Any bets on how long this engine will survive?

Hard to say. The worst I see are the vertical scratches in the #2 cylinder. If that's the worst of it that probably wouldn't affect longevity as much as compression and oil burning.

What were the PO thinking? Chipping and turning up the boost OK but you better step up the maintenance and inspection schedules to match.

That's what I have been thinking/hoping also, maybe some mild effects of imperfect ring seal but no major accelerated ongoing wear. Will be a lucky outcome if so. I could have kept running the hone some more and probably eliminated the scored areas completely, but I figured it after a while it would increase ring end gap and piston-bore clearance too much and begin to hurt more than help, so it was a difficult call as to where to stop. I figured I would aim to make the scored areas much shallower but not completely gone. I think you're right that it has to be losing some compression there and presumably allow some oil past too.

It will be interesting to see what this engine is like to start in the winter. Maybe I'll try a compression test on it sometime for curiosity's sake. No obvious change in oil level so far to indicate bad oil consumption, but I have only put about 500 miles on it.

Good question. I have no idea. I suspect unfortunately (for them) they might have been mainly just misinformed. The engines have a reputation for being "bulletproof" and it seems like they sometimes suffer from harsh use and neglect as a result, from owners who think it means nothing can kill them. The PO may have believed that. The guy who sold him the van (and had done the conversion) may not have tried to dissuade him.

I like those low budget, not-much-to-loose projects.

Except time!!!

It's amazing how abused an engine can be and still run well. Nice recovery of that vehicle.

It sure is possible to lose a lot of that. :p

As long as it's fun and/or interesting, though, I guess there are worse ways to waste time. :cool:

The TDI I was working on in this thread is still running nicely and to my great surprise, appears to be using very little or no oil so far. I have done a couple thousand miles in it now, running it on my commute to try to find any bugs, but so far I can't tell it apart from an average decent condition motor. As you say, amazing sometimes how an engine can get right up to (or even beyond) the brink of destruction but still carry on afterwards with seemingly minimal effect.

The one issue I have had with this engine, as I mentioned earlier and unrelated to the internal engine problems and repairs, is a very bizarre injection pump failure that I will share here for curiosity's sake when I have a little time and can get some pictures taken. As a result of that problem, shortly after getting it on the road I had to tear it back apart again and replace the IP with a used one, which I resealed beforehand. I also replaced the timing belt while I was that far back into it, given the indications thus far that this engine is ready to run for a while now and is seemingly worth one or two other new consumable parts.