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Bosio DLC 520 (ULSD RATED) Single Nozzle

Pricing: $98.00


Bosio ULSD 520 - Single Nozzle

ULSD Rated

Product ID: 520ULSD


Direct replacement for the AFN / ASV Nozzle but with DLC Coatings


OEM style nozzles are 205 m nominal
Stock replacement for European 110 hp AFN / ASV motors. 

- Optimized spray pattern
- Closer tolerances
- Hardened wear surfaces
- DLC Coated needle for superior wear characteristics with ULSD fuel
- More power than the OEM parts
- More torque than OEM parts
- Less exhaust smoke for the same power output
- Improved economy 
- Better Throttle Response
- Cleaner Startups


All of our Bosio VE nozzles ship with new OEM sealing washers included.


Optimized 205 m Nominal Hole diameter


ULSD (Ultra Low Sulfur Diesel) Rated Nozzles 
ULSD aka "Ultra Low Sulfur Diesel" has brought about a new set of challenges to the Diesel Injection Systems industry. ULSD specifications more specifically "ASTM-975 1.1.4- S15". 
ULSD Rated Nozzles are unique in that they are literally built around an ultra-hard "Diamond Like Carbon" coating aka "DLC".   DLC provide a "Diamond like" surface with superior surface qualities in respect to smoothness and uniformity that greatly reduce sliding friction. This allows the nozzle's needle to cycle faster, with improved fuel quantity control thru better needle response.
Another key benefit of DLC is that it results in a 50% or more increase in component life when compared to a non-DLC nozzle type running ASTM 975 USLD fuel. A nozzle is comprised of two precision made pieces, a high nickel alloy nozzle and a high carbon steel needle. A non-ULSD Rated nozzle suffers from the effects of reduced lubricity as a result of the loosely controlled lubricity specifications under ASTM 975. As a result, there is a wide range of actual fuel quality from one retailer to another.
Unfortunately, wear is greatly increased due to reduced lubricity on the internal sliding surfaces. More specifically, ULSD fuel increases the wear rates in the needle support regions which over time (3,000-4,000 running hours) leads to decreased nozzle performance.  As wear increases, the gap between the needle and nozzle widens and fuel (pressure and volume) leaks back into the injector and power and efficiency are lost due to poor pressure response of the injector nozzle.
DLC increases the hardness of the needles sliding surfaces thus increasing its service life by reducing the sliding friction and increasing the hydrodynamic support that the needle utilizes to remain centered in the nozzle bore.
ULSD nozzles carry a small premium over the non-DLC types but with nearly double the service life(or more) of the nozzle your direct savings are realized not only thru greater durability but improved function of the nozzle meaning better fuel economy and lower emissions all of which translate into greater longevity of your diesel engine.
Nozzles Explained:  Please click here to read the fact sheet.


Reviews / Q&A

Reviews and Q&A


  • DLC520single
  • DLC520single
  • Bosio
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Shipping Information

  • Item Requires Shipping
  • 0.1 lbs.
  • W3.0000” x H3.0000” x L3.0000”