Split injector nozzle

I got a set of 4 nozzles "thrown in" with a bunch of stuff I bought from another TDIClub member in Europe. They are DSS R 0.360R which are sold here:

https://dss-fr.com/tdi-tdim-vp/51-dss-r-0360r.html

I sent them to DFIS in Portland to have them mounted and balanced and one of the nozzles split all the way through the tip as soon as pressure was applied with their diesel testing equipment. I just thought it was interesting so I'm posting these pics in case anyone was interested.

Holy Moly!

Hot dog indeed. I wonder what caused that.

i guess they really were "thrown in"

When the nozzle was manufactured, it was machined improperly down into the tube that the needle slides into and the metal was too thin. The spray holes in the tip became a weak point when combined with the thin metal and it split when pressure was applied. Basically it’s a manufacturing defect.

I'd bet on a material defect rather than machining
easy to get bar stock with laminations in it

Dang, talk about nozzle imbalance!

Fan spray pattern would be good for +100 HP.

DSSR 0.360 quality issues are quite bad. I have like 12 bad nozzle...

I still dont understand that size, 0.320 is good up to 380bhp.

Yucca said:

I still dont understand that size, 0.320 is good up to 380bhp.

Click to expand...

I remember someone over there noticing lower power with the .360s than with .341s

has it been tried to remove the edge filters in the inlet of the injector bodies yet? Pretty common thing to do with higher flow injectors in tractor pulling over here.

I think that problem is just rotary pump. Injection pressure goes too low with 0.360 or bigger nozzle sizes.

Yucca said:

I think that problem is just rotary pump. Injection pressure goes too low with 0.360 or bigger nozzle sizes.

Click to expand...

I was under the impression that its not how that works for these type injectors and pump. (X) in PSI at the pump head is the same (X) in PSI at the nozzle before it opens. THe Orifice size should not dictate (X) PSI of the pump at all and only would create a lower pressure from the spray pattern and orifice size by decreasing velocity, but my understanding is that the spray pattern is MUCH better with larger newer nozzles and thus even a lower velocity in fuel leaving the nozzles is negated by the spray pattern and thus WHY most tunes end up lowering (raising the number) IQ on the pump its self.

The only real reason an IP upgrade is usually necessary is to retain a high PSI at a high RPM as injection pulse increases as with flow but pump head pressures maintain the same PSI but lower velocity at the nozzle due to buffer time from the nozzles opening more often.
Adding a 2nd pump (intank or Inline) usually only combats the higher fuel output at higher RPM's for this reason stated above, and thus the IP cant keep up enough fuel to the body from a vacuum draw alone.

Or am i mistaken is what pump your referring to?
This was a discussion i had with Chris from Kerma years back about IP mods and nozzle requirements. It has been years since that conversation but thats the jist of what i remember.

I abandoned the DSSR nozzles and ordered the .360 version of these:

https://www.darksidedevelopments.co.uk/products/gibonta-race-nozzles-for-1-9-2-5-ve-engines.html


I have a 12mm pump so hopefully it will be ok when it’s all done. (I’m still building everything in my “free” time.)