How to know if a radiator is getting sufficient airflow

Question

I have recently purchased a dune buggy as displayed in the photo below. Note the position of the radiator located above the seats.

What I am wanting to do is install some clear perspex in the window area but what I am concerned about is the potential that such an installation will disrupt the airflow received by the radiator and cause overheating problems.

I understand that no-one will probably be able to give a concrete answer but could anyone please be kind enough to comment, having a look at the design below will a clear perspex window at the front of this vehicle cause potential problems with the radiator and overheating?

Answer 1

This window will almost certainly reduce the effectiveness of the radiator somewhat. The real question is whether that ends up being significant for your application.

Others have suggested monitoring the temperature gauge--if the temp rises above the normal range, you've created a real problem. However, just because the gauge doesn't rise above normal doesn't mean you haven't created a problem (albeit a less severe one).

If your buggy has an electronic, thermostatically controlled fan, this fan will kick on whenever there's not enough natural airflow to cool the radiator. Generally this should only happen when moving slowly on a hot day. By installing this windscreen, you may find that your fan comes on more frequently, and runs for longer; or worse yet, runs constantly. This would represent an extra load on your buggy's electrical system, and may lead to early fan failure.

The only way to know is to give it a shot with the windscreen. Monitor your temp gauge, but also monitor the operation of the radiator fan, if you have one. It may help to wire up a temporary indicator light that goes on when the fan runs.

If you need the windscreen, and you end up with cooling issues, maybe you can add some ducting to bring more air to the radiator, which may help offset the loss of airflow from the windscreen.

Answer 2

Without a wind tunnel the only way to tell is by monitoring the temperature gauge. Air flow/cooling capacity can get complex as there are many variables. Thing to consider are engine size, radiator capacity/effiency, fan size and direction of airflow all of which are influenced by each other and air flow over and around the vehicle at different speeds. If you look at cars from the 50's or 60's they had large grill openings and large radiators to cool the engines. In comparison modern cars have very small grill openings and very efficient radiators so visually it is tough to form an opinion for your case.