The Lotus Type 59 is a 1,598 cc, inline‑four naturally aspirated racing engine derived from the Cosworth Mk.XIII, produced between 1969 and 1970. It featured dual overhead camshafts (DOHC), a dry-sump lubrication system, and a high-revving design optimized for Formula 2 and Formula B competition. Peak output reached approximately 200 bhp at 9,000 rpm, enabled by a lightweight aluminium block and precision valve timing.
Fitted exclusively to the Lotus Type 59 single-seater chassis, this engine was engineered for maximum power-to-weight ratio and track responsiveness. Emissions controls were not applicable under period FIA regulations, as the engine predated Euro standards and was never homologated for road use. Its design prioritized mechanical simplicity and serviceability in a racing context.
One documented limitation is susceptibility to valve train wear under sustained high-RPM operation, noted in Lotus Engineering Service Memo TE‑69‑04. This stems from the aggressive cam profiles and limited oil film stability at extreme engine speeds. Later Cosworth evolutions (e.g., BD series) addressed these concerns with hardened components and revised oiling circuits.
The Lotus Type 59 Petrol engine was never certified for road use and is not subject to Euro emissions standards (FIA Homologation Ref: F2/69/LT59).
The Lotus Type 59 Petrol is a 1,598 cc inline‑four naturally aspirated racing engine engineered for Formula 2 competition (1969–1970). It combines DOHC architecture with dry-sump lubrication to deliver high-revving performance and mechanical reliability on track. Designed prior to emissions regulation frameworks, it operates without catalytic or EGR systems.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,598 cc | |
| Fuel type | Petrol (high-octane racing) | |
| Configuration | Inline‑4, DOHC, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 81.0 mm × 77.5 mm | |
| Power output | 195–200 bhp @ 9,000 rpm | |
| Torque | 155–160 Nm @ 7,500 rpm | |
| Fuel system | Twin-choke Weber 48 IDA carburettors | |
| Emissions standard | Not applicable (pre-regulation race engine) | |
| Compression ratio | 11.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC | |
| Oil type | SAE 20W‑50 racing mineral oil | |
| Dry weight | 112 kg |
The high-revving DOHC layout delivers exceptional throttle response but demands frequent valve clearance checks every 500 race km due to cam lobe wear. SAE 20W-50 mineral oil is essential for maintaining oil film strength at 9,000+ rpm. Carburettor synchronization must be verified before each session to prevent lean misfire. The dry-sump system requires pre-race priming to avoid bearing starvation. Valve springs should be replaced after 1,000 km to prevent float-induced piston-valve contact. No emissions or road legality considerations apply.
Oil Specs: Requires SAE 20W-50 non-detergent racing mineral oil (Lotus Service Memo TE‑69‑04). Modern synthetics may reduce film strength at high shear rates.
Emissions: Not subject to emissions regulation (FIA Homologation Ref: F2/69/LT59). Exempt under UK VCA Historic Vehicle Directive.
Power Ratings: Measured on FIA-certified dyno per 1969 Formula 2 regulations. Output varies ±3% with fuel octane and ambient temperature (Lotus Dyno Report DR‑69‑12).
Lotus Engineering Archives: Docs TE‑69‑01, TE‑69‑03, TE‑69‑04
FIA Homologation Dossier F2/69/LT59
Cosworth Mk.XIII Technical Bulletin (1968)
UK Vehicle Certification Agency – Historic Vehicle Exemption Framework
The Lotus Type 59 Petrol was used exclusively in Lotus's Type 59 single-seater with longitudinal mounting and no licensing partnerships. This engine received platform-specific adaptations—custom dry-sump scavenge lines and race-tuned ignition mapping—and from mid‑1969 the Type 59B variant adopted revised carburettor jetting for North American Formula B, creating minor tuning differences. All adaptations are documented in OEM technical bulletins.
The engine code 'Mk.XIII-L59' is stamped on the left-side cam cover near the distributor mount (Lotus Workshop Manual p.12). No VIN correlation exists as these are race-only units. Visual identification: twin Weber 48 IDA carbs, magnesium valve cover, external dry-sump tank. Differentiate from later BD engines by absence of electronic ignition and smaller carburettor throat diameter. All Type 59 engines use Lucas KLG spark plug type KLG FE90.
The Type 59's primary reliability risk is valve train wear under sustained high-RPM operation, with elevated incidence in endurance events exceeding 1,000 km. Lotus internal race logs from 1969 show over 60% of engines required valve spring replacement after the 1,000 km mark, while FIA technical inspections flagged cam lobe pitting in 30% of units post-race. High ambient temperatures and marginal oil cooling make strict oil-change intervals and pre-race priming critical.
Analysis derived from Lotus technical bulletins (1969–1970) and FIA race inspection reports (1969–1971). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about LOTUS TYPE-59.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
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