Question for ya, OK three questions Options

[Elliot_Cannon]

Hi,
I am restoring my 73 914 and have a few (more) questions. Can I leave off the bellows and flappers or will I need them? I will have the engine built to 2.2 and will be using webers. Can I do away with the expansion chamber on top of the fuel tank? I would like to mount a wider tire (205 50 15). What wheel offset do I need to mount these tires under stock fenders?
Cheers, Elliot (IMG:style_emoticons/default/icon14.gif) (IMG:style_emoticons/default/icon14.gif) (IMG:style_emoticons/default/icon14.gif)

[Lawrence]

I'm quoting from George Hussey.

The flaps are installed both for warm-up and for engine cooling. It is necessary for all engines to reach operating temperature as quickly as possible and then, when at that temperature, air cooled engines need to get as much cooling air over the cylinder fins through the oil cooler as possible. The cooling flaps do both of these things.

First, when the engine is cold, the termostat bellows are collapsed, pulling hard on the wire connected to the flaps. This holds the flaps closed in the following way: the right (passenger's) flap is up and against the cylinder cover. This allowes all air flow to blow over the cylinders and out the engine without passing through the oil cooler. The left (driver's) flap is vertical, blocking all air from entering the cylinder cover cavity.

Second, as the engine warms up, the thermostat bellows relax gradually, relieving the tension on the wire until the flaps are fully open. The right (passenger's) flap now completely covers the oil cooler, laying horizontally while dividing the cooling chamber in two. This now allows cooling air to flow simultaneously over the cylinder fins and forces air through the oil cooler. The left (driver's) flap is horizontally up against the top of the cylinder cover, allowing all cooling air to flow over the cylinder fins.

Without these bellow flaps installed the engine takes too much time to warm up, and after warming up, it will run hot, as the cooling air is not forced through the oil cooler.

-Rusty