Quote:
Originally Posted by tomnik
Waiting for you high speed shots.
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I've accumulated a a few shots so here we go. All these were filmed at 240fps and played back at 24fps so you're seeing 1/10th speed.
The DN0SD265 stock nozzle that came out of my car. I cleaned and rebuilt it 15K miles prior.
dn0sd265 15k - YouTube
DN0SD265 from the JY, unknown age and mileage.
Pop testing old DN0SD265 - YouTube
Brand new DN0SD193 Bosch India nozzle made for VW set to 2100 psi. This nozzle has less lift than the stock MB nozzle with a simple non flat cut pintle. It also has less lift than the stock MB nozzles. I ran these for about 1000 miles before switching them out. I notced they are louder on cold start but quieter once warmed up than the stock nozzles. After a while they started to smoke at idle and high RPM WOT which I didn't like. The fuel coming out of these nozzles seems to hit with a lot more force than any other nozzle. I figured that would be good but I guess not.
DN0SD193 India brand new - YouTube
The last video is what I'm running right now. Bosch France DN
12SD290. have a 12 degree spray angle. They were originally used on early 90s Fiat and Alfa diesels. Yes, they are very different from stock MB nozzles and quite the opposite of what MB considers a GOOD spray pattern. The video doesn't really tell you enough about the spray pattern. As seen from the top on small strokes it makes a triangular pattern, sort of looks like the MB star. On large strokes it makes a perfect cone spray pattern.
Driving these nozzles I notices a few things. Once warmed up the engine is extremely quiet. I can hear my sticky valve lifter quite clearly. There is ZERO smoke at idle and low throttle angle, a little bit of smoke at high. Theres a lot more torque at low RPM before the turbo builds any boost. Works well with the manual transmission.
DN12SD290 - YouTube
I wasn't able to capture a good screen shot of the DN12SD290 nozzle but the pintle looks like the picture on the right.
The DN0SD193 nozzle looks like drawing "1". The stock OM603 DN0SD265 nozzle looks like the picture "2b" with its flat cut.
Here's what MB has to say about nozzle spray pattern. Clearly the DN0SD193 nozzle is most like the picture so naturally I assumed this would work well in the OM603. It didn't.
Even compared to the stock OM603 nozzle, the 12 degree Fiat/Alfa nozzle has more low end torque. The plan right now is to put a few miles on these nozzles and see how they do in the long run. I have a couple of other nozzles I want to test out if these don't do well.
The 12 degree nozzles are popular on the German language SVO/WVO/biodiesel forums, mostly in swirl chamber engines, not MB prechambers. The theory is that the 12 degree nozzles can push fuel onto the walls of the prechamber without hitting the inpingement ball in the center of the chamber thats supposed to atomize the fuel. My experience is that the 12 degree nozzles work very well in the MB prechamber but its something to keep in mind.