apilot2(at)gmail.com
Guest
|
 Posted: Mon Dec 04, 2006 8:05 am Post subject: engine wars was Re: Eggenfellner |
 |
|
A lot of folks don't realize that a lot of incremental improvements
have, in fact, been made on the Lycomings. While the basic cylinder
design does date back 50 years, at that time TBO was around 1200
hours. Cylinder flange was changed from narrow flange to wide flange.
The valve stem size was increased from 7/16s to 1/2 to reduce valve
stem breakage, rings and honing have improved, valve guides were
improved as recently as 1995 to reduce the need for a valve wobble
check from 400 hours to 1000 hours, and within the last 5 years they
have gone to roller lifter/cam configuration. In the bottom end,
dowels were added to the bearings and various bearing configurations
changed. Oil pumps changed for worse, then for better. Until the
bearing configuration was updated TBO's were stuck in the 1600 hr
range.
If you choose carefully, you can get a fast break-in(less than 5
hours), very low oil consumption engine with CermiNil cylinders, a
roller cam/lifter, improved valves and porting, improved sump and
intake manifolding to give you a better engine, built by your favorite
engine builder, with virtually no Lycoming branded parts, that will
still be recognized by your DAR as a certified engine for fly-off
purposes. That engine will give you more power and better economy,
with vast parts availability, compared to any alternate engine
configuration, and be very likely to give you more than 2000 hours of
reliable service.
JMHO, KM
A&P/IA
Do Not archive
On 12/4/06, linn Walters <pitts_pilot(at)bellsouth.net> wrote:
| Quote: | > I also don't understand why Lycoming hasn't come up with a cutting
> edge engine design.
Because it's cost prohibitive to re-certify the engine and the
engine/plane combination. thank the FAA for that one!
> Every auto maker seems to improve their engines one way or another
> every year. 50 years for Lycoming and no major changes? Where are
> there more internal combustion engines of similar horsepower to GA
> aircraft than autos. My feeble opinion is that the best odds for an
> alternative engine will be found in automotive engine technologies.
> Go Egg.
Well, I have to agree that auto engines are definitely more state of the
art, but comparing the life of your car engine to your Lycosaur isn't
really fair. You don't treat them any where near the same, as was
alluded to in some posts. Your car doesn't sit idle for weeks (or
months) at a time and then get run a little bit. Most airplanes in
private ownership (non-flight school or other business related
operation) get treated that way. The accelerated cylinder wear that
causes high oil consumption is due to the rust that forms in the
cylinders when the plane sits for an extended period of time. If the
plane is flown regularly and about 100 to 150 hours a year, the lycosaur
will go to TBO without even getting a top!!! The secret is regular use
and care.
Linn
|
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
