auto carbs
Hi There,
Car engines have been known to suffer from icing. In my days as a student in the early 90s I was running a 1967 Triumph that would 'loose power' on motorway driving, to the point where I couldn't maintain speed. After a few minutes standing, whilst I scratched my head, I could restart it, drive off and everything would be fine - for about 1/2 hour, when it would loose power again. Only when I started flying did I work out what used to cause this problem. Some seventies cars used to have a vacuum operated device that would draw hot air into the filer from a shroud round the exhaust manifold on any power setting except full throttle.
The seventies cars lead to an interesting thought - why don't light aircraft draw hot air to the filter, instead of using unfiltered air when we pull carb heat on?? I was getting icing whilst taxying and holding at Coventry this morning, so using carb heat on the ground was essential, despite the fact that this can draw dust and debris into the engine. . .
Cheers,
David