Project
VW T4 1.9 TD Engine Simulation
An estimated educational engine and optional manual-FWD drivetrain reference with component inspection, kinematic playback, illustrative flow and synthetic audio.
Purpose
An interactive reference for exploring the components and movement of a Volkswagen T4 1.9 TD engine, alongside the practical work on my own vehicle. The current model uses a 2001 configuration with power steering and no air conditioning. ABL engine identity is assumed, not confirmed from its stamping.
Current version
The browser viewer uses frozen models prepared on 17 October 2026. Engine is the default: revision 7, with 271 named components or component aggregates. Engine + drivetrain selects the complete 398-part assembly: combined revision 8, including engine revision 7 and powertrain revision 1. It adds a clutch, five-speed manual gearbox, differential, CV sideshafts, front hubs and wheels. Parts are colored and selectable, with visibility, isolation and exploded views. Cutaway starts on and remains an ordinary toggle.
Playback illustrates slider-crank and valve movement. Schematic tracers show air, fuel, exhaust and combustion-event windows. An optional sound mixer adds synthetic source and cylinder-specific cues, including injection-phase changes. Sound starts off and requires explicit activation; it is not an engine recording. Live RPM edits preserve its independent phase. Turbo remains a separate opt-in, with a load-estimate control and an explicitly illustrative spool response.
The drivetrain has neutral, gears 1-5 and reverse, clutch-coupling and wheel-speed-split controls, shaft/wheel RPM and a no-slip reference-speed readout. These are browser kinematics, not a solved vehicle simulation.
Geometry and equipment are read-only in this version. Runtime inspection, playback and mixer controls work in the browser without a server-side CAD service. This stage does not regenerate dimensions or offer a configurable mechanical digital twin.
GLB, native STEP and individual STL downloads contain the fixed crank-zero reference pose, not the current animation, cutaway, visibility or exploded state, including the current gear or clutch release. The timing cover is absent; it cannot be revealed with a visibility toggle. Earlier revision-6 files remain unchanged at their published URLs, but do not include the rotation correction.
Limits and sources
Estimated geometry. Illustrative flow / no CFD. Synthetic cues / not measured engine sound. No acoustic prediction.
Bore, stroke and compression ratio have source references. Castings, most dimensions, component placements and mounting interfaces remain estimates. Firing order, valve timing, cylinder numbering and mechanical clearances have not been verified against the vehicle.
Manual, front-wheel drive and five gears are user-confirmed; the gearbox code is unknown. The 215 mm clutch, ratio set, axle/hub/tyre dimensions and installed placement are estimates. Clutch coupling interpolates speeds, not friction or torque; neutral and an open clutch do not coast. Differential split does not solve traction or steering. CV envelopes do not calculate articulation or plunge, and smooth gear envelopes are not meshing teeth.
The app does not solve combustion, torque, contact, damage, vibration, airflow or the acoustic field. A possible-issue cue is a scripted illustration, not a measured fault signature or diagnostic result. Injection timing offsets move fuel markers and injection ticks; combustion timing and native pump/belt geometry stay unchanged. This is not a repair drawing, replacement-part library or assessment of safe engine operation.
Audio timbre, noise filters, durations and relative gains are hand-chosen, not produced by the CAD geometry. There is no microphone calibration, dB/SPL prediction, spatial acoustics, structural resonance or noise-source ranking. The drivetrain adds no validated clutch, gearbox, CV or tyre sounds. Turbo load and spool use arbitrary illustration coefficients, not cylinder/exhaust pressure, temperature, boost, compressor/turbine maps, wastegate behavior or operating limits. The visual rotor’s reference-rate animation is separate from audio spool.
Engine source notes and drivetrain source notes describe what each reference supports and its limits. External manual artwork and engine recordings are not redistributed.
Original model copyright: Santeri Hukari. No open redistribution licence has been selected for the model. Three.js and icon dependency licences apply only to their respective code and assets.