REFLECTOR: Update on N173VS static RPM

[Geoff Gerhardt]

Hmm, yes, several folks have talked about intake leaks as a possibility.  I
kept thinking about intake leaks before the fuel controller, not the intake
tubes that go from the intake plenum to the heads.  I had all those off to
clean them.  I'll have a look at those and see if maybe that hot cylinder
has a leaky intake tube making it run real lean.  Thanks.

Geoff

On Thu, Feb 23, 2012 at 9:10 AM, Grover McNair <grover at mcnairperformance.com
> wrote:

>  Try swapping the injectors on #2 and #3. If the temps follow the
> injector, you know you have an uneven flow from those two injectors. I
> would also recommend rechecking the timing. You apparently have plenty of
> fuel and can regulate it to the proper mixture. The only things left are
> air flow and timing. An intake leak could cause one cylinder to be lean. If
> it were a car I would check for a clogged catalytic converter…****
>
> Grover McNair****
>
> ** **
>  ------------------------------
>
> *From:* reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] *On
> Behalf Of *Jeff Barnes
> *Sent:* Thursday, February 23, 2012 8:50 AM
> *To:* geoff.gerhardt at gmail.com; Velocity Aircraft Owners and Builders list
> *Subject:* Re: REFLECTOR: Update on N173VS static RPM****
>
> ** **
>
> anything blocking your air intake ?
>
> --- On *Thu, 2/23/12, Geoff Gerhardt <geoff.gerhardt at gmail.com>* wrote:***
> *
>
>
> From: Geoff Gerhardt <geoff.gerhardt at gmail.com>
> Subject: REFLECTOR: Update on N173VS static RPM
> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
> Date: Thursday, February 23, 2012, 6:37 AM****
>
> As I've described, I recently started up my engine for the first time.
>  After sorting out some minor issues with the EI, when I tried to go to
> full power, I was only getting ~1900RPM static.  Also, I could only reach
> this power when I pulled the mixture lever way back - the engine sputtered
> when both the throttle and mixture were all the way in. ****
>
> ** **
>
> On Tuesday night, I discovered that one of my fuel injector lines was
> leaking at the connection to the injector (bad solder joint).  I repaired
> this and tried it again last night.  But, before I did, I pulled all the
> injectors out, turned the fuel pump on and observed their spray.  I
> measured their volume output over a 10s period and they were all
> approximately equal.  So, I started it up hoping all problems were solved,
> but it behaved exactly the same.  This time, though, I was a bit more
> observant of some of the engine data.  ****
>
> ** **
>
> First thing I noticed was that the Dynon Skyview indicated it was running
> very rich.  I forget exactly what the number was, but it was something like
> 30% ROP.  By pulling the mixture back at full throttle I could maximize
> power and the Dynon did show the mixture going from very rich to
> perfect/slightly lean (I forget exactly what mixture full power was
> reached).  But, my static RPM was still only ~1850-1900 RPM.  It was neat
> to see the EGT's bounce around very quickly to these mixture adjustments,
> tho.****
>
> ** **
>
> The second thing I noticed was the CHT's - #3 was running significantly
> colder and #2 hotter than ~#1/4.  Here's a snapshot of the temps at one
> point from 1:341, 2:409, 3:290, 4:381.  Generally, 1/4 tracked pretty
> closely, but #2 got pretty hot and #3 was always at least 50deg colder than
> 1/4.****
>
> ** **
>
> Just an update on the history on the engine - it was a 500hr SMOH engine
> that I bought from another Velocity owner who was parting out his plane.
>  He's an A&P who had bought the engine, pulled off the jugs, inspected the
> crank, replaced the rings and had it running on his velo and taxing around.
>  He ensures it was running well and I'm taking his word on this.  Since
> then, the engine's been mostly sitting in my shop or hanging on my plane
> pickled.  This is the first startup since I've rec'd it.****
>
> ** **
>
> So, I'm going to check the plugs next.  Anyone else have any other
> suggestions?****
>
> ** **
>
> Thanks.****
>
> ** **
>
> Geoff****
>
> ** **
>
>
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