Lead. Plumbum. Solder. Fish sinkers. The dense metal that makes us dense. Previous PC discussions have been about how removing tetra ethyl lead from auto fuel may have had benefits. House paint no longer contains lead, but I am sure that some here have had some experiences with remediation. There is still one vehicle fuel that contains a lot of lead. General aviation folks, I'm talking to you. See the link: EHP – Leaded Aviation Gasoline and Child Blood Lead Levels, with Marie Lynn Miranda I understand that there remains only one refinery in the US making this stuff. We probably should be planning our exit from this self harm. The metal itself ain't no thang, unless you get hit on the head with a bag full of lead shot. The ions are not your friends.
Well I think the article fails to convince me. I do not know if EPA is ignoring an important issue, or that EPA knows the trajectory is down as older planes phase out. Interesting TEL is still used in planes...the inventor of the 3-way cat converter said Pb should never have been used in autos because it was so corrosive to car engines. Seems inconsistent to the layman (me). I am more worried about mercury I am thinking that's going to get worse globally due to the fossil fuel of the solid phase.
Before you were even born, you were dying. Life is a dynamic progression of dying and regenerating. Everyone ever born will die. Some poisons will have little effect in smaller quantities. Others will. The big worry about lead is massive exposure and for the very young.
Aviation engines use such old technology, it is one of the reasons why I'm putting a different engine in N19WT. Sad to say, 100 octane low-lead is a threat . . . to my spark plugs! I will be hauling high octane, lead and ethanol free gas to the airport. The plug failure does not happen instantly but when I return to my home base, I'll go back to lead-free and ethanol free. My understanding is the older engines where designed to use the high-temperature, lubricating features of lead to prevent exhaust valve erosion. These older aviation engines use: magnetos - horrible things dating from the days of Model-T carburetors - inefficient, subject to icing, manual mixture control air-cooled - inefficient, draggy, subjects engine to temperature extremes exhaust cabin heat - one crack and at high altitude, carbon monoxide poisoning So this was the first replacement engine I looked at: This is what I'm going with: liquid cooled - lower high speed drag and safe, cabin heating dual electronic ignition - uses either integral alternator or battery fuel injection - automatically adjusts mixture and eliminates carb heat oil injection - no more oil changes except for reduction drive low prop speed - 60 hp @2350 rpm vs 60 hp @3200 rpm lighter - 45 lbs less simpler mechanical - no valve camshaft or exhaust valves Bob Wilson
Ok, I watching a 3 week old cosmos last night, and learned a lot about lead. Neil Tyson said that lead gasoline additive, was the first product that used a scientist - Dr. Kehoe, to falsely reassure the public that a unsafe product was safe. Society of Toxicology On low lead gasoline for general aviation, I doubt its having much of an impact, but idk. There is just so much less fuel burned than when tetra ethyl lead was added to most of the nations gasoline. A large part of the problem is that all these old engines were designed for lead. Congresses special treatment of general aviation liability, basically the manufacturer is responsible forever, has had a chilling effect on cost of new aircraft so just about everyone learns on a old plane, made to burn 100 low lead gasoline. I learned in a cesna 152, last built in 1985. These old engines get overhauled, to keep them in service. I am sure if you created a modern ice, that was kitted to fit in the engines place, and was as reliable, and you took away the liability forever (make it 20 years?) in doing the conversion, people might swap out engines. Otherwise you will just kill general aviation if you say all the old planes are grounded, and you need to replace them with much more expensive new planes.
Midgely and Kehoe were called out above so I will add Clair Patterson. The latest issue of PNAS can tell you how much [Pb] increased from source springs to the final outlet of Roman lead pipes. Kinda interesting how they inferred millenial-old water concentrations Bob's chosen engine appears to have a lawn-mower pull start. That's one way to reduce engine weight.
Hirth 3502 also found in jet ski and snowmobiles. To improve reliability, water cooled, oil injection and fuel injection. Better still, inflight adjustable prop. Two strokes are very sensitive to the load. Too much torque and they overheat the cylinder head and burnout the piston. Too little torque and the exhaust gets too hot and welds the piston rings to the cylinder. So an inflight adjustable prop lets us keep the engine load just right and temperatures in the green. They also sell a 3-cylinder version that weighs as much as the original engine with 30 more HP but that leads to higher fuel consumption and less useful load. I am into keeping the 140 mph at less than 4 gal/hr. Bob Wilson
cool... yeah I know smaller air cooled two strokes (landscape equipment).... WOT is the only time they are really happy...
I found the parts kit that could turn most of the trainer planes into ones that could burn auto gas and higher octane unleaded avgas. flyefii.com Lycoming Fuel Injection and Ignition This kit that could be added features duel ECUs, fuel injection and electronic ignition. That should make for a more reliable modern engine. Unfortunately I don't see that you can legally add the kit to normal aircraft. They need to be experimental or homebuilt to shield the liability. Auto Fuel STC News | Airplane Fuel News I am a little surprised you are advocating a two stroke design. I don't think these should be approved for normal design, only homebuilt, experimental, and ultralight. I assume that you are in one of those categories. 4 strokes should run cooler so a radiator is not needed especially in a horizontally opposed motor that can get good airflow (porsche until the mid 90s did this with much more powerfull ices). I do agree completely that fuel injection and electronic ignition with redundancy makes for a better ice than those old designs with carbs and magnetos. I would add the other tech that has been established since is variable valve timing, variable lift. I do understand the draw of 2-strokes for lower cost and power to weight, but I would want the reduced posibilities of something going wrong along with better fuel efficiency of a 4 stroke.
Indeed! I see N19WT with the new engine as being a Goldwing with real wings and no speeding tickets! FYI, I did look at a Goldwing engine but apparently it has a weight-to-power performance problem. But I was thinking keep the gear box and put a fixed pitch prop on the end. Start with a gear ratio that supports takeoff and climb. Then reaching cruise altitude, lower the nose and shift to a higher gear ratio. . . . Bob Wilson
