At 11:02 AM 8/3/2010 Tuesday, Jake de Villiers wrote:
> > Was thinking of alternatives to installing a vent on pop top. They are
> > pricey, and I've read they can leak. But that's likely due to install
> > error. Still. If there was a less expensive way for us w/o the factory
> > installed vent....

The skylight/vent is darn useful, worth real money in my
opinion.  Among other things it gives substantial convective
ventilation when you park the thing with a couple windows
cracked.  Since the hole isn't already there you can get a standard
size, and have a built in screen, built in fan with or without
thermostat, built in rain detection, probably a built in 105 mm
howitzer.  Because of the diameter, the fan will either move a lot
more air or be a lot quieter or both, compared to a little muffin
fan.  The smaller a fan is the worse it works, even without the motor
taking up a big chunk of real estate in the middle.

The stock location is in a neutral pressure zone  when you're under
way -- air will flow either in or out depending on what the other
windows and  vents are doing.

The village wisdom of the list says don't leave (the stock one) open
under way to save battering the mechanism; however my experience is
that if you bring it wide open with the lifters tight against the
stops, it will travel forever that way without bothering a thing.  I
did it that way for 160,000 miles with no discernable effect on the mechanism.

Yours,
David