loss of oil pressure under heavy braking

[Ronin 09]

I was looking at the oil pressure gauge (a trust aftermarket jobbie) yesterday, and i noticed that under heavy braking it drops down (from whatever reading say 5-6bar) to virtually idle pressure (say 1.5 bar). Now i repeated this scientific study a number of times further, and on each occasion it still happened. Note that i did not de-clutch the car and run neutral - obviously pressure will fall off as RPMs drop to idle.

What is causing this, and should i be worried? The oil pressure gauge is working normally - is this a form of surging that would require a larger sump? Or is this simply a normal thing on RBs?

A little worried, but no nasty noises.

[Jay95R33]

Could be the oil rushing to the front of the sump and away from the pickup ?

You might need a baffled sump if you go to the track a bit...

It's interesting though, I'll keep an eye on my gauge and stomp on the brakes a few times and see if I get the same..

J

[Ronin 09]

yeah just a bit worrying... it was just on the road, doing maybe 65 with a stomp...

was going to hijack your Mobil 1 / Shell Helix thread but thought this'd be better

[Jay95R33]

LOL - it'd be good to bring it up in the other thread, see if anyone else has had the problem.

It's interesting though. I've heard that the Rb26 sumps are prone to oil surge due to lack of baffles, so it's possilbe that the same goes for the RB25's...

As long as you've got some pressure there it should be OK

[Ronin 09]

Just got home from a spin around the (big) block, another quick note - this will not show up on the factory oil pressure gauge - it is far too slow reacting. You will only really notice it with an aftermarket gauge

[Jay95R33]

Ahhh, OK - I won't notice anything then cause I've just got the factory crap one

[Bl4cK32]

How much would it cost to get a sump baffled anyways? - could you do it yourself? (I'm a welder)

[Ronin 09]

if you were going to baffle a sump i would think you'd want to increase the capacity from 4.5L to at least 6L... there are a couple of shops that have increased capacity sumps available - can't remember off the top of my head. I think it would be a good idea anyway, because 4.5L isn't much

[Ronin 09]

Unique auto sports has bigger sumps for 900 bucks:

http://202.139.242.57/

[Bl4cK32]

Yeah - im still waiting for something i ordered from them 2 months ago. I wont be buying off them again soon.

[Ronin 09]

if we could get a sump maybe we can get a custom baffled one made up?

[hungry6]

when i rebuild my motor one of the area that i invested alot of time was oil presure problem associated with rb motor, more rb dies due to spun bottom end bearing than aany other form of death. what i did was welded 2 surge plates with 10mm holes drilled into them and inline with my oil cooler is a 5 litre oil reservoir where oil is stored and cools off before re-entering the motor. as under hi rev 5000+ u will find the sump ia basically empty and ll the oil is sitting up in the rocker covers, this is a fact!!

[antuanstylar]

just an idea, check out this accusump, i thought it was a great idea

www.accusump.com

[Zensoku]

I'd be interested to know if anyone has bought an "off-hte-shelf" sump from these guys yet:

http://www.highenergy.com.au

[JimX]

Can you get that accusump thing anywhere locally?