Managed to obtain permission to spend some time hiding in the garage over the Christmas break! Over the last few months I've been thinking through the things I want to do on the car and I came to the realization that I'll not be happy going forward unless I really know what state the engine is in. The engine that the car came with was a bit of an unknown. It wasn't installed really - it was sitting in the engine bay with the transmission connected but that was about it. We've had the engine running and done a grand total of about 20 miles but as mentioned previously I'm heading down the EFI route and it's off the road anyway so why not put it right out of action and take the engine apart?! Why not indeed.
Armed with a copy of "How to Rebuild Your Nissan and Datsun OHC Engine", an engine hoist and stand from SGS and a bucketful of naivety I started spannering. All-in-all it's gone pretty well (yes, I know that taking things apart is the easy bit
) . Apologies for the quality of the pictures that follow - I'm blaming poor lighting and also I've no idea how a camera works really.
I've yet to go through the book and look in detail at any components but things don't seem bad on the surface (but what would I know?). The conrod bearings appear to be in good shape with no visible scoring except on piston 4 which has some minor scoring.
The main bearings and the crankshaft journals have no visible scoring as far as I can see or feel. Before I lifted the crankshaft out it span very smoothly and freely.
The only real snags I hit in this process was removing the front cover as a number of the securing bolts had completely rotted and therefore they sheered easily and welded themselves into the block pretty tightly. It was touch and go but in the end I managed to tap them out without busting any threads. I'm assuming there has been some gasket failure or something which lead to all the water ingress in the bolts? The bolts that failed were the ones around what I think is the main water jacket inlet/outlet on the left front of the block.
Everything's mostly apart now with only a couple of minor things to do (although I haven't done anything about the oil galley plugs yet...). Obviously, I've not touched the head yet but it's next on my list.
I'm still forming a plan on what to do as next steps so all input is welcome! I'd like to get the block cleaned up really well inside and out - a thermal pyrolysis/blasting/ultrasonic treatment if possible but not sure how feasible that is from a price perspective! I'll look to overbore by as much as I can so I'll be looking for a machine shop who knows what they're doing with L6's - I don't want a lead paperweight because it got machined out too far!