What is "hydrolocked" with regards to the carb?

Never heard the term used before in this context.


"Orval Fairbairn" wrote in message
news
In article ,
wrote:

My Cherokee has an 8.5:1 O-360 with autogas STC for 91 minimum.
You
could get
a 6-cylinder version of the same engine (O-540 straight-valve) STC'd for
91
in some
planes. The Comanche hydrolocked the carb on autogas (Peterson told me
that), so it
couldn't pass.... it's a combination of engine and airframe.

That said, if you run premium an O-540 at 8.5:1 and 2700 rpm is
260
HP on
autogas. If you keep it sufficiently cooled and well cowled, you could
reduce the
vapor locking problem. I don't know of any fuel-injected Lycomings that
can
be STC'd
for autogas, so the O-540 is probably the biggest. If you run 7:1
compression for 235
HP (e.g. PA-28-235), it runs happily on regular 87.

-Cory

John Skorczewski wrote:
: I appreciate the info--- but I still have questions. Say, I wanted to
: built an RV-10 with a 260 lycoming engine. How do I find out if it can
: be stc-ed for autogas??? ---and if not what is the biggest lycoming
: engine that can burn autogas? Who has info like this??


When you use autogas, you have to pay close attention to fuel system
design, to avoid sharp corners in lines, cooling paths to gascolators
and even locating boost pumps on the cabin side of the firewall, to keep
things cool.