# Lotus Twin Cam race engine

- Source: https://racingcarnetwork.com/wiki/lotus-twin-cam-race-engine/
- Publisher: Racing Car Network (racingcarnetwork.com), the race car marketplace
- Type: engine · Brand: Lotus
- Discipline: parts
- Era: 1960s
- Last updated: 2026-07-06
- For sale on RCN: https://racingcarnetwork.com/for-sale/lotus-twin-cam-race-engine/ (0 live listings right now)

The Lotus Twin Cam is the 1960s in aluminium: Chapman's Ford-block twincam that powered Elans, Lotus Cortinas and the 23's giant-killing — still the beating heart of historic racing's most beloved class of machinery.

## Specifications

| Spec | Value |
|---|---|
| Type | 1.6 L DOHC alloy head on Ford Kent block |
| Power | ~105 hp road / 140–180 hp race spec |
| Application | Elan/26R, Lotus Cortina, Lotus 23, Seven |
| Carburation | Twin Webers (period spec) |
| Tuning | BRM/Cosworth Mk XIII period tiers |
| Servicing | Full remanufacture ecosystem (UK) |
| Years | 1962–1975 (historics ongoing) |
| Class | Appendix K / HSCC historic engine |

## History

Lotus's Twin Cam (1962, Harry Mundy's design brief) put an aluminium twin-cam head on Ford's pushrod bottom end — the Kent-block pragmatism that became a template — creating the engine of the marque's golden road-and-race era: Elan and Elan 26R, Lotus Cortina's touring-car theatre, the Lotus 23B's sports-racer legend and Europa/Seven applications through 1975, with race tuning by BRM, Cosworth (Mk XIII) and the era's specialist trade reaching ~140–180 hp by specification.

The competition record made icons: Jim Clark's Lotus Cortina seasons, the 23B's Nürburgring embarrassment of bigger machinery, Elan 26R's GT class career and a decade of clubman racing that installed the engine in British motorsport's collective memory.

Historic racing never let go: 26R and Cortina grids at Goodwood-tier meetings, HSCC and FIA Appendix K fields run Twin Cams by the hundred, and a complete specialist ecosystem (blocks, heads and cranks all remanufacturable) keeps supply honest. Specification correctness for eligibility — period head castings, correct Webers, capacity — is where the money concentrates.

## Palmarès

British and European Touring Car theatre with the Lotus Cortina (Clark's sideways seasons the monument); Lotus 23/23B sports-racer wins across Europe; Elan 26R GT class careers — then six decades of historic victories at Goodwood, HSCC and Appendix K meetings worldwide.

## What to check before you buy

Eligibility spec is the price ladder: an Appendix K-correct engine (period head casting, correct carburation and capacity, documented internals) is worth far more than a hot road-spec twincam of equal power — verify the file against your class's papers. Head provenance matters most (original versus remanufactured castings both legitimate, differently priced); check crank and rod specification, Weber setup correctness, and hours since a name-builder refresh. The remanufacturing ecosystem means everything is obtainable — which makes documentation, not parts, the scarce asset. Buy the invoice trail.

## Did you know

- Jim Clark's three-wheeling Lotus Cortina made the Twin Cam's induction bark the sound of 60s saloon racing — the era's most photographed cornering attitude had this engine underneath.
- The 23B's 1963 Nürburgring legend — Clark leading the field's prototypes on a fraction of their capacity — is the Twin Cam's giant-killing certificate.
- The aluminium-head-on-Ford-block formula was so right that Cosworth's BDA simply repeated it with four valves — the Twin Cam is the BDA's conceptual parent.

## Related entries

- Cosworth BDA engine — https://racingcarnetwork.com/wiki/cosworth-bda/
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