REFLECTOR: Air Filter (was: RAM air and a "cold box" intake)

[Brian Michalk]

Sid Knox wrote:
> I also think feeding the engine hot air is nutty so this is how I did it on
> my Starduster XIO-320 with homebuilt EFI. I welded plates over the original
> holes in the sump. The four-into-one exhaust I built from an idea I read of
> in an old Sport Aviation back when there was often some interesting
> technical articles (before it was dumbed-down to the level of People
> Magazine). I think it was a CAFE (?) evaluation of various configurations
> of exhaust schemes.
> No air filter...ram air directly into the throttle body.
> This system has been running well for about five years now.

I also have not put on an air filter.  I intend to do some oil analysis 
to see if I should add one later.

My thought is that if this were a trainer flying low and slow doing 
touch and goes all day, then an air filter would be a good thing. 
However, I expect a very small percentage of engine time to be spent in 
dirty air.

What is your experience with not having an air filter?

Heck, my '56 Dodge truck originally didn't have an oil filter, and the 
air filter was an oil bath.