Received-SPF: none
 receiver=logan.com; client-ip=204.127.192.81; envelope-from=rlwhite@comcast.net
Date: Sat, 14 Apr 2007 21:11:11 -0600
From: Bob White <rlwhite@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] single rotor testing
Message-Id: <20070414211111.9e3d189e.rlwhite@comcast.net>
In-Reply-To: <list-1985761@logan.com>
References: <list-1985761@logan.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

Great report Rusty,

Maybe the low idle problem is related to the mixture problem. 

Bob W.

On Sat, 14 Apr 2007 20:11:08 -0500
"Russell Duffy" <rusty@radrotary.com> wrote:

> Greetings,
> 
>  
> 
> Well, my neighborhood probably still thinks I'm a lunatic.  I drove out with
> my engine test trailer, and got some funny looks.  You'd think they'd be
> used to this sort of thing by now :-)
> 
>  
> 
> The Autoflight redrive looks quite well made, and is 12 lbs lighter overall
> than the RD1C that I had before.  As I mentioned though, this one is limited
> to 160 HP, so not really what you want for a healthy 2 rotor.  Overall
> weight of everything you see (except the trailer and prop) is about 230 lbs.
> 
> 
>  
> 
> Anyway, I hauled the engine trailer to the airport, and fired it up.  It
> actually cranked with little difficulty, but the mixture was way off.
> Basically, I ended up running it with the cold start on, but mixture turned
> way down.  I'll have to reset everything and start over eventually, but I
> just wanted to see it run. 
> 
>  
> 
> The bad news is that it's still rough as a cob below 2500 rpm, which is to
> be expected with a single rotor and no flywheel.  The test stand has some
> flex to it as well, and I spent far too long marveling at it could possibly
> jump around that much.  The drive was quiet during all this shaking though.
> 
> 
>  
> 
> The good news is that it smoothes out above 2500, just like you flipped a
> switch.  As you increase rpm, there are still small bands were I heard a
> brief light rattle.  I assumed this was the drive, but was much less severe
> due to the rubber damper, and tight gear mesh.   It certainly could have
> been something else, since there are plenty of things on the test stand to
> rattle (including the intake).  This is much better than with the RD1C, but
> not as good as I had hoped for.  
> 
>  
> 
> I didn't go above 4000 rpm, and never saw more than 105 F on the water temp.
> Oil was at 128 F as I recall.  I know I may need some more water flow
> through the oil/water exchanger, but this might work OK.  I'll have to get
> the temps up farther to find out, and that might require covering up some of
> this radiator.  
> 
>  
> 
> The prop still has the odd fore and aft tip movement that it had on the
> Kolb, so that has not changed at all.  This just has to still be the torque
> reversal, but maybe off resonance of the mount.  I took some video of this,
> but there was some technical difficulty retrieving it, so I'll have to try
> again.  Rats.  
> 
>  
> 
> While playing around with the rough point, I found that the engine wouldn't
> idle below 2400 anymore, and the throttle was getting stiff.   I was done
> anyway, and put the stand away.  When I was looking for leaks (amazingly
> none found), I noticed that my telltales on the intake manifold were telling
> the tale.  In fact, the intake had all but broken loose due to the shaking.
> Partly this is due to my crappy welding, and partly it's due to the shaking.
> I'll have to re-weld this, and make it stronger.  I'll also look into some
> other way to brace the TB so it's not all being supported by my crappy
> welds.  Notice the theme here :-)
> 
>  
> 
> I've given up on running the engine on the Dominator gyro, and already have
> a 582 Rotax for that.  My goal is to decide whether the single rotor will
> work well enough to be worth messing with on a plane, then perhaps build a
> Zenith 601XL for it.  The main limitation seems to be the low rpm roughness
> issue.  I can go as low as maybe 2400 rpm, but that still give me about 970
> rpm on the prop.  This is a bit high, but not a complete deal breaker,
> particularly on a plane that isn't too slick.  If that's the only issue,
> then it will probably be a go.    
> 
>  
> 
> Cheers,
> 
> Rusty (don't think I can blame the idle problems on my EC-2) 
> 
>