Here's some info reguarding the pintle, ball and disk types.
Taken from
http://importnut.net/ignitionfuel.htm originally posted on
http://www.automotiveforums.com/
Fuel Injectors
There are two common types of fuel injectors, pintle and disc (Lucas style). Pintle injectors have a superior spray pattern to disc actuated injectors, but disc injectors are less expensive and generally flow large amounts of fuel easily. If possible, always choose high flow pintle style injectors, as fuel atomization at anything other than full throttle (high velocity port flow) is superior, leading to better drivability and economy. Below is a picture illustrating what I mean about the spray patterns…(pic below)
The following is taken from SDS (simple digital systems fuel management systems) websight
http://www.sdsefi.com/injectors.htm
Nozzle Types
There are essentially 3 different types of nozzles:
Pintle
This is the most common type and still the best. A tapered needle sits on a tapered seat. When the solenoid is energized, the core and needle is pulled back, allowing the fuel to discharge. This design has been well proven for over 30 years.
Disc
The Bosch disc type uses the same type of actuation mechanism as the pintle type but replaces the pintle with a flat disc and a plate with tiny holes. These work fine with a good spray pattern but are slightly more prone to deposits plugging the holes. The Lucas type buries the disc up inside the body to reduce the mass of the assembly for quicker response. The Lucas types typically have a very narrow spray pattern which can affect idle and throttle response in some cases.
Ball
The Rochester division of GM makes the ball type injector for OE applications as well as the larger flow race types for MSD. These use a ball and socket arrangement. These have excellent atomization and a wide spray pattern but are also prone to partial plugging by varnish deposits.
Injectors: ball-style fuel injectors or pintle-style injectors
