LS4 wizards? Need help with oil passageways! (Page 1/1)
85-308 DEC 14, 09:56 PM
hi guys. Back on my LS4/F40 swap-in after a longggg delay. Block is prep'd for reassembly. Looking at the back of it and trying to figure out if I've missed something really serious. The issue I see is that the oil feed (supply) from the filter 'seems' to pass thru a BIGGGG open volume at the back of the block. Is this right? Or am I missing something?
I'm attaching a drawing of the oil feed thru the DoD system, then 2 pix to show what my question is.
Drawing 'seems' to show a direct (ie uninterrupted) feed line from the filter to the DoD oil pressure sensor. In fact, this isn't uninterrupted. See the pix.
The cleaning brushes I use to show the passageways are shown in pix 1 and 2. I put green tape on them to help see where they run. Obviously the two brushes intersect BELOW the DoD oil pressure sensor location. What happens in this space? Is all of this volume subject to (ie) 75 psi pressure? Seems unlikely.
My number 1 shows where the first brush comes up from the oil filter.
My number 2 shows where the two brushes meet. The 2nd brush comes down from the DoD oil pressure sensor location.
I don't get it.
All and any input appreciated.
Thanks in advance; GP
85-308 DEC 14, 10:35 PM
OK so the pix didn't come out like I wanted but I think it's still fine. I'm posting this as well. It's pretty much everything that goes on the back end of the block. You can see that the gasket deliberately joins the two sides of the oil galleries (the way I'm reading this).
Again, any input appreciated. Thanks.
GP.
fieroguru DEC 15, 06:52 AM
Don't take the drawings as being to scale or showing 100% of the details. The first drawing is only showing the oil flow for DOD solenoids and omitting the oil flow to the crank, cam and lifters for simplicity.

You don't have any issues. Yes that large opening above the crankshaft is filled with oil and exposed to pressure. I am pretty sure that large area has the oil passages to the cam and lifters. Do make sure you put the barbell piece back into the lower hole.


If you are deleting DOD, then you also need to block oil flow from the 8 towers in the lifter valley that go to the DOD lifters. This can be done with threading them for pipe plugs or running a LS3 valley cover with o-rings on each tower to seal them.

[This message has been edited by fieroguru (edited 12-15-2022).]

85-308 DEC 15, 09:46 AM
Well, ask for a wizard, get a wizard! Thanks for taking the time, Guru.
I'm doing both those things: the delete, pipe plugs and flat O-ringed plate on them anyway, simply because any plate I could find comes like that. I guess I should (or could) plug the hole to the former DoD pressure sensor, too. I'll be taking my oil pressure from your spacial fitting (almost here) and this stock location just mostly inaccessible now. Thread it and plug it too, I guess. I'm going to have some questions I think about what looks like a 'plunger' in the oil pan above the filter. Want to take it out to clean everything as best as possible, but it doesn't look cooperative.

Thanks for the quick reply!
GP

[This message has been edited by 85-308 (edited 12-15-2022).]