Oil Pressures/Filters/Oils

[hrforever]

Been investigating the engine oil and its pressure Vs temps.

Until today, I have the standard small oil filter (Ryco Z418) and 10w30 oil. The main issue was the idling pressure that would sit around 16PSI when the water temp was 90+Cdeg. When cruising at around 2600rpm, pressure was 67psi.

After research, discovered that I could fit a larger filter (Ryco Z9ST) and discovered the oil pressures increased at 2600rpm (78psi) but idle stayed the same.

When the oil is cool the pressures remain within what I believe are normal ranges but its the hot idle that has me questioning if its too low when its hot.

Anyway, I have always wondered if I could fit a cooler and on the front of the filter housing there are two connection points that I'm not sure what they are for. Any clues?

 

[Zuffen]

Those two plugs seal off machined bores for the oil flow.

I've used one for an oil temp gauge and one for oil pressure and still maintaining the oil light switch.

To run a cooler I would look at a proper adaptor.

Have you thought about just increasing the sump capacity a bit?

Also if the oil light doesn't come on at idle there's enough pressure.

Most oil lights come on at 7psi.

 

[hrforever]

Ok. I've got my pressure gauge running off another hole which is on the other side of the housing to the filter. There's no low pressure sensor but with those access points I will look at installing one.

The sump is a custom made item with a capacity of 7.5l which should be enough. My main concern has been the low idle reading I'm seeing. The motor runs fine but I have it in my head that 20psi was a better target pressure. I suppose heat and 30 grade oil will lower this figure but still keep the motor happy.

 

[hrforever]

I'd like to share some of the results from some testing I've done between two different oil grades over the last couple of days. It was interesting to see the changes in pressures between the oils. At least I now know whats going on.

Used the same Z9ST filter (new), both are Penrite, full synthetic oils and the car was stationary in carport. Motor has approx 150k on it.

10w-30 Oil
Cold Start Idle-900rpm 82psi
80decC Idle-670rpm 20psi 90degC Idle-670rpm 16psi
80degC 1000rpm 48psi 90degC 1000rpm 40psi
80degC 2000rpm 72psi 90degC 2000rpm 68psi
80degC 3000rpm 82psi 90degC 3000rpm 78psi

10w-50 Oil
Cold Start Idle-900rpm 86psi
80degC Idle-670rpm 34psi 90degC Idle-670psi 22psi
80degC 1000rpm 58psi 90degC 1000rpm 48psi
80degC 2000rpm 82psi 90degC 2000rpm 74psi
80degC 3000rpm 92psi 90degC 3000rpm 82psi

 

[Zuffen]

Interesting figures.

Around 10psi difference except for the very last 90degree @ 3,000rpm which was only 4psi improvement.