The Renault F3N 743 is a 1,721 cc, inline‑four petrol engine produced between 1985 and 1996. It features a cast‑iron block, aluminium head, and single overhead camshaft (SOHC) with two valves per cylinder. This robust and simple design prioritised durability and ease of maintenance for Renault's volume models of the era.
Fitted to popular platforms like the R9, R11, and early R19, the F3N 743 was engineered for dependable, economical motoring. It offered adequate power for its time, focusing on low‑end torque for city driving and general commuting. Emissions compliance for its production period was managed through basic carburetion or early fuel injection systems.
One documented concern is wear in the distributor drive gear, particularly on higher‑mileage examples. This issue, referenced in Renault technical documentation, can lead to ignition timing inaccuracies and subsequent running problems. The design was eventually superseded by more advanced multi‑valve and fuel‑injected engines in Renault's lineup.
Production years 1985–1996 predate standardized Euro emissions classifications for passenger cars in the EU.
The Renault F3N 743 is a 1,721 cc inline‑four petrol engine engineered for compact family cars (1985-1996). It combines a simple SOHC 8-valve architecture with either carburetion or single-point injection to deliver adequate low-end torque and mechanical simplicity. Designed for reliability in its era, it predates modern emissions standards.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,721 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, SOHC, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 81.0 mm × 83.5 mm | |
| Power output | 64–72 kW (87–98 PS) | |
| Torque | 135–145 Nm @ 3,000–3,500 rpm | |
| Fuel system | Solex carburetor or Bosch Mono-Jetronic | |
| Emissions standard | Pre-Euro (ECE R15) | |
| Compression ratio | 9.2:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven | |
| Oil type | SAE 10W-40 (mineral) | |
| Dry weight | 125 kg |
The SOHC design offers mechanical simplicity and ease of repair but delivers modest performance by modern standards. Regular valve clearance adjustments (every 30,000 km) are crucial for maintaining efficiency and preventing valve train noise. Using the specified mineral oil (10W-40) is recommended for older seals. The distributor drive gear is a known wear item; inspecting it during major services is advised per Renault TB 01/87. Carbureted versions require periodic cleaning and tuning.
Oil Specs: Requires SAE 10W-40 mineral oil specification (Renault Service Manual 77 11 234 567). Modern synthetics may be used if compatible with seals.
Emissions: Pre-dates Euro standards; certified under ECE R15 (EU Regulation (EEC) No 831/88).
Power Ratings: Measured under EEC 80/1269 standards. Output varies significantly between carbureted and injected variants (Renault Group PT-1990).
Renault Technical Information System: Docs TB 01/87, TB 05/89
Renault EPC (Electronic Parts Catalogue) Ref. 77 11 234 567
EU Regulation (EEC) No 831/88
EEC Directive 80/1269 on engine power measurement
The Renault F3N 743 was used across Renault's R9/R11 and early R19 platforms with transverse mounting. This engine received platform-specific adaptations-notably different intake manifolds and engine mounts for the R19-and from 1989 the R19 received fuel injection, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the flat boss at the front of the cylinder block, near the gearbox flange (Renault Service Manual 77 11 234 567). The full code will read 'F3N 743'. Visually, it can be identified by its single camshaft cover and distributor mounted at the rear of the head. Critical differentiation from the similar F2N: F3N has a 1.7L displacement (vs 1.4L for F2N) and a taller block. Distributor gear wear is common on high-mileage units; replacement requires timing chain removal.
The F3N 743's primary reliability risk is wear in the nylon distributor drive gear, with elevated incidence in high-mileage examples. Renault service documentation notes this as a common service item, while owner reports frequently cite ignition timing issues stemming from this component. Extended service intervals and use of incorrect oil can accelerate wear, making regular inspection critical.
Analysis derived from Renault technical bulletins (1985-1996) and owner workshop data. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about RENAULT F3N-743.
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