I prefer to go by what the block says...The smaller diameter stem allows a wider stem seal. The seal's flex (same valve stroke) can be better tolerated over a 'longer' distance from seal outer edge to stem. Longer lasting seal, less seal wear.
The valve, seal and upper spring seat change took place (on the engine assembly line) at engine 770 001 going to 7 mm. The lower spring seat was then changed at engine 800 001.
The "1Z" in the 1997 B4 Passat is using the AHU engine despite the sticker in the trunk. Since the 8 mm valves are not available and 8 mm seals are not available, there isn't any reason to not transform a 1996 B4 1Z head into an AHU head with the better 7 mm seals as were used in the 1997 B4 with its "1Z".
The sticker (probably long gone by now) on the cam sprocket cover has the engine code and engine build serial number.I prefer to go by what the block says...
That I believe. It's why "Made in USA" means nothing anymore, except that there's no overseas cargo shipping in the cost.The Wolfsburg plant has, since its start, been a soup of all kinds of refugees and languages, and has struggled to maintain a consistent workforce and is easily not paying the local equivalency of "above average".
Yeah, never really had a concern over Puebla cars personally.And yet the Puebla plant is VAG's most awarded assembly plant on the planet, including the Wolfsburg plant.
The Puebla plant enjoys an almost entirely Spanish-speaking workforce, that are paid well above average, and jobs there are very sought after.
The Wolfsburg plant has, since its start, been a soup of all kinds of refugees and languages, and has struggled to maintain a consistent workforce and is easily not paying the local equivalency of "above average".
Some really good books out there regarding Volkswagen's history around the world. If more people availed themselves of that, they'd ditch the notion that "other-than-German" assembled cars are somehow inferior.
Puebla has been assembling Volkswagens since long before Audi designed the first water-cooled engine for Volkswagen.
I've purchased five Volkswagens brand new. Three Puebla cars, one Wolfsburg, one Emden. The Puebla cars all were flawless. Both the German cars had several build quality issues. When I PDI'd them new, the Puebla cars were rarely ever a concern.