REFLECTOR:Timing Change for Lycoming IO 360 C Engines?

[Ronnie Brown]

This is an angle valve engine with 8.7:1 compression ratio.  The operator's
manual says 20 degrees but to consult the name plate.

My name plate says 25 degrees.

I agree with you, 20 degrees would definitely reduce the 200 HP, probably
down into the range of the 180 HP parallel valve engines, which are lighter.
OTOH, the angle valve engine has better cooling fin design.  But Lycoming
admitted they had a valve guide sticking problem and issued a new part
number for improved guides for the parallel valve engine - but none
available for the angle valve.

Oh well, I seriously considered a 6 cylinder Franklin.


----- Original Message -----
From: "Brian Michalk" <michalk@awpi.com>
To: <reflector@tvbf.org>
Sent: Thursday, April 22, 2004 9:03 AM
Subject: RE: REFLECTOR:Timing Change for Lycoming IO 360 C Engines?


| What's the compression ratio of this engine compared to the other IO360
| variants?  It could be because it is higher in this particular engine.
| Also, is the cylinder dome (squish volume) geometry different in this
engine
| than the oer flavors?
|
| My guess is that they are having detonation problems.
|
| The downside is that retarding the timing will also decrease the
horsepower
| or efficiency.  Pick one, not both.
|
| I would sure like to see the horsepower curves with these two timing
| changes.  Too bad the ignition is not electronic.  Retard for high
manifold
| pressures, then advance for part throttle cruise ops.
|
|  Brian Michalk  <http://www.michalk.com>
| Life is what you make of it ... never wish you had done something.
| Aviator, experimental aircraft builder, motorcyclist, SCUBA diver
| musician, home-brewer, entrepreneur and barely single
|
|
| > -----Original Message-----
| > From: reflector-admin@tvbf.org [mailto:reflector-admin@tvbf.org]On
| > Behalf Of Ronnie Brown
| > Sent: Thursday, April 22, 2004 6:14 AM
| > To: reflector@tvbf.org
| > Subject: REFLECTOR:Timing Change for Lycoming IO 360 C Engines?
| >
| >
| > A discussion on the RV list says that Lycoming issued S.B. 380A
"IO-360-C
| > Timing Change"  - requiring a change from 25 degrees to 20 degrees BTDC.
| > Any body got the contents of this bulletin or know what the reasoning
is?
| >
| > THANKS
| > Ronnie Brown
| >
| >
| > _______________________________________________
| > To change your email address, visit
| > http://www.tvbf.org/mailman/listinfo/reflector
| >
| > Visit the gallery!  www.tvbf.org/gallery
| > user:pw = tvbf:jamaicangoose
| > Check new archives: www.tvbf.org/pipermail
| > Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
| >
|
| _______________________________________________
| To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector
|
| Visit the gallery!  www.tvbf.org/gallery
| user:pw = tvbf:jamaicangoose
| Check new archives: www.tvbf.org/pipermail
| Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
|