I can attest to the lowered ceiling with a low compression engine. My
RV-6 had the E2A engine which is the 150 hp version, low compression.
On a trip coming home from Canada, with two of us in the plane and
baggage, we topped out at 13,200 density altitude. Couldn't go any
higher.

John

karel wrote:
"abripl" wrote in message
ups.com...

Builders who plan to fly in mountains needing higher altitude should
consider their engine choices. Typical Lycoming low compression engines
have a limit of about 13,500 feet. You need higher compression engines
or turbocharging for higher altitudes. I tested my high compression
(10.5) Franklin 6A-350 to 18,000 legal VFR limit and quit - still was
doing about 200ft/min. A friend of mine with a 0-320 maxed out at
13,300.


To my understanding turbocharging OR diesel is the way to go high up.
Yes yes one more reason to go diesel!
But isn't there a pressurizing issue also, above 10k or so ft?
It's just a different game, high up there, or so I'm told.
KA