MONTY THE ANSWER MAN
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CONTINENTAL
O-300 INFO Page Five...
C125 vs O-300 CARBS...
(060301)
Subj: Carburetors
From: Bud England <Dalswift1@aol.com
Jim:
I've got M/S carburetors P/N 10-3237 and P/N 10-2848. They came off of
the 145 and 125 respectively (I think!). How can I find out which on would
be preferable, performance-wise, for the 145? Bud
Bud
Either will work but the 10-3237 is the correct one for a 145 and the
10-2848 is correct for a 125. Performance probably depends a the individual
carburetor. Probably the 10- 3237 is preferred although the Swift Association
STC for the O-300A calls for a 125 carburetor. I would use one of your
carbs for a core and trade it in and get a new Precision Carburetor. They
run about $600 with core. -- Jim
SLICK MAG TIMING FOR C-125... (060401)
Subj: Slick Mags
From: SwifterDon@compuserve.com (Donald Thomson)
Monty:
I just got off the phone with Howard Means (Scappoose, OR Swifter), who's
reinstalling the Slick mags on his C-125 Swift. he wanted to know the
settings. I think the manual says 28 & 30 degrees, can you confirm???
I seem to remember the O-0300 is set at 28 & 26 degrees...... I suggested
that he check with you, but I think he was calling from his hangar and
I was planning to fly up that way this morning anyhow... maybe I could
stop by and talk with him..... Any thoughts?? Don
Don
The 125 is 30 degrees Left and 28 degrees right. It's the 145/O-300 that
is 28 & 26. -- Jim
WOW, A DASH ONE??? (060401)
Subj: C-125-1
From: jerryk0jj@columbia-center.org (Johnson Gerald A)
Hi, Maybe you can help me with a problem. A fellow aircraft owner asked
if I would help time his continental C-125 on his Swift. I looked up the
TCD for timing info and got 28 R and 30L no problem. He had the older
SF6 mags that had just been gone through and repaired. On looking at the
engine I assumed that the left mag would fire all the bottom plug and
right mag all the top plugs. The mag harness was split like Lycoming the
left mag would fire left bottom two plugs and then the top two right plugs.
I can't see this being correct or am I missing something. I thought the
idea of firing the bottom plugs first was to correct for exhaust delusion
and get the flame front too meet at the same time when the top plugs fire
2 degrees later. He said he had checked with a couple of different people
and they said that's the way the harness was to be. This is the first
swift I have seen and it is all original with C-125-1 engine. Before doing
anything I would like to find out just how the plug harness was originally
installed. Retired A&P Jerry J.
Jerry
Wow, a C-125-1? Is that right? I have only seen two of those in my life,
almost all C-125's are the C-125-2 version. It doesn't make much difference
whether the plug wires go to the upper or lower plugs, just so each mag
fires 1-2-3-4-5-6 in that order and is routed to cylinders 1-6-3-2-5-4.
Originally, the Left magneto fired the lower plugs and the Right magneto
fired the upper plugs. Someone along the last 50 years evidently changed
that. Since the Left mag fires at 30 degrees and the Right mag fires at
28 degrees mixing the leads from one mag from top to bottom will cause
the timing to vary by 2 degrees from that mag -- which will not make much
difference. I just re-read your letter and it sounds like you are working
on a 4 cylinder engine. A C-125 of course, is a 6 cylinder engine. Am
I missing something? Regardless, the left mag should fire the lower plugs
and the right mag the upper plugs. -- Jim
ALLS WELL THAT ENDS WELL IN THE DASH ONE DEPARTMENT... (060401)
Subj: Re: C-125-1
From: jerryk0jj@columbia-center.org (Johnson Gerald A)
Thanks Jim, Yes I slipped should have said bottom 3 and top 3 plugs. 90
% of engines I have worked on are 4 cyl. I know all the smaller continental
4 cyl's fire the bottom ones first. Also the engine may be a dash 2 will
have too take another look as thought I saw -1. same timing on either
one. Since they have it split up like that can't see any reason for timing
2 degrees apart. Nice web site will have to see if the owner of this Swift
has use of internet and can check out all the useful info. Thanks again;
Jerry
IS THIS THE RIGHT CARB??? (070101)
From: Anonymous
Subject: a question from anonymous
The question about carb number got me wondering and after checking .....
it appears that the carb on my C-145 is a # 10-4252, which is not one
of the ones listed. Not that anybody has ever noticed in the last twenty
years it has been in this area. It is a model MA3SPA. Any ideas what this
is and how appropriate this carb is ? Is this carb different enough to
be a performance issue?
Dear Anonymous: YEP! That is a carburetor for a C-90! It has a smaller
venturi than a 10-3237 or a 10-4895, the two listed p/n's for the O-300.
I would say you are losing 10% to 20% of your power. -- Jim
CARB AND PROP ADVICE FOR THE C-145... (070501)
Subj: C 145 2F Carb?
From: Wilsey2
Jim, I have been following your discussion because of my similar problem,
but still have lots of questions. I have an MA3SPA Model #10-4895-1 which
I believe is one of the two that you said is approved for my engine. However,
my Continental "C" Series maintenance and overhaul manual says
on page 44 that it should be a Model #10-2848. I do know of a 125 with
a 10-2848. My compression is good on all cylinders, I have had both mags
rebuilt, all new wiring and plugs, rebuilt the carb, checked valve and
mag timing several times and still can't get over 2050 static rpm (sea
level) or 2300 on the take off roll. It just seems slow on acceleration.
I should also mention my prop is a McCauley fixpitch IA170/DM7458. diameter
is 74 1/2" pitch is 58". Sincerely, Larry D. Wilsey N80878
Larry
You have the right carb for a C-145. A 10-2848 is the carb for a C-125.
I suspect your prop is near full dimension. If the tips are wide, as on
a new McCauley prop, it won't turn up or perform like a prop that has
had the tips narrowed or rounded. If you have your prop reworked, or find
another one to try out, get a 1A170DM7359. The 74 dia will not perform
as well as a 73 dia on a Swift. I like to round the tips on a McCauley
-- that unloads it a little for higher static rpm and better takeoff performance.
If the tips are not rounded, the chord should be narrowed to near the
repair limit. -- Jim
MONTY IS ON THE "CASE"... (080101)
Subj: c-125
From: Greg Milner <tldrgred@execpc.com>
Jim,
A gentleman at Oshkosh told me to go with 145hp or more. I like 2000ft.
grass strips. I`m interested in one in Michigan but am leery of cracks
in the case also. Where exactly do they crack? Greg
Greg,
There are very few "light case" 125's around anymore. Is that
what it is? The "heavy case" engines can be identified by the
3 ea. 7/16" studs and nuts in the vicinity of the fuel pump on the
right crankcase half. (there are also 2 thru studs per cylinder, but they
are hard to pick out visually) The light case engines usually crack internally.
The first indication that the case is cracked is an excess of aluminum
in the oil screen, and a lack of torque on the 2 forward studs for #1
cylinder. There were a few light case C-145's too, but they were all made
in 1948 for Aeronca Sedans. All O-300's are "heavy case". You
should buy any light case 125 with the idea that a 145 engine is going
to be a necessary purchase sometime in the next year or two. Beside the
case problem, a 125 is not a good 2000' strip airplane. Good luck! --
Jim
O-300D CAMS... (090301)
(Editor says: Warning... highly technical stuff follows... please do not
read if under the influence of any mind altering substances... I made
that mistake...)
Subj: Cams
From: Mike Williams <mike@wingworksusa.com>
Hi Monty, I have found a bad cam lobe on my 0-300-d. I have measured four
other cams and found the absolute dimension from one side of the lobe
to the other to be 1.486 on the d cam and 1.455 on all the other cams
c-145 and 0-300b. My dry lash has been on the wide side. Do you know of
longer pushrod part #'s? I will measure the lift on all the cams this
am. Thanks, Mike Williams
The cams vary a lot on the O300's -- the p/n is 539803, but they have
a suffix such as -AN, -AT or -AU and the earlier ones have more pointed
lobes. The early cams, like what came in the C-145-2 develop good torque
below 2500 rpm. The later cams develop more power at 2700 rpm. You can
tell which cam is in an O-300 by simply running the engine and observing
the manifold pressure guage. The early cam will idle at 600 rpm and about
10 inches of manifold pressure. The late cam will idle at 600 rpm and
about 16 inches of manifold pressure, because of the increased valve overlap.
TCM only lists P.030 pushrods for the O-300 in their parts catalogues.
Fresno Airparts (3rd page of Trade-A-Plane) sells a P.070 pushrod. Longer
pushrods are not too hard to make. Many old time mechanics and shops do
this routinely. Use heat and remove one end of the pushrod. Select a steel
washer the thickness you want to increase the length of the pushrod by.
Put the washer in place and press the end back in the pushrod. With new
valves and valve seats, you almost always need at least P.030 pushrods.
With a reground cam, lifters, and rocker arms, P.030 just isn't enough.
I called TCM and pointed that out to them, they seemed unconcerned and
suggested I replace the camshaft, lifter bodies and rocker arms! Nothing
like spending a couple thousand bucks of someone else's money! -- Jim
ps... Remember, the rocker arm ratio is 1.2:1 (1 1/4" : 1 1/2")
so if you have say, .130 clearance, (.020 over limit) You don't need a
.020 longer pushrod. You can figure it out, but the pushrod needs to be
about .015 longer. Also, TCM says you can get by with more than .110 clearance
these days with the new lifters, but they wouldn't give me a number.
NO MORE SNAP-CRACKLE-POP...
(100301)
From: Swift97B@aol.com
Subject: "Snap-Crackle-Pop"
While I was perusing Denis' excellent website the other day, I toured
the "Answer Man" area where I saw my discussion concerning the
"snap-crackle-pop" I was getting from my O-300A last year. To
complete the story -- I (indeed) confirmed that it was an intake leak,
like you were all telling me. I found that the previous mechanic had installed
the exhaust pipes using "no blo" exhaust gaskets but did not
grind them off where they hit the adjoining cylinder intake pipe. The
bulging exhaust gasket eventually caused the intake gasket to leak. When
I installed new cylinders recently I was careful to grind off the "no
blo" gaskets to ensure they did not hit the adjoining intake gasket.
Thanks for the help, guys.
HYDRAULIC LIFTERS... (100301)
Subject: Re: O-300A Hydraulic Lifters
From: Swift97B@aol.com
Hopefully, I can explain this while looking at the O-300 parts book. Recently,
I had the occasion to pull out a pushrod from an O-300. The "Socket,
Pushrod" P/N 637268 came out stuck to the end of the pushrod (by
oil suction). It went back in easily. Is the "Socket, Pushrod"
held inside the "Body, Hydraulic Lifter" P/N 530851 by the "Ring,
Snap" 530940? Or, is the "Ring, Snap" used to hold the
"Unit, Lifter Hydraulic" P/N 637269 in the "Body, Hydraulic
Lifter"? Does the "Socket, Pushrod" just ride atop the
"Unit, Lifter Hydraulic" without something holding it in (other
than the tension of the pushrod and valve springs)? Thanks, Steve
Steve
The early engines did not use that snap ring to hold the lifter parts
together. I believe the snap ring started with the O-300A, but these engines
are now so old and have been overhauled so many times you might find the
lifter bodies without the snap ring groove in any series O-300. You are
right, the early engines just depend on the tension of the valve springs,
thru the pushrods, to hold the lifter together. The snap ring has no function
when the engine is assembled. It only prevents the "guts" of
the lifter from being drawn out with the removal of a pushrod when a cylinder
is being removed. -- Jim
ENGINE TEMPS...(070302)
Subj: Engine Operating temperature
From: Bruce Ray (swiftfly@hotmail.com)
Monty,
This pertains to operating temperature on the C-145 0-300D engine. I have
been noticing that the operating temperature has been running about 75
to 78 on my engine. The other day taxing out of Savannah I had several
delays due to other traffic coming in. So they stopped us in place. I
didn't shut down the engine and the temperature creeped up to about 82-83.
So then I shut down and let it cool for a bit and then took off and utilized
a faster speed for climb and it cooled right off. But it seems to run
right around 75-78. I know that is in the continuous use range but is
there a way to bring it down just a little cooler? Thank you for your
time. Bruce Ray N80644
Bruce
The max. oil temperature limit for a C-145 and all O-300s is 225F or 108C.
So as you can see 82-83 is nothing to worry about. The cylinder head temp.
limit is 525F or 275C. Don't worry, be happy! -- Jim
KARL THE STUD...(090302)
Subj: O-300A Cylinder Base Studs
From: Karl Johnason <karl.johanson@hs.utc.com>
Hi Jim,
After flying just a few hours with 78103 (with it O-300A 320 hrs TSO),
we were getting ready to go up and observed rough running on the left
mag during run up check. Pulled all the plugs and found the lower plugs
to be fouled, particularly the number 1 and 2 cylinders. Also observed
oil collecting in the carb heat box as well as fuel/oil residue in the
carb throat. Looking into the cylinders we noticed that the number 1 and
2 were oil wetted as compared to the other four. Suspecting oil scraper
rings and/or valve guides, made a decision to pull all six cylinders and
have them overhauled. That's now done and during re-installation we ran
into a snag. The number 6 cylinder lower left 7/16" stud would not
hold torque. Also observed that this stud showed more threads than others
indicating that it was not run in as far as others. This stud is one that
goes in blind (as opposed to some of the others that go through to the
cylinder bases on the opposite side) and bottoms out internally behind
the fuel pump pad. Splitting the engine to install a helicoil is obviously
one option but I suspect there are alternatives to try before going to
that extreme. Any suggestions/procedures you might recommend would be
greatly appreciated! Regards, Karl
Karl
Yes, that one stud is just threaded into the rt. crankcase half. They
couldn't make it a thru stud because of the proximity of the fuel pump.
When I overhaul an O-300 anymore, I helicoil that stud as a precautionary
measure. The O-300s are now 40 years old and the aluminum cases are getting
tired! Having said that, there might be something you can do. You can
drill the hole slightly deeper and tap it a little further. Then thread
the stud in a little deeper. You may be able to get it in 1/4" further.
You might try locking it in with LockTite. Let it dry overnight and try
torquing the stud. If it pulls out, you are committed to splitting the
case and installing a HeliCoil. -- Jim
PS -- From my notes: The stud extends 5 - 5/16" from the rt. crankcase
parting surface normally.
KARL REPLIES...(090302)
Subject: RE: O-300A Cylinder Base Studs
Jim, Thanks for your help! Per your advice, first checked the remaining
run-in. Was able to run it in 5 more threads (and still had adequate remaining
threads showing on the stud, which also indicated that the stud was not
all the way in to begin with) and hold the required torque. Will use the
highest Locktite number 262 to insure that it will not budge! -- Karl
OIL LEAK...(NOV 02)
Subj: Crankcase oil seal
From: Jack Gladish <jargladish@adams.net>
Hi Jim! Flew ol 21K yesterday, after words, I took of the rudder off to
repair the rudder horn, has a bit of play in it.. The crankcase oil seal
is leaking alittle, guess I'll replace it while she's down. Looked up
the seal in my Cont. parts manual, but it didn't list the #. My power
plant is a 0-300D..Can you help? Also, it's been a long time since I've
done this, isn't it pretty much R&R, with a careful cleaning of the
crank, lubing the crank, but keeping the seal dry?? 2002 was a good year
for my Swift, and me, thanks for all your help
Jack
My parts book has 539241 as the p/n for the front seal. I think you have
the right idea as far as the changing procedure. If the seal persists
in leaking, some fine sandpaper can be used, angle the sanding scratches
to direct oil back to the engine. -- Jim
IT ALL HANGS IN THE BALANCE...
(JAN 03)
Subject: Re: Engine Balancing
From: Bud England <Dalswift1@aol.com>
Bought a pretty good digital scale and have started weighing rotating
parts for the C145. I bought the "matched" set of pistons from
ECI and was impressed to find them within a 3 gram range. Piston pins
all identical down to the gram. Old reconditioned rods run from 727 grams
up to 734. Can you, or anyone else, tell me where I can remove a tiny
bit of material on the rods? I'm not expecting any variation in rod bolts
and nuts (both new style), but will check them anyway. The car guys tell
not to even bother weighing rings.
Bud
TCMs tolerance for piston weights is 1/4 ounce difference. (7 grams) So
extending that figure to the rods 727 to 734 is 7 grams difference. The
rod weight is reciprocating on the small end and rotating on the big end.
Rod weights can only be lightened a gram or two by polishing off the forging
flash at the center of the rod. Rather than grind off metal to get the
rods the exact same weight, I pair opposing rods to try to get them exactly
the same. i.e. 1&2 -- 3&4 -- 5&6. For example, if you have
two rods weighing 727 grams use them in #1 and #2 position. If you have
some that are several grams light match them with pistons that are several
grams heavier. The big and little end can be checked by using a dead rest
on your workbench and just weighing the one end at a time with the other
end on the rest. If you can't come up with a combination of weights with
the rods and pistons you have, I would suggest you get some additional
rods and/or pistons that are near equal weights. When I built up the engine
for my Swift I had one piston that was a little heavy but the rest were
all within 3 grams. I exchanged the heavy piston for one that was the
same as the other 5 at the distributor where I had bought the cylinders
(and pistons). Recently, I built up an O-300 using Superior Millennium
Cylinders and all 6 pistons weighed exactly 725 grams. -- Jim
BALANCE PART TWO... (JAN
03)
Subject: Re: Engine Balancing
From: Bud England <Dalswift1@aol.com>
Jim: Thnx for the info on balancing. Now I wonder if I could get you to
go just a bit farther: You mentioned weighing the large end and the small
end separately, using a dead-weight set up, but I didn't understand what
I was to do with this info, once weighing was complete. Also, there are
a couple of things that kind of nag me: (1) It seems that the rod weight,
WITHOUT THE CAP, is more important than the total weight of both, since
this is the weight the crank is "throwing" into the cylinder,
and (2) further, it seems top me that the weight of the small end is more
critical than that of the large end, in that the large end has essentially
become part of the mass of the crank, while the small end is is being
thrown and pulled pulled back as part of the weght at the piston end.
Does this make any sense at all? I'm sure it's quite obvious that I've
never tried to balance an engine before, so I need all the help I can
get. You've given me a lot of help and advice the last few years. Believe
me when I say how much I appreciate it. Bud
Bud
I don't think you understood the dead-rest part. That is just a stack
of wood or whatever to put one end of the rod on while weighing the other
end. I have never weighed a rod without the cap and see no reason to do
so. I have never given any thought to which end is the most important
and would never get tied up in such detail! I learned about balancing
from John Halling who had the first FAA Certified Balancing Shop. I balance
every engine I put together and have never had a rough one since I started
doing that so I must be doing it right! I mentioned not grinding metal
off the rods to reduce weight. You can remove about 2 grams from the forging
flash at the middle of the rod but you must be sure not to leave any scratches
or other stress risers. The FAA prefers you shot peen the rods after any
rework. That's why I prefer to just match rods in pairs and get other
rods if necessary. Remember I said the big end is rotating and the small
end is reciprocating? I think that fits your statement in para. (2) above.
I don't agree one end is more important than the other just get 'em as
close as you can, and don't worry about 2 or 3 grams. Remember, TCMs tolerance
is 7 grams. -- Jim
p.s. The reason you weigh the ends of the rods is to make sure they aren't
grossly different. I once found on that had a casting (forging) irregularity
and one end was way heavy. Most of the time you will find they are very
close.
SWIFT MUFFLER REBUILD... (APRIL 03)
Subj: exhaust
From: Grahame Gibson <grim_downunder@hotmail.com>
Giday Jim, the right side muffler on my C-125 is requireing total rebuild.
Was there a standard muffler used when the straight stack originals were
not used. I assume a C-0300 system would have been incorperated. If you
could assist me with the muffler part No. I may be able to track down
a new unit or a quality used item, prior to persueing the rebuild option.
2nd question, the O ring that can be used to replace the metal spacer
in the gear actuator, is that the same size as the O ring behind that
spacer. I have not flow my swift since last August, family priorities
overide all pleasures, all I have done is rotate the prop regually. Regards
Grahame, swifter downunder.
Graham
If you take a look at the original Aircraft Specification (available on
the Swift site) you will note Hanlon-Wilson Model 193 mufflers. These
are specially made for the Swift airplane. A Cessna 170 version is not
directly interchangeable, the exhaust pipe is canted inward below the
muffler. The Cessna 172 version is bigger in diameter as well. Several
Repair Stations in the US can repair these mufflers and I believe Hanlon-Wilson
is still in business in Pennsylvania, USA. I doubt if there are any new
mufflers available, but I did hear talk several years ago that Hanlon-Wilson
was considering making some new ones, the price was high enough that I
doubt if they sold any. There are used mufflers around and I have several
myself. The ones I have need overhaul and I would not represent them as
airworthy parts. I have installed two "O" rings instead of an
"O" ring and the leather ring, I suppose another "O"
ring instead of the steel ring would work Ok. Good luck to you. -- Jim
DO IT YOURSELF HEAT MUFFS??? (APRIL 03)
Subj:exhaust heat shrouds
From:Grahame Gibson <grim_downunder@hotmail.com>
Giday Jim, I searched the web and found that Hanlon-Wilson were bought
out some time ago by Wall Colmonoy Corp.,I emailed them without reply,
probably to my advantage. Tony Green, the other Auatralian swift owner,
has a set of the original pipes. If they are not in the best condition,
I can have a set fabricated, using them as a template. NOW! I would like
to sorce a set of heat shroud assemblies, item numbers from parts book,
7 and 14. I'm not familiar with this assembly, so if you can affirm this
assumption as to parts book item numbers, please do so. These are not
available with the pipes. So if you can help me in this area I would be
most apprieciative, even a set that can be used as a template, as a mate
is a wize at metal forming. This guy made a set of belly door frames after
underbelly damage in '95, and the with the doors that snuggly fit added
speed to my swift. A servicable set of heat shrouds would be better by
far.I'm going to duplicate this shroud search on the Swiftnews page set
up by
Denis Arbeau. Regards Grahame.
Grahame
Making up a set of muffs may be your best idea.Yes, they are items 7 &
14 in the Parts Book. The reproductions wouldn't have to be stamped out
like the originals with their curved edges but made with flat sides riveted
or screwed to a flanged end piece about 1 - 5/8" wide. -- Jim
REDUCTION IN MAINFOLD PRESSURE ON JUST REBUILT ENGINE... (MAY 03)
Subj: Manifold Pressure Question
From: Tom Yoder <tryoderjr@aol.com>
Hi Jim,
I have a quick question for you....any idea what might cause a reduction
in manifold pressure.......I just rebuilt a C145 and installed it on N33TC.....everything
on it is yellow tagged or new......including carb heat box/ filter/carb......Problem
is that I am now only getting about 25.5/26" MP and 2150 rpm static
at sea level full throttle.....I have replaced a new Air Maze filter with
a new Brackett...no difference.....MP gauge shows 29.5/30 before start
so I know the gauge is at least close to right......the engine also seems
to be running pretty rich.... Net result is a less than spectacular take
off run and climbout.....have you heard any reports of misjetted carbs
or anything else that might explain the restricted airflow ??....the only
thing I haven't done yet is swap out the carb with my old one and see
if that helps.....one way or the other, I will see you at nationals and
perhaps pick your brain some more. Respectfully.......Tom Yoder
Tom
I think I know what the problem is. The C-145 has a steel splitter above
the carburetor in the oil sump. It is held in there with two rivets. If
one or both rivets shear what you are experiencing will happen. Take off
your carburetor and look up and see if the splitter is loose. If that
is not the problem you should pull both intake manifolds and check for
abnormalities. Then try another carburetor. If all of this doesn't find
anything I would suspect the cam to crank timing is mis-indexed. (wrong
tooth engaged at the gear) I think the splitter is the most likely culprit.
-- Jim
ANOTHER IDEA ON TOM YODER’S LOW MANIFOLD PRESSURE PROBLEM... (JUNE
03)
From: Harvey Putsche <putsche@wt.net>
Subject: RE: May #4 GTS Internet Update
I had a problem similar to the one about the rebuilt carb. It was on a
Navion E-225 PS-5 carb. When it was sent in for overhaul The mechanic
did not specify what engine it was for and the shop flowed it for an 0-470
which it usually is mounted on. Trouble is it was mounted on an E225 and
therefore was flowed too rich. When we had it flowed for the correct engine
everything worked like it should. I would have the carb put on a flow
bench and check it for proper flow for the engine it's being used on.
I only mention this because the symptoms he describe are so similar to
what I experienced. Harvey Putsche
Harvey & Tom,
The thing is, there is no engine in the 145/0-300 family that is greatly
different in flow rates or settings. However, that certainly doesn't mean
that the carburetor could be set wrong. The recent one piece venturi AD
has caused all sorts of problems. For one thing, the casting on the three
legs is very crude and may offer an additional restriction in the venturi
area. I have taken a small file and dressed those legs down so they were
more "streamlined". If you don't feel qualified to be working
on your carburetor, I would return it to the overhauler. If you know someone
who can work on it, I would say to lower the float level and file down
those venturi legs. While the carb is apart check for proper part numbers
as well as condition of parts. Are you still using that carburetor or
did you leave your old carb on? Make sure the throttle valve opens fully,
that the overhauler didn't mis-index the butterfly on the shaft. -- Jim
YOU CAN GET THERE FROM HERE...(JUNE 03)
Subj: O300-D accessory cover installation on O300-A in my Swift
From: Richard McLellon <richard.s.mclellon@lmco.com>
Jim,
I'm interested in pursuing a 337 to install an O300-D rear cover on my
O300-A, to allow installation of a vacuum pump. I was talking to Charlie
Nelson, yesterday, and he recalled that you had collected Continental
documentation supporting such a change quite a few years back. Could you
provide a copy of the information that would support such an alteration?
I'm willing to do additional research, if necessary, but it would be helpful
if I didn't have to start from scratch. My O300-A doesn't have that many
hours on it, and I don't want to swap engines. Charlie said quite a few
people had installed O300-A cranks in O300-D's, but he didn't think very
many had tried what I am proposing. Any help you could provide would be
greatly appreciated. Best wishes, Steve McLellon
Steve
The short answer is, no you can't do that. Actually, you can and it will
work for a while, but the O-300D main case has an oil passage to lubricate
the O-300D shaftgear. The O-300A case has no such passage. (the "D"
bushing and the "A" pivot may have different dimensions too)
TCM published a Service Bulletin some time ago to permit swapping of parts
in a family of engines but unfortunately this is not permisssible in this
case. It is permissible to swap crankshafts between a "A" and
"D". -- Jim
SWAP C125 FOR O-300A... (JUNE 03)
Subj: 0300-A Engine
From: Bob Price <BobPriceSwift@aol.com>
I have located an 0-300-A Cont. Will it bolt up directly in place of the
C-125-2 that is on the Swift? Thanks Jim for all your help! Bob Price
3361K
Bob
Yes, it is an easy replacement. Oh, there might be a few slight differences.
The oil cooler fittings at the front of the case are a size smaller and
some of the baffling may require trimming to fit the cyl. head fins. The
mag "P" lead connections are different. Be sure to use new fuel
and oil cooler hoses. The prop will bolt right up although it should be
repitched to a 59". -- Jim
MORE ON THE SWAP C125 FOR O-300A DEAL... (JUNE 03)
Subj: 0300-A Engine
From: Bob Price <BobPriceSwift@aol.com>
Jim: Thank you so very much for your timely response.... with the 300-A
can I expect an increase in performance? At this time I am operating out
of a 3000 ft. paved strip.... I am indicating a climb rate of 500 FPM
or less @ 85 to 90 MPH air speed....and a cruise of 125 MPH on an average....
I like MPH...that is how I was trained... The question... will the 300-A
give me better take off performance and a higher cruise?...say 145 to
150 MPH? and maybe 700 feet per minute? As always... I am in appreciation
of your expert guidace.... Bob Price 3361K
Bob
Like any thing else with a 50 yr old airplane "it depends".
I had a Swift (N2334B) that I could depend on 150 mph if I wanted to burn
the fuel or 135 - 140 mph at 7.5 to 8 gph. Under optimum conditions it
climbed 1000 fpm or better, hot and heavy it might have been under 500
fpm. My present Swift does about 140 mph at 24"x2600. -- Jim
HOLD THE PRESSES!!! BOB’S ABOUT TO CHOOSE... (JUNE 03)
From: Bob Price <BobPriceSwift@aol.com>
Subj: 0300-A Engine / 0300-B Engine
Jim:
I am about to choose between a 300-A engine and a 300-B engine... will
the 300-B engine bolt up as well as the 300-A? Also, I have a McCauley
DM7357 prop on the 125 engine...will that prop work on the 300-A or 300-B?
Can the 125 carburetor bolt up to the 300-B? Will either engine affect
the weight and balance very much? also are these engines considered to
be the ones with the heavy case? Thank you for your exceptional guidance....
Bob Price >>
Bob
The O-300B is the same as the O-300A except for the prop control valve
at the left forward side of the case. If it has been operating with a
fixed pitch prop it will have a 1-1/2" plug in the crankshaft held
in with snap ring. The Swift Assn. STC, SA1-326 for the O-300A formerly
did not include the O-300B but it does now. The 1A170DM7357 prop will
bolt right up, but should be repitched first to a 59" pitch. Any
prop shop can do this. The 125 carburetor (10-2848) will work but the
145 carburetor (10-4895 or 10-4439) is preferred. All O-300 engines are
heavy case. According to the book, the 125 weighs 257 pounds and the 145
weighs 268 pounds. However the mags are lighter on the 145 so the net
increase may be nil. -- Jim
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