3/12/11 - And the Engine Maintenance begins...

Ah, Saturday.  A nice pleasant breeze, on a clear day, with the sun shining brightly in the sky.  Pleasant temperature...what a nice day to be working in the shop all day.

Pretty fruitful day.  Dad and I managed to tear down the whole engine.  We took off the timing chain from the head, and took off the head with the cam and rocker arms and valves still inside of it.  I looked at the valves that were open, and they needed to be reground.  They weren't terrible, but while it's off the engine, it wouldn't be a bad idea.  The cylinders are for the most part, clean.  Dad noticed that it seemed like it could have been bored, but it was only a matter of 0.010".  When we had to bore the D16Z6 Honda engine I had, the oversized pistons started at 0.020", so the previous owner probably didn't bore it because the Nissan pistons are the same way.  While turning the crank, everything seemed okay.

Here's the block:

As far as machine work goes, it seems pretty solid and not in need of any.  The bearings were all new, and so were the pistons and rings.

The pistons were stamped, so we decided to put them all in one box.  They were just cast pistons.

That's about the size of the pistons and rods.  They were dished-top pistons, so they are truly out of a late 70's 280Z, and not a 280ZX.  The ZX model had flat-top pistons to up the compression from about 8.3:1, to 8.8:1 for the extra turbo.

It's not much of a dish, so we'll probably leave those alone.  They were dirty, but the rings and pistons looked new.

There's the crankshaft.  It was surprisingly pretty light, for being an inline 6 cylinder!

That's the valve-side of the head.  The design is pretty standard for the time; large intake valves and smaller exhaust valves, with only two valves per cylinder.  The head is aluminum though, so it was pretty easy to pick up and move around.  We spotted a few problems, like broken off studs and missing studs.  No cracks, though.

After being so used to Hondas, I saw the camshaft side of the head and immediately kept wondering what was wrong with it.  Something didn't seem right...then I remembered they didn't have Variable Valve Timing, Lift, and Duration back in the 70's in production vehicles, so it only has one set of lobes.  Oops.  It is overhead cam though, which really is nice.  Makes maintenance easier in the long run, in my opinion.

Pretty much after we got the crankshaft out of the block and put it away, we decided to stop there for the night and come back at it tomorrow.  It doesn't look like it will take much to get this engine back into shape.

Keep coming back for more updates!

Sincerely,

Chris