TD42 engine upgrades

Q. I own a LWB GQ wagon with more kilometres on the clock than I care to remember. It’s running a TD42 engine with a DTS turbo kit that was installed when I picked it up about 5 years ago. Recently the engine has started to blow blue smoke and use a far bit of oil, so I’m planning to pull it off the road and have the engine rebuilt.

The question I have is, I’m wondering if there is anything extra that can be done to these engines during the rebuild to get more performance out of it. I figure while I’m going through the process of rebuilding it, I may as well go all out and beef it up if it’s possible. I always hear of guys with petrol engines putting in different parts, like aftermarket cams, ceramic coated pistons and upgraded fuel systems, during rebuilding. Can these be done to diesels and do they give you any benifits or am I wasting my time and money? 

A. Firstly make sure you use ‘name brand’ parts when rebuilding your engine. There are so many poor quality parts around now. Secondly make sure you accurately measure ‘piston protrusion’ (piston protruding past the top of the engine block) and then match the right thickness head gasket to that protrusion. This is where a lot of rebuilds simply come unstuck (too much piston to Cyl head clearance…less kick in the engine!). Sure you could clean up and open the porting in the head up a little bigger. Havent seen a ‘hot cam’ work successfully in a Diesel so best to stick to stock cam. Leave the Fuel system stock because it can be adjusted to easily blow the engine which you don’t want. Larger exhaust will help. Final tuning on a dyno with particular care taken to the exhaust AFRs and turbo boost.