> the aerodynamics are such that too much air gets > around instead of through > the radiator if the fan isn't doing it's job. Of > course there is a lot more > heat rejection at high speeds also (that extra gas > goes partly into heat). Partly? I think the efficiency of a MODERN engine is only around 20%. I'm pretty sure that ol' 440 is heating up like an oven at high speed. Luckily, there's so much metal there to heat up. Interesting about the areodynamics, though. It would be fun to put one of the old boxcars into a wind tunnel and see how it did. Dimitris Dardalis has an air dam he put together out of sheet metal at the lower leading edge of his '68, below the bumper. I wonder how that would affect airflow, and if it improves flow thru the radiator. I'm a big fan (pun partially intended) of electric fans. They are much more efficient than mechanical fans, even clutch fans, and extend water pump life greatly. I've used them with good luck on everything from 2 litre 4 bangers to the 6 litre small block in my Satellite. I'm definitely considering a setup for the Imperial...especially if I get the A/C charged up this summer. > Another cause of high speed overheating is the lack > of an anti-collapse > spring in the lower radiator hose. The average gas Good point. My volvo was missing its, and I formed a spring out of coat hanger wire wrapped around a broom handle. With a little finnessing it fit perfectly. We mechanical engineers, we're good at making things out of coat hangers. ===== --Mike Pittinaro One point eight litres Stromberg carburators sing Loose nut at the wheel __________________________________ Do you Yahoo!? Read only the mail you want - Yahoo! Mail SpamGuard. http://promotions.yahoo.com/new_mail