Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
N/A DI Diesel engine mods


N/A DI Diesel engine mods

I’m about to rebuilt an Isuzu 4JA1 2.5L 4 cylinder non-turbo direct-injection diesel engine, with mechanical injection pump of my little shop truck.
Generally the only significant way of gaining a decent power boost, over stock, would be to turbo-charge the engine, and it probably would be a lot easier.

But, if kept naturally aspirated, what can be done during the build-up, to improve efficiency just a little over standard? Will drive-ability be improved by balancing the bottom-end, gas-flowing/port-matching and polishing the cylinder-head? What sort of gains would be likely possible on an engine like this? Does the same principles apply as with gas/petrol engine tuning?

If you do port, how should it be done? Exact port match, or do you aim for a slight mismatch?
Any tips on keeping up air speed?
Should both exhaust and intake ports be polished?

On the bolt-on/external side, one could fit tubular exhaust manifolds, would it be worthwhile to custom fabricate a set? And also set up a cold-air intake and free flow exhaust system? Turning up the injection pump, could yield more power, but probably increase the fuel consumption.

Anyone done something similar to an OM616, or Ford Transit 2.5 DI?

10-22-2015, 02:12 AM

Forum Jump:

Users browsing this thread: 1 Guest(s)