Isuzu G-series Twin Cam

Hopefully someone can elaborate on what the inlet and outlet lines are for on the side of the block - before the oil filter.

Is it for a oil cooler or more of a catch system for when there's too much pressure - I see if you wind out the bottom bolt it has a coil spring and steel ball bearing that blocks the path of the flow?

Was curious so pulled apart the one on my spare motor to have a look. After I'd disconnected the oil cooler I had originally put on, there was no traces of oil coming out the lines. (the motor had only been driven 1.5km up the road to be fair) so may not have had enough time to properly get up to temp or pressure?

Chris.

Interesting discovery. No idea but keen to find out a bit more about these.

Both my motors have them. The g180w (from the ZZ/R) and the G200w (from the piazza)

I'll try find a picture..

Here like this one... You can see the top fitting has been changed for a Earls AN fitting..

Without having a pump in front of me to investigate more thoroughly, I'd say the spring loaded ball would most likely be a pressure relief vent to limit maximum oil pressure preventing over pressurising the system.

Any line designed to serve as an oil cooler supply would need some sort of restriction in place to prevent loss of pressure to the main gallery and a thermostat of some sort to control when the cooler begins to operate.

More inclined to think its perhaps a overflow/recovery system then?

Jackpot! Found these randomly online!

Couldnt have asked for better pics!

With reference to cul8r's last pic; the oil filter housing is split into 3 sections;
1 - the aft section is the oil return or dump section which returns excess oil back to the sump.
2 - the middle section is where the oil is delivered and is the high pressure source of the oil from the pump.
3 - the forward section is the filtered oil section; oil from the part goes into your engine's internals.

The upper hose outlet (as seen with the earl's fitting on cul8r's previous pic) is the high pressure source for the oil and should go straight through to your oil cooler inlet.
The lower banjo fitting is the oil cooler return and plumbs oil to the oil filter.

You will need to utilise a good low restriction oil cooler of "plate and bar" construction.
You may wish to bump up the oil pressure to 80psi @ 3000rpm by using 2mm of shim on the relief valve.

I have in the past utilised hoses sourced from a hydraulic equipment supplier - they can cut and swage to suit your application at a fraction of Earl's prices (though not as pretty).

Cheers

Denny

Thanks for the information!

Are you running a oil cooler on yours out of interest? I have this B&M 12 row oil cooler for mine..