[v8volvo]

Meyle plugs probably won't last as long as Bosch but should be able to get the engine going.

With oil in the cylinders, correct timing, and functional glow plugs these engines will usually start right up no matter what their condition. The added oil is a major starting aid since it not only helps the rings seal but takes up some combustion chamber volume, providing a compression ratio boost, plus the oil itself is combustible as a fuel. Even a heavily worn engine will usually start easily when given this treatment. Also, you know this engine used to run because it must have been running up until the point when the timing slipped and damaged it (correct? I forget the circumstances when you got it).

It is theoretically possible that while it sat since then it got some stuck rings but that is not a common occurrence with these, especially not on all cylinders. Fuel washed cylinders can be an issue also but in either of these scenarios the added oil should help give enough sealing to start.

Don't give up yet. I think you're almost there. Sounds like you have fuel to the injectors and have seen smoke, so fuel is getting in and trying to light off. The question is whether it is getting into the cylinders at the right time. I suggest checking injection timing again. It could be off by 180 degrees, in other words pump timed correctly to the crank but not to the cam. Probably everyone here has had this happen once or twice at some point since it is easy to miss.

Can you confirm your injection pump timing setting relative to the crank TDC mark, and then with the crank and IP marks at their TDC reference, check the position of the camshaft? There are two ways to do this: 1) remove the valve cover and confirm both lobes for #1 cylinder are pointed upwards, OR 2) slacken the two mounting nuts for the vacuum pump enough to see if the pump is under spring tension (drive plunger fully extended) or not (plunger fully retracted). The plunger should be fully retracted with the cam at #1 compression TDC. If it is extended, then the cam and IP are out of phase and you need to retime the IP 180 degrees from where it is now, and that will be the cause of the failure to start.

If you confirm the timing of the IP and cam is already correct, then the next step would probably be to take a video of the engine cranking so we can see and hear it, to find out if there is something else going on that we have all missed so far.

Good luck, I still have a hunch it will run.