Diagrams of Taylor-drilled Crankshaft - 01.08.2008

Let's start w/ a stock 928 crankshaft. For a stock 928 crankshaft the:

- 1-5 rod journal is connected to the #1 main cross-drill.
- 2-6 rod journal is connected to the #2 main cross-drill.
- 3-7 rod journal is connected to the #4 main cross-drill.
- 4-8 rod journal is connected to the #5 main cross-drill.
- The #3 main (center thrust bearing journal) has no cross-drill

Taylor leaves all of these existing oil passages in place but then adds a bunch more. They add:

- new cross-drills at #2, #3 and #4 mains
- connect 1-5 rod journal to #2 main
- connect 2-6 & 3-7 rod journals to #3 main
- connect 4-8 rod journal to #4 main

With a stock 928 crank, each rod journal is supplied from a single main. After modification, each rod journal is supplied from two adjacent mains. For example, in the stock crank the 4-8 rod journal is supplied from the #5 main. Taylor adds a cross-drill at the #4 main. They drill out the existing plug and extend the intercept from the #4 rod cross-drill to the #4 main. The whole oiling system within the crank is now inter-linked.

Here are some diagrams: