At one time I hung out with a dune buggy crowd. They tried to get every extra cubic inch out of their VW engines. Some had stroker cranks built up. this entailed welding up the up of the rod journals and then regrinding the crank pins and re heat treating the entire crank shaft such that the stroke was increased.

The flywheel was held to the crank by four or on extreme cases eight dowel pins and a single large bolt through the center. Pop the clutch hard enough with a strong enough clutch would shear off the dowel pins flush with the crank. With many hundred dollars invested in the crankshaft there was a market for salvaging the crank by removing the dowel pins. Those shops that did this were very secretive of the method employed. I caught one of the experts who told me that this crank was the last one that he would ever do as he was giving up his shop that day. He agreed to divulge the secret of the process.

His method was to grind the exposed end of the dowel pin so that there was a flat spot so that a drill would not wander. Then he carefully with a tungsten carbide drill bit and copious lubrication would drill through the dowel pin. Then fill the cavity with thick grease such as wheel bearing grease. He then used a drift punch that was the same diameter as the hole in the dowel and with one sharp hit, the hydraulic pressure would pop the pin out. One of the tricks was to use the smallest diameter of drill/drift punch to develop the greatest pressure and have the maximum surface area on the dowel pin to work on.

His method was to grind the exposed end of the dowel pin so that there was a flat spot so that a drill would not wander. Then he carefully with a tungsten carbide drill bit and copious lubrication would drill through the dowel pin. Then fill the cavity with thick grease such as wheel bearing grease. He then used a drift punch that was the same diameter as the hole in the dowel and with one sharp hit, the hydraulic pressure would pop the pin out. One of the tricks was to use the smallest diameter of drill/drift punch to develop the greatest pressure and have the maximum surface area on the dowel pin to work on.