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1. 07:19 AM - Re: cub quitting on landings........ (Rick Lutes)
2. 08:11 AM - Re: cub quitting on landings........ (Phil Sisson, Litchfield Aerobatic Club)
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| Subject: | Re: cub quitting on landings........ |
--> Cub-List message posted by: "Rick Lutes" <rlutes@fvi.net>
Phil,
Interesting findings & information. THANKS for taking the time to let us
know what you found. Hope that's the end to the problem. Do you know if
Peterson's or EAA's Auto-fuel STC guidelines support your findings (ie:
brand of auto fuel they suggest) ?
FYI, our C85 w/Stromberg carb will idle rich and sometimes try to quit on
landing in cold wx only. We always run either 80 or 100LL Avgas in it.
I admire your ambition to fly the Cub to Sun-n-fun! Great!
Hope you get better wx than we have in Northern IL today...approaching 2" of
snow just this morning...probably my own fault as I switched from ski's to
wheels last week!
Happy St. Pat's Day,
Rick
Hampshire, IL (68IS)
'46 Cub (Wheels, Skis and Floats)
rlutes@fvi.net
----- Original Message -----
From: "Phil Sisson, Litchfield Aerobatic Club" <sisson@consolidated.net>
<ikvamar@gte.net>; "Larry Robbins" <larrybojac@earthlink.net>
Subject: Cub-List: cub quitting on landings........
> --> Cub-List message posted by: "Phil Sisson, Litchfield Aerobatic Club"
<sisson@consolidated.net>
>
> This is long dis-regard all spelling and punctuation flaws.....
>
> We have the Cub purrring like a kitten.
>
> This was a hard one. It is not real logical but it is fixed.
>
> We bought this cub in December at
> Centralia, IL. Our location is perhaps 50 "crow" miles North-West of
> there. The airplane had not been flown for a couple of years. In 1994
> the engine was given a good overhaul. This included all accessories. hmm
> Carb and two mags. However, the engine wasn't installed until 1998 as
> the airframe was also going through a complete restoration also. This
> all happened in SW Texas. The airplane was ferried to Southern IL and
> there it made its home until we came along and heard it was for sale. We
> looked it over in early December and everything seemed in order, so a
> gang of us got some dough together and bought it on December 17th.(100th
> aniversary)
> December 18th, we drained the fuel and put in new car gas. It was cold
> that day and it took a while to get it started and warmed up. We had put
> some hair driers into it to warm thngs up and they did a real good job
> getting the kidney warmed up.
> It was a little stubborn to keep running, but finally we got it going.
> We knew we were going to put a lot of hours getting it ready for the
> annual.
>
> I took off and headed out. We planned a stop at Greenville, IL to trade
> pilots. This was maybe 20 or 25 crow miles. There are a lot of crows
> around here. After landing at Greenville, the engine quit on landing
> roll, we then knew something was not quite the norm. While there we put
> in 3 1/2 gals of avgas to mix with the car gas. We traded planes, I flew
> a pretty RV3 the rest of the way while Perry flew the Cub. It was a
> short trip to Litchfield, (3LF). When he landed, again the engine quit.
>
> Funny thing, it would restart real easily about the third blade
> everytime withought touching anything, but you had to get it above 1000
> to keep it running smoothly.
>
> The engine was not going to be our real problem because most of us were
> somewhat up on engines, besides that, this was just an A65.. (dumb asses
> we are)
>
> I did one of them for my A'n'P back in the late 60's. Simple little
> thing....
>
> So we went into the airframe and boy did we open a can of worms there.
> Nothing real bad, but a lot of little bitty things, like no cotter pin
> in the nut and bolt that holds "up" elevator cable on right behind the
> seat, etc, etc, and on and on and on.....
>
> Oh well that was what inspections are for. except I missed that on the
> ferry inspection and the nut was nearly off.
> I think I am getting carried away. Back to the engine. When we checked
> the oil screen, it was caked full of hard sludge, not completely. No
> metal was in it, but a lot of hard sludge build up. (Keep this in mind
> for later)
>
> We finally got the airplane in real good shape and annual'd. It had
> great compression and from the looks of things all was done right. We
> started flying it and again nearly every landing it would die unless you
> were very clever with the throttle. While analyzing this we noticed that
> when the engine warmed up good the oil pressure would drop to a pretty
> low level. after a couple of hours, we decided that this was more
> important than the running problem, so we tore it apart.
>
> All crank journals were bad. All other steel parts showed no signs of
> excessive wear. Most things were new at overhaul. Case was align bored,
> new cam, cam followers, hydraulic plungers, new pistons valves, oil
> pump, and almost everything you could think of except case and crank.
> But for some crazy reason this shaft went bad, we suspect possible oil
> starvation, but it seems there would have been severe wear on some of
> the other rotating parts and cam to cam follower wear, but there wasn't.
>
> This shaft had been turned down 10 thous. and I was wondering if there
> was a metalergical problem with it. Maybe supposed to have been nitrided
> and not. or wrong alloy to begin with. Who knows.... As luck would have
> it, back in the 60's I found an old engine in the junk yard. The man at
> the junk yard said he would have to have $2 because it had that much
> aluminum in it. It was missing a jug and there was a rats nest in it.
> probably had been in a coal shed. I took it to the local airport and the
> shop mechanic offered to buy the three jugs from me for $25 each so I
> sold them. At that point of time, I was $73 ahead and still had some
> internal parts and a case. I took it apart looked things over, and threw
> away most of it. I kept the case and shaft. For 40 years now I have been
> stumbling over that shaft. Every so often, I would pour some oil on it
> and grunt about it. A few months ago, I had made up my mind that I would
> throw it in the trash this spring, because I was never going to use it
> and I was tired of stepping over it, and besides it was probably out of
> specs.
>
> When our shaft went bad we checked this one with thoughts of just maybe
> it would go a 10 under grind. We got it out and bingo, it was a perfect
> ten under and all was great, it looked like new shaft. We checked it and
> stuck it in. Purrs like a kitten, except it still quits on landings and
> doesnt want to keep running.
>
> That is where our story began.
>
> We took the overhauled carb apart to check it. Again, almost everything
> seemed new in it, it was done right by a carb overhaul shop. We wondered
> about mags. It has Eisemans on it. We took one apart, it was like new
> inside, they had both been in a shop in the NorhtWest that specializes
> in mags. all kinds of new parts and just the slightest motion makes a
> great spark.
>
> Checked intake system, changed all gaskets, tightened all hoses. Primer
> was sucking some fuel, the guy who rebuilt airplane had installed it
> wrong, we fixed it, still no luck.....
>
> We took the carb apart a couple times to check and recheck the float
> settings, check all passages again and again. We changed mags with one
> that was working on another engine. Changed spark plugs a couple of
> times. (Not new ones-cleaned old ones)
>
> Still it quit on landings--- But we have great oil pressure now.
>
> Finally after trying different auto fuels, we switched to some avgas,
> which we should have done right off. Ureka, This was the problem. For
> some reason, this engine does not like car gas.are we getting some
> additives in the winter time that they are preparing for St. Louis EPA
> problems??? DUNNO
>
> We had ran it on avgas earlier, but it was a mixture. This time we ran
> all car gas out of it and it works perfect on pure av-gas.
>
> There is a reason for this. I don't know it yet, but a Luscombe right
> next door runs good on car gas. but he hasn't ran it since cold weather
> set in. We used its mag and carburetor which did run his, but ours
> doesnt. Our friend who has the RV-3 always runs car gas in his 150 lyc.
> I ran it most of the time in my 180 Pitts. But this Cub does not like
> it.
>
> A friend of mine, Giles Henderson has a Clipped Cub, he runs car gas
> most of the time. Giles is retired from Eastern Illinois University
> where he was a Chemistry Professor. He told us some things about auto
> fuels that he learned when testing these fuels with a gas chromatograph
> in their laboratory. He said that sometimes a fuel will leave a very
> sooty-oily residue which alludes to being rich when in fact it is
> running lean. It is because of the different flame propogation of the
> different components in the car gas. He was refering to fuels with lots
> of benzine to replace lead which is no longer the anti knock agent.
> This was one of our problems, we would check the plugs and they almost
> always had the appearance of being oil and soot fouled. The engine uses
> hardly any oil. After we switched to av gas, they cleaned up, the
> exhaust pipe cleaned up and all is good.
>
> The fuel we used the most of was a Mobile premium. We tried small
> quantities of Amoco premium.
>
> The Mobile premium has an amber color to it while the Amoco almost looks
> like 100 LL....
>
> We are going to test some different fuels hoping to find one that works
> good for us here.
>
> When I first mentioned this problem to Cy and the Cub list, I said we
> had tried all fuels with the same results. It had slipped my mind that
> we had mixed the av gas at Greenville with an equal amount of Mobil.
> Perhaps the Mobil fuel was older, has different additives for the
> winter, or who knows.
>
> I hope I didnt bore everyone with this, but I said I would let people
> know what I found.
>
> I plan to leave here with it about the 11th for SnF. It will take two
> days plus to get there. I will try to park at IAC tent. If you see It or
> me there, say hi or stick a note inside it, up on the instrument panel.
> Here is a picture of our Cub and the website for our city airport
> http://www.wamusa.com/members/airport/
> go to pilot information. Photography by Jim Wright in his Luscombe 8A.
>
>
> Phil Sisson in Litchfield, IL
>
>
Message 2
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