BPZ3 head on a BP4W block in a NB1
 

Hey all...

Just picked up a used BPZ3 engine with rod knock. I am planning on putting the VVT head on my BP4W bottom end. Almost everything I am seeing is people putting the BP4W head on the higher compression BPZ3 block... What all needs to be done to make it plug in and work? I see the ignition is different, but is there anything else? I am using a flattop intake manifold and have a MS3X set up for VVT, but will probably just run it full retard once I get it on until I end up tuning it

You can keep the same ignition. You'll need to install the vvt hardline that goes from the passenger side of the block to the vvt solenoid on the top of the head. You'll also need to extend the cas wiring as that's now located to the top rear of the valve cover as well.

I would never give up vvt for a half point of compression. Too many ways to get compression back up, to not use vvt. But I am not a pro builder either.

You misunderstood - I am adding a BPZ3 head to my BP4W block, not putting a BP4W head on a BPZ3 bottom end.

I see now.

Well, found a decent guide for the ignition pinout, so I'm going to cannibalize the BPZ3 harness so that I can use the ignition from the new head...

Then, I guess only other thing I have to do is run the hardline from the side of the block up to the head to control VVT (assuming it fits...)

I followed the trubokitty.com build guide when I made my MS3X; I can use the wire that previously ran to VICs to splice into the VVT solenoid, and then I can snake a wire up through the firewall from MS-30 (since I did both jumpers) to power the other part of the VVT control? Or is there anything else I can splice into in the engine bay that would be recommended to pull the power?

You will need the bigger oil pump of the BPZ3. You can get oil pressure issues without it.
But if you have rod bearing failure there is a pretty good change that the pump has a seen a lot of bearing material and is unusable ... Did you inspect the heads oil passages for any bearing material?

I've been reading that the BPZ3 oil pump not being present wouldn't be much of an issue, and it was the sintered oil pump gear that would be a point of failure if anything... I didn't check passages, but I do have a boundary engineering oil pump sitting on my parts shelf waiting for me to install it eventually.

The BP4W block is still in my car and I don't have a cherry picker to pull it, so I was hoping to just go with the BP4W oil pump and if I get issues or a sudden drop in oil pressure, rebuild my older NA8 block with forged internals and take advantage of the oil feed on the side, or if that is in poor condition, rebuild my BPZ3 block, and do the clutch at the same time.