Disc vs Pintle style EFI injectors

[tjwong]

OK all of you fuel experts out there, can someone tell me the advantages of the disc style injector over the more popular pintle style that are most commonly used in Bosch, Rochester and GM Multec injectors. I already know that Disc injectors of the same rating are very accurate from injector to injector. What I want to know is would a disc injector offer better drivability, better performance in High HP applications, durability, and reliability under high fuel pressures (50 to 75 PSI).

 

[PJGD]

The disc type EFI injector has several advantages over the pintle style, and some disadvantages:

- The disc is significantly lighter than a pintle valve. This results in less audible noise (Yes, I know, it is a small effect, but noticeable at idle if you have a refined engine).

- The lighter disc valve typically allows a wider turndown ratio, or dynamic range than pintle injectors.

- The disc valve, being a lot shorter than an equivalent pintle means that the discharge orifice is back up in a long tunnel and is demonstrably less susceptible to tip deposits. This may provide a longer service life.

- It may offer a different set of orifice and spray pattern options relative to pintle injectors.

-On the down side, because the valve has to lift against the fuel pressure, the combination of geometry and magnetics associated with the disc mean that it is probably less able to work at elevated system pressures than a pintle; ie, it will quit working before the equivalent pintle does.

- Extra manufacturing effort is required on valve and seat flatness to achieve the same standards of seat leakage as pintles.

Hope that helps

PJGD