When KM-Tronics introduced its ambitious plan to install Saab’s twin-turbo V6 prototype into a rescued 9-3 Turbo X, the focus naturally centered on the engine itself and the car that would eventually receive it. Since then, the project has progressed through chassis restoration and extensive NVH improvements, all driven by Mark van Kampen’s vision of completing the project in the spirit of what Saab engineers might have delivered had development continued.
The latest episode marks another important milestone. For the first time, the prototype engine is completely dismantled, allowing the team to inspect components that have remained hidden since Saab’s development program came to an abrupt end nearly two decades ago.
Rather than confirming the image of a nearly finished high-performance engine waiting for production approval, the tear-down tells a different story. It reveals a development program that was still experimenting with solutions, validating concepts and refining individual components.
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A prototype still searching for answers
One of Mark’s main conclusions after opening the engine is that this prototype belongs to a very early stage of Saab’s twin-turbo V6 development.
That observation explains why the engine combines seemingly contradictory details. Some parts appear to be hand-made or specially reinforced, while others remain remarkably similar to components found in the standard B284. Instead of representing inconsistencies, these differences suggest Saab was still evaluating which existing components could support the intended power levels and which would eventually require complete redesign before any production version became viable.
It also reinforces the idea that this engine was built as a proof of concept rather than a production-ready package.
Prototype engineering can be seen throughout the engine
Several components immediately stand out during disassembly.
The intake manifold shows characteristics that resemble early rapid-prototyping techniques, something already used by automotive manufacturers during the mid-2000s for prototype development. The fuel system is equally unusual, featuring a dual high-pressure fuel pump arrangement and a custom fuel rail design that differs significantly from production V6 engines.
Another striking detail is the presence of six metal tubes running through the cam covers toward each combustion chamber. According to Mark, these were most likely used to monitor individual cylinder pressure while the engine was running on the dyno. Although the original sensors are no longer present, the arrangement itself illustrates how closely Saab engineers monitored combustion during development.
These are not features intended for production. They are the kind of instrumentation normally found only on engines whose primary purpose is gathering engineering data.
The pistons reveal how early this engine really is
Perhaps the most surprising discovery concerns the pistons.
Although the engine uses direct injection, Mark notes that the piston crown is very similar to that of the standard B284. Modern direct-injection engines typically use a bowl-shaped piston crown to improve mixture formation and combustion efficiency, but that feature is largely absent here.
Rather than suggesting a design mistake, KM-Tronics believes this reflects the stage of development. Saab appears to have been evaluating which elements of the existing engine architecture could be retained while identifying those that would eventually need redesign if the project moved toward production.
In other words, the engine was still evolving.
Storage caused more damage than testing
Not all discoveries relate to Saab’s engineering decisions.
The tear-down also revealed damage to the cylinder heads, the oil pan and parts of the high-pressure fuel pump assembly. Several head bolts had broken, and Mark believes most of this damage likely occurred during transport or long-term storage after the development program ended rather than during engine testing itself.
Fortunately, the news is not entirely negative. The cylinder bores still retain good honing marks, the block remains straight enough for refurbishment, and although light corrosion is visible after years in storage, the engine itself remains a realistic restoration candidate.
The damaged external components will inevitably increase both cost and build time, but they do not threaten the overall project.
Even the crankshaft raises new questions
The crankshaft also attracted attention.
It closely resembles the unit used in the 3.2-litre GM High Feature V6 family, yet several areas have clearly been machined differently. Material has been removed from locations where production crankshafts retain more mass, suggesting Saab was experimenting with balancing or rotating mass.
At this stage, however, Mark is deliberately avoiding firm conclusions. More measurements and comparisons will be needed before they can explain exactly why those modifications were made.
The project is becoming more historically valuable
One of the most interesting aspects of this latest episode is that it changes how the prototype itself should be viewed.
Earlier updates naturally focused on performance targets of around 500 horsepower and the possibility that this could have become Saab’s ultimate factory V6. After examining the engine internally, a different picture begins to emerge.
Rather than uncovering a finished engine that never reached production, KM-Tronics is documenting Saab’s engineering process at a point where many technical decisions were still being evaluated. The combination of prototype components, experimental fuel-system hardware, measurement equipment and evolving internal design shows a development program that had not yet reached its final form.
That makes this engine valuable for a different reason. It is not simply an unfinished performance engine; it is a rare snapshot of how Saab engineers approached one of their most ambitious powertrain projects while it was still under active development.
With the tear-down now complete, the next stage of the project will focus on assessing the financial impact of the damaged components before work begins on rebuilding the prototype and eventually installing it into the restored 9-3 Turbo X chassis.
