Alfa Romeo Owners Club of Australia Forum

Technical => 900 Series (Alfasud, Alfasud Sprint, 33) => Topic started by: Martinsifredi on March 17, 2013, 10:52:22 AM

Title: Oil pressure on Alfa 33 16V
Post by: Martinsifredi on March 17, 2013, 10:52:22 AM
 Hi all ,

I was wondering if any one could confirm what is the correct oil pressure at "full load" conditions for the 33 16V ?

I am trying to find specs. on this but found nothing so far . 

thanks ,

Martin
Title: Re: Oil pressure on Alfa 33 16V
Post by: Neil Choi on March 17, 2013, 11:15:41 AM
In general, 10Psi per 1000 revs when hot.  If running at full revs and pressure is low or lower than 60Psi, you would start to suspect something is not right. 

This is in reference to a 2L Alfetta motor.  So don't know about the 33.  You can probably equate.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Steve S on March 17, 2013, 11:24:52 AM
The oil temperature and grade will make a huge difference to the oil pressure so you need to take that into account also.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Martinsifredi on March 17, 2013, 03:09:20 PM
the oil I am currently using is Mobil 1    (5w50) supersyn  full synthetic .  the temps of the oil while on the track have been around 120-130 degrees C .  maybe I need to look into the Penrite 10 tenths "racing" oil , I think a 10-60 grade would probably be a better choice
Title: Re: Oil pressure on Alfa 33 16V
Post by: Evan Bottcher on March 17, 2013, 04:39:37 PM
The oil pressure on the Sud goes up when I go around left hand corners, and down when I go around right hand corners.  It occasionally goes to zero as well, suddenly, while zipping down the straight.  The first time that happened I pulled off the track and had to be recovered, and Bruno said 'well did the light come on?'.  I've almost got to the point of putting a bit of black tape over it...

I guess your engine might be more precious to you than mine.

This probably isn't related to your question either, but it's been suggested to me to fit an oil pressure switch and a really visible light in the cockpit that comes on when the pressure drops below a certain amount - not the near-zero pressure switch that's fitted from the factory but something higher (maybe 30 or 40 lb?).  It'd be on constantly while you're idling around the pits and you'd have to ignore it, but if it comes on while you're on the track then you'd turn the engine off immediately.  I think Vin said this to me - and a big piezo buzzer too.  Sounds like a good idea.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Neil Choi on March 17, 2013, 04:52:59 PM
The GP coverage is pretty crap, more like an Entertainment Tonight crap show.  Much more interesting to be here.

Yep, as advised by the Alfa guru's, I have installed that "YOU NEED AN ENGINE REBUILD, IDIOT" and "$$$" lights.  Comes on when at 30psi and below.

Factory is about 5 Psi which is too late.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Martinsifredi on March 17, 2013, 04:54:59 PM
Bit off topic , but thanks anyway

Title: Re: Oil pressure on Alfa 33 16V
Post by: Ray Pignataro on March 17, 2013, 09:10:05 PM
Anything above 60 psi is safe
Title: Re: Oil pressure on Alfa 33 16V
Post by: colcol on March 17, 2013, 09:23:41 PM
The oil pressure would depend on oil temperature, oil viscosity, oil type, synthetic vs mineral, condition of engine, condition of oil pump gears, type of oil filter and blocked filter or new, you don't want too much pressure in it at high revs, as you will put pressure on seals, just make sure it doesn't drop below about 7 lbs at any time or whatever pressure the idiot light comes on at, if you find it flickers at idle, just go to Repco and get another one, as they don't last forever and they leak after a few years, Colin.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Steve S on March 17, 2013, 09:49:06 PM
Quote from: Martinsifredi on March 17, 2013, 03:09:20 PM
the oil I am currently using is Mobil 1    (5w50) supersyn  full synthetic .  the temps of the oil while on the track have been around 120-130 degrees C .  maybe I need to look into the Penrite 10 tenths "racing" oil , I think a 10-60 grade would probably be a better choice

For racing you could probably benifet from something more shear stable, if using Mobil 1, 15w50 would be a better choice, Penrite racing 15w50 would be fine too. Get a UOA on the oil done and see if there is a problem. You may find there is nothing to worry about. I would look at the oil cooling though. If you can drop the temp to 110 it will give you more oil pressure.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Martinsifredi on March 18, 2013, 11:16:28 AM
Ok . I have spoken with a good friend of mine who races a 33 16v in Europe
He is telling me if you have 1.5 bar at idle and 4 at WOT . This is
Fine .
Regarding a UOA , what do you mean by that ?

Collin all the points you have mentioned make sense , the other
Important thing is , have I matched the oil pressure sender for
The gauge I am using ?

I feel a racing 10 60 is on the cards
Title: Re: Oil pressure on Alfa 33 16V
Post by: Neil Choi on March 18, 2013, 11:26:11 AM
4 bar is 60 psi

UOA, have the oil analysed by a chemist (I am one but with drugs), used oil analysis.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Evan Bottcher on March 18, 2013, 11:58:13 AM
Quote from: Neil Choi on March 18, 2013, 11:26:11 AM
...analysed by a chemist (I am one but on drugs)...

Fixed that for you.  I hardly see why that's relevant.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Neil Choi on March 18, 2013, 12:26:36 PM
Thanks Evan, I too can't see the relevance neither.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Southern75 on April 13, 2013, 10:22:18 PM
Anything above 60 is good ... mine's usually 70-80 ... but it doesn't drop even when cornering on the track ..

Have you got a baffled sump Evan?

I have tried a few different sumps all with varying success ... but onto a good thing now, new designs are working well ... sumps are cheap so is oil .. engines aren't :(
Title: Re: Oil pressure on Alfa 33 16V
Post by: colcol on April 13, 2013, 10:53:58 PM
Make sure you have an oil cooler, it should go hand in hand with a baffled sump, oil gets too thin when hot and you can't hold pressure, thats why race cars have oil coolers for everything, don't worry about the pressure, just make sure the idiot light is working properly, whatever you do, you don't want it coming on, Colin.
Title: Re: Oil pressure on Alfa 33 16V
Post by: Southern75 on April 29, 2013, 10:34:38 PM
I've fiddle with my sump a little (a lot) and oil temp isn't an issue when racing, no oil cooler though.

But with standard sump ... even baffled ... oil cooler is a must.