With the short block out for rebuild, time to get busy on the top end. If all goes as planned, all I will need to do is decarbonize the combustion chambers and valves, and replace the valve seals. This was a strong running head when I pulled the L20B for an SR20DE conversion in 2001. It is an A87 medium port peanut chamber head port matched to 1.5" Mikuni intake runners, with an Americam .480"/280 cam (O-65 grind), Americam HD valve springs, and stainless SI 44mm intake and 35mm exhaust valves.
I started by removing the rocker arms. Here I've removed the first two:
Then I removed the valve springs, retainers, and camshaft. Special thanks to my buddy Seth for loaning me his Datsun Comp valve spring compressor. This tool (seen at left) kept my cussing to a minimum.
Here's all the parts in a tray to keep things organized and make especially sure that the rockers go back on the correct cam lobes.
Did I mention it was a bit warm today? 100F in the shade on my patio. Probably a bit warmer at my workbench in the garage...
This head has been shaved quite a bit, as evidenced by the missing lower edges of the "Nissan Japan A87" script:
To compensate I was running a stock head gasket with a Felpro .020" copper head spacer shim which I'm finding no one currently has in stock and availability from Felpro is indefinite. If I can't find a new one, I may consider re-using the old one (I was careful removing it, so it may be possible to clean and re-use) or install cam tower "headsaver" shims and taller lash pads (have 0.180", would need 0.200"), or find a NISMO 87mm headgasket (0.060" thick vs 0.040" stock), or possibly use one of the NISMO 88.5mm headgaskets from my stash (not thrilled with the extra volume). First I will mock up with a used stock HG and see how much slack there is in the timing chain but I'm pretty sure I'll need to shim. Anyway, here is the head minus cam, valve gear and seals. This is as far as I really want to go with head teardown if I can help it.
Next up is the messy job of decarbonizing the combustion chambers and cleaning up the valves. I did a cursory check and none of the valves appear to be bent or burnt, and they pass the wiggle test in the guides, so that is all good.