Hi
First of all I'd like to thank everyone (especially Datsun Mike) for the help this forum has provided in working on my recently purchased 85' 720 king cab 4x4, carbureted z24.
Here are some pics of that -
I bought this off craigslist about 6 weeks ago and 2 weeks ago the head gasket blew. It has 117k miles on it and otherwise the engine was running pretty A1. From what I have read this is about par for the course. Although I've never done anything beyond oil/tranmission fluid/oil filter change I read through all the words on this forum and decided to do it myself. It was my plan to learn about auto repair with this truck and I figured this was a good time to start and save myself about $1000 (not to mention there was no way I could afford to send it to a shop having just purchased the truck with cash a few weeks before). So far I've spent about $350 on tools, parts, and both the Factory Service manual and the Haynes as well as $40 on machine shop service (resurfacing and compression check on the head).
Anyway - I have 2 questions/issues
1. Last night I got the the head, cam sprockets and everything bolted up again. I pulled out the timing chain tensioner wedge and was thrilled that everything seemed to be holding together/tensioner did not pop out. So I'm feeling pretty good at this point and was getting ready to put the valve rocker cover back on when I noticed this small metal ring in a pool of oil on the shelf where I first put the cylinder head.
It was one of the rings that slots into the head bolt hole in the block between cylinder 3 and 4. I did not know there were 2 - this one must have come off with the head and fallen out without me ever noticing it. The other one stayed in the block and was reinstalled when reassembling the engine.
After I finished loosing my shit at the thought of having to redo everything and get a new wedge etc. I decided to stop and consult a higher power (...no god, im talking about Ratsun...) about whether this was a big deal or not. On the one hand I don't want to do anything that would put me at risk of blowing another head gaskets. On the other hand this ring just loosely fits around 2 of the head bolts and its not involved with any fluid movement in the engine so maybe its just there as a way to easily align the cylinder head and the block? I am worried that it does the important job of controlling/guiding the expansion and contraction of the aluminum cylinder head. (FYI, I used a Factory OEM head gasket)
So that's my first question: Do I need to take everything apart again and reassemble with this ring?
2. My second question is - What is the thing between the starter motor and the oil filter (caked black with grime and an electrical plug going to it). I cleaned it off and its a goldish metal cannister similar looking to a fuel filter. What is it and could it be leaking oil?
I've scoured both the FSM and Haynes and there seems to be absolutely no mention of it and its left out of every engine diagram or drawing. My Guess is that is some kind of electronic feedback for oil lever, pressure, or temp.
I'm pretty sure the oil pan gasket is leaking, but there must be something else leaking all over the intake side of the block just above the oil pan gasket... or maybe its old oil and dirt from previous leaks...
(also you can see where the head gasket was completely blown between cylinder 1 and 2 and coolant sitting on top cylinder 4..... also notice how beat up the blue wedge is... i broke it while wedging it in and the chain was taking chunks of plastic out of it as it went.)
Thanks everyone for your help!
(I also have a new 32/36 weber carb that I will be installing with this. Will probably post about that soon.)