Contact Information

an image
G.W. Dale Ltd
139 Newcastle Street
Stoke on Trent

Phone: +44 (0) 1782 837 665
Fax: +44 (0) 1782 839 550

Injector Technology

Product Function

Directly secured to the engine cylinder head, the injector introduces fuel into the engine in the best form for optimum combustion. This requires the breaking down of fuel into tiny droplets, ranging in size from twenty to one hundred microns diameter, and spreading the droplets evenly through the combustion chamber.

The injector consists of the nozzle-holder and the nozzle, with the nozzle having to close rapidly at the end of the injection in order to prevent the combustion gases forcing their way up into the injector.

In the more technically advanced diesel systems (i.e. EPIC, DPCN), the nozzle holder acts as a sensor for measuring the injection flow rate and sends this information back to the electronically controlled pumps.

Product Range:

Multi-hole long-stem nozzles - Used on direct injection modern diesel engines that require an injector with a small nozzle stem diameter. These nozzles are generally used on engines fitted to commercial vehicles and for industrial / agricultural applications.

Multi-hole short-stem nozzles - Working in an identical manner to the long-stem, this nozzle was fitted to DI engines throughout the 1970's and 1980's. The majority of applications were fork-lift trucks and cranes.

Pintle type - Used on indirect injection diesel engines, pintle nozzles can have either long or short bodies depending on cylinder head design. The needle valve is extended to form a 'pintle', which protrudes through a single central hole in the nozzle body. Pintle profile can vary to suit a particular engine type.


Pintaux type - The pintaux is a variation on the basic pintle nozzle, incorporating an additional auxiliary spray hole. The auxiliary spray is directed towards a glow plug and hence aids starting under cold conditions and reduces engine knock when idling.

Two-stage injector - the two-stage injector has been designed to combat the problem of excessive engine noise. The injector allows a low rate of fuel flow initially, followed by injection at a higher rate, reducing the rate of combustion pressure rise, this results in significant reduction of noise without a loss of power.

Service Policy

We strongly recommend that nozzles are replaced as a complete set every 50,000km. Whilst beyond 110,000 km the whole injector unit should be replaced.

nozzle spray pattern

Scaled or worn nozzles are detrimental to the efficiency of diesel engines and replacement at these recommended mileages will ensure:

  • Improved driving comfort
  • Increased vehicle lifetime
  • Reduced fuel consumption
  • Improved emissions to comply with the increasingly strict European legislation