REFLECTOR: Fw: IO-550 Fuel Flow Issues and running LOP

[Sid Knox]

From: "John Dibble" <aminetech at bluefrog.com>
To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
Sent: Wednesday, October 08, 2008 5:09 PM
Subject: Re: REFLECTOR: Fw: IO-550 Fuel Flow Issues and running LOP


> John Dibble wrote:

> Sid,
> Very interesting.  I have been thinking that 100 octane is overkill for my 
> Franklin
> engine, especailly with dual ignition which helps reduce detonation.  I 
> just wasn't
> sure how to go about determining how low an octane is acceptable.  My 
> engine always
> runs cool so it seems like a good candidate for lower octane.  What is the 
> compression
> of your engine?

I believe it to be 8.5:1     Victor Black Edition

> What about for take-off?

Full rich of course.  Home field elev about 850 msl.  Fuel flow is about 17 
gph

> What about the lead deposits for the valves?  How many hours have you been 
> running
> this way?

Presumably, the small amount of 100LL I use provides some of the "required" 
lead.(?)
I've got perhaps 250-300 hours on the engine since I balanced the injectors 
and began the LOP operation.
Compression readings have not been more than 2 psi (loss) on any cyl.

Sid