oil pressure general question to chuck out there for opinions

[Not a Number]

so, I've recently met this lady, a twenty something birkin kit that came to me in an 'assembled' state.   As I go through it I've discovered the oil pressure dumps under braking.  Under normal running indicating around 5 kpa, at idle drops of to a hair over 3.  But when stab the brake hard it'll dump to around 2.  It's a 2L zetec in there with a low profile sump( low capacity too), no idea if there is adequate windage in there tho.  Coincident discovery as I was researching dry sump kits last night only to discover this trouble oil pressure concern today.

 

The question is this.  How low is too low. 

 

Advice on dry sump for that engine also welcome.

 

 

[locost7018]

I am not an expert on this subject but is the motor from a front drive car and still has the front drive oil pan on it?

[Croc]

You were right to flag this as a concern.  

 

A low profile sump on an engine which was designed for a transverse installation not fore/aft installation like you have. I am inferring from your post but a low profile sump does not sound like the standard one - a later add on?    Oil pressure sensor is probably mounted at the back of the engine closest to driver?   I would be looking at a Raceline baffled sump or dry sump.  Maybe compare what sump you have on the car now to the Raceline website and see if you can make a positive ID - it was a fairly common mod in these cars.  

 

The problem with low pressure on a gauge is that it is a guide and not perfect.  There could be moments of the oil pick up in the sump running dry in which case low oil  pressure under braking is the least of your worries as damage is being caused already.  Relative locations of oil pick up in sump and oil pressure sender are worth evaluating here as similar could existing under hard acceleration.