Oil Pressure Warning Switch (aftermarket)

[sport1901966 8]

Hi everyone. I'm trying to sort out pressure switch for my mi16 conversion (see project thread in my sig) think auto have come up in a few searches and so has the fact that 25 psi is a good pressure to have it activate a warning light.

 

It seems that thinkauto don't have the equipment to adjust the warning light senders they have to 25 psi (or any other pressure) so my question is does anyone have any ideas how I could go about adjusting it myself?

 

I had in mind some kind of sealed container that had a thread for the warning switch (that would be wired in circuit with a buld) and some kind of input to pump up the pressure to 25psi then adjust the sender until the bulb just comes on and then turns off when I pump the pressure higher. The problem is all that is a bit of a pain in the backside as I have no means to fabricate such a container.

 

Any suggestions would be excellent!

[DrSarty 90 1 Cars]

Can't comment on calibration, but the Haynes 405 manual states oil pressure warning switch operates at 0.8 BAR, which is 0.8 x 14 psi = 11.2 psi.

 

Just giving you the info; not arguing with your/the manufacturer's suggestion above.

[sport1901966 8]

Can't comment on calibration, but the Haynes 405 manual states oil pressure warning switch operates at 0.8 BAR, which is 0.8 x 14 psi = 11.2 psi.

 

Just giving you the info; not arguing with your/the manufacturer's suggestion above.

 

No I think you are right - the manufacturer pressure is as you say. Just in the threads I've read 25psi just gives that extra safety margin without being over the top and after spending all the money rebuilding the engine I wanna be as safe as possible!

Edited September 21, 2009 by sport1901966

[DrSarty 90 1 Cars]

I totally agree, because running pressure is supposed to be around 4.5 BAR+.

 

0.8 BAR is less than air pressure (obviously ) and dangerously low, making 25psi (just <2 BAR) give that safe margin.

 

You didn't mention above, but it may say in the literature that it's factory set to 25psi which means you don't have to do any faffing with pipes and plastic bowls.

Edited September 21, 2009 by DrSarty

[sport1901966 8]

I totally agree, because running pressure is supposed to be around 4.5 BAR+.

 

0.8 BAR is less than air pressure (obviously ) and dangerously low, making 25psi (just <2 BAR) give that safe margin.

 

You didn't mention above, but it may say in the literature that it's factory set to 25psi which means you don't have to do any faffing with pipes and plastic bowls.

 

Oh yea neglated to mention the fact completely - they are sold at 20psi so still higher but I'm just being picky. I see by your sig you've seen you're fair share of Mi16's! Would I be right in believing that the oil pick up extender peter t sells require cutting and re-welding of the oil pump?

[DrSarty 90 1 Cars]

Pete's jobby just bolts on.

 

I haven't had anywhere near as many Mi's as some other people.

[jackherer 543]

Someone posted a pretty ingenious idea on here recently. Get an old push bike inner tube, cut it and seal it around the senders inlet. Then put a footpump with a gauge on it and pump it up to 25 psi. Use a multimeter or bulb and battery so you can see where the switch point is then adjust so it switches at 25 psi.

[sport1901966 8]

Someone posted a pretty ingenious idea on here recently. Get an old push bike inner tube, cut it and seal it around the senders inlet. Then put a footpump with a gauge on it and pump it up to 25 psi. Use a multimeter or bulb and battery so you can see where the switch point is then adjust so it switches at 25 psi.

 

Excellent idea that was the one thing I was unsure was how to seal things but how could I forget about the trusty old jubilee clips. Thanks mate thats spot on!

[sport1901966 8]

Pete's jobby just bolts on.

 

I haven't had anywhere near as many Mi's as some other people.

 

Oh right, do you know where any pics of that would be, I've been on taylor-engineering (his site?) and it talks about welding on an extended pick up!

 

Fair enough,I'm still on my first so plenty to learn!

[Bally123 0]

This may be a bit late but may help someone.....

 

I recently modified at standard one, it came from a 405 block, had a grey plastic body and is longer than the standard "stumpy" 205 type. Using a file I removed the rolled lip on the body, popped out the plastic body. Replaced the spring with a stonger one and tested. Note here I tried 3 or 4 springs before I found the right rating to switch around 25PSI (2bar ish). Test method below.

To seal it back up I simply dressed the plastic body with a file so it sat a little deeper in to the body and remade the rolled edge with a hammer and an old socket. works fine if your on a budget

 

Test method:

 

Use an air compressor with an inline regulator, some flex pipe to connect to the switch (I used a blow gun to connect the pipe to the switch) make sure regualtor is set at zero. Wind up regualtor and monitor switch function with a multimeter on continuity (Ohms) setting. If the meter has a buzzer setting use that to listen for the switch making. Simply read the pressure of the gauge on the regulator.

 

HTH

 

Bally

[wardy18 33 1 Cars]

Sorry to jump start this thread again but im interested in this

 

I run the std 205 pressure switch and so run std settings, you all mention the 11psi minimum margin for the switch to activate the light but my light comes on ALOT when i rev the engine due the oil pressure getting so high from my uprated oil pump spring, so do the std switchs have minimum AND maximum margins for the light to be switched on?!

[welshpug 1,661]

your XU10 spring wont increase it that much, only from 5 to 6 bar.

[jackherer 543]

Are you saying your oil light comes on at high pressure as well as low? If so it is faulty IMO.

[wardy18 33 1 Cars]

Is that all the Uprated Oil Pump Spring is, an XU10 one instead of a XU9 one?!

 

Would this extra Bar of pressure make the pressure switch activate at its maximum margin more though as it comes on ALOT and its not due to low pressure as my guage is reading off the scale in oil pressure when cold or when revved hard

[wardy18 33 1 Cars]

Are you saying your oil light comes on at high pressure as well as low? If so it is faulty IMO.

 

Exactly what im sayin, my gauge goes off the scale when cold and also when revved hard and so the pressure light comes on

[jackherer 543]

Thats definitely not right, it should only illuminate when pressure is low.

[wardy18 33 1 Cars]

oh..... ill have to look into that than