bump
anyone bought these nozzles before?
i've got a set of these in my car right now .
they have a flat spot on the needle if the injector that many people claim is desgined for self cleaning and thusly ideal for veg oil .
the flat spot causes a different spray pattern , and i found that at stock vw pop pressures , about 1/3 of the spray was droplets rather than mist .
until i got around 2500 psi then things started to clean up .
before my next trip to edmonton i've got a set of gtd nozzles i think i'm going to try .
FWIW Giles says he wouldn't use Merc nozzles himself, and having seen the spray pattern I've put the set I bought on the shelf unused as well. Like burnt_servo I found that the stock breaking pressure wasn't enough to generate the mist that the VW swirl chamber is expecting.
It's my understanding that the topology of a Merc head is quite different from the heads we use, and it would make sense that the nozzle design reflects that. Mind you, I don't use veggie....
My guess is that Burnt_servo is going to like the GTD nozzles just fine, at stock breaking pressures.
I just went from the Merc tips to the "GTD" tips as well.
I didn't notice a difference in power but I do get a smother idle.
there is a "white paper " from vw on the beginings of the vw diesel around here somewhere .
after reading that i found out that vw uses a "swirl chamber " not the standard precup chamber alot of other engines use .
the swirl chamber allows the diesel to rev like a gas engine .
that also means the injectors need to produce a even . circular spray pattern to have a even swirl and even burn .
the merc tip only produce 2/3's of a circular spray , and 1/3 kind of sprays back in toward the centre of the circle with much much larger droplets .
this wouldn't be so bad if a guy could index the injector to the combustion chamber so a even amount of fuel is sprayed to both of the swirl impresions on the piston .
but the needle in the tip is able to turn in the injector , so this is impossible.