lee2cossies

iTrader: (2)

Iv just rebuilt my 2wd cosworth engine,crank regrind,new shells, new cosworth racing oil pump,etc. on tickover when cold the oil pressure is 70psi but once its warmed up after around 15 minutes the pressure drops to 20psi,its on 10w40 mineral oil,and has only run for approx 2 hours.Is this normal or have i been cursed with one of the faulty cosworth racing oil pumps.Also noticed that the oil return from the breather has water dripping from it,only a small amount could be condensation?

tabetha

As said condensation.
The oil pressure at idle is not dreadfully important so long as it picks up, when revs are raised, though I would not be upset with that pressure.
tabetha

lee2cossies

iTrader: (2)

Ok,thanks.Had a look in the manual and it states 40psi on tickover.Just a bit nervous after building my first engine and throwing 3k at it.Its a lot of cash to throw away if it dies,and im sure my oil pump is from that dodgy batch!

scoooby slayer

iTrader: (4)

pressure at idle with 20/50 at 80c should be 1.8 bar or 26 psi minimum ford specification. i think your fine at 20 psi mate.

cossie4i+

iTrader: (15)

I would want it to be higher than 20psi myself.

Mine even after a hard thrash in very hot weather only drops to 30psi.

Steve

NEIL A

iTrader: (6)

On my running in mineral oil i was getting between 6/7 bar cold idle and just over 2 bar at 80 degrees at idle.

tabetha

At idle where no load exists is not that important, so long as it picks up ok when revs are raised, your gauge may not be accurate anyway.
tabetha

scoooby slayer

iTrader: (4)

ive got 1.9 bar at idle with 80c oil but if lights are on, cooling fan and heating fan im down to 1.5 bar. most important factor imo is the ford specification 2.2 bar at 2000 rpm iirc. if in doubt though mate an oil pump is cheaper than a new engine.

lee2cossies

iTrader: (2)

Im a bit worried but it does go up when revved.The oil seems very thin to me,its 10w40,its at 60psi when cold but as soon as it warms up drops off to 20psi,and this is without it being driven.Goin to drop the oil and try new oil.What oil would you recommend for running in?

scoooby slayer

iTrader: (4)

get a 10w 50 mineral oil will be thicker when hot than a 40.

lee2cossies

iTrader: (2)

Thanks,il try that.

rapidcossie

specs on the cosworth web site for the pump say min pressures are

Oil pressure @ 3000 RPM – 4 BAR (58 psi)
Oil pressure @ 5000 RPM – 4.8 BAR (70 psi)
Test was completed using 10/40W semi-synthetic oil @ 37 degrees C. on a newly rebuilt engine)

lee2cossies

iTrader: (2)

Thats mor or less the same as i got just when warm on tickover is the worrying bit! 20psi

rapidcossie

20 psi at idle is a touch low but that can be effected by what the car idles at?

what temp is the oil when its 20psi?

Turbo lag

Mine is just below 2 bar on idle with Mobil 1 motorsport 10/50

Dave.

Brentoncosworthmk1

Hi New to this site just a question to lee2cossie if still on this site of this old thread.Did you continue with just having the low oil pressure on 20psi on warm idle and was ok or did you change anything and fix the low pressure. Cheers thankyou for you time Brenton

PercyCurtis

The oil pressure at idle is not dreadfully important so long as it picks up, when revs are raised, though I would not be upset with that pressure.