[HarryD]

would guess the real answer to a built VW motor vs a stock 912 is what is different.

To get 90 hp out of the 1600 cc motor, Porsche had to do something different than what VW did in their 46 hp 1600 cc motors while making motors that would last 100,000 miles plus.

While I am no expert, I am thinking the extra power came from differences in fuel induction, head design, exhaust design, compression ratio and cam. Longevity for the higher hp comes from better material selections and improved cooling.

If you look at the cost of building a high hp vw motor, I would think you come close to the cost of rebuilding a stock 912 motor.

What do the experts think?