Sunday, November 26, 2006

Rat's Nest No More

I was looking at the rats’ nest of wires and tubes that made up the engine compartment on my car. There had to be a way to clean that up so you find a problem when it occurred.

When they first started building formula vees they used dead stock engines. That doesn’t last long in any kind of racing. Soon all the racers were "blueprinting" their mills.

That means they made sure that all the rods were the same weight, as were the pistons and valves. The valves springs all had the same compression strength and the cam followers and pushrods were dead equal in length and weight. It didn’t mean big changes but when you only have forty horses to start with even a little bit is big.

But still you had a big fan shroud enclosing a fan, which rotated about the main shaft of the generator, which was driven by a belt connected to a pulley on the end of the drive shaft. The job of the fan was to force air over the cylinders and cylinder heads and also to push air through the oil cooler. That’s why it’s called an air cooled engine. Actually it’s as much oil cooled as air cooled, but you use air to cool the oil as well.

All this cooling comes at a price. Engine power. Since every thing drives off the crankshaft of the engine, you burn horsepower to make all the stuff turn.

Vee racers are an inventive lot. They are also very skilful at reading rules. The rules said you had to have a generator, and it had to be driven by the belt connected to the pulley. Nobody said it had to be functional.

Soon the guts were stripped out of the generator and a freely spinning shaft drove the fan to cool an engine with a couple of extra horses.

The next step was to loosen the fan belts. If it slipped a bit, who cared? Certainly not the guy who was getting the advantage of the extra power not used to whirl all that stuff around. There were even a few cases of drivers who worked out squirters which on demand, sprayed a little oil on the belt so it would slip a lot during that few seconds when they needed an extra little burst of power.

Then some smart guy figured out that you get a pretty good breeze at a hundred miles per hour. Why not use that moving air to cool the motor rather than a fan. Again the rules stated that the fan shroud had to be there but it didn’t say that there had to be a fan in it. Next thing you know they were ducting air from the outside, through the fan shroud and over the engine and oil cooler and the fan was junked. And since the generator casing no longer had any function what so it was done away with along with the fan belt, and the fan.

Once everyone was cooling with out side air, there was no longer a reason for the fan shroud and it went away. Finally that left the old generator tower sticking up there with no function except to supply a tube to pour oil through and provide a breather for the engine case.

So someone devised a little plate that serves that function and bingo, there goes the generator tower. And with it a stumbling block which makes it possible to start cleaning up the rats nest.


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