Quote Originally Posted by irmscher
I think we're talking about knee-deep floods on ordinary streets with ordinary cars. Not 4X4 off-roading. The rationale behind riding the cluth and overrevving while traversing a flooded area is to keep the exhaust velocity enough to prevent water from stalling the engine by going in the exhaust. How can you do this on a normal car if you're in idle? Maintenance of the engine has nothing to do with it. The point is to prevent water from getting in the exhaust. Another thing to consider is that catalytic converters in the exhaust works at high temperatures. Getting it submerged in water can crack it. It's very expensive to replace.
That's what most people believe in. Over-revving your engine will prevent water penetrating your exhaust manifold. BUT a driver doesn't have to over-rev his/her engine. The common well-maintained car with 800-1000 rpm can AND will prevent water sipping into the catalytic converter, besides it is mounted right after the headers. The muffler part will have to be over-filled with water before it can cause further damage. And yes, you can let a vehicle idle without over-revving the engine.

Actually, it is the driver's choice whether you want your flywheel cracked while engaging your clutch in a subrmerged clutch/tranny assembly or much more cheaper option of changing a water-filled muffler.