Category Archives: Engine

Next Project – Finish Engine Build

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.

Don Istook Built Engine
Istook Built Engine

The Past:

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:

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
Istook Engine Clean Up
Engine Cleanup

The Heads:

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
Istook Motorsports worked 2.8L Cylinder Heads
Istook Motorsports worked 2.8L Cylinder Heads

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
Istook Engine Date Marking
Date Marking

The Body:

After all that work the engine was placed in an unassuming B5 A4 and parked outside a shop waiting to be finished.

Audi B5 A4
Audi B5 A4

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.

Istook Motorsport Engine Retrieval
Istook Motorsport Engine Retrieval

The Present:

Now back in my garage this piece of Audi history is again slowly progressing towards completion.

Mamba Billet Wastegates

I’ve been waiting for some time for Turbo Concepts to finish the development of their billet wastegate actuators and with the arrival of the FrankenTurbos I had the itch to try out some different wastegate actuators.  After some searching I came across these and decided to give them a try.

Mamba Billet Wastegates for the Audi B5 S4
Mamba Billet Wastegates for the Audi B5 S4

The Mamba wastegate actuators are built for the B5 S4 and outwardly look to be a quality product.  Hopefully they perform as well as they look.

Engine Time Capsule

I’ve started the initial clean up of the project engine, the first step was to take off a number of 2.8L engine specific parts that I will not be using.

Istook Engine Clean Up
Engine Cleanup

The engine does have 2.8 heads, and I plan to give them a try.

Working on this engine is like opening a time capsule:

Istook Engine Date Marking
Date Marking

I was reminded of just how long it has been sitting waiting to be completed.