Anyone know what the reasoning / purpose for the air intakes being connected to the timing belt cover via the holes on the bases of the intake tubes. Surely this just drags any dust / dirt straight into the air flow? just curious.

 

I havent heard the real reason but i think it serves as a kind of chimney...venting the heat out as the intake air is drawn across the top.?????

 

I'm with Tony. If you watch your TB closely at different engine temp. points, you'll see it stretches across the cam gears a good bit. I've checked this closely since it was the first time I did my belt, and when the engine is cold the belt is about 4mm away from the front and back edges while running and when I take the covers off.

If you've been driving, look in the hole and you'll see it's about 2mm away from the front edge. That scared me so I took off the cover to see if the belt had moved and it had stretched across so it was 2mm from the back edge too, but did not move from center.

I've also looked after driving and letting it cool overnight, but before starting the engine in the morning. The part of the belt on the cam gear stays stretched until the engine is started and it moves off the cam gear. Pretty wierd, but not scary like a moving belt.

Anyway, I think it needs the ventilation to keep from really stretching to the possible point of sliding off the gear.

 

Point taken, but wouldn't that mean it would be venting warm air straight into the intake - warmer the charge, less the power? Is the heat generated negligable?

 

less than negligible

mk

 

Maybe this is simply a way to anchor the air tubes to keep them in place.??