Corvair conversion engines

In article , "Peter Dohm" wrote:

At this point, the Jabiru 3300 is the only engine that really looks to me
like a promising replacement; and I really don't know its service record.
However, albeit at a higher dollar price, its features seem to preserve: 1)
similar or lighter weight, 2) similar or higher power, 3) six cylinder
smoothness, 4) reasonably slow idle, and 5) similar dimmensions. Additional
benefits are designed in dual ignition and an updraft intake system, similar
to Lycoming and Continental, which should be more resistant to ice.

Peter


Why would an updraft intake system be more resistant to ice?

Heat rises, so I would expect a downdraft system, mounted above the engine
block, to be more resistant to icing.