with a drop off due to cool water entering and closing stat again then another small spike then normal OP range.
 

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Verified with own eyes that water flows OUT of the intake and not out of the water pump hose. Then put my trusty vacuum/fuel pump gauge on the intake hose and got only 1psi idling cold at 500. As I ran the rpms up the pressure increased; at 1,000 rpm I had 5 psi. I did not wait to see what happened when it warmed up. Figured Gary knew that, too.

So for my switch I think I will go with Jegs 555-41363, it is adjustable down to .5 psi and should, in theory, not light up when idling but will light up if I blow a heater hose or core plug. I'll wire it with the temperature light per David and that one should light up if the radiator runs out of water.. I'm covered everywhere - now I'll never run out of water again!

JEGS Performance Products 41363 JEGS Gauge Kits with Flat Panel and Warning Lights
 

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If you are still trying to pursue a water "pressure '' guage, after maket pressure guages are available to be used on outboard motors. You tap into a water passage and run a +/- 1/4'' line from motor to guage. The idea on an outboard is the rubber water pump impeller slowly wears out and you can monitor it's condition by watching the current pressure readings compared to what it was when the impeller was new. It's better than waiting for it to fail. I've seen them at Bass pro, Cabelas & ..... Don't know if it's what you want or not, it's just a thought.
 

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If you are still trying to pursue a water "pressure '' guage, after maket pressure guages are available to be used on outboard motors. ...
Interesting. I may have another use for that. Do they read-out in PSI or something else? What pressure range do they cover?

David
 

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Done and done!

Installed in the heater hose elbow, the Jegs pressure sender 41363 lit up the warning light on idle and went out at 900 rpm. Even after warming her up, every time I came to a stop sign the light would go back on.

That sender came preset at 3 psi. So I set the car in drive (600 rpm) got out the allen wrench and turned it CCW till the light went out That is probably 1 or 2 psi. Now when the pressure falls below that (eg, massive coolant loss) the switch will close. I have it on the same wire as the original water temperature light switch, so if the water either starts boiling or empties out the idiot light will go on.

Here is the layout, the red wires tie together. Thoughts?
 

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