A64Pilot

To start with most terms we throw around are not recognized terms by the FAA, like field overhaul for example. People mistakenly have the belief that the best is factory, and often they are correct but not necessarily. Decades ago you could get a properly done field overhaul for much less than a factory one, this is when the factory was running hard to produce new engine for the thousands of new aircraft, but then the new aircraft market fell apart and to keep the doors open and not layoff employees the factories got heavy into overhauls, in order to compete price wise with the field overhauls as they obviously have a much higher overhead they jacked their parts prices up thereby raising the price of a field overhaul so they could be competitive. This is where the big PMA manufacturers came into their own, the Factories learned there is a limit to how much they could charge for parts because the PMA guys would build possibly better for less. Sadly what Keeps Lycoming in business is I’m sure overhauls and I bet most new engine sells are for Experimentals. Having said that the “best” engines are from speciality engine shops, they run smoother, longer and make more power than a brand new factory engine, but of course they aren’t cheap. Then even what an overhaul means differs, some overhaul or replace everything, fuel system, alternator, starter, mags, prop, prop governor etc. remove engine mount have it inspected for cracks and some powder coat, most don’t, most do just the “core” engine. Not too many years ago an aircraft’s value was determined to a great extent by how many hours were on the engine, prop etc. Using say 50K for the engine overhaul an aircraft with a new overhaul was worth 50K more than one at TBO. The newer theory of hours don’t matter won’t last I don’t think, and those running past TBO will I think be in for a shock when that engine starts making metal, because the cost to Overhaul an engine once it starts making metal is way higher than it is for one that isn’t. I think what’s driving it is we are flying older and older aircraft, and the cost of overhauls goes up every year, what used to be 10% of the value of an airplane is now 50% or maybe higher, that coupled with we fly less on average than we used to means a couple hundred hours may be years. But remember the commercial about oil changes I think it was, the “Pay me now or pay me later” one, well I believe that has merit. But that’s my opinion

I’ve never heard of an insurance difference between a repaired and Overhauled engine, the actual difference is for it to be an Overhaul, the Overhaul manual has to be followed as in if there is a list of parts to be replaced, they have to be replaced, where a repaired engine they don’t have to. I’ve even heard that some mechanics may even put on the beer googles and only replace what failed and not measure the other parts to ensure they meet serviceability requirements. I do know that when it’s time to sell that an aircraft with a recently overhauled engine vs one that past TBO and has been repaired will sell for a lot more.

I’m not sure what the triplicate form tango is, but you did get a DAR to reissue you a new Airworthiness Certificate didn’t you?

Attached article is the Deny and make Counteraccusations part of “being caught” Issue is as I see it is that unlike automobiles for example the average GA aircraft was built 50 years ago, https://generalaviationnews.com/2019/05/27/aging-pilots-aging-airplanes/ that’s the AVERAGE. So whatever solution is adopted it needs to be applicable to a 50 yr old aircraft. Requiring the entire fuel system to be replaced is unrealistic, and I maintain that the more “aggressive” fuel will significantly shorten even new components life, replacement / reseals every 7 years isn't viable from an economics perspective.

Most probably as there is a min climb grade requirement that must be met, and that’s one of several things that can determine gross weight. It’s sort of self correcting of course because altitude reduces MP. Perhaps the charts for 5,000 DA might be close enough to be acceptable to keep from having to do a complete performance test profile. ‘I’m using 25MP from the ADI number, but think it’s very conservative, 94UL would I assume allow higher than 25 MP. Not sure what would happen with the Cyl head temp limit though because it’s probably at least as important as MP. War birds if we are talking real Warbirds anyway have by Civilian standards an excessive power to weight ratio that combined with the fact that they were never Certified means I’m sure that they easily have enough power, but as they weren’t Certified that requirement doesn’t exist. AH-64 could climb at sea level in excess of 5,000 FPM, but I bet P-47’s, P-51’s etc without ordnance would beat that even with 100 LL. 94UL just might require engine modification maybe? I keep using 94UL as Auto fuel has all kinds of other issues like vapor pressure, phase separation etc that 94UL shouldn’t, and I’d prefer a fit for purpose Aviation fuel myself.

I just read that Shell will be shipping 100VLL in Europe soon, I assume it’s even lower lead than LL, is an ASTM fuel apparently. I know nothing about it. I’ve come to believe that it’s not achievable either, or it would have been done by now. I’d bet lunch that this G100UL fuels health risks are greater than the lead in 100LL, but that’s just a belief. Way I see it is there is only two paths forward if lead must go, either a yet to exist new engine, or ADI for those that must have 100 Aviation Octane. Well three I guess we could just scrap our airplanes. I can’t afford a yet to exist engine and don’t want ADI, but if lead must go, ADI is all I could afford My bet is a new water cooled four valve engine could meet the HP requirements on Premium car gas, but it’s vaporware at this point and I don’t expect to see one either

If the FAA has any sense and I believe they do, then they know how many aircraft have used it, and face it only people with problems will report, so no report? No problem is a safe assumption. That is why I think anyone with problems should report, because if they don’t then the assumption is they didn’t have problems. But sure report no problems if you want to, can’t hurt. Data is data. My belief is this fuel aggressively attacks “rubber” paint etc., that’s in my opinion been proven beyond a reasonable doubt, and I believe given enough time it will cause many more failures of those components, it’s getting the weakest first is a pretty safe bet, but given enough time the percentage of problems will increase. Even if it “only” reduces the average life expectancy of new tank seal job by half, is that to be considered acceptable? How much degradation is acceptable? We know it swells common O-rings well beyond the FAA acceptable limit already, that should have been enough to not issue an STC in my opinion. Then the paint issues are apparently real too, and no level of refueling hygiene is going to keep it from staining and apparently destroying paint around the vents etc. Maybe it would be acceptable to only fill tanks half way if you’re burning the G100UL? That ought to prevent vent staining / deterioration? But the real Damning thing in my opinion is Cirrus saying that they are concerned that this fuel destroys their wings structural integrity, now to be fair I don’t think that’s what they said, they only said they had concerns about the airworthiness of their aircraft that had used this fuel. For Cirrus to come out and say that is huge in my opinion, because they are no Dummy’s, they know that any statement like that they had better be prepared to defend it in a court of law. Of course this is my opinion, and we all know what our individual opinions are worth.

Maybe not, I hate to say it depends but it does. This may sound dumb but I open the cowl flaps on final and if it’s Summer I leave the oil filler door open after shut down, both seem to help and if I had to go around having the cowl flaps open before hand is one less thing to remember to do. 1. Don’t do what I hear so many Bonanza and Cirrus driver do for some reason, and that’s start immediately at a high RPM, sure use full throttle but pull it as soon as she starts. I don’t know why those guys do that, the IO-520 in my C-210 was easy to start when hot or cold. Must be different in them. 2. Boost if she is running rough right after starting seems to help, I believe as has been stated it helps prevent vapor lock / pump cavitation, so once running if she starts surging turn the boost on and see, why not give it a try and see. What happens of course is due to there being vapor and not liquid fuel in the system she goes lean almost immediately after starting eventhough the mixture is at full rich and eventually if it keeps running that vapor will clear and she will run smooth, but your right after firing is not good for the muffler. Excessively lean mixtures may cause after firing. Excessively rich may cause back firing. I haven’t watched any video, but add cold starts to your statement about the normal state for starting is flooded, priming when cold slightly floods the engine unless you get lucky and hit that sweet spot, most don’t. It’s just like the old cars with carburetors, pumping the gas pedal caused the accelerator pump to spray, slightly flooding the engine.

I put mine full rich, throttle to idle and just start the thing. it does take a few seconds but not many. I do this every Sun after we fly to breakfast, often in the Summer when I go to lunch she is still hot and needs the hot start procedure. Done correctly the “hot start” procedure will work at any temp, because it’s simply intentionally flood the thing, crank with zero fuel flow then push mixture in. It will work because turning a flooded engine over at any temp will clear the flooding if you spin it long enough, hot or cold. 95% or more of hard starting problems assuming a good battery are weak ignition, can be as simple as the plugs need cleaning.

Assuming people reply, but honestly I’d expect the STC to be withdrawn first.

ALL of the kids in the paint shop around 1983 or so at Hunter Army Airfield failed their Liver function tests, because they had been painting Imron on landing gear for Army fixed wing aircraft with only dust masks and eye protection. I say kids because they were in their 20’s.

No, if there is rust under powder coat it will bubble up just like it does paint, I think your thinking of primer when you say it shows through. Thats why it’s important to bead blast just before you paint or powder coat. Ideally you go from one directly to the other. Now I’ve never lived in the rust belt, but bet money people that do know exactly what rust under paint looks like.

I think it IS something, for example they didn’t issue one for 20W50XC. PLEASE, anyone who has had difficulty with this fuel fill out the forms, they NEED complaints, that’s what drives the FAA, without complaints or accidents there is no problem

Remember I was a helicopter mechanic for 4 years and a helicopter maintenance officer for 15. EVERYTHING on a helicopter vibrates, the trick is to minimize it as much as possible if you do everything lasts longer even the electronics

@TangoTango I was afraid someone would ask that, I’ll come up with his name eventually. He’s in North Ga and I believe was a Nascar engine builder, he does do overhauls to very exacting specs, he does offer a performance engine where he has the heads ported and polished, a 7 angle valve job and the guides are honed not reamed to size. Pretty sure he CC’s the heads etc like you do in a well build car hot rod motor. I think he balances all his engines to less than 1 gram, but maybe that’s just the performance overhauls, not sure. You know his engines right off because lots of bits are powder coated red, but I’ve heard he will do other colors, or I’m sure leave them stock. Finally came to me, his Name is Carlus Gann, if your interested call about a performance engine. https://www.gannaviation.com/engine-overhauls

My Lyc all rotating components are balanced to 1 gram or less, it’s the only smooth 4 cyl I’ve ever flown behind, I believe being smooth means it and everything else will last longer, of course the prop needs to be balanced too.

From my experience it depends on how hard they are run, 1000 hours is good if you bought a Mooney to go fast and don’t mind paying for the speed, some won’t get that. But average use I think is about 100 hours a yr, 1,000 hours is 10 years. So there’s that. I’ve seen Conti cylinders if run at 65% power or less go to full TBO

Ref powder coating, Maule went to powder coating of the fuselage and motor mount a couple decades ago. The aircraft on floats in the Bahamas had serious airframe corrosion in 5 or 6 years before they did, once they were powder coated, then the corrosion pretty much stopped. Of course on a Maule the only way to get to the tubing is to remove the fabric, a really expensive proposition. So I had Moultrie Manufacturing, the same guy who did Maule powder coat the Thrush fuselage, engine mounts and landing gear etc., and that also pretty much stopped steel corrosion on the Thrush. ‘As far as crack detection that’s incorrect, at least on the powder coat Moultrie Manufacturing uses, it’s a bright white “anti graffiti” powder coat meant apparently so that spray paint can easily be removed. In the event of a crack you will see a very obvious rust line on the bright white surface and on a Thrush you will most likely see linseed oil leak out. Cracks are more easily found than on the Navy Grey paint Thrush used to paint their fuselages. If I had my gear off I’d certainly send it to Moultrie manufacturing and get the same powder coat used by Maule and I hope Thrush still. It’s good stuff. Ref being porous, maybe it used to be or maybe this special anti graffiti powder coat isn’t where normal is, but I know it removed the yearly maintenance of cleaning rust spots off of the Thrush fuselage and repainting. The Thrush is unusual as all the skins on the fuselage are just Camloced on, so 10 min and you’re looking at the tube frame with the side skins removed.

While it is possible and would work, a possible stumbling block is that Mogas doesn’t really exist anymore. The current Auto fuel is actually many different fuels, one for Summer, and a different one for Winter, apparently a third for high density population areas and California of course has its own special fuel, and even if we ignore that Auto fuel keeps changing, I think MTBE is gone? Replaced by aeromatics? ETH or alcohol fits in there somewhere too. So what do you certify to? Either way MTBE wasn’t in the fuel back in the day when the Auto fuel STC’s were issued, so are they even valid now? That is why I think, in my opinion and yes I know what my opinion is worth, but a way forward is ADI with 94UL. I think it’s the only viable option right now, don’t need ADI because your low compression, fine burn 94UL, have a high compression motor? Fine burn 94UL with ADI. Only need to sell one fuel, one that should work fine with existing trucks, tanks etc. I guess maybe the perfect 100LL replacement could come out tomorrow, but as they have been trying for more than 20 years my guess is if it were possible it would have happened long ago? Even bladder guys I believe will have problems. My bladders are made from the same material O-rings are made from, so if it causes O-rings to swell and soften, won’t it affect my bladders the same way? I just hope the Feds don’t mandate this stuff

You know now that I think about it I think the compression ratio of the newest and most efficient PT-6’s is about 14 to 1,I think, older designs were much lower like half that. But say the new ones have 200 PSI coming off of the last compressor stage, that is the highest pressure in the entire engine, if it were higher in the hot section then you would get reversion or backwards gas flow like you do in a compressor stall.

A turbo extracts energy from the exhaust stream. That energy is primarily heat as there isn’t much pressure, there is of course significant gas flow that comes from expansion from heat and mass times velocity squared = energy. I don’t know the HP a turbo makes but it’s considerable, a turbo is similar to a turboprop or jet engine. Massive HP but I think the max pressure in a jet engine isn’t but about 40 or 50 PSI? Not sure really but if the HP was derived from pressure it would be massive pressure. I don’t know what the max pressure is in a turbine but am pretty sure it’s orders of magnitude higher in a piston engine. If you search glowing hot exhaust or similar you’ll see some turbo systems where the exhaust is yellow hot while the turbo side is a dull red, there is a large drop in temp. Argued a different way, heat is solely the driving force behind the entire engine, we could argue I suppose the pistons are driven by pressure, but the pressure comes from the heat from burning fuel. Chicken or Egg? Like arguing I guess that John died from blood loss and not the gun shot, but the gun shot caused the blood loss.

I would absolutely bring my own tie downs, In truth not much works well as it’s sand, but they require tie downs. I have the claw as well pretty good in clay soils but not much holds well in sand, maybe if you had real long nails? I’ve never considered IFR to be honest, I don’t think IFR is forecasted this week.

You must tie down, they sell them to you pretty cheap. They are just cheap dog screw in anchors, some cheap rope and a piece of PVC pipe to use for the dog screw in anchors, although it’s been a few years since I’ve been just for the day. Often the ground guides are just kids, so don’t let them guide you where you might get a prop strike I think sometimes you may be on pavement but usually not, years ago I parked the 210 on pavement but I assume those spots go fast. Of course there are only a few arrival / departure windows, be slow on final so you can spot land on the dot they tell you. I personally shoot for 100 or so feet short, so I usually have to add a little power, but that’s easier than being long because the wind changed on short final. The wait at the lake usually isn’t long, but watch for idiots, they are out there. I think during the week the wait is shorter as it’s only the day traffic and not those camping

TIT should be higher, it’s from pressure I believe as combining cylinders doesn’t drive temp higher, even if you accept the argument of the heat is in pulses coming from the exh and the egt probe averages temps Its sort of similar to how steam at 212F will burn you more than water at 212F, because the steam is at a higher energy state. If you had downstream temp, known as EGT in a turbine it’s markedly lower than TIT, as in much lower because the energy has been extracted from the gas flow to drive the turbine.

This is the way I’d go. Often if they are well worn they can hone to an oversize with new pistons and if you get the valves done, many replace exh valves, it’s in effect an overhaul. By valves being done I mean new valve guides too. Apparently factory Continental cylinders have very poorly done valve guides, many better shops disassemble new factory Conti cylinders and rework the guides and those last longer. As far as balancing, sure why not, but all you can balance is the pistons of course. You get the most from balancing the crank and rods but of course you can’t do that now. Often by addressing just the weakest cylinder your in the shop every other month replacing the next one when it goes, you end up with an airplane that lives in the shop because they don’t have spares on the shelf and it ends up costing way more doing one at a time. Plus you may not be at home when one demands attention. Other side of that argument is it does spread the costs out if you simply can’t afford to get them all done at once.