A64Pilot

Today they are scraped to fit, ideal is 1.5 thou on a T, often the bearing caps are shimmed to obtain clearance. Originally there was zero clearance, hence the factory hooking the motor up to a huge electric motor and burning in clearance, I think that was much faster than hand fitting each bearing, just burn it in. The production rate was phenomenal there were more than 15 million of the cars made and the engine stayed in production until WWII I think powering just about everything and Ford supplied replacement engines. I have not found any part that’s not available for the Model T, even obscure interior parts. There are still thousands of them on the road

It’s still done for the Model T engines at overhaul. Babbitt material as it gets old gets brittle and can fracture. Our engine is 100 years old and hasn’t ever been overhauled so I’m crossing my fingers. On model-T engines apparently they have shims under the rod and main bearing caps, when or if you get a rod knocking you pull over. pull the cap off of the oil pan to access that rod, there are four caps, remove the rod cap, remove some shim replace the caps and go on your way. I’ve heard of leather being used for bearing material as a temporary fix. The pistons are cast iron, there are two cast iron compression rings above the wrist pin, each a 1/4 inch wide, the oil control ring is on the piston skirt and it’s one piece cast iron also 1/4 inch wide. You have to see these rings to believe them, they are HUGE. I think insert bearings first appeared in the early 1930’s, I know Packhard production in either 34 or 35 was full insert bearings, but I don’t know when even cheap cars did, I’d guess before WWII though as I assume they sped up the production process quite a bit. I think the Model A had an oil pump, there were no pumps on the T, no oil pump, no water pump, but our 1923 Tourer has electric start, a gear driven generator and electric headlight, with if you can believe it, but high and low beams, 1915 in model T’s, older T’s have acetelene headlights, like old time miners lights. You drop a piece of carbide rock into water, it fizzes a little like alka seltzer but it’s acetelene gas, screw on the top and light the tube the gas is coming out. It’s actually surprising how modern and well built a Model T is. I expected those God awful square nuts like you see on furniture, but everything is modern hex nuts and they are all SAE thread. It wasn’t until I think about 1916 when SAE thread became standard, until then there were different threads and of course that had to be a nightmare with different machines having different threads and nothing standard.

Did you read the SC link? He says leaving it loose is worse. Here I cut-n-pasted part for you, he seems to be well informed and what he says jives with my experience. The padded zip ties are outside my experience Zip ties will cut wires. Period. The plastic ones rarely last anyways, as they get brittle and break. The nylon ones are much higher quality. IF you decide to go with nylon zip ties on wires, remember two items at each tie point. One, pad the wire with something like a loop of silicone tape. Two, get the zip tie tight! You're not doing the wires any favors with a loose zip tie. The vibration will cause it to cut into the wire. I've seen some sizable wires cut off by a simple nylon zip tie.

I’m an IA and my opinion is the FAA would say no, but I can’t come up with a logical reason why your allowed to replace a tire under preventative maintenance but not rubber shock disks. I think in truth the answer is that’s it’s always been that way. I think one inspector would say it’s OK and another have a fit A little reading that may help? I think as usual it falls to you to decide what you can and cannot do. https://www.faasafety.gov/files/gslac/library/documents/2011/Aug/56398/FAA P-8740-15 Maintenance Aspects of Owning Your Own Aircraft [hi-res] branded.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43-12A_CHG_1.pdf Also FAA part 43, Appendix A sub paragraph c gives you a list

Wasn’t there and can’t do anything but speculate but at taxi speeds if you lose a brake, locking up the other one pretty much makes you pivot around that gear and brings you to a stop pretty fast, at least on non steerable tail wheel airplanes anyway, which I think all bigger tailwheels are that way. Most people don’t consider that and if they haven’t table talked what to do in a brake failure often pretty much lock up and don’t do anything but crash straight ahead. Completely different thing sort of but years ago there was an outcry about the “Killer Prius”. An off duty California Police officer driving a borrowed car, turned out it was a Lexus but don’t let that get in the way of the Prius hate crowd. Anyway the gas pedal got trapped between the two floor mats, the owner just put the all weather mats on top of the normal fabric ones. This stuck the gas pedal. This guy tried pushing the start button to no avail and even made a 911 call, eventually he burnt the brakes so bad they caught fire and he crashed killing him and his his family I believe, car caught fire from the brakes I think in the crash. As I had a Prius I looked into this as it was a concern. Pressing the start / stop button will kill the engine but it has to be held for a sec that's intentional so you don’t accidentally kill the engine by brushing your hand across that big button. But if you put the car in neutral, the computer retards the engine speed to idle even with the pedal held to the floor and you can stop normally of course and have full control. If you try to put the car in park, the computer won’t, instead it goes into neutral and you guessed it, engine to idle and you can stop the car normally. Same thing if you attempt to put the car in reverse, I was a little nervous trying that but thought surely Toyota’s Engineer's are smarter and they were. I hate to speak I’ll of the dead, but this guy had time to make a 911 call and talk to the operator, but never did anything except hold the brakes down until the highway eventually came to and end. If you have time to make a phone call, who wouldn’t at least try to take it out of gear? https://www.nbcsandiego.com/local/chp-officer-family-killed-in-crash/1859153/ So if this California CHP Officer whom I believe has training in high speed driving never thought to take it out of gear, or read his owners manual where it tells that the start / stop button has to be held for a second or so, well anything is possible. Oh, Toyota recalled millions of their cars and cut off about a half inch from the bottom of the gas pedals, and quit selling all weather floor mats, at least on the Prius anyway. I guess there was a lawsuit. https://www.latimes.com/archives/la-xpm-2010-mar-03-la-fi-toyota-saylor3-2010mar03-story.html Seems it grew “legs” millions recalled, thousands suddenly complained about sudden acceleration, Congress fines Toyota over 16 Million dollars. https://www.nytimes.com/2010/09/19/business/19autos.html Toyota settles case for 10 Million dollars https://jalopnik.com/toyota-settles-for-10-million-in-deadly-san-diego-cras-5717045

Are the rod bolts in a 550 cotter pinned?

I ascribe to the likelyhood that the pin came out myself or even possibly broke and came out from being re-used, but the report seemed to postulate it was never installed. I assume because the remains weren’t found? I’d like to think it wasn’t missed. In fact it’s not common for rod bolt nuts to be cotter pinned, and yet it’s extraordinarily uncommon for a nut to fall off, just like the cylinder stud nuts don’t have cotter pins. Engines have always had me wondering, pretty much all the bolts are course thread while everything thing else on an aircraft is fine thread, because fine thread is better?, and only odd ball things have safeties but things like spark plugs, ignition harnesses, the intake and exhaust, magneto’s etc don’t? I believe it’s only the smaller and older Continentals that have cotter pins on rod bolts and the newer and bigger motors don’t? Do any Lycomings have cotter pins? I believe thread pitch difference may be why and I’m not abdicating leaving cotter pins out, just it’s interesting is all.

Years ago when the Longbow Apache came out I got my HVAC license in theory so I could legally purchase refrigerant if needed when we were away from home, but mostly just to get it, you never know. Things that operate at high efficiency interest me, the Prius for example from an Engineering standpoint the thing is brilliant, I spent hours understanding as much as I could. For example many electric vehicles have an AC of course but heat the interior with electric resistance, it works but it is terribly inefficient. Tesla could make different frequencies from the inverter so that the drive motor would heat up and the car could harvest that heat to heat the cabin, along with a heat pump of course. But then they really got to thinking and do things like if the car is parked in the sun the heat pump can harvest solar heat in the cabin and store it in the mass of the battery, then rob the heat from the battery to heat the interior when your driving. They came up with three different cooling modes, and twelve different heating modes and if you delve into this thing it’s an Engineering marvel of complex operation but simple mechanicals. Model Y was first but I believe ALL Teslas use the system, I know our 2021 Model 3 does, but if this kind of thing interests you, read this article and there are Videos with animations that explain it well too. This was done because the more and more efficient the Tesla’s became the greater the power required to heat the car dropped the range and efficiency of course, normally waste heat is used in an internal combustion car so you can stay as toasty warm as you would like with no efficiency penalty, but an EV can easily lose a third of its range heating the cabin The Prius ran into the problem as well because it’s engine is off so much that in city driving in real cold weather it never really gets fully up to temp, the early Prius upon shutdown would pump all the engine coolant into a thermos bottle to retain the heat and the later ones circulated coolant around the catalytic convertor because those things get really hot. In cold Wx the Prius will run the engine just as a source of cabin heat and of course when it’s doing that mileage tanks. https://insideevs.com/news/452464/tesla-model-y-heat-pump-system-details/ If you find this stuff interesting watch the videos, I think there was more Engineering time spent on this than is spent designing most engines.

I was a young Private just started working on helicopters, watching the old Warrant Officer pre-flighting a Huey that just came out of Phase (Army Annual). Never thought that years later that would be me He was slapping the bottom of the tail boom pretty hard and I was wondering what for, well he would slap it, and hear a thunk. They took the cover off and took out the torque wrench that was used to torque the Sync elevator. Worst thing we found though was a baseball grenade in a Huey fuel cell, we were changing the cell and found it, hangar was evacuated and EOD came and got it. We think it had been there since Vietnam, the trick was to wrap the spoon on the hand grenade with duct tape or electric tape, then just before putting it into the tank to pull the pin, fuel would dissolve the tape later giving the culprit time to get away, well on this one they forgot to pull the pin. Years later I worked at Thrush and we were replacing the main spar caps in a set of wings and found a bucking bar that had been there since the wings were new. Over the years I feel like I could have filled a tool box with the tools I’ve found, worst is Civilian airplanes and it’s tools laying in between the cylinders on the engine, they seem to hide there. Some I have found based on the rust etc I know they were there for years

I’ve had the claw forever, used it a couple of times, I used to do the back country thing in my Maule years ago and of course there aren’t tie downs in backcountry strips so you have to bring your own. From testing I’ve seen on tie downs it doesn’t perform real well, but especially if it’s directly under the tie down points, apparently you want a good angle so it’s being pulled sideways, but having said that it comes with everything even a hammer to drive in and remove the nails. Now if I could just find much longer nails I believe it would work much better in Fl sand. Here’s one test, in it I believe they recommend putting the claw directly under the tie down, which is opposite of one of their older tests, so who knows, but I think an angle is better. There is a video link at the end of the article. https://www.avweb.com/insider/sun-n-fun-tiedown-tests/ This test says put them in at an angle https://www.aviationconsumer.com/accessories/portable-tiedowns-claw-is-a-top-pick/ Last thing if you have LASAR’s combo tie dow / jack point I believe it could cut a rope pretty easy, but get two S hooks at a hardware store and use them to tie the rope to and it won’t cut a rope. Oh, and at least at Sun-N-Fun you can buy them all at a discount, but Sun-N-Fun won’t let you leave your aircraft untied long enough to buy them, so you end up buying their three dog tie downs with a piece of PVC pipe and cheap rope. I don’t think they make a nickel off the things, they aren’t overpriced or weren’t several years ago when I last went.

Yeah several years ago, at least ten I think I stopped in at Zephyr Hills waiting for the Airspace to open up at Sun-N-Fun. They sell those trikes there with Rotax engines. I couldn’t believe what they were asking for those things, when he told me the price what immediately came to mind was it was about what I had paid for the Maule I flew in on, with a Lycoming 540. I’ve heard they are up to about 90K now?

I don’t think you understand lacing, it’s not used on steel tubing. You have not laced wires, you don’t tie it hugely tight and it’s soft, a zip tie is hard and is a band that holds the wires tight. Second post in this thread says it better than I can, with a name of wireweenie I can only assume he is an avionics tech / electrician https://www.supercub.org/forum/showthread.php?50022-Wiring-Harness-Tie-Wraps-vs-Shrink-Tubing-vs-Lacing I’ve never posted over there and don’t follow the forum, Google found it for me

Old things are new again, actually burnishing in is very, very old school. The Model T engine was built so tight that it couldn’t run, so Ford hooked them to a huge electric motor and spun them without oil and burnished in the babbitt material that was used for the bearings, only then could it start and run on its own. ‘It was called “burning it in” they would spin it until the bearing caps smoked.

I have yet to have anyone complain when a job comes in at less than estimated cost, but buddy let it go a couple hours longer and your expected to eat that time. To quote Scotty on one of the Startrek episodes “ You didn’t tell him how long it would actually take did you”. Found it

Aircraft bottom ends are to some extent greatly overbuilt, a lot of that is due to operating RPM. 2700 or so RPM isn’t really that high an RPM for a crankshaft unless it has huge stroke and ours isn’t huge. Lycoming and Chevy big block have very similar strokes, yet the Chevy regularly turns twice the RPM. However, rarely you do hear of a rod letting go and of course that’s sudden and catastrophic. Usually for both engines it’s the valve rain that “makes metal” and or prop strikes that push an engine into overhaul. Prop strikes because if your already at or past TBO and the engine is being completely disassembled many decide to toss some of their own money in with the insurance money and overhaul. The bottom end of an aircraft is so tough that no consideration is given to it in break-in, unlike almost every other engine where your supposed to baby it durning break in to break in the bottom end, with an aircraft the best way to break it in is to run it like you stole it. Of course that’s because the cylinders are difficult to break in, but it has no deleterious effect on the bottom end. It’s not changing oil frequently that causes bottom end wear, if they are run with fresh oil they will go a very long time.

No, lacing is soft and very flexible, a zip tie is a hard band, and you don’t lace anything but wiring. It’s movement as well as grit that makes a zip tie cut and no matter how tight you can get a zip tie add a drop of oil and it will move on a tube, the cushioned ones perhaps not I don’t know, a DG clamp doesn’t move easily. Many things will work, but just scream Ghetto if you will, then there is doing things right. Why not do things right especially if it’s just a little time and very little money, literally a few cents more? Its like bending over the tail on safety wire, isn’t required, cost no money, but it’s the right way to do it, yet I see all the time it not being done, screams unprofessional to me. Using PK screws in a Tinnerman nut is another thing that annoys me, it works I’ve never heard of an accident from a PK screw falling out, but it’s just wrong. Using Walmart butt splices and terminals on wiring is another.

6 NIB cylinders are $12K? Verify these are the correct cylinders because I have not, but it’s of course everything new, pistons rings etc. https://www.aircraftspruce.com/pages/ep/superior_millenium_continental_o550/superiormillenium08-11208.php That leaves 5K to R&R? I guess that’s about right. I don’t own a shop or anything but believe I could R&R cylinders in a week, that’s a grand a day. I don’t know what you could run into with turbos etc. But surely a week would do it? But as I was buying I’d want new cylinders and would price for that. On edit, If new cylinders aren’t possible then I would want the old ones overhauled by an engine shop, not just honed by an A&P. Very often corrosion pits are too deep to clean up honing. Having done this kind of thing myself often it’s the stuff you discover that runs into more money than you were considering, exhaust repairs, maybe new ignition harnesses etc.

I’ve seen several instances of zip ties breaking wires, they make a hard point where the wire bends until it breaks, same for solder joints, wire breaks right at the end of the solder. They are prohibited at least on the AH-64, but whenever we got a kit to install something it always came with a bag of zip ties, so every crew chief had a bag to take home. We laced wires on the AH-64, we had wire bundles the size of an arm in places. We used zip ties to repair camo nets and lots of other uses from these kits, they are great for all kinds of things, just not on my airplane. I’ve also seen several instance of zip ties getting dirt, often it’s a little oil that attracts the dirt but vibration etc cuts into a steel tube engine mount until the tube has to be repaired or replaced. It’s amazing how good a zip tie with sand and oil will cut, you have to see it to believe it. One can render your engine mount un-airworthy in less than 100 hours. Then as they age they get brittle and break off easily leaving whatever they secured, unsecured, and they don’t tolerate heat well in the engine compt, it’s not that they melt but heat makes them brittle. Thrush used bags of them on every new aircraft, it was the one thing I couldn’t get rid of, they are so cheap easy and fast that the owner wouldn’t spend the money, and the FAA allowed them. If you must use zip ties, the black ones seem to last longer and never put them directly on a tube, but put some kind of cushion between the zip tie and the tube. By the time you do all of that you may as well spend $1 or less for a DG clamp or two. https://www.wicksaircraft.com/shop/ms21619-cushion-clamp/?woo_id=107723&gclid=Cj0KCQjw2eilBhCCARIsAG0Pf8uqmcMSYeYn2WgRR1eVacDbqIBZ6hrhvJFF0d_s8vkcLrxBH3NpITMaAhk8EALw_wcB

The after firing, burbling in the muffler is from mix being too rich. If you lean lean aggressively, so much that you can’t attempt a takeoff, or I promise you one day you eventually will takeoff leaned out and that’s killed people in the past. You can’t hurt an engine at all at taxi power with mixture, many even promote it to keep plugs clean. The roughness after starting is most likely vapor lock, it’s hot now so of course it’s worse, depending on where the vapor lock is occurring boost may help, pressure raises the boiled point of a liquid and vapor lock is of course the liquid fuel boiling.

Any recent work? Start there. Just as a pure guess because it could be anything it looks like the bolt that attaches the ground wire. I’d suspect mechanic dropped it, couldn’t find it and put new bolt in, and it surfaced later. You need to de-cowl and give things a good look though.

Interesting thing about @philiplane is he lives within spitting distance of MT which is in Deland Fl. Surely if his issues were correctable they would have been done so by now.

Your absolutely correct and while lapping could possibly mask the problem temporarily it’s not going to actually correct anything. A valve especially a Lycoming with excessive clearance (wobble) is a verily likely candidate to stick because the excessive clearance will have the oil coke on the stem, It’s more likely in a Lycoming because they are sodium filled valves, the liquid sodium cools the valve largely by dissipating the heat trough the stem and into the head through the guide, so the stem and guide are hotter in a Lycoming than a Conti. A sticking valve of course can mean the piston contacts the stuck valve and the head breaks off, often this can lead to a destroyed engine. Most don’t but it’s not improbable. If your going to lap a valve, do a wobble check first, if it fails you need to fix that. On edit, and I know I’ll get flack from this from the faithful, but a leaking valve is not a normal operating condition, if you have one, you might want to investigate why, very often it’s just a bit of carbon build up and would clear itself very quickly, but staking a valve can also break up the carbon and restore compression, but it’s also likely from worn valve guides. Lapping really doesn’t do much to the hard valve and seat at all, many cylinder shops don’t even lap anymore when they do valve jobs, personally I lap, but not to finish the machining job, your not doing that, but just to ensure I have nice even contact all around as the compound removes just enough of the shiny metal to leave a matt like finish where contact is made. If you building a performance engine with a three or even a five angle valve job you move the seat to valve contact to the edge of the valve, and you lap to ensure that’s where contact actually is. With a multi angle job your in effect making the valve slightly larger, slightly increasing flow and power, a little. Lapping shows where the contact is. If you don’t know what your doing and especially if you use anything but the wooden handle with a suction cup, like a drill you can remove metal, and cut a groove into the valve, ruining it. Quick Google brought this up, it seems it’s a motorcycle forum but they seem knowledgeable. https://www.dotheton.com/index.php?threads/valve-lapping-for-dummies.28553/

Are you renting spaces? How many airplanes do you have?

Never said if your ROP or not, Cyl head temps follow power and power say 100 ROP is quite a bit higher than say -25 LOP. I can’t keep my cyl head temps down at higher power cruise with trailing flaps in Summer either, if I want high power they stay fully open. My 2c if temps creep toward 400 with flaps trailing, open them fully. Do whatever you need to with the flaps to keep cyl head temp cool. On a hot day I have to climb at 130 indicated full rich, cowl flaps full open to keep it in the middle of the green, Winter time I can hang it on the prop at Vy. Don’t put too much into what you read on the internet, not saying others aren’t running cool with trailing flaps, but they may not be in Tx, or may be running lower power settings or maybe their engine is older and more worn and just doesn’t run as hot a newer tighter engine. Depending on where in Tx and time of day, it’s awfully hot there, many have never experienced that level of heat.

I’ve seen metal type zip ties, but I’ve not seen what you have. Is it easily removable and re-usable? Be interesting to see a photo. As a general rule I dislike zip ties, I don’t think they belong on aircraft in most cases, I think wires ought to be laced and lines, tubes etc held by DG clamps. Zip ties and PK screws go hand in hand I believe, they both have uses but do to them being cheap and fast I think are overused, just my opinion.