2003 Golf SVO Nozzles - Fuel Economy, Hypermiling, EcoModding News and Forum

Lostyankee · 02-08-2009, 11:37 PM

Anyone know the #'s ( true hole size) & angle of nozzles recommended for SVO in a 1.9l Golf TDI automatic?

tasdrouille · 02-09-2009, 08:04 AM

What are you concerned about? Stock size is fine. Since you have an auto with an 11mm pump head, your nozzles are .158. You could go to .184 (stock 5sp size), but that would not help economy without tuning.

Lostyankee · 02-09-2009, 04:27 PM

Other sites state there is a issue with stock nozzles spray angle + VO resulting in deposits on far cly. wall / rings & Elsbett (sp?) of Germany claims to have 'specially made' nozzles for their kits. While most problems should be moot with preheating injectors to 190*F, there is human error lurking out there & mechanical goodies do fail, so I would like to have nozzles better 'tuned' for VO.
Is this just a dream or are VO nozzles available? Or is this not a major issue.

tasdrouille · 02-09-2009, 04:59 PM

I am unaware of "VO" nozzles. With stock nozzles the spray angle makes it so fuel is sprayed into the piston bowl, right at the bowl's lip, so fuel is never directly sprayed towards the walls.

What can happen though is that since VO is more viscous, it will form bigger droplets than USLD. If the droplets are too big, the fuel might not all burn and you will get deposits on exhaust valves along with crankcase oil dilution. If anything, bigger holes will just make bigger droplets.

Just make sure you heat the VO properly, be anal about your system, and you'll be fine with stock nozzles.

Lostyankee · 02-09-2009, 06:32 PM

Thanks Tasd.
That agrees with my research.
I think some folk want us to believe in their 'magic' to sell parts.