⚠️ L’essentiel en 20 secondes An adaptable plastic fan (Renault Master type) can puncture the radiator of an R8 Gordini or an Alpine A110 — even if everything looks fine at a standstill. The cause: engine movement while running. A few millimetres are enough.

For more than 50 years, the Alpine A110 and Renault 8 Gordini have run with a very particular architecture: a rear-overhung engine combined with a rear-mounted radiator. This layout, unusual today, actually works very well… provided the original design is respected. Originally, these cars were fitted with a copper radiator paired with a steel fan, the whole assembly designed to operate with precise clearances. This setup has proven itself. Yet for several years now, we have seen a significant increase in damaged radiators, sometimes very soon after reassembly. In the vast majority of cases, the common factor is the same: the fitting of a plastic fan, often sourced from a Renault Master, in place of the original steel fan.

Mespiecesauto's choice: respecting the original dimensions

When developing our aluminium radiator for R8 Gordini and Alpine A110, built to the original dimensions, we made a clear choice: to strictly respect the installation designed by Renault. This approach makes it possible:

to refit the original fan cowl;
to keep the original steel fan;
to preserve the clearances specified by Renault;
and therefore to greatly limit the risk of contact between the fan and the radiator.

This choice was not made by chance. It stems directly from our field experience. The same logic guided the development of our Alpine A110 1600 S / SC / SX / SI radiator.

Why plastic fans are a problem

Many customers contact us after puncturing a radiator, often an original one or sometimes one fitted recently. The scenario is almost always the same. At a standstill, everything looks fine. The fan appears correctly positioned, with no apparent contact. But in operation, the reality is different. Under the effect of acceleration, deceleration and load changes, the engine-gearbox assembly rocks slightly on its mounts. This movement is normal. It is part of how the vehicle works. But it has one important consequence: it brings the lower part of the fan closer to the radiator core.

Schéma du basculement du groupe moteur-boîte sur silentblocs rapprochant l'hélice du radiateur — R8 Gordini / Alpine A110 — The rocking of the engine-gearbox assembly brings the lower part of the fan closer to the core.

Key point A check made with the engine off tells you nothing about behaviour on the road: it is the engine's rocking movement that brings the fan closer to the core.

With a Master-type plastic fan, the risk increases significantly. A few millimetres are then enough for the blades to touch the core and eventually puncture the radiator. An original-specification R8 Gordini steel fan, on the other hand, was dimensioned for this environment.

Trace d'usure en arc de cercle laissée par une hélice plastique sur le faisceau d'un radiateur R8 Gordini — The typical signature of contact: an arc-shaped mark on the core.

Faisceau de radiateur R8 Gordini percé par une hélice plastique type Renault Master — The same core, punctured.

The problem of engine-gearbox rocking on its mounts

The essential point to understand is that the problem is not necessarily visible at a standstill. This is precisely what catches out many owners. The powertrain is not fixed. It pivots slightly around its rotation point, and this engine-gearbox rocking on the rubber mounts changes the relative position of the fan with respect to the radiator. The original sheet-steel fan was designed for this environment. On the other hand, some adaptable plastic fans, more flexible or of different geometry, can become particularly dangerous in this configuration.

Bon à savoir Worn engine-gearbox mounts amplify the rocking of the assembly — bringing the fan even closer to the core. Remember to check them at the same time as the radiator.

The other trend: thicker aluminium radiators

Another trend we are seeing: the fitting of aluminium radiators thicker than the original. On paper, the idea may seem attractive. Many people assume a thicker radiator will necessarily cool better. In practice, it is not that simple — we covered the subject in detail in our article copper or aluminium radiator: which is more efficient? — and this trend even raises several problems.

Idée reçue Thicker ≠ more efficient. A thicker core mainly reduces the safety clearances in an area where every millimetre counts.

1. Reduced available clearances

Increasing the thickness of the core changes the overall installation. It reduces the available clearances in an area where space is already tight. In some cases, this extra thickness can bring the oil cooler into contact with the water radiator. With vibrations and vehicle movement, this can eventually cause fretting wear, and end up puncturing one or the other.

Proximité entre le radiateur d'huile et le radiateur d'eau sur R8 Gordini — jeux réduits avec un faisceau plus épais — The space between the oil cooler and the water radiator is already tight with the original dimensions.

2. A fan even closer to the radiator

The other consequence is just as important: by moving the radiator towards the fan, you further reduce the safety margin. The slightest engine movement then becomes more critical. Here again, a few millimetres are enough to turn an acceptable installation into a risky one.

Is a radiator built to the original dimensions enough?

Yes, in the vast majority of cases. It is worth remembering that a radiator built to the original dimensions, with a new core and paired with an engine in good condition, provides perfectly adequate cooling for an R8 Gordini or an Alpine A110 under normal driving conditions. Before trying to artificially "oversize" the radiator, it is often more relevant to check:

the general condition of the engine;
the correct operation of the cooling system (see our overheating diagnosis guide for classic cars) ;
the condition of the engine mounts;
the conformity of the fan;
and the actual quality of the radiator fitted.

Our recommendation

Our field experience is very clear: a few millimetres can be enough to destroy a radiator.

✅ Our 3 rules for a reliable installation 1. A metal fan conforming to the original. 2. A radiator built strictly to the original dimensions. 3. Caution with "adapted" setups and overly thick aluminium radiators.

On these cars, respecting the original design is often the best guarantee of reliability. That is exactly the specification behind our R8 Gordini / Alpine A110 aluminium radiator : Renault's dimensions, nothing else.

FAQ — R8 Gordini / Alpine A110 fan and radiator

Can you fit a Renault Master plastic fan on an R8 Gordini or an Alpine A110?

We advise against it. This adaptable fan was not designed for the rear installation of these cars. Its geometry and flexibility mean that when the engine rocks, the blades can touch the core and puncture the radiator — even if everything looks fine at a standstill.

How do I know if my fan is touching the radiator?

Inspect the core on the fan side: flattened, scratched or shiny fins in an arc shape are the sign of contact in operation. Also check the condition of the engine-gearbox mounts: when worn, they amplify the rocking of the assembly and bring the fan even closer to the core.

Ailettes pliées par le contact de l'hélice sur un radiateur R8 Gordini — Bent fins: the first sign of fan-to-core contact.

Faisceau de radiateur percé suite au contact avec l'hélice — R8 Gordini / Alpine A110 — Final stage: the core is punctured.

Does a thicker radiator necessarily cool better?

No. A thicker core reduces clearances in an area where space is already tight: the fan gets closer to the core, and the oil cooler can come into contact with the water radiator. A radiator built to the original dimensions, with a new core and an engine in good condition, is sufficient in the vast majority of cases.

Aluminium or original copper radiator: which to choose?

Both work, provided the original dimensions are respected. Modern aluminium offers a new, efficient core without changing the installation. We compare the two technologies in detail in our article copper or aluminium radiator.

Article written by Benjamin
Engineer and founder of Mespiecesauto
Reverse engineering specialist, developer of radiators and parts for Alpine A110 and Renault 8 Gordini.

R8 Gordini and Alpine A110 radiator: why a plastic fan can puncture the core