Got the head back from the machine shop. It's installed along with:
Intake manifold, fuel rail, plenum, throttle bodies, oil cooler assy and air distribution assembly.
The ugly part involves the valve lash. It takes a really long time to do the lash adjustments on these motors because the cams need to go in and out so many times. I've made my initiall measurements and now need to find/wait for shims...
The intake side all the shims are too big, which is cool because I can have them ground down.
The exhaust side, however, are almost all too small. I can get 13mm kawasaki motorcycle shims, but the RB are 12.3mm. This means I'd have to somehow turn them down some... I'm not sure what I'm gonna do yet. The outside profile isn't critical, so I might be able to do this on a belt sander...
I checked the exhaust valve clearance. They were all OVERSIZE, which means all the shims I have are too small and can't be cut down. To make matters worse, the Kawasaki ones do not get as thick as I require them to be. (I need eight >3.10mm which is the Kawi max)
I checked the rockwell hardness on the OEM parts and they're 65C, which is bearing hard, probably 52100 chromium alloy steel.
So I ordered up a 1/2"OD 6 foot piece (shortest I could get) for 15 bucks. I'm going to turn the OD down just a hair to ~.475", then use a wire EDM to cut it into discs about .150 thick.
Then I'll send them out to get heat treated to 60-65C, then put them on our surface grinder (magnetic table) to make them the appropriate thickness.
A huge fucking pain, but better than waiting 4 weeks for OEM parts from japan for 10-20 dollars each.
I have about 20 blanks done right now, but i'm making about 50 so if I ever change cams, I can reshim without having to wait... I am going to get them to the heat treating place tonight, I hope...
Ok, so... I didn't want to wait weeks for valve shims, and I also
didn't want to pay 10-22 dollars each for them. I called around to a
few vendors in the states and no one had the sizes I needed.
So I made my own (did a few tests on the shims I pulled from the car to determine surface finish, hardness and material):
1) Started with a 6 feet of 1/2" 52100 bearing steel rod. $15
2) Using a CNC lathe, turned the OD to 12.3mm
3) Using the same CNC, chopped the rod into discs of varying thickness, about 40-50 total (no pic)
4) Sent the discs out to a local heat treating facility to be hardened to 62-65C (pic below, left) $50
5) Used a surface grinder to take the shims to within .0005" of what I needed. (pic below, right)
Here's a little video of the surface grinder in action. If you look closely you can see the sparks flying. The table moves left to right then indexes forward and backward. Once it has completed a whole plane, it drops down .0005" I could have incremented in .00025" steps, but that seemed like overkill, since nissan specs call out +/- .001"