turbo injectors in a NA engine
 

What would happen if I put injectors from a turbo 617 engine into a non turbo 617? I as because I have a good set of injectors for my 85 SD, and just purchased a 240D with a 617 engine. The SD didnt need injectors. The "340D" as it has been called by my mech., needs injectors.

Thanks.

I would just check the opening pressure on the side of the injector and see if they are they same. If they are, they should work just fine.

NA 617's use a 115 bar injector while the turbo uses 135 bar opening pressure. Be interesting to see if it they would work or not though....

I don't think they would work. Even if the nonturbo IP pump could produce enough pressure to open the injectors the timing would be way off.

I think the pump will be able to make the pressure and since it is a positive displacement type pump, the time for the fluid to reach 135 bar instead of 115 bar is probably negligible. Long term it might not be ok for the injection pump, as the (less than 20%)higher loading on the parts may wear things out sooner.

In all likelihood the vehicle will run, and possibly a little better due to the better fuel atomization and shorter duration injection event (more time to burn the fuel). One of the features of the new CDI systems is a very high fuel pressure in the "common rail" so the spray pattern is more consistent for each injector, and also between injectors (they all see exactly the same pressure, theoretically). Additionally the duration of the injection event can now be controlled, as it takes less time to get the fuel in there, which leaves more time to burn the fuel, or as MB has elected to use the time, they can vary the injection rate by throttling the injector. They use this feature to get a little initial squirt burning, and then spray the rest of the fuel into a burning flame front. Gives lower noise and much better emissions and economy.

So, before I would put those injectors in the head, I would check to see what the max design output pressure of the pump is. I have no data to give you here, but I am sure if you check with a Bosch injection pump service facility they can advise you.

Good luck, hope this helps, and if you elect to do this keep us informed. Jim