26 replies to this topic

[jonlad]

Hello

I've replaced my single connection oil pressure switch for a minispares one which has two spade connections on it and operates at higher pressure...

http://www.minispare...|Back to search

 

I'd like to lash up a test lamp so that I can spin over the newly rebuilt engine on the bench and test for oil pressure.

 

So, how do these work and do both connections do the same job?

 

Are they a link to earth (the block) that opens when pressure is reached?

 

Many thanks

Jon

 

[gazza82]

If spinning up for the first time I would use a mechanical pressure gauge.

[jonlad]

If spinning up for the first time I would use a mechanical pressure gauge.

 

Thanks, any reason why? 

 

Original questions still stand if anybody knows the answer?

[timmy850]

The one you've linked is a warning lamp sender. All it does it illuminate the warning lamp if you have less than 20psi. It won't tell you the actual pressure reading (which can also be too high if you have some problems). I don't know why it has two terminals though 

 

A mechanical one is very simple to install and requires no wiring to make it work. It also never has a problem with the wrong sending unit or voltage. 

[gazza82]

If spinning up for the first time I would use a mechanical pressure gauge.

 
Thanks, any reason why? 

A) if your wiring is dodgy you may not know until too late

B) you want to know the exact pressure not just >20. You also need to know if it's too high.

You can swap it out and put the sender back later ... or fit a t-piece and have both for piece of mind

Edited by gazza82, 06 May 2018 - 11:50 AM.

[rww]

The 20 lb Minispares switch is exactly that. The electrical connections, spade terminals 1 & 2 , are connected when engine oil pressure is below 20lbs and disconnected when engine oil pressure exceeds 20lbs. One spade terminal should be connected to a local earth and the other to the (existing) warning lamp and battery.

 

This will, at the least, indicate your new engine has oil pressure but not how much. For your own peace of mind it is well worth having a mechanical oil pressure guage as well. 

[jonlad]

The 20 lb Minispares switch is exactly that. The electrical connections, spade terminals 1 & 2 , are connected when engine oil pressure is below 20lbs and disconnected when engine oil pressure exceeds 20lbs. One spade terminal should be connected to a local earth and the other to the (existing) warning lamp and battery.

 

This will, at the least, indicate your new engine has oil pressure but not how much. For your own peace of mind it is well worth having a mechanical oil pressure guage as well. 

 

That's what I was wondering, thanks. 

 

The one you've linked is a warning lamp sender. All it does it illuminate the warning lamp if you have less than 20psi. It won't tell you the actual pressure reading (which can also be too high if you have some problems). I don't know why it has two terminals though 

 

A mechanical one is very simple to install and requires no wiring to make it work. It also never has a problem with the wrong sending unit or voltage. 

 

Cheers    

 

 

 

If spinning up for the first time I would use a mechanical pressure gauge.

 
Thanks, any reason why? 

A) if your wiring is dodgy you may not know until too late

B) you want to know the exact pressure not just >20. You also need to know if it's too high.

You can swap it out and put the sender back later ... or fit a t-piece and have both for piece of mind

 

 

Thanks gazza, makes sense now :)  and extra question for bonus points is what pressure should i be looking for with a 1275 with new pump?

[nicklouse]

you can get a gauge that screws directly into the block. great for checking what is actually going on. one of the best bits of kit i have.

[nicklouse]

 image.jpeg   39.04K   3 downloads  image.jpeg   37.47K   1 downloads

That's what I use on first starts.

[jonlad]

​​great idea, thanks nicklouse, those little gauges are quite cheap. What pressure am I looking for when turning over on starter?

Thanks again

[cal844]

​​great idea, thanks nicklouse, those little gauges are quite cheap. What pressure am I looking for when turning over on starter?
Thanks again

40 psi on the starter,

About 60 psi once running, anything higher than 75 needs investigation

Edited by cal844, 06 May 2018 - 07:48 PM.

[jonlad]

Coming back to this thread now I have a gauge...

 

Spinning on the starter is giving me 80psi. Engine is rebuilt 1275 with minispares GLP138 'standard' pump.

 

Going by your figures this is high, is this due to everything being new or have I done something wrong? Wondering how accurate the £4 Chinese gauge is...

Thanks all

Jon

Edited by jonlad, 20 May 2018 - 08:54 AM.

[nicklouse]

i would be happy with that to start it up.

[jonlad]

Thanks Nicklouse, I appreciate the advice!

[cal844]

That's a good pressure, especially on the starter