With all the 8mm M pumps that are out there I am really surprised that there has not been more of an effort to bring the Nozzles up to the same delivery specks. then again, maybe there has been and it was not promoted much.

To that point, I just learned that a fellow forum member Greazzer has developed his own nozzle for the 617a.. He calls it the 242 nozzle and that does not reverence the Bosch 242 nozzle.

A link to a video of him pop testing the 242 nozzle https://www.youtube.com/watch?v=-CcZTrFWZGo

I do not know any specks on this nozzle. I believe he started a thread on it but I can't find it.





I have been out of the MB game for a bit, but after acquiring a very clean 300d I am newly inspired and the Nozzles are the next piece in the fueling puzzle. These nozzles are intended to go with larger element pumps. I will be running 10mm elements.

After reviewing my notes from the last time I looked at this I resumed the designing of what I want. I have seen extra flats ground into the pintle to increase flow at the same lift, but I am not of fan of that because it reduces the throttling capability of the nozzle and creates streams of fuel which leads to black smoke and worse high EGTs at higher fueling and speeds.

Stock nozzles were never intended to pass 2X+ the about of fuel in the with the same pulse width as the fuel left the factory delivering. The increased quantity over the same pulse width forces the pintle up higher then it was intended to be and at an extreme fuel surge, the pintle can be pushed out of the throat entirely.

My goal is to at lest double the flow area at the same pintle lift, maintaining throttling and hopefully minimize heavy streaming at higher delivery rates and speeds.

Material came in yesterday to make the prototype pintles out of so I am excited to see things progressing. Once I have the Nozzle bodies modified and the new pintles made, I will set up a flow rig to test the flow and pattern at 2000 psi. If that looks ok, then I will test run them on a 617a I have yet to set up on the dyno. Still several ducks out of place but making progress.

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I am waiting on parts for a different project and the tooling I needed to modify the nozzle body came in so I thought I would open up the hole and lower the seat in the nozzle body.

The sock hole diameter is .040 inches.. I opened it up to .070 inches. Doing that took away most of the original seat area and increased the throttle throat depth, so I had to lower the seat to restore the sealing area and restore the throttle throat depth.

Next step is to make a new pintle.

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