Thomas Borchert wrote in message ...
John,

Liquid cooling looks like it'll make it difficult to retrofit to
existing designs.


Why? The Thielert diesel is liquid cooled and is being retrofitted to
C172s and PA28s as we speak. Everything firewall forward is replaced,
so where's the problem?

I didn't say it was impossible. Maybe I should rephrase that to say
"...looks like it'll make it difficult to cost-effectively retrofit to
existing designs".

From what I've seen over the years, most firewall forward engine
conversions tend to approach the value of the unconverted plane.
Unless these engines are going to sell for substantially less than
their air cooled bretheren, all of those necessary bits and pieces are
going to make the conversion look pretty unattractive from an economic
standpoint (at least for the lower end of the market, i.e C-172s and
PA28s).

John Galban=====N4BQ (PA28-180)