Lovely preflight check

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TCABM

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We’ve been chasing a tiny oil leak for a little over a year and about 400 hours or so, and replaced the oil return lines last week. Post maintenance check flight didn’t turn up anything new, good or bad. Still a tiny leak somewhere. By tiny, I mean we’ve been loosing well less than a quart every 10 hrs.

Saturday, a partner flew a 3.5hr XC, noticed the leak was still there and put the plane to bed. Sunday, during preflight, I noticed this
13813b45957f84c52f12297beea97e93.jpg


Well, that’s new so I took a look under the nose and found this.
547378a58f7358cfa467e0e1bb514fdf.jpg


The belly was also pretty well coated with probably a couple ounces of oil. Since this was a significant change in the leak characteristics, I abandoned the pre-flight and put the plane back in the hangar.

Went out this morning with our partner who’s an IA and did some detecting.
ab9b4bbd4d1f13d3563f08fefe88d919.jpg


That’s the #2 cylinder. I’ve got quote requests out right now, but with 1973SMOH and multiple OHs, we’re going the exchange route.
 
Good find! It sucks, but glad it was found before the crack lead to a cylinder departing in flight. I hope you have better luck than we've been getting on exchange engines in any reasonable timeframe... have 2 O-360 reman exchanges on order from Lycoming (thru AirPower). First one has been on order for a year, was supposed to deliver in Sept, got pushed to Oct, now end of January. The other was just ordered, and given 18 month lead time.
 
Cracks in that area are fairly common. They often can be fixed but if all the parts have a lot of time on them (and multiple overhauls) you may be better off heading in the direction you’re going. Hopefully the engine replacement experience isn’t too painful for you.
 
mondtster said:
Cracks in that area are fairly common. They often can be fixed but if all the parts have a lot of time on them (and multiple overhauls) you may be better off heading in the direction you’re going. Hopefully the engine replacement experience isn’t too painful for you.
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Yeah; this particular case was repaired by Divco about 7 or 8 years ago, which was a couple hundred hours after the last OH. The long term partners are adamant they’re done with this particular engine.
 
Bummer.

Nose strut looks low.
 
Airworx recently had an O200 for 25k outright. Replace those steering arm boots while you have it apart so you don't get exhaust gasses into the cabin.
 
1973 SMOH, this engine only owes you 28 hours, assuming 2000 TBO. I agree, you didnt sent a cylinder through the cowl, it sounds like money saved. It hurts financially but if you get an OH’d engine, you will have hours of peace of mind and after it’s break in-should have years of a reliable engine. No more leaks, maybe get the prop dynamically balanced…how about an electronic mag/ignition?
Once you get flying again, the pain of this situation will recede into the propwash. Most aircraft owners have some story like this. Mine was replacing the doubler under the wing walk in our Cherokee that cracked. Plus a nearby rib. Also, one cylinder that lost acceptable compression a few years ago. I’ve been meaning to make the old cylinder into a table lamp one day.
 
TCABM said:
That’s the #2 cylinder. I’ve got quote requests out right now, but with 1973SMOH and multiple OHs, we’re going the exchange route.
Click to expand...

Sounds like you got your money's worth. Hope the wait is not too long. Just finished first trip with my new engine, and it is a pretty cool feeling. In the end, it is worth the hassle and wait.
 
Grum.Man said:
… Replace those steering arm boots while you have it apart so you don't get exhaust gasses into the cabin.
Click to expand...
Lots of new FWF stuff going while we wait.

Michael Castle said:
…No more leaks, maybe get the prop dynamically balanced…how about an electronic mag/ignition?…
Click to expand...
As an owner group, we already decided dual electronic ignition, Challenger cleanable oil filter, and better engine monitoring “while we’re in there”. Inside, we’re thinking about finally removing the ADF.
 
TCABM said:
Lots of new FWF stuff going while we wait.


As an owner group, we already decided dual electronic ignition, Challenger cleanable oil filter, and better engine monitoring “while we’re in there”. Inside, we’re thinking about finally removing the ADF.
Click to expand...

New engine is great time to install an engine monitor. Big plus to be able to closely watch OP, OT, and all CHT during break in flights.
 
Quotes are in from Western Skyways, Penn Yan, and Air Plains. 4-6 month lead time on an exchange or factory new engine. 160hp starts at $33K and runs up to $45K, 180hp runs from $55K-68K.

Core charges start at $5500 for the case to 13,500 for case, crank, and prop for the 180hp options at exchange. If the exchanged parts are serviceable or repairable, there will be no core charge.

Partners are all over the place on what to choose, will be talking as a group this weekend.
 
Wow that is a really good price and lead time on certified engines and excellent core return values! Not sure what the airplane is but is there additional stc cost going to 180hp or is that reflected in the 55-68 estimate? That's a lot of extra money... unless you find your self not doing certain things with the airplane because due to lack of power I'd say stick with 160 and use the extra money elsewhere.
 
It really depends on the mission so discuss with partners:

I REALLY LIKE the 180 but not for that $$ difference.

There are also other mods that would need to be done too.

On your bird it seems pretty much just an engine change n prop twist

for 160 hp. That will give you better climb and maybe a little

( emphasize little) better speed.

The 180 will provide better climb, speed and an increase in useful load.

There are Gross Weight Increases for many 172’s regardless of engine type.
 
TCABM said:
Quotes are in from Western Skyways, Penn Yan, and Air Plains. 4-6 month lead time on an exchange or factory new engine. 160hp starts at $33K and runs up to $45K, 180hp runs from $55K-68K.

Core charges start at $5500 for the case to 13,500 for case, crank, and prop for the 180hp options at exchange. If the exchanged parts are serviceable or repairable, there will be no core charge.

Partners are all over the place on what to choose, will be talking as a group this weekend.
Click to expand...

As a compromise, perhaps price a LyCon overhauled O-320 with their ported cylinders on it. Their claim is +20 horsepower. I don’t know that I can say that I think their cylinders offer a 20 horsepower improvement but the 160hp O-320 on my cub that they did definitely makes more power than any other 160hp Cub I’ve flown, even one with cylinders that were ported by a competitor. My guess is that you’d get 2/3 of what you’d get from an O-360 conversion for 1/3 the price difference.
 
Grum.Man said:
… Not sure what the airplane is but is there additional stc cost going to 180hp or is that reflected in the 55-68 estimate? ...
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It’s a 1975 C172M. The stc cost is baked into the quotes. The $56K 180hp is from Penn Yan using OH’d steel cylinders; we put about 300hrs/yr om the plane so steel should be fine.

Most of our partners feel at 160hp, we’re performance-limited in south Texas summers. These are the same folks that want a GFC500 for their $100 hamburger though. Only a small fraction of travel more than 200nm with the plane though all but one are instrument rated.

We have the reserves to do the $56K 180hp option, through in a CGR-30 and do tue GFC500, but that’d eat it all up and we’re really wanting to add a leased 182, so we can’t do it all.
 
TCABM said:
Quotes are in from Western Skyways, Penn Yan, and Air Plains. 4-6 month lead time on an exchange or factory new engine. 160hp starts at $33K and runs up to $45K, 180hp runs from $55K-68K.
Click to expand...
:eek:
Now I'm really scared of what my 300 HP overhaul will be.
 
TCABM said:
We’ve been chasing a tiny oil leak for a little over a year and about 400 hours or so, and replaced the oil return lines last week. Post maintenance check flight didn’t turn up anything new, good or bad. Still a tiny leak somewhere. By tiny, I mean we’ve been loosing well less than a quart every 10 hrs.

Saturday, a partner flew a 3.5hr XC, noticed the leak was still there and put the plane to bed. Sunday, during preflight, I noticed this
13813b45957f84c52f12297beea97e93.jpg


Well, that’s new so I took a look under the nose and found this.
547378a58f7358cfa467e0e1bb514fdf.jpg


The belly was also pretty well coated with probably a couple ounces of oil. Since this was a significant change in the leak characteristics, I abandoned the pre-flight and put the plane back in the hangar.

Went out this morning with our partner who’s an IA and did some detecting.
ab9b4bbd4d1f13d3563f08fefe88d919.jpg


That’s the #2 cylinder. I’ve got quote requests out right now, but with 1973SMOH and multiple OHs, we’re going the exchange route.
Click to expand...
What’s that worth for exchange? I wouldn’t think a cracked case would be much, if anything.
 
luvflyin said:
What’s that worth for exchange? I wouldn’t think a cracked case would be much, if anything.
Click to expand...
Just depends on the shop. Lycoming gives $6,500 regardless, Barrett doesn't give much, Continental last I heard was based on condition.
 
rickgn said:
:eek:
Now I'm really scared of what my 300 HP overhaul will be.
Click to expand...

A field overhaul from numerous places
would likely be less but you’ll wait for the disassembly line, wait at the various inspectors, and wait at the assembly line. Due to the history of this particular engine, we are solidly in the camp of exchange from a known shop with warranty to back it up and we’re paying a premium for that.
 
Dan Thomas said:
It's a Lycoming in a 172. A Continental O-200 from a 150 is a bit light on power. Even in the 150 it's pathetic.
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originally looked like a 150 and a picture of the bottom side of a continental :rofl: I know that isn't the case now... no pun intended.
 
Glad you found it on the ground!

I love the "made a good decision and no loud noises" happened stories. Well, except for the $$$ for the engine.
 
Decided on Western Skways for an exchange OH on a 160hp O-320. We’re adding electronic ignition and deciding between an EI CGR-30, JPI 830, or a GI275 EIS for engine monitoring. We’re looking at an April delivery.

Meanwhile, I’m working to convince partners we can remove the ADF and indicator and decide whether to put in a 2-axis GFC500 (quoted at 19 AMUs installed) to make this a TAA since several want to get a commercial certificate in the next two years.
 
TCABM said:
and deciding between an EI CGR-30, JPI 830, or a GI275 EIS for engine monitoring.
Click to expand...
TCABM said:
Meanwhile, I’m working to convince partners we can remove the ADF and indicator and decide whether to put in a 2-axis GFC500 (quoted at 19 AMUs installed) to make this a TAA since several want to get a commercial certificate in the next two years.
Click to expand...
Hope you can pull it off. It's a worthwhile trade, I think.
 
We sent the prop off for overhaul since it’s never been recorded in the 8,000 or so hours it’s been on the plane. Dressing here and there through the years has taken its toll and it’ll be condemned as unserviceable.

New prop: $8000.

Next up we’ll drain the tanks and send the fuel selector off to be rebuilt as it’s allowing fuel to flow while in the off position.

Partners don’t see the value in an engine monitor, so that’s not happening and neither is a lease on the 182; kind of a long story with that, but bottom line is an exclusive use requirement stopped that show.
 
I'd be interested to know what the breakaway torque on the crack-adjacent cyl base nut is.
 
If it were me....and since you're already considering the gfc500... I'd go the Dynon route. Save some money on the autopilot by going Dynon over garmin and put it toward the dynon engine monitor.
 
Racerx said:
If it were me....and since you're already considering the gfc500... I'd go the Dynon route. Save some money on the autopilot by going Dynon over garmin and put it toward the dynon engine monitor.
Click to expand...

I’ve flown the Dynon AP and, unless you’ve got Dynon displays you don’t get the advanced AP controls.

Also, my experience with the Dynon AP is that is captures altitude better going up than coming down. The planes I’ve flown with the Dynon AP tend to lag capturing altitude in the descent and oscillate in the recover back to the target altitude.
 
If you get another whack at your partners on the engine monitor, here are some talking points on benefits:

Set %HP without tables
Greatly reduced risk of running out of fuel
Lower fuel cost due to more accurate leaning
Increased engine life due to monitoring all CHT
Early warning on engine failure
Detects reduced power and cylinder issues
More accurate digital readings for engine gauges such as OT and OP
Better data to monitor progress during engine break in period
 
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