Ford Cosworth YB 2.0 NA Engine – Genuine YAC Kit, Mountune Inspected

A rare opportunity to acquire a genuine Cosworth YB normally aspirated engine, built from a new YAC kit in the early 1990s.

This is not a converted road engine, but a correct-period Cosworth assembly, originally installed by Van Diemen in a single seater and only run for a handful of test hours before removal.

Prior to purchase, the engine was professionally stripped and inspected by Mountune (UK), confirming it to be an exceptionally low-wear, original unit.

Specification:

Genuine Cosworth YAC NA engine Desirable “200” block (stronger casting) Later 4x4 type cylinder head Standard Cosworth forged crank (standard size, excellent condition) Standard Cosworth rods Cosworth NA pistons (undamaged, original type) Approx. 9.5mm lift cams (reground on Cosworth blanks) Standard, unported cylinder head

Mountune Findings:

Crank: standard, unground, excellent condition Bores: minimal wear Head: very clean, no corrosion or detonation issues Overall: extremely good, low-use internal condition

Engine has since been lightly reassembled for storage.

Included Components:

Aluminium dry sump pan (no pump) Genuine Cosworth dry sump cam cover Twin 45DCOE Weber carburettors (some covers missing, no linkage) Distributor and HT leads

Use Cases:

Period-correct engine for historic race / RS2000 / single seater High-quality base for a competition NA build Strong foundation for turbo conversion (200 block / Cosworth bottom end)

Estimated output in current NA configuration: ~200hp

Overview:

Engines of this type — genuine YAC-built, low-use, unmodified assemblies with known history and Mountune inspection — are increasingly difficult to source.

A very original and correct Cosworth YB that would suit a serious enthusiast, collector, or race program.