Myth: Yeah, I used to have one of those VW buses with the Porsche engine in it.
Rant: Probably every bus owner has heard this line at least once, usually from some stooge who comes strolling up to them in the parking lot at KMart. But sadly, it just ain't so.
this one's a fuelieVariations on the 1700/1800/2000 cc engine--commonly though somewhat mistakenly often referred to (including by yours truly) as the "Type IV" engine--were installed in...
...the VW 411,
...the VW 412 (and what a lovely pair of monsters those two make),
...the Porsche 914/4 (tellingly, sold under the marque VW-Porsche everywhere except North America),
...the 1976 Porsche 912E, and, of course...
...1972-1979 VW Type IIs (buses) bound for the USA, like this one. (And, I should add, 1980-1983.5 Vanagons.)
The temptation to mention these lofty Porsches as they relate to the lowly VW bus is too much for some to resist, so the connection gets strengthened and offered as some esoteric, wildly counterintuitive fact. Those perpetuating this myth are typically the same kind of people who insist that we only use 10% of our brains, or that engineers can't explain how bumblebees can fly.
that's not to say there aren't a few genuine Stuttgarter powerplants hidden under Wolfsburger clothing; don't try this at home
The boring old truth is that the blame for the 1700/1800/2000 engine belongs to VW. Sure, the VW and Porsche engineering camps were at least as incestuous in the 1960s (when the engine was designed) as they are now; Porsche almost certainly helped VW with it just like they helped VW with everything, and vice versa. But you don't think a Beetle has a Porsche engine in it simply because a Beetle's engine and a 356's engine were dreamed up by the same guy and look a lot alike, right? Right. Porsche significantly tweaked it, mostly in the cylinder heads I'm told, before installing it in either of their cars in any case. So don't go thinking that the engine designed to push a slick little 2,100 lb. 914/4 down the road is at all appropriate for moving 4,600 lbs. of bus around. It isn't.