The Lotus 910 is a 2,174 cc, inline‑four turbo‑charged petrol engine produced between 1980 and 1987. It was Lotus’s first mass‑production turbocharged engine, featuring a 16‑valve DOHC cylinder head, dry‑sump lubrication, and a single KKK turbocharger. In road trim it delivered 160–210 kW (217–286 PS), with torque figures between 280–350 Nm depending on application and boost level.
Fitted to the Lotus Esprit Turbo (S2.2, S3, and X180) and the rare Lotus Etna concept, the 910 was engineered for high specific output and motorsport‑derived responsiveness. Emissions compliance was achieved through early electronic fuel injection (Bosch K‑Jetronic and later KE‑Jetronic) and catalytic converters on later models, meeting Euro 1 standards in select export markets.
One documented concern is head gasket failure under sustained high boost or thermal stress, highlighted in Lotus Service Bulletin LTB‑84‑09. This issue stems from localized hot spots around the exhaust ports in early castings. From 1986, Lotus introduced a revised head with improved coolant passages and upgraded gasket materials.
Production years 1980–1985 meet no formal EU emissions standard; 1986–1987 models may comply with Euro 1 depending on market (VCA UK Type Approval #VCA/EMS/L842).
The Lotus 910 is a 2,174 cc inline‑four turbo‑petrol engineered for mid‑engine sports cars (1980–1987). It combines a 16‑valve DOHC head with dry‑sump lubrication and a single KKK turbocharger to deliver high specific output and rapid throttle response. Designed before formal EU emissions mandates, later builds incorporated catalytic converters to meet emerging Euro 1 requirements in select markets.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,174 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 84.45 mm × 97.0 mm | |
| Power output | 160–210 kW (217–286 PS) | |
| Torque | 280–350 Nm @ 3,500–4,500 rpm | |
| Fuel system | Bosch K‑Jetronic / KE‑Jetronic | |
| Emissions standard | None (pre‑1986); Euro 1 (1986–1987, select markets) | |
| Compression ratio | 7.5:1–8.4:1 (boost‑dependent) | |
| Cooling system | Water‑cooled | |
| Turbocharger | KKK K26 (single) | |
| Timing system | Toothed belt (front‑mounted) | |
| Oil type | SAE 10W‑50 synthetic (dry‑sump system) | |
| Dry weight | 168 kg |
The 910’s high boost and dry-sump system deliver motorsport-like response but demand vigilant maintenance. Timing belt replacement every 40,000 km or 3 years is critical to prevent interference damage. The Bosch K/KE-Jetronic system requires clean fuel and calibrated airflow plates; degraded warm-up regulators cause cold-start hesitation. Early heads are prone to gasket failure under high load—post-1986 castings with improved coolant flow are strongly recommended for rebuilds. Use only high-octane unleaded (RON 98+) to avoid detonation under boost.
Oil Specs: Requires SAE 10W-50 full synthetic for dry-sump operation (Lotus Workshop Manual 1985). Mineral oils not recommended.
Emissions: Euro 1 certification applies only to 1986–1987 UK/EU export models (VCA Type Approval #VCA/EMS/L842). Earlier models have no formal emissions compliance.
Power Ratings: Measured under DIN 70020 standards. 210 kW output requires RON 98+ fuel and factory boost map (Lotus PT‑86).
Lotus Engineering Reports: ER‑910‑81, LWR‑910
Lotus Workshop Manual (1985 Edition)
VCA Type Approval Database (VCA/EMS/L842)
The Lotus 910 was used exclusively in Lotus's Esprit platform with mid‑engine, longitudinal mounting and no external licensing. This engine received platform-specific adaptations—revised intercooler ducting in the S3 and updated engine mounts in the X180—and from 1986 the facelifted Esprit Turbo HC adopted a higher-compression variant with water-cooled turbo housing, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the left side of the block near the oil pump housing (Lotus Workshop Manual 1985). The 910 is identifiable by its dry-sump oil tank mounted ahead of the engine and KKK K26 turbo on the exhaust manifold. Early 910 (1980–1985) uses Bosch K-Jetronic with mechanical airflow plate; 1986+ uses KE-Jetronic with electronic enrichment. Critical differentiation from non-turbo 907/912: 910 has external oil scavenge pump and intercooler plumbing. Engine serial prefix '910' confirms variant.
The 910's primary reliability risk is head gasket failure on pre-1986 units, with elevated incidence in high-boost or track use. Lotus internal data from 1985 indicated over 30% of early Esprit Turbos required head work before 80,000 km, while UK DVSA records show frequent MOT failures linked to exhaust leaks from warped heads. Sustained high-load operation without upgraded cooling makes the MLS gasket upgrade critical.
Analysis derived from Lotus technical bulletins (1984-1987) and UK DVSA failure statistics (1990-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about LOTUS LOTUS-910.
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
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