Today's Message Index:
----------------------
1. 12:07 PM - pumps (Pat Ladd)
2. 01:42 PM - pitch? (Stuart Harner)
3. 02:04 PM - Re: pitch? (John Hauck)
4. 03:03 PM - Re: pitch? (Beauford)
5. 05:03 PM - Re: pitch? (t41pilot)
6. 06:49 PM - Re: pitch? (Richard Pike)
7. 07:05 PM - Re: Re: pitch? (John Hauck)
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 |
|
Hi,
My ex flying partner still flies a Eurostar, the same type we shared but
not the same machine. He is a good pilot and meticulous about
maintenance. I forwarded our recent posts about pumps to him and this
is his reply.
For what its worth.
On another tack John flew me to a local airshow last weekend where we
had a flyover of the only two Lancasters still flying.The Canadian one
is over her for a month. A once in a lifetime experience
Cheers
Pat
Pat,
Don't know whether you are inclined to forward this to your Kolb list?
As you may know, mine - a 4 year old example - was one of the series of
Rotax 912s recommended for a change of fuel pump. Apparently, several
of the previous type had failed in service. A replacement was provided
free by the then UK Rotax agent and it certainly looked a
better-engineered piece of work than its predecessor. That said, the
previous one had given me no trouble over 4 years and 300 hours. Nor
had the one on a previous Rotax-powered aircraft I had owned over 6
years and 650 hours.
Experience with the new pump belied appearance. I try to stay safe by
being attentive to anything about the aircraft which changes - sight,
sound or feel - and investigating. The new fuel pump showed big and
seemingly random variations in pressure, between 0.2 and 0.4 bar. (The
previous pump had given virtually constant readings under all
conditions.) It therefore didn't feel "safe".
Matters came to a head when flying over one of the more inhospitable
areas of the UK, when the pressure dropped off from its "norm" at just
over 0.3 bar to 0.2 bar before recovering several sweaty minutes later.
I raised this with the Rotax agent and with our Light Aircraft
Association. The answer was that nothing could be done about it. The
new pumps did give variations in pressure and my results were within the
specified range. I subsequently borrowed a new-type pump from elsewhere
and this gave better results, although still subject to some variation.
I have since returned that to its rightful owners and purchased a
further new pump. This also gives better results, but still subject to
some variation. I may be deluding myself but I think the variability
may be diminishing with time. It appears, from talking to others, that
the new type fuel pump is just not engineered to very tight tolerances:
strange given the strong engineering tradition of where in Europe I
assume it comes from.
Not being an engineer or an expert, I cannot advise on what your
colleague Dennis Kirby should do! I just add my tale to the request for
thoughts.
Regards,
John
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 |
|
Hi,
My Warp Drive prop (3 blade- 60") arrived yesterday and I am getting ready
to set it up. It is going on my Firefly with a Rotax 447 (single
carb),B-Gearbox with 2.58 ratio.
Is anyone running this same setup?
What amount of pitch do you think I should start with?
Do I shoot for 6500 or 6800 RPM static?
Just waiting for muffler mount and engine instruments so I can do the final
assembly.
Getting anxious!
Thanks in advance,
Stuart
Message 3
| 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 |
|
If I was flying it, I would prop it to bump 6,500 rpm, wide open throttle,
straight and level flight. Without looking for the book, I think the 447 is
rated at 6,500 rpm max continuous. 6,800 rpm is like military power, can
only be run at that speed for 5 minutes max. If you had an in flight
adjustable prop you could pitch to turn 6,800 rpm, but a ground adjustable
prop works best propped as described above.
I don't know what static rpm would be, probably 6,300. Been too many years
since I had a 447 on my FS.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Stuart Harner
Sent: Thursday, August 28, 2014 3:41 PM
Subject: Kolb-List: pitch?
Hi,
My Warp Drive prop (3 blade- 60") arrived yesterday and I am getting ready
to set it up. It is going on my Firefly with a Rotax 447 (single
carb),B-Gearbox with 2.58 ratio.
Is anyone running this same setup?
What amount of pitch do you think I should start with?
Do I shoot for 6500 or 6800 RPM static?
Just waiting for muffler mount and engine instruments so I can do the final
assembly.
Getting anxious!
Thanks in advance,
Stuart
Message 4
| 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 |
|
Brother Harner:
Cannot speak directly to the Warp. Mine has a 66 inch IVO. But load is load.
That said, I would suspect that anything over
6100 or 6150 static might be a tad skinny on loading. When I set 6150
static WOT, I get easy 6600 in level flight WOT.
Personally fer me, that is about enough. 6800 static would be like an
argument with my first wife. makes my few remaining teeth hurt.
(how mad are you at your bearings.?)
Worth What Ye Paid Fer It.
beauford
FF-076
Brandon, FL
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Stuart Harner
Subject: Kolb-List: pitch?
What amount of pitch do you think I should start with?
Do I shoot for 6500 or 6800 RPM static?
Stuart
Message 5
| 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 |
|
I'm running a 447 on my firefly with a 60 inch IVO prop. 6500 WOT is by the book
and typically 200 RPM less static on the ground would yield whatever WOT setting
you are looking for. That being said, I have found from a lot of reading
on the subject that not all 447's are going to run identically. You should dial
in your prop to whatever setting makes your CHT and EGT fall within the normal
operating range during flight conditions.
On my particular engine that ended up being 6000 static and 6300 WOT. It took a
few flights to get that figured out. Definitely 6800 WOT is too much. I would
start at 61 or 62 static and see how she goes. Add more pitch if the EGT is too
high. Fiddling with carb jets to get the temps right can lead to a vicious
circle of prop pitch changes and wrong conclusions. I did end up with my clip
set rich and one size larger on my main jet but in most cases the stock size
jets should work.
--------
Gregg Kaat
2011 Firefly
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429555#429555
Message 6
| 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 |
|
What John & the others said. Let me add a few remarks from my own experience: leave
the jets alone and fine tune the EGT with prop pitch. When the pitch is ideal,
your EGT's will stay roughly between 1050 & 1150 at any typical in-flight
throttle setting except WOT, where they will be 1000-1050. As the EGT rises
and falls from summer to winter, once again, leave the jets alone and add or remove
pitch.
I marked this on my Ivo hub abut 3 years ago, so the arrows are a bit faded, but
coarse is one way, fine is the other. Takes less than 2 minutes, usually a half
a turn is enough.
--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
My soul shall be joyful in the LORD; It shall rejoice in His salvation. Psalm 35:9
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429559#429559
Attachments:
http://forums.matronics.com//files/p1030840_small_127.jpg
Message 7
| 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 |
|
If I remember correctly, ROTAX sets up their two strokes, before they leave
the factory, for operation from sea level to 3000 feet on a 70F day. It has
the correct heat range spark plugs and is jetted correctly. It will run
perfect right out of the box.
It is up to the operator to load the prop correctly. Do it by pitch
adjustment and leave the engine alone.
My experience with two stroke aircraft engines, which are continuous duty
engines, is WOT, straight and level flight, just bump the red line, 6500
rpm. I discovered if I set up the engine this way, my EGTs would be right
in the green. Loading and unloading the prop by changing pitch attitude
also affects EGTs, but temporarily. EGTs can be controlled with throttle
settings.
This info is nothing new. We have been doing it this way since 1984, and
others long before me.
john h
mkIII
Titus, Alabama
What John & the others said. Let me add a few remarks from my own
experience: leave the jets alone and fine tune the EGT with prop pitch. When
the pitch is ideal, your EGT's will stay roughly between 1050 & 1150 at any
typical in-flight throttle setting except WOT, where they will be 1000-1050.
As the EGT rises and falls from summer to winter, once again, leave the jets
alone and add or remove pitch.
I marked this on my Ivo hub abut 3 years ago, so the arrows are a bit faded,
but coarse is one way, fine is the other. Takes less than 2 minutes, usually
a half a turn is enough.
--------
Richard Pike
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! --
|