A64Pilot

I imagine it is fast, the 250 is no slob, it was one of the airplanes on my short list. The Mooney works for us as since I’m old and retired there are only two of us, but if there were occasionally four I would have looked harder for a 250

Surely that occurred after the cam removal, i’d guess he still has it and it sat around in a shop etc and rusted. ‘However I believe how or where an aircraft is kept as well as frequency of flight has a lot to do with it, an airplane kept outside will get corrosion faster than one in a hanger and a Florida airplane will get it before an Arizona airplane. I now live in Fl and from my little bit of looking at aircraft to buy, would recommend avoiding Fl aircraft, and if its been kept on the ramp to most likely don’t even go look. I went to look at a 79J, new paint in 05 and new interior a couple of years ago, thought it sounded real good. Airplane wasn’t in my opinion even airworthy from excessive corrosion, sad to say but I think he killed it, I didn’t even bother looking close, the liner in the wheel wells actually had holes in them from corrosion. ‘School aircraft usually makeTBO or well beyond, and if you think about it, they are operated in a manner we were always told will kill engines, not properly warmed up, excessive, repeated full throttle excursion and pulled back to idle after full throttle over and over So far as checking can lobe condition, about all you can do is pull two cylinders and look. and even that’s not a guarantee, as was said, all it takes is a small defect and it will spread, once you get through the exceedingly thin hardened surface, it goes fast. ‘How will DLC protect from cam corrosion? Is it the cam, or the lifter or maybe either one that starts it?

I believe that 4th bladder at least for a J is available, I don’t know about other models. I’ll just live with the lower capacity due to cost myself.

Or from the hose on the fuel truck or tank. ‘I’ve gotten small pieces of rubber in my C-140 tanks which are aluminum, so I figure the suppliers hose is breaking down. Old bladders will break down and shed black granules, that’s what told me our C-210 bladders were about ready for replacement. It was a 76 model and I have no idea how old they were.

That’s an excellent use of a helicoil. I would put blue loctite on them when I installed them. Don’t use red. Loctite is to keep them from backing out with the screw, and blue isn’t nearly as permeant as red is. When I was building drag bikes back in the day when we got over about 200 HP, the transmission gears would have so much torque going through them that they would pull the bolts out of the case and split the case, bolts stripped the aluminum case of course. ‘The fix was to drill out and helicoil the case, the larger diameter of the helicoil made it hold into the case much stronger and we never had any more split case problems. ‘Plus for items that are often removed, you have steel on steel threads as opposed to steel on aluminum, I believe that’s why our cylinders heads are helicoiled from the factory, but a lot of cars and motorcycles screw plugs into aluminum heads and it works just fine, so maybe not? ‘However I’ll agree with the other poster, a Timesert is likely superior in most cases, but I would not put one in a head, it could possibly interfere with the plug dissipating heat to the head, probably not, but I wouldn’t do it.

Yes, all exhaust valves are primarily cooled by transferring heat to the head, well except for flat head motors of course, they transfer heat to the block. but there is some oil cooling, just not a whole lot. But the head is partially cooled by oil, as you said the oil can’t take the heat, so enough oil has to be pumped though the head so that the oil doesn’t stay in there long enough to coke, if it just sat there it would. As there is oil flow, and as the head is about the hottest thing in the engine, up to and sometimes even over 400F, and oil is about half that, it will pick up significant heat. There isn’t as much oil flow as we might think though, it’s not much more than a dribble. Just like pistons, most of their heat is transferred to the cylinder, but many pistons get significant cooling from the oil. many engines spray oil onto the bottom of the piston solely to oil cool them. Then turbo’s the center section anyway on aircraft turbo’s is oil cooled. ‘Just saying oil is a coolant too, not just a lubricant. ‘On edit, the primary reason for what seems like excessive cooling fins around the exhaust is to cool the exhaust portion of the head, that is a very hot area as of course all of the heat from combustion passes through there, the fins aren’t for valve cooling.

Your cars and trucks are air cooled too. Yes they have radiators full of coolant, but what cools the radiator? Point that out to someone with a Rotax and see how confused they become A not insignificant amount of heat is carried away by oil in any four stroke motor, just saying oil is an important coolant too, to say nothing of turbo’s that’s why we have an oil cooler, and low oil level usually will mean hotter oil. The oil cooler won’t “know” there is less oil. it remains full, but the same amount of heat will be carried to the oil cooler with less oil, dumping the same amount of heat into less fluid raises its temp.

It’s not uncommon, in fact it is what should be happening. The same amount of heat has to be carried away by the oil regardless of the amount of oil. so the less oil there is, the less there is to carry the same heat, so it’s hotter. Hot oil loses its viscosity and therefore pressure will drop with viscosity. I know I’m going to start another you don’t know what your talking about fiasco, but here goes. Our engines and actually pretty much all engines are more oil cooled than air or water cooled. It’s actually really only the heads that are air cooled, everything else is oil cooled. The cylinders don’t actually get very hot and yes they are primarily air cooled. The cylinders are more of a heat sink for the heads than get hot themselves But the camshaft, the crankshaft and everything else in the engine case and accessory case is oil cooled and the oil is air cooled, so in point of fact all engines are air cooled, except boat motors if you look at it that way. ‘But my point is that oil carries a significant amount of heat away, it’s an important cooling medium

There are a few like that where I live too, and I’ve participated in one and it was flaky, not sure I will another. This was years ago, maybe 1989? Anyway there were 6 ships staggered right. Gun 6 took the photo. ‘Good thing about airplanes is if you bump wings it’s probably OK, helicopters, not so much

We are a CAR 3 airplane so we don’t need the flammability test, but if you desire one it’s not all that expensive to have it tested. ‘Aircraft I manufactured were CAR 3 and we didn’t do burn tests, but we had almost no interior fabric, I was told at the time, but didn’t verify that if we placarded the airplane no smoking we didn’t need to do the flammability test. One we did was FAR 23 and even though it was required,we didn’t do any burn tests, I guess it just got missed? ‘I’ve since done a little reading and found that if you don’t placard no smoking, then you have to provide a certain number and type of ash trays. ‘But I really don’t think any inspector would ever get that deep in the weeds? How many smoke anymore? So in short in my opinion a good high quality automotive interior is very good and legal. I found this, this guy did his homework https://forum.shortwingpiperclub.org/showthread.php?3033-Interior-materials-and-regulations

I believe the 2 quarts is called min bearing safe level, If I remember correctly from my IO-540, if for whatever reason you got below two quarts you were supposed to overhaul ‘So 2 quart is the min before damage can occur. Our upper oil level limit doesn’t come from where you might think, we get from being car owners that we should run the oil at “full” on the dip stick. But where the upper level comes from on an airplane is take the max allowable oil consumption, which I think is just under a quart per hour on our 200 HP motors and then multiply that by the number of hours endurance of fuel you have, burning the max allowable amount of oil you can’t fall below the min safe level. ‘So most often the “full” mark on an airplanes dip stick is actually overfilled, so being overfilled it will expel the excess. So if your like most and your oil consumption is something like 1 quart in 10 hours, then maybe you don’t need to be at the max fill limit. ‘Now some will do the math and say we don’t have over 6 hours of fuel on board, so that can’t be it. But Lycoming thankfully doesn’t have a different dip stick for every model of aircraft so if 8 is a little more than needed, that’s OK.

I believe the issue is that as the old insert is removed, it’s going to mess up the threads some as it was staked in there, so it may not be possible to simply thread a new one back in. ‘ Then you still have the staking issue.

I would suggest having an A&P pull the cylinder and I’d take it to an engine shop and let people that do it all the time do it. Have them inspect the cylinder and maybe go back with new rings unless the old ones show no wear, the engine shop will know exactly how much to hone the cylinder if needed. I know you just want to screw in a new Heli-coil, but that may not be the best course of action. it can be replaced on the engine but requires tooling that your not likely to be able to get, and as easy as it is to pull a cylinder I’d just do that, it’s the safest way, safest as in least likely to cause further damage.

I think you maybe right on the sump drains, I’ve never put anything on the screen cap either, never knew to. ‘But maybe just as important, I’ve never seen anything on the threads when I removed one either and you would expect some loctite to be visable

A former Vice President used to fly into KABY often, to hunt at the Victoria Secret plantation. ‘There was little notice of a TFR it seemed and of course it grounded me, but I have been airborne and seen AF2 reporting to tower on the radio a location that they weren’t at, and tower didn’t call them on it either, I spoke to the controller and he pretty much admitted that they had a code so they didn’t report actual location over the radio. ‘Made sense to me, not often but every now and again the Secret Service would show up and set up on the roof of the plant, the plant was just outside of the western side of the airport. we had a “hole in the fence” agreement with the airport. I guess it was a good place to set up an observation post. ‘I often wondered just what it was he was hunting at the Victoria Secret plantation

Person I bought the airplane from wouldn’t add oil until close to 5, that made me nervous, so based on other aircraft I filled it to 7. In an hour and a half flight it blew it out until it got to 6, on the hour and a half flight back level still seemed to be 6. ‘So I guess the previous owner was right. If I want over 6 it seems I need to fit an oil sep, butI think I’ll just keep it at 6

Turbo’ s are really a cool thing, they make little motors, big, but without the weight. ‘It’s amazing how long ago that forced induction was developed, been over a Century I think. I lusted for one, but as I live on the East coast and only rarely climb over 10,000, I didn’t need one, plus probably a little out of my budget. You don’t run into any ITT issues running LOP?

I wasn’t aware of them, do you have any cyl head temp issues. the Braves I believe did. ‘Is it the same airframe as the 250?

Agreed, but with both you will lose some power, if that’s acceptable then sure.

Skip, ‘My concern was it seemed some didn’t know there was a procedure to be followed and especially parts to be changed in order to prevent damage to their engine to say nothing of not being airworthy, invalidating their insurence etc.. ‘I have a (D) engine, so I don’t have a dog in this “fight” really, it’s not an option for me. ‘From an efficiency / performance perspective an engine needs to run as much timing as it will tolerate, and what it will tolerate changes of course based on load and RPM and of course Octane, temperature etc. ‘Way back I guess before I was even born automobile engine manufacturers recognized this and equipped distributors with flywheel weights and springs to advance timing with RPM, then later added vacuum advance so that under light loads the distributor advanced timing. ‘Then I’d guess about 30 years ago knock sensors were added so that the engine can be operated right at the edge of detonation, which is exactly where you want to be for performance and efficiency., but without a knock sensor thst can retard timing, it’s a dangerous place to be. However of course we don’t have any of that, we rarely operate at low loads and then for only short periods so we don’t really need vacuum advance, and as we operate in relatively narrow RPM bands, our need for mechanical advance is less too, but we don’t have knock sensors, so we should have a cushion. Which brings us to why do you think Lycoming chose to go to the trouble and expense of turning the timing down from 25 degrees to 20? The SIL seems to allude to that it was done to improve longevity, so if you decide to undo the SIL understand why it was done to start with. There are gains to be achieve with more advance, but there are trade offs too, there is no free lunch

If that’s what’s happening, then your likely fine, but that’s not what I’ve read here. ‘I think some may have done as you say, but I believe some have just retimed the mags to 25 degrees, and those people need to know what that may cause

No, I don’t own a repair shop, I ran an aircraft manufacturing plant and was accountable manager for the repair station for 15 years

You don’t want to understand, besides are you guys really having your Magnetos rebuilt to old specs and changing data plates?

OK, another example, the same engine is also Type Certificated as a 160 HP engine, a person who has an aircraft with a 160 HP engine isn’t allowed to turn the prop RPM up to 2700 RPM and operate at 200 HP. But why not the TCDS says he can right?

No, it’s not the TCDS, besides placards and data plates are mandatory, if the SIl was complied with as evidenced by the data plate, the Type Certificate was changed. ‘But yes, I think calling Lycoming would be called for, just be sure to give them all the info, don’t leave out a small detail like the data plate says 20 degrees. ‘You guys seem to also ignore that the magneto retard was also changed, just ignore that? Do you understand why timing is retarded for starting?