Today's Message Index:
----------------------
1. 05:56 AM - Re: Hot heads (Richard Pike)
2. 06:03 AM - Re: Hot heads (N27SB@aol.com)
3. 06:12 AM - Re: Hot heads (John Hauck)
4. 08:10 AM - Re: Hot heads (Thom Riddle)
5. 08:26 AM - Re: Re: Hot heads (Herb Gayheart)
6. 09:45 AM - Re: Re: Hot heads (Herb Gayheart)
7. 10:18 AM - Re: Re: Hot heads (Richard Pike)
8. 10:33 AM - Re: Re: Hot heads (Herb Gayheart)
9. 01:16 PM - Re: Re: Hot heads (Thom Riddle)
10. 02:35 PM - q (russ kinne)
11. 03:11 PM - Fuel Tank Options (jctuck3@excite.com)
12. 04:02 PM - Re: Fuel Tank Options (Richard Pike)
13. 04:32 PM - Rotax's Patented Hell (Beauford)
14. 06:01 PM - Re: Rotax's Patented Hell (John Hauck)
15. 06:36 PM - 925 Battery (Dallas Shepherd)
16. 07:51 PM - Re: Rotax's Patented Hell (Beauford)
17. 08:12 PM - Re: Rotax's Patented Hell (Richard Pike)
18. 08:12 PM - Re: Rotax's Patented Hell (John Hauck)
19. 08:32 PM - Re: Hot heads (DAquaNut@aol.com)
20. 09:23 PM - Local Kolb (Rick Pearce)
21. 10:40 PM - Re: Rotax's Patented Hell (possums)
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 |
|
--> Kolb-List message posted by: Richard Pike <richard@bcchapel.org>
Don't know who said what, but here is how it works:
Think of your 2-stroke engine as an air pump.
You adjust RPM at any given throttle setting (X) by changing the load (prop
pitch/diameter)
For the rest of this post, assume X equals a constant throttle position
Air flow through the engine at X throttle will vary with RPM change
(Raise the nose, lower the nose, change the prop pitch)
Fuel flow at X throttle is more constant than air flow at X throttle as
RPM's change
Therefore, as you change the RPM's at X throttle by changing the load,
the mixture will richen as rpm's decrease, (less air, almost constant fuel)
the mixture will lean as they increase (more air, almost constant fuel)
In practice, this works out like this:
More load at X throttle = the engine works harder = CHT up
Less load at X throttle = engine works less = CHT down
Less load at X throttle = higher RPM = leaner mixture = higher EGT
More load at X throttle = lower RPM = richer mixture = lower EGT
It is possible to change EGT and CHT independently of each other by
changing jetting and prop load
(These are generalities, - there are grey areas where things overlap)
A high prop load and big jets will give you low EGT and high CHT
A low prop load and small jets will give you a high EGT and low CHT
A low prop load and big jets will give you a low EGT and low CHT
A high prop load and small jets will give you a high EGT and high CHT
And probably a real hit in your Visa card as well.........
Assuming an engine jetted/propped for normal temps, give yourself a
demonstration:
At cruise, lower the nose and let the airspeed and rpm's go up -
The EGT should go up, the CHT should go down.
Raise the nose and let the airspeed and rpm's go down -
The CHT should either go up or stay constant, and the EGT should decrease
Here is a link to a web page I did on this topic:
http://www.bcchapel.org/pages/0003/pg11.htm
Having said all this, a healthy engine with Rotax recommended jets and
propped for around 6200 or so static, that will reach around 64-6600 RPM in
level flight ought to have normal temperatures with both the CHT and EGT,
assuming the prop diameter & blade count is anywhere close to typical for
that engine. For instance, the Rotax 582 has a max allowable speed of 6800
RPM, but propping to hit that RPM in full throttle level flight causes the
EGT on my MKIII to be too high in cruise, so I am pitched for 6500 max RPM
in level flight, and EGT's stay constant between 1000-1100 with good
overall performance.
Richard Pike
MKIII N420P (420ldPoops)
At 01:58 AM 8/4/05 -0400, you wrote:
>--> Kolb-List message posted by: DAquaNut@aol.com
>
>
>In a message dated 8/3/2005 9:50:42 P.M. Central Standard Time,
>richard@bcchapel.org writes:
>
>
>Ed, too little pitch gives you high EGT's.
>Beauford's problem is high CHT's, which might be happening
>
>
>Richard. I guess I am confused. I sure thought someone on this list said If
>your rotax gets too hot when you are breaking in a new engine you need to
>crank more pitch in the prop. Wont to high of EGT readings cause the
>heads to
>get hotter too? I am paying attention because I might need to know the
>remedy
>myself.
>
> Ed
>
>
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 |
|
--> Kolb-List message posted by: N27SB@aol.com
Hey Beauford, I seem to remember a little episode you had with VGs. Is it
possible that this could be a replay? I smell a rat.
steve
do not archive
ps The heads go on fins up!
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 |
|
--> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
| RPM, but propping to hit that RPM in full throttle level flight
causes the
| EGT on my MKIII to be too high in cruise, so I am pitched for 6500
max RPM
| in level flight, and EGT's stay constant between 1000-1100 with good
| overall performance.
|
| Richard Pike
Morning Richard/Gang:
I believe all Rotax engines are rated at 6,800 rpm full throttle for 5
minutes. Like "military power". Only thing that is good for is folks
with inflight adjustable props. Ground adjustable props and fixed
pitch props need to adjust pitch for 6,500 rpm WOT straight and level
flight. 6,500 rpm is max continuous power.
Propped at max continuous power of 6,500 rpm, carb adjusted at factory
settings = EGT's in the green at most all throttle settings. Also
gives you best climb and cruise combo for a fixed pitch prop.
We run into the "military power" thing on the 912 series engines also.
5,800 for 5 minutes. So....I set up for 5,500 rpm which is max
continuous rpm WOT straight and level flight.
On a two stroke, overload pitch and the EGT's go down and the CHT's go
up. Too little pitch and the EGT's go up and the CHT's go down.
Screwy, but that's the way it works with two strokes.
Take care,
john h
MKIII - 2,370.0 hours
912ULS - 1,025.0 hours
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 |
|
--> Kolb-List message posted by: Thom Riddle <jtriddle@adelphia.net>
Richard Pike,
Your explanation of CHT and EGT variations was excellent and definitely
worth archiving. It was simple, straight forward and easily understood
by most folks, I think.
Thom
do not archive
'
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 |
|
--> Kolb-List message posted by: Herb Gayheart <herbgh@juno.com>
Thom
As you say ; Richard did a good job of explaning the operation of 2
cycle engines on airplanes. To my mind he also showed us why only those
who are presumably closer to God can hope to operate these little buggers
successfully. Or better said--if you fly 2 stroke--you had better say
your prayers!! :-) Herb
On Thu, 4 Aug 2005 11:09:51 -0400 Thom Riddle <jtriddle@adelphia.net>
writes:
> --> Kolb-List message posted by: Thom Riddle <jtriddle@adelphia.net>
>
> Richard Pike,
>
> Your explanation of CHT and EGT variations was excellent and
> definitely
> worth archiving. It was simple, straight forward and easily
> understood
> by most folks, I think.
>
> Thom
> do not archive
> '
>
>
>
>
>
>
>
>
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 |
|
--> Kolb-List message posted by: Herb Gayheart <herbgh@juno.com>
Thom and Rev Pike
Gotta say that Bro Pike also explained all of the various world
religions in his dissertation also. :-)
Kinda goes like this----In the beginning there was one god(Rotax) --all
believed in the factory installed main jet----and recommended prop.
Then there were those of little faith who deviated from the true path.
These became the Rotax Reformed group--they changed main jets and chased
their tails with needle sects--prop pitch sects---. finally someone
discovered a lost tablet that seemed to mention something like "syn" and
" Marv". Along came a prophet who claimed to interpret this as
Synthetic and Marvel.
Another desciple --lets call him John--said that the true way was to
go down the "main path" as preached in the Rotax Bible. This caused
great hardship and suffering to John--for this bible was subject to many
interpretations. Some who were weak; claimed that one size did not fit
all. After all many sizes were mentioned in the newly found tablet from
a cave in Austria.
These groups 'seized" on new discoveries and claimed that the word
Marvel was no mystery and that their religion was no more "synthetic"
than any other. Herb
On Thu, 4 Aug 2005 11:09:51 -0400 Thom Riddle <jtriddle@adelphia.net>
writes:
> --> Kolb-List message posted by: Thom Riddle <jtriddle@adelphia.net>
>
> Richard Pike,
>
> Your explanation of CHT and EGT variations was excellent and
> definitely
> worth archiving. It was simple, straight forward and easily
> understood
> by most folks, I think.
>
> Thom
> do not archive
> '
>
>
>
>
>
>
>
>
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 |
|
--> Kolb-List message posted by: Richard Pike <richard@bcchapel.org>
ROTFL!
That's really pretty good. There's just one problem...
The Prophet Hirth (PBUH) has received a message from the angel HKS
commanding all of us to repent and proclaim Lycoming akbar,
(Lycoming is greater) or we will all suffer stuck rings and snapped cranks.
Bummer.
Richard Pike
MKIII N420P (420ldPoops)
At 11:42 AM 8/4/05 -0500, you wrote:
>--> Kolb-List message posted by: Herb Gayheart <herbgh@juno.com>
>
>Thom and Rev Pike
>
> Gotta say that Bro Pike also explained all of the various world
>religions in his dissertation also. :-)
>
> Kinda goes like this----In the beginning there was one god(Rotax) --all
>believed in the factory installed main jet----and recommended prop.
>Then there were those of little faith who deviated from the true path.
>These became the Rotax Reformed group--they changed main jets and chased
>their tails with needle sects--prop pitch sects---. finally someone
>discovered a lost tablet that seemed to mention something like "syn" and
>" Marv". Along came a prophet who claimed to interpret this as
>Synthetic and Marvel.
>
> Another desciple --lets call him John--said that the true way was to
>go down the "main path" as preached in the Rotax Bible. This caused
>great hardship and suffering to John--for this bible was subject to many
>interpretations. Some who were weak; claimed that one size did not fit
>all. After all many sizes were mentioned in the newly found tablet from
>a cave in Austria.
>
> These groups 'seized" on new discoveries and claimed that the word
>Marvel was no mystery and that their religion was no more "synthetic"
>than any other. Herb
>
>On Thu, 4 Aug 2005 11:09:51 -0400 Thom Riddle <jtriddle@adelphia.net>
>writes:
> > --> Kolb-List message posted by: Thom Riddle <jtriddle@adelphia.net>
> >
> > Richard Pike,
> >
> > Your explanation of CHT and EGT variations was excellent and
> > definitely
> > worth archiving. It was simple, straight forward and easily
> > understood
> > by most folks, I think.
> >
> > Thom
> > do not archive
> > '
> >
> >
> >
> >
> >
> >
> >
> >
>
>
Message 8
| 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 |
|
--> Kolb-List message posted by: Herb Gayheart <herbgh@juno.com>
Richard
Should have sent it to Bro Beauford for some touching up! :-) I
suspect that he is on a prymidal comtraption doing omage to the sun gods.
Florida--South America somewhere?? Herb
do not archive
On Thu, 04 Aug 2005 13:19:06 -0400 Richard Pike <richard@bcchapel.org>
writes:
> --> Kolb-List message posted by: Richard Pike <richard@bcchapel.org>
>
> ROTFL!
>
> That's really pretty good. There's just one problem...
>
> The Prophet Hirth (PBUH) has received a message from the angel HKS
> commanding all of us to repent and proclaim Lycoming akbar,
> (Lycoming is greater) or we will all suffer stuck rings and snapped
> cranks.
>
> Bummer.
>
> Richard Pike
> MKIII N420P (420ldPoops)
>
> At 11:42 AM 8/4/05 -0500, you wrote:
>
> >--> Kolb-List message posted by: Herb Gayheart <herbgh@juno.com>
> >
> >Thom and Rev Pike
> >
> > Gotta say that Bro Pike also explained all of the various world
> >religions in his dissertation also. :-)
> >
> > Kinda goes like this----In the beginning there was one
> god(Rotax) --all
> >believed in the factory installed main jet----and recommended
> prop.
> >Then there were those of little faith who deviated from the true
> path.
> >These became the Rotax Reformed group--they changed main jets and
> chased
> >their tails with needle sects--prop pitch sects---. finally
> someone
> >discovered a lost tablet that seemed to mention something like
> "syn" and
> >" Marv". Along came a prophet who claimed to interpret this as
> >Synthetic and Marvel.
> >
> > Another desciple --lets call him John--said that the true way
> was to
> >go down the "main path" as preached in the Rotax Bible. This
> caused
> >great hardship and suffering to John--for this bible was subject
> to many
> >interpretations. Some who were weak; claimed that one size did
> not fit
> >all. After all many sizes were mentioned in the newly found tablet
> from
> >a cave in Austria.
> >
> > These groups 'seized" on new discoveries and claimed that the
> word
> >Marvel was no mystery and that their religion was no more
> "synthetic"
> >than any other. Herb
> >
> >On Thu, 4 Aug 2005 11:09:51 -0400 Thom Riddle
> <jtriddle@adelphia.net>
> >writes:
> > > --> Kolb-List message posted by: Thom Riddle
> <jtriddle@adelphia.net>
> > >
> > > Richard Pike,
> > >
> > > Your explanation of CHT and EGT variations was excellent and
> > > definitely
> > > worth archiving. It was simple, straight forward and easily
> > > understood
> > > by most folks, I think.
> > >
> > > Thom
> > > do not archive
> > > '
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> >
>
>
>
>
>
>
>
>
Message 9
| 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: Re: Hot heads |
--> Kolb-List message posted by: Thom Riddle <jtriddle@adelphia.net>
Oh engine prophets all, is there any wonder why I stay tuned to this
list, even though I no longer own a Kolb? The entertainment value is
priceless.
Thom
Message 10
| 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 |
|
--> Kolb-List message posted by: russ kinne <kinnepix@earthlink.net>
Amen Thom! -- entertanining and educational! --I've even learned some
new words.
like,
do not archive
Message 11
| 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: | Fuel Tank Options |
--> Kolb-List message posted by: "jctuck3@excite.com" <jctuck3@excite.com>
Hey fellow Kolbers! The original tanks on my Mark II Twinstar Kolb are looking
pretty shabby (and leak a little too). What options do I have as for replacing
them? Of course I could buy the same 2 five gallon jugs, but if possible I'd
like to gain a little more fuel capacity. I tried installing a 13 gal Tempo
fuel tank; it would fit in the space for the original containers but installing
it is impossible unless I want to recover the rear fuselage as I would have
to remove the fabric to shove it in there. ; ( I've seen a homemade fibreglass
tank molded in between the wings, but since I do not have an appropriate
workspace to fashion one, it's a no go. Please let me know if any of you have
had any success with replacement fuel tanks. Thanks. Julian
Message 12
| 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: Fuel Tank Options |
--> Kolb-List message posted by: Richard Pike <richard@bcchapel.org>
Don't know about a Twinstar, but a MKIII will accept two 6 gallon red
plastic boat tanks like they sell at Wallyworld. You do need to make a
couple small mods to the original tank bracing setup, & cut out some of the
original tubing brackets, but it ought to be possible to weld it up a mod
on the bench and then put it in place, and then put the tanks in.
The tanks are sort of bigger at the end away from the cap and the handle,
that is the end that goes down and toward the seat back. The handle & cap
end is up and to the rear, and the thing goes in at about a twenty degree
angle. At that angle, they actually hold a bit over six gallons each. They
will bulge the MKIII fuselage side fabric out a tad, but not much. I used
this setup for a while until I made the present 15 gallon in-the-wing-gap
system
One other important thing: if you decide to use them and can make them fit,
be sure and check the original fuel pickup line inside the tanks. They are
about impossible to see from looking through the fill cap hole, but you
want something that goes down to the lowest corner after you install the
tanks at an angle. The original fuel pickup does not reach that far, and
after you get down to half a tank, a steep climb will result in fuel
starvation. (Guess how I know this?)
Richard Pike
MKIII N420P (420ldPoops)
At 06:10 PM 8/4/05 -0400, you wrote:
>--> Kolb-List message posted by: "jctuck3@excite.com" <jctuck3@excite.com>
>
>
>Hey fellow Kolbers! The original tanks on my Mark II Twinstar Kolb are
>looking pretty shabby (and leak a little too). What options do I have as
>for replacing them? Of course I could buy the same 2 five gallon jugs,
>but if possible I'd like to gain a little more fuel capacity. I tried
>installing a 13 gal Tempo fuel tank; it would fit in the space for the
>original containers but installing it is impossible unless I want to
>recover the rear fuselage as I would have to remove the fabric to shove it
>in there. ; ( I've seen a homemade fibreglass tank molded in between
>the wings, but since I do not have an appropriate workspace to fashion
>one, it's a no go. Please let me know if any of you have had any success
>with replacement fuel tanks. Thanks. Julian
>
>
Message 13
| 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: | Rotax's Patented Hell |
--> Kolb-List message posted by: "Beauford" <beauford@tampabay.rr.com>
Kolbers and Kolbettes...
Another refreshing character-building day out on the old airstrip with my favorite
engine...
Long story short -- Rings did not seat.... engine is damaged
Ran the standard Rotax break-in sequence on the honed and deglazed cylinders with
Pennzoil Air Cooled 50 to 1 and Amoco gas... actually ended up running it
twice back to back.
Total run time was about 90 minutes. Tail was tied to ground.
-- CHT's both remained high during procedure... 370 to 390 at 5,000... would quickly
build to over 400 degrees if rpm went over 5,000 and I would
be forced to quickly throttle back and let it cool for a minute until temps came
down.
-- EGT's were normal to just slightly high throughout the process.... 1040 to 1160
observed.
-- Started with completely clean pistons, rings, exhaust manifolds and heads. Piston
crowns and cyl heads were shiny, rings and grooves were whistle-clean, exhaust
manifolds were shiny and smooth to touch inside. Following the 90 minutes,
took the top of the engine apart and was amazed to find extensive rock-hard
carbon coke everywhere... crowns of pistons, behind rings, in exhaust manifolds...
all new deposits from the 90 minute run.
-- Pistons and rings had no scuffing before run ... after the 90 minutes, they
now have substantial scuff marks.
-- No changes made in carb jetting or metering rod... metering rod in second notch
from top... both came on the engine new as stock items provided by Rotax.
-- Choke (enrichment piston) was NOT engaged during the run.
Took photos of the aftermath... George Alexander generously agreed to put them on part of his website for anyone who wants to look at them.... http://home.comcast.net/~kolb-driver/Beauford/ In the pics I removed the top ring on one piston and took shots of both sides of it to show carbon infiltration into groove and coked on deposits on ring.... other shots are provided of plugs, heads, exhaust manifold, and the pistons. 100% of the carbon you see was deposited during the 90 minutes. Except for deposits on heads,(which are semi soft) all other deposits are hard as glass.
Am totally baffled as to why this engine is suddenly manufacturing large amounts
of carbon coke....
Sure is exciting to be part of the big extended Rotax-owner family...
Please excuse Beauford a moment... he must go to the latrine and vomit again...
He'll be right back after he cleans up a little
and makes himself a Martini...
Beauford
FF #076
Brandon FL
Message 14
| 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: Rotax's Patented Hell |
--> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
| -- CHT's both remained high during procedure... 370 to 390 at
5,000... would quickly build to over 400 degrees if rpm went over
5,000 and I would
| be forced to quickly throttle back and let it cool for a minute
until temps came down.
|
| -- EGT's were normal to just slightly high throughout the
process.... 1040 to 1160 observed.
| FF #076
| Brandon FL
Beauford/Gang:
In my uneducated mind the only thing that could cause those kinds of
temps are an engine that was working too hard, e.g., over propped, too
much pitch. Seems that high temps are what caused the coking of the
piston tops. Easy to see where the cooling fuel oil mix was exiting
the ports and flowing over the tops of the pistons, areas that are
clean. Small areas.
The engine is working harder, producing more heat, than it can get rid
of. Lighten the load, let the engine turn up more rpms to produce
same power while pumping more cooling air through and around it.
That is my take on your problem. If it was ignition, especially early
timing, the pistons would have been drilled clean through early on.
Same same too lean condition caused by jetting or float level,
restricted fuel flow, etc. I believe every thing is correct except
prop loading.
john h
MKIII/912ULS
Message 15
| 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 |
|
--> Kolb-List message posted by: "Dallas Shepherd" <cen23954@centurytel.net>
What is the address where you guys are getting the 925 battery
shipped to you for your Kolbs? I recall you paid $100 for them and did that
include shipping?
Dallas Shepherd
Norfork, Ar.
Message 16
| 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: Rotax's Patented Hell |
--> Kolb-List message posted by: "Beauford" <beauford@tampabay.rr.com>
John...
I agree that the temps are what did the coking... but I wonder whether it
was overpropped.
Today it turned 6,000 static with no hesitation... ran strong... did not
seen to be laboring. I've always set it to
turn about 6K on the ground and 6,400 in level flight. Do you think that is
too much prop?
Beauford
----- Original Message -----
From: "John Hauck" <jhauck@elmore.rr.com>
Subject: Re: Kolb-List: Rotax's Patented Hell
> --> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
>
>
> 5,000... would quickly build to over 400 degrees if rpm went over
> 5,000 and I would
> until temps came down.
> process.... 1040 to 1160 observed.
>
>
> Beauford/Gang:
>
> In my uneducated mind the only thing that could cause those kinds of
> temps are an engine that was working too hard, e.g., over propped, too
> much pitch. Seems that high temps are what caused the coking of the
> piston tops. Easy to see where the cooling fuel oil mix was exiting
> the ports and flowing over the tops of the pistons, areas that are
> clean. Small areas.
>
> The engine is working harder, producing more heat, than it can get rid
> of. Lighten the load, let the engine turn up more rpms to produce
> same power while pumping more cooling air through and around it.
>
> That is my take on your problem. If it was ignition, especially early
> timing, the pistons would have been drilled clean through early on.
> Same same too lean condition caused by jetting or float level,
> restricted fuel flow, etc. I believe every thing is correct except
> prop loading.
>
> john h
> MKIII/912ULS
>
>
>
Message 17
| 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: Rotax's Patented Hell |
--> Kolb-List message posted by: Richard Pike <richard@bcchapel.org>
If it's not too much prop, well - based on what the pistons look like,
it missed a good bet.
I would take pitch out of the prop until it turns at least 6250 static.
If that gets the EGT too high, raise the needle another notch.
One other thing. if you are going to have to go with new pistons,
have the shop check your cylinder bores for roundness.
It will only take them a minute, but with all that heat,
something could be distorted, and if it is,
you need to know it.
Richard Pike
MKIII N420P (420ldPoops)
do not archive
At 10:58 PM 8/4/05 -0400, you wrote:
>--> Kolb-List message posted by: "Beauford" <beauford@tampabay.rr.com>
>
>John...
>I agree that the temps are what did the coking... but I wonder whether it
>was overpropped.
>Today it turned 6,000 static with no hesitation... ran strong... did not
>seen to be laboring. I've always set it to
>turn about 6K on the ground and 6,400 in level flight. Do you think that is
>too much prop?
>Beauford
>
>----- Original Message -----
>From: "John Hauck" <jhauck@elmore.rr.com>
>To: <kolb-list@matronics.com>
>Subject: Re: Kolb-List: Rotax's Patented Hell
>
>
> > --> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
> >
> >
> > | -- CHT's both remained high during procedure... 370 to 390 at
> > 5,000... would quickly build to over 400 degrees if rpm went over
> > 5,000 and I would
> > | be forced to quickly throttle back and let it cool for a minute
> > until temps came down.
> > |
> > | -- EGT's were normal to just slightly high throughout the
> > process.... 1040 to 1160 observed.
> > | Beauford
> > | FF #076
> > | Brandon FL
> >
> >
> > Beauford/Gang:
> >
> > In my uneducated mind the only thing that could cause those kinds of
> > temps are an engine that was working too hard, e.g., over propped, too
> > much pitch. Seems that high temps are what caused the coking of the
> > piston tops. Easy to see where the cooling fuel oil mix was exiting
> > the ports and flowing over the tops of the pistons, areas that are
> > clean. Small areas.
> >
> > The engine is working harder, producing more heat, than it can get rid
> > of. Lighten the load, let the engine turn up more rpms to produce
> > same power while pumping more cooling air through and around it.
> >
> > That is my take on your problem. If it was ignition, especially early
> > timing, the pistons would have been drilled clean through early on.
> > Same same too lean condition caused by jetting or float level,
> > restricted fuel flow, etc. I believe every thing is correct except
> > prop loading.
> >
> > john h
> > MKIII/912ULS
> >
> >
> >
>
>
Message 18
| 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: Rotax's Patented Hell |
--> Kolb-List message posted by: "John Hauck" <jhauck@elmore.rr.com>
whether it
| was overpropped.
| Today it turned 6,000 static with no hesitation... ran strong... did
not
| seen to be laboring. I've always set it to
| turn about 6K on the ground and 6,400 in level flight. Do you think
that is
| too much prop?
| Beauford
Beauford/All:
If every thing else is squared away, what else is left to increase
operating temps? OAT and prop load.
What kind of instruments are you using? Digital or analog?
Have you done tach check with prop tach?
Strange problem. Got me scratching my head.
john h
Message 19
| 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 |
|
--> Kolb-List message posted by: DAquaNut@aol.com
In a message dated 8/4/2005 11:46:50 A.M. Central Standard Time,
richard@bcchapel.org writes:
In practice, this works out like this:
More load at X throttle = the engine works harder = CHT up
Less load at X throttle = engine works less = CHT down
Less load at X throttle = higher RPM = leaner mixture = higher EGT
More load at X throttle = lower RPM = richer mixture = lower EGT
Richard,
Let me see if I have it right. During break-in of a new engine, stock
jets. If the head temp gets to high, approx 80% throttle, Taking pitch out of
the prop will lower cylinder head temps? I guess that means an engine propped
for cruising would run with hotter heads than if it were propped for climb.
Is that correct?
Ed
Message 20
| 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 |
|
--> Kolb-List message posted by: "Rick Pearce" <rap@isp.com>
Is there any Kolbs located within a few hours driving of South east Kansas
I could look at to get some clarification on building. I have very old plans that
don't agree with the current parts. I would like to look at were & how the
trim is now done & how the brake resovors are installed also how the winter
package is installed. I have allot of parts no drawings or instructions. I have
asked TNK to send me these details twice now no luck. I would welcome people
sending pictures of these details. Rick Pearce MK3 anphibious floats.
Do not archive
Message 21
| 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: Rotax's Patented Hell |
--> Kolb-List message posted by: possums <possums@mindspring.com>
>
>Am totally baffled as to why this engine is suddenly manufacturing
>large amounts of carbon coke....
>
>Sure is exciting to be part of the big extended Rotax-owner family...
>
>Please excuse Beauford a moment... he must go to the latrine and
>vomit again... He'll be right back after he cleans up a little
>and makes himself a Martini...
>
>Beauford
I hate to see that - I've been there with my old 447 - before it got
water logged.
But--I got still about 500 hours on it first. I did "decarbon" it
several times.
BTW - you can forget trying to keep the carbon off the top of the pistons.
You can have it "spick & span" and the tops will carbon up in 10 minutes
of use - but "that carbon" comes and goes.
Your rings seem to be the problem. ...like you didn't know that already.
It seems you "had to decarbon" your engine since the rings were stuck -
so I can't chastise you with the "don't fix it if it ain't broken" theory.
After enduring the Cyuna back in the 80's,(which, by-the-way you
could replace for $500)
the 377 Rotax with the wrist pin bearing problems, the 447 Rotax,
which was great after the
other two.
This thing just keeps on running like the Eveready Bunny.
I know it weighs more, and isn't rated for a FireFly ---But,
for the rest of the kids - I would like to say that I am amazed at the
endurance of my "Dual Carb 503 CDI E gear box machine".
Cost in 1999 was $4,300 wholesale including the gearbox, Muffler etc.
648 + hours. Ain't a bad deal - and it's still running. I think the 503 is the
best they are going to do on a 2 cycle, 52 HP machine.
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! --
|