G8Pumpkin

Replaced the oil pump on mine so took some pics of the old one and did a little port work to improve the flow. Pictures show the stock parts and the area of the pump that is the discharge to the main oil gallery in the block. The area circled in blue shows where the flow can be improved a lot with a little bit of port work to remove the stock restriction. On Ytube there are videos from Melling on an LS3 pump which shows how to reinstall the pump and PRIME it before you start the motor the LS7 pump is not available from Melling as an upgrade so its OEM or a Katech. The stock LS7 pump is basically just like the LS3 pump with another stage added to it if you disassemble yours mark all the pieces so the go back together in exactly the same order. When I took mine off the car I used a bunch of thin feeler gauges 3-4-5 thou and slid them between the pump and the pan gasket before I took the pump off so the sharp edges would not tear the pan gasket if you do tear the gasket you will have to drop the pan and replace the gasket. You could also use a piece of .004 or .005 brass shim stock to do the same thing. On reassembly I tried to put the pump back on as an assembled unit but gave up and did it piece by piece, watch Mellings LS3 pump video and its shows the steps with a couple of things different as there are 2 stages instead of one, also the bolts on the LS7 pump have black plastic injected at the factory to take up the space in the casting holes and this controls the alignment of the pump unlike the LS3 pump where you need to center the pump gears etc with shim stock in order to center the housing before bolting it down, the LS7 avoids this step because of the plastic injected into the pump housing and the bolts. This makes it simple to reinstall in pieces just oil every thing up as per Mellings video as you go.

freddyvette

What's the diameter of that port on the engine? It would make no sense to hog it out more than the hole in the block

G8Pumpkin

The diameter of the hole is fine its where it turns the corner inside the pump when you turn the piece over that I show in the picture and look at the 2 intersecting holes there is a huge restriction as they are just drilled from both sides and dont meet very well the cross sectional area drops to about 1/2 this is what needs to be ported its obvious when you look at it just doesnt photograph very well, remember this is the main feed to the engine.

freddyvette

How would you port something like that? Tight spot

G8Pumpkin

Standard rotary files and either an electric drill or die grinder will work, I also used a flexible shaft grinder and some long shafted small stones to clean up the casting areas a bit but the main culprit is the restriction on the outlet where I circled in blue it is not hard to do. Just dont touch any of the machined areas leave them alone.