D24T.com - Diesel swap (build thread)

Nice. You definitely have the only one of these. Cool that it worked out and actually made it through some events.

You will probably find the mains and rods are in good condition to reuse and can save some money there. They virtually never wear at all unless the engine gets run out of oil. But you might discover a rebore and a set of pistons will be required to bring the blowby under control. These engines are almost completely immune to bore wear when synthetic oil is used but many of them had poor quality conventional oils used in the early parts of their lives and Volvo specified long oil change intervals to make matters worse. Deposits behind the rings led to rapid ring and bore wear under those conditions. If blowby is an issue you may find a pretty big ridge and some taper and then fresh rings won't be much use to you. But you can rest assured that if you keep good oil in it in the future it won't happen again.

If you're digging into the bottom end and thinking of adding a turbo someday you may just want to start fresh with a turbo block and rotating assembly. The turbo bottom end provides piston cooling jets and a bigger oil pump and other upgrades that will help it survive at the boost levels you mentioned. Not much point in spending money going through the NA engine if you plan to add a turbo. To make use of the turbo boost you will also need a turbo injection pump or to do a lot of work to your NA pump to retrofit the turbo aneroid device.

As for the fuel leaks you mentioned, the top cover seal can be replaced without rebuilding the pump, though you need to know what you are doing and work carefully to avoid damage or contamination and get it dialed back in after the work is done.

Someone did compound turbos and it worked out well, but be cautious with your injection timing settings and consider head studs if you want to run significant boost and keep it reliable for an enduro. Wouldn't be much fun to pop a head gasket halfway through. 20 psi should be perfectly fine for reliability if the engine is built well and you keep EGT and EOT well within reason and ensure it makes no smoke. Too much fuel will cause more damage than too much air.