RH bonnet air duct

[BobC]

I have a Series 2 FHC that I have recently refurbished including a bonnet re-build. The LH air duct in the bonnet clearly feeds fresh air to the fan unit for blowing round the cabin. The RH duct just leads into the general vicinity of the carbs without really being sealed into/onto anything (like the LH duct). Can anybody give a purpose for the RH duct? It is my intention to put a plate over it at the inboard end to force more air through the radiator, the duct must serve as a significant bypass of air that could otherwise be used for engine cooling. The carbs have plenty of free air volume to breath in without the duct. Many thanks. Bob

[Jeff Cecil]

Ever drive on a cool day and notice how much better the engine runs than on a hot day? Ever wonder why hot rodders and muscle car guys want an air intake cooling system on their car? More HP!

If you block off the duct to the carbs, they will only get hot air from the radiator. The air does not Ramjet into the carbs from the duct, but is delivered right to the air filter intake area. Cooler air to the carbs is a good thing.

And, the series 2 mouth is big enough to allow plenty of air for cooling to the engine.

[malcolm]

Not sure why you wanted more air to the rad. I've driven through very high temps in Spain in summer, and never overheated in my series 2. The bigger mouth (not mine!) is a tad ungainly, but does the job.

[BobC]

Thanks for replies. Aware of advantages of cold dense air through the carbs but termination of duct at wheel arch does not seem a very efficient way of getting cooler ambient air to carbs. Anyway my question is answered so will leave things as they came out of the factory. TTFN.