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To: flyrotary@lancaironline.net
Date: Mon, 19 Feb 2007 07:51:04 -0800
Subject: Re: [FlyRotary] Re: Cowling and engine installation RV 7A
Message-ID: <20070219.082200.2644.0.alwick@juno.com>
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From: al p wick <alwick@juno.com>

 I've seen dyno reports that show Hp gain at certain cam timing settings.
However, I expect I'll eventually lock the timing at one ideal setting
and then remove the unneeded components. It will be fun playing with it
and measuring the difference. I do my best to avoid speculative
decisions.

If you go back thru the archives for just about any engine, it's not the
OEM systems that represent our big risk items. It's the changes we make.
I just got report of pilot that died recently in Canard crash. Same root
cause as revealed in our recent fuel line discussions. He used materials
and installation method that is sensitive to the environment. Heat and
vibration sensitive. 

In his case, he used plastic fitting for fuel flow measure in high heat
area. We don't know if the plastic fatigued first, or melted. When we
analyze this, we realize he added unnecessary component to fuel system,
changed the system design, and unexpectedly ended up with system
sensitive to both heat and vibration. Same cause as hard plumbing fuel
system. No OEM system hard plumbs these systems. Yet we innovate and
increase our risk. It's difficult to appreciate the effects of vibration
and stress concentrations simply because it's not something we see. 


-al wick

On Mon, 19 Feb 2007 08:33:36 +0800 david mccandless
<daval@iprimus.com.au> writes:
> Hi Al,
> what is the point in having variable valve lift and cam timing in an 
> 
> aircraft engine?
> As I understand it, these features are for low speed torque 
> enhancement 
> in cars. Not applicable in aircraft engines.
> Seems to me you have extra complication and failure modes built in 
> .
> BR, Dave McC
> 
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
> 
> 
 
 
-al wick
Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam
timing. 
Artificial intelligence in cockpit, N9032U 240+ hours from Portland,
Oregon
Glass panel design, Subaru install, Prop construct, Risk assessment info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html