After putting in a solid three months to the Silver S4 that drove away in August I’ve been eyeing this engine that is sitting in the corner of my garage.
The story of this build goes back to the early days of the B5 S4 when the S4 and driver (Don Istook) were actively racing.
Istook’s Motorsports in Fort Worth Texas took on the project that was envisioned to match a B5 S4 engine block, A4 2.8L cylinder heads, and a Supercharger.
The engine underwent a substantial amount of work consisting of:
- Modification to the oil pump
- Micro honed engine bores
- Polished engine bearings
- Boat tail crank saddles
- Lightened crankshaft flyweights
- Cryo treated and micro polished crank
- Pauter rods
- Thermal ceramic treated pistons and skirts
The 2.8L cylinder heads saw some work as well:
- Port & Polish of the heads
- Multi-angle valve/seat work
- Before and after flow testing
- New springs with Cryo treatment
- Surfaced cylinder heads
- Thermal ceramic treated exhaust ports
On the back sat an Unorthodox Clutch Kit:
- Ultra G Aluminum Flywheel
- Ultra G Feramic 6 paddle spring disc
- Ultra G high force pressure plate
After all that work the engine was placed in an unassuming B5 A4 and parked outside a shop waiting to be finished.
And there it sat and waited, and waited, and waited. Then I was contacted and asked if I’d be interested in trying to complete the project, only now doing so with Turbochargers instead of a Supercharger.
It isn’t often that something new and unusual comes along with the B5 S4, and this was unusual. I said yes and headed off to pick up the engine.
Now back in my garage this piece of Audi history is again slowly progressing towards completion.