Today's Message Index:
----------------------
1. 09:33 AM - Re: Engines-List Digest: 3 Msgs - 08/04/12 (speedy11@aol.com)
2. 02:08 PM - Re: Re: Engines-List Digest: 3 Msgs - 08/04/12 (Monty Barrett Sr)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Engines-List Digest: 3 Msgs - 08/04/12 |
Wow! Lots of great responses from several guys. Thanks!
After reading the responses I realized I had not made a complete post. I l
eft out too much info.
The engine is an IO-390 with filtered and ram air induction running two P M
ags with automotive iridium fine wire long reach spark plugs. It has 135 t
ach hours total. The AFS-3400 engine monitor allows me to download and ana
lyze engine readings - which I do regularly. This all began just after I a
dded Camguard to the oil although I cannot imagine that the two are related
. I believe it was coincidental that the problems coincided with the use o
f Camguard. I have taken a Blackstones Lab oil analysis and it showed incr
eased iron, but not to a significant degree to warrant concern. I will fol
low up with another oil sample soon so as to have something to compare.
E Mag Air overhauled the P Mags and added new circuit boards. I've been ru
nning the P Mags at 39 degrees advance, but reinstalled the jumper wire to
bring them back to 35 degrees. I've added cooling tubes for the P Mags bec
ause they had indications of running too hot. I considered replacing the P
Mags temporarily with regular mags, but the changeover would be a huge tas
k and I'd rather save it to last.
I check the fuel vents and they are clear.
I cleaned the injectors in Hoppes #9 in a hydrasonic cleaner and flow check
ed the injectors. They were evenly matched. I have a purge valve on the e
ngine and I use it for shutdown per recommendation from Airflow Performance
. I have not yet taken apart the fuel spider so the fuel divider could be
a problem. I checked the fuel injector lines and found no damage. I have
a plenum on the engine that does a good job of controlling air flow. Oil t
emps and CHTs are in the heart of the envelope but for the #3 CHT which run
s on the high side, but still well within limits.
I tested all of the spark plugs before installation using a maintenance sho
p tester. I replaced the lower wiring harness and tested the upper one.
When running the engine, I set high RPM for takeoff and did not change it o
n any of the flights, so RPM changes were eliminated.
We borescoped the engine and all cylinders look good except for a bit of co
rrosion on the cylinder walls. We also compression checked and readings we
re in the high 70s. I'm not familiar with SB-388 but I will check on it.
The engine runs the same regardless of filtered air or ram air. The ram ai
r intake is metal, so it is not collapsing to restrict flow. I also switch
ed off each mag airborne and each is running good now. Before the mag over
haul, I would lose significant power (one cylinder quit firing) when switch
ing a mag off. After overhaul, the mags are running correctly and the powe
r loss is related to high throttle settings.
I've checked the sniffle valve and it appears to be working properly, but I
may remove it anyway.
Next I'm going to look at the intake tubes. If one of the gaskets is leaki
ng that could cause a problem. I'm also going to inspect the manifold pres
sure hoses and then remove them for testing. The P Mags also have MP sensi
ng so I'll recheck those lines.
If that does not work, then my next step will be to start taking apart the
fuel system. That is another task I dread, but it may have to be done.
I will be sure to post on the forum if I find a solution.
Keep those ideas coming. Maybe someone will think of something that works.
Thanks,
Stan Sutterfield
From: Steve Thomas <lists@stevet.net>
Have you checked the integrity of your engine electrical ground? Steve Th
omas
From: FLYaDIVE <flyadive@gmail.com>
Stan:Some ideas I had: - How did you clean the injectors? A standard way
is to soak them in Hoppies #9 Gun Solvent. The flow could be all equal
- But they could be all slightly restricted. - Does the fuel lines from
the spider contact any part of the engine? HEAT could be causing a vapo
r bubble. - Since you have a CS prop, do you think or feel the loading ON
LY when increasing the RPM? This could be a SLOW reacting Governor and t
hat would cause loading. - Can you monitor your ALL your EGT 's at the
same time and see if a cylinder drops in temperature at the same time los
s of power occurs? - The spark plug that was a problem: Was it indicatin
g Oil or Carbon? Keep an eye on that plug and see if the problem begins
again. It could indicate a sticky Exhaust Valve. So, replacing the plug
will not fix the valve. - Have you done the Valve Wobble test (SB-388)
? - OK, with this one I am reaching a bit: I have read about someone that
"Improved" the intake air flow to the engine. And in doing so, the forc
ed air was so great that it disturbed the airflow through the Carb. - I
know you do not have a Carb, but how does it fly without the Ram Air? -
Have you inspected the ducting - I'm guessing SCAT Tube. Could that hav
e an obstruction or could it be collapsing?That's all for now...Barry
From: "DEAN PSIROPOULOS" <dean.psiropoulos@verizon.net>Subject: Engines-Lis
t: RE: Engine power lossI had a problem with a bad idle on my AFP injected
parallel valve 0-360Stan. After 5 months of trouble shooting I discovered
that the flow divider(on top of the engine) was sticking. How I figured th
at out was to tee in amechanical pressure gauge between the servo and the f
low divider (not atfuel pump outlet, you won't get accurate readings there)
. You'll need onecalibrated with a 0-10 PSI range. I ran a hose up to the
canopy from the teeand connected it to the gauge there so I could see the r
eading from thecockpit. Then I started the engine and watched the gauge wh
ile I wasadvancing the throttle. The engine stumbled and the pressure read
ing went acouple PSI above where it should have been before dropping back a
nd actingnormally (ie. going up and down with throttle movement). After co
nsultingwith Don Rivera at AFP the conclusion was a sticky flow divider so
Ireturned it to him for repair. The engine ran like a top after it was fixe
d.Another friend with a Bendix system found a small piece of black tapeplug
ging up one of the fuel ports in his flow divider but that was duringfirst
run when one EGT showed a cold cylinder (so much for the integrity ofFI reb
uilders). After that was fixed it still ran a bit rough and when hedid the
flow matching test (with the 4 cups under the injectors) he foundone somewh
at constricted. So he soaked that injector in Hoppes gun cleanerand viola,
engine runs great. Troubleshooting the fuel system can be veryfrustrating.
By the time I finally figured out the flow divider problem Iwas so disgust
ed that I had started to look for a Marvel carb. And I'm apretty patient gu
y. Dean PsiropoulosRV-6A N197DMFL to Indy 2012 without a hiccup
From: john kent <jakent@unison.ie>
Just a thought, have you checked your fuel tank venting?
J.K. EI-DIY RV4.
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Engines-List Digest: 3 Msgs - 08/04/12 |
Do not remove the sniffle valve. The reason is that after shutdown fuel
will " dribble " out of the nozzles if the fuel percolates, it then runs
down in the inlet portion of the plenum, condenses back to liquid and
becomes a fire hazard at the next start if you do not have the sniffle
valve installed.
Monty Barrett
Barrett Precision Engines, Inc.
-----Original Message-----
From: owner-engines-list-server@matronics.com
[mailto:owner-engines-list-server@matronics.com] On Behalf Of
speedy11@aol.com
Sent: Monday, August 06, 2012 11:31 AM
To: engines-list@matronics.com
Subject: Engines-List: Re: Engines-List Digest: 3 Msgs -
08/04/12
Wow! Lots of great responses from several guys. Thanks!
After reading the responses I realized I had not made a complete
post. I left out too much info.
The engine is an IO-390 with filtered and ram air induction
running two P Mags with automotive iridium fine wire long reach spark
plugs. It has 135 tach hours total. The AFS-3400 engine monitor allows
me to download and analyze engine readings - which I do regularly. This
all began just after I added Camguard to the oil although I cannot
imagine that the two are related. I believe it was coincidental that
the problems coincided with the use of Camguard. I have taken a
Blackstones Lab oil analysis and it showed increased iron, but not to a
significant degree to warrant concern. I will follow up with another
oil sample soon so as to have something to compare.
E Mag Air overhauled the P Mags and added new circuit boards.
I've been running the P Mags at 39 degrees advance, but reinstalled the
jumper wire to bring them back to 35 degrees. I've added cooling tubes
for the P Mags because they had indications of running too hot. I
considered replacing the P Mags temporarily with regular mags, but the
changeover would be a huge task and I'd rather save it to last.
I check the fuel vents and they are clear.
I cleaned the injectors in Hoppes #9 in a hydrasonic cleaner and
flow checked the injectors. They were evenly matched. I have a purge
valve on the engine and I use it for shutdown per recommendation from
Airflow Performance. I have not yet taken apart the fuel spider so the
fuel divider could be a problem. I checked the fuel injector lines and
found no damage. I have a plenum on the engine that does a good job of
controlling air flow. Oil temps and CHTs are in the heart of the
envelope but for the #3 CHT which runs on the high side, but still well
within limits.
I tested all of the spark plugs before installation using a
maintenance shop tester. I replaced the lower wiring harness and tested
the upper one.
When running the engine, I set high RPM for takeoff and did not
change it on any of the flights, so RPM changes were eliminated.
We borescoped the engine and all cylinders look good except for
a bit of corrosion on the cylinder walls. We also compression checked
and readings were in the high 70s. I'm not familiar with SB-388 but I
will check on it.
The engine runs the same regardless of filtered air or ram air.
The ram air intake is metal, so it is not collapsing to restrict flow.
I also switched off each mag airborne and each is running good now.
Before the mag overhaul, I would lose significant power (one cylinder
quit firing) when switching a mag off. After overhaul, the mags are
running correctly and the power loss is related to high throttle
settings.
I've checked the sniffle valve and it appears to be working
properly, but I may remove it anyway.
Next I'm going to look at the intake tubes. If one of the
gaskets is leaking that could cause a problem. I'm also going to
inspect the manifold pressure hoses and then remove them for testing.
The P Mags also have MP sensing so I'll recheck those lines.
If that does not work, then my next step will be to start taking
apart the fuel system. That is another task I dread, but it may have to
be done.
I will be sure to post on the forum if I find a solution.
Keep those ideas coming. Maybe someone will think of something
that works.
Thanks,
Stan Sutterfield
From: Steve Thomas <lists@stevet.net>
Have you checked the integrity of your engine electrical ground?
Steve Thomas
From: FLYaDIVE <flyadive@gmail.com>
Stan: Some ideas I had: - How did you clean the injectors? A
standard way is to soak them in Hoppies #9 Gun Solvent. The flow could
be all equal - But they could be all slightly restricted. - Does the
fuel lines from the spider contact any part of the engine? HEAT could be
causing a vapor bubble. - Since you have a CS prop, do you think or feel
the loading ONLY when increasing the RPM? This could be a SLOW reacting
Governor and that would cause loading. - Can you monitor your ALL your
EGT 's at the same time and see if a cylinder drops in temperature at
the same time loss of power occurs? - The spark plug that was a problem:
Was it indicating Oil or Carbon? Keep an eye on that plug and see if the
problem begins again. It could indicate a sticky Exhaust Valve. So,
replacing the plug will not fix the valve. - Have you done the Valve
Wobble test (SB-388)? - OK, with this one I am reaching a bit: I have
read about someone that "Improved" the intake air flow to the engine.
And in doing so, the forced air was so great that it disturbed the
airflow through the Carb. - I know you do not have a Carb, but how does
it fly without the Ram Air? - Have you inspected the ducting - I'm
guessing SCAT Tube. Could that have an obstruction or could it be
collapsing? That's all for now... Barry
From: "DEAN PSIROPOULOS" <dean.psiropoulos@verizon.net> Subject:
Engines-List: RE: Engine power loss I had a problem with a bad idle on
my AFP injected parallel valve 0-360 Stan. After 5 months of trouble
shooting I discovered that the flow divider (on top of the engine) was
sticking. How I figured that out was to tee in a mechanical pressure
gauge between the servo and the flow divider (not at fuel pump outlet,
you won't get accurate readings there). You'll need one calibrated with
a 0-10 PSI range. I ran a hose up to the canopy from the tee and
connected it to the gauge there so I could see the reading from the
cockpit. Then I started the engine and watched the gauge while I was
advancing the throttle. The engine stumbled and the pressure reading
went a couple PSI above where it should have been before dropping back
and acting normally (ie. going up and down with throttle movement).
After consulting with Don Rivera at AFP the conclusion was a sticky flow
divider so I returned it to him for repair. The engine ran like a top
after it was fixed. Another friend with a Bendix system found a small
piece of black tape plugging up one of the fuel ports in his flow
divider but that was during first run when one EGT showed a cold
cylinder (so much for the integrity of FI rebuilders). After that was
fixed it still ran a bit rough and when he did the flow matching test
(with the 4 cups under the injectors) he found one somewhat constricted.
So he soaked that injector in Hoppes gun cleaner and viola, engine runs
great. Troubleshooting the fuel system can be very frustrating. By the
time I finally figured out the flow divider problem I was so disgusted
that I had started to look for a Marvel carb. And I'm a pretty patient
guy. Dean Psiropoulos RV-6A N197DM FL to Indy 2012 without a hiccup
From: john kent <jakent@unison.ie>
Just a thought, have you checked your fuel tank venting?
J.K. EI-DIY RV4.
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|