Lizard928

I am wondering if anyone knows what part of the manual I should look at for the oil circulation system.
Mainly the cooler system.

I am wishing to disable the the lines which are thermostaticaly opened and closed which run to the cooler in the rad.

I am wanting to confirm that I can simply block them off/seal them will not prevent oil from circulating through the rest of the engine.

This is on a 1986.5 engine block if that makes a difference.

TIA

Tom. M

That is how my S4 engine transplant was...when I had the old 82 radiator in there. Had good oil pressure and it behaved as normal. Later, I added the 928 Intl rad with end tank cooler, added the oil cooler lines in place of the plugs, and also had to add the internals to the oil thermostat (spring/plunger). My block is a 91 with only one oil bypass spring too.

Tom. M

Oh yea..some of it is covered in the Vol 1 Engine section 17-1.

Lizard928

Thanks Tom,

I will look in there.

So are you saying that when they plugged off the ports they removed the piston and spring assembly from behind them above the oil pressure sending unit?

Ben

Hmm,

I need to add the oil cooler lines to my replacement engine.... I was hoping just to bolt them on, but it now looks like I need to add the spring/plunger too?

For some strange reason, my old engine and replacement engine are both the same year, and were delivered to the same country, but one has the oil cooler as standard and one didn't.

What exactly do I need to retrofit?

Tom. M

Yep...I bet they grabbed the oil pressure sending unit from the old engine (mine has the old style two prong one on there now) and just popped it up in there. I added all the oil thermostat internal bits...

There was nothing behind the oil cooler line ports (just a screwed in plug at the block).

Tom. M

You'll need the two parts that screw into the block (that allows the connection of the oil lines), and then drop the oil pressure sending unit assembly. Get a new crush ring for the aluminum part that holds the oil thermostat. If your old engine had the oil cooler lines..just grab all the parts from that one and swap over.

James Bailey

Colin the thermostat when it closes directs all the oil to flow through the cooler simply remove the thermostat and you can block the fittings for the lines at the block. The secondary bypass spring plunger allows oil to flow if there is more than a 10-15 lbs pressure increase in the lines to the cooler this was eliminate when aircooled external heat exchangers were added.

Lizard928

Thanks again fellows,

Ben

I don't have the old engine anymore, but I did take every part from it. So basically I need to swap the plugs for the hose connections, and install the spring and piston behind the pressure sensor?

Its just that I remember there being other springs and pistons from the two ports with brass plugs above the oil cooler conections, and didn't know if I needed to install these too.

Tom. M

Those are oil pressure bypass holes (my 91 block only has the one). Those I believe are present on all engines regardless of oil cooler or not (not sure) but they are simply a plunger and spring, and your new engine should already have them..easy to check (when the engine is out)...pain in the buttttttt while the engine is in the car....

Ben

Thanks, I'll take a look tomorrow.

Colin, Sorry to hijack your thread!

Lizard928

No worries Ben, I got the info I needed.

I also got my new rod bearings in, as well as my I-J crankscraper.
Then I cleaned/prepped my drysump pan for install tomorrow, by then it was too cold to have the garage door open which I need to have for working on the pan area. So I went onto wiring up the car.
Got the center console almost completed.