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#1
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![]() Every once in a while i see someone wondering if an auto conversion will make it to 2,000 hours before rebuild.
MMMMM - first of all, most lycomings are RATED at 2,000 hours and most continentals are rated at 1400 hours. I personally know of a commercial operator that, because of operating history, was able to increase his TBO to 2900 hours on his continentals. Don't have the stats, but it is common knowledge that many airplane engines do not make it to TBO, many needing a top end. On the automotive conversion side, a BIG reason that most want to go conversion is rebuild cost - a mere pittance compared to rebuildin a certificated engine. So in my book, ifin the auto conversion engines are makin it 1,000 hours - good to go
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Enjoy the build,njut av byggandet, godere il costruire, nyd bygningen, geniesse den Bau, apolafse tin kataskevi, disfrute la construcción, curta a construção, Pidä hauskaa rakentamisen parissa, bouw lekker,uživaj grade?inaslajdaites postroikoi, geniet die bou dust maker of wood, fiberglass, foam dust, metal bits and one day a Cozy will pop out and swiftly whisk me from meeting old friends and family to adventures throughout the world |
#2
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![]() Quote:
NEW rotary woulda been $5k. PLan on 180 hp, Mistral says 190 hp on normally aspirated. (they also sell 30k complete package, and are pursuing certification) controller/monitor: $2k PSRU: $2.8k Incidentals such as radiators and other things air cooled engines need: Less than $1k. Prop, alternator, oil coolers and other things that both air cooled and water cooled engines need are not included in that figure. Thats a NEW package buy in of approx $10-11k US Dollars. New MISTRAL with PSRU is $30K USD So.. whats the cost of a NEW lycosaurus? in the 180 hp range? the 200 hp range? If You go mistral, its near break even til the first rebuild. If you roll your own, you are in the game for 30-50% of the ante. I could rebuild the engine every 150 hours and still cost the same as a NEW lycosaurus that makes it to TBO. And if I do it right, I wont be rebuilding ANYTHING anytime soon. I can assure you, it wasnt JUST cheap rebuilds that motivated us. Dave |
#3
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![]() Quote:
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Enjoy the build,njut av byggandet, godere il costruire, nyd bygningen, geniesse den Bau, apolafse tin kataskevi, disfrute la construcción, curta a construção, Pidä hauskaa rakentamisen parissa, bouw lekker,uživaj grade?inaslajdaites postroikoi, geniet die bou dust maker of wood, fiberglass, foam dust, metal bits and one day a Cozy will pop out and swiftly whisk me from meeting old friends and family to adventures throughout the world |
#4
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![]() Both of you make very valid observations. One of the questions I would have about certified engines is how do they make a recommended TBO? Is this based on soley on empirical data?
Conversions installations, with very few exceptions (Eggenfellers, for example), are unique that follow some general guidelines generated by a combination of theorical or empirical data. This makes, in my opinion, TBO speculative. That said a SWAG TBO is probably good enough since the rebuild costs are so low. Heck you could put together a complete engine core ready to go for a pittance of the cost of a certified engine's TBO. For non-certs the major drawback has been reliability. It would be hard to believe that Mazda or Subaru is going to loose much sleep over an experimental aircraft crash involving one of its engines, but I will bet Lycoming or Continental will.
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Nathan Gifford Tickfaw, LA USA Cozy Mk IV Plans Set 1330 Better Still --> Chapter 9 |
#5
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![]() Stupid sube question - RV6guy - you gonna replace pistons and such when you rebuild or just replace as needed?
what do you figure a 4 and 6 cylendar rebuild will cost?
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Enjoy the build,njut av byggandet, godere il costruire, nyd bygningen, geniesse den Bau, apolafse tin kataskevi, disfrute la construcción, curta a construção, Pidä hauskaa rakentamisen parissa, bouw lekker,uživaj grade?inaslajdaites postroikoi, geniet die bou dust maker of wood, fiberglass, foam dust, metal bits and one day a Cozy will pop out and swiftly whisk me from meeting old friends and family to adventures throughout the world |
#6
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![]() Quote:
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~Nathan |
#7
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![]() What about when you get to TBO. This is another important consideration. Check out what these people have to say. (URL is Below) I just had my engine done by them.
I got new cylinders, pistons, rings, bearings, intake and exhaust valves,seals, all the AD's, New slick mags, new wires, rebuilt carb and rebuilt starter with their respetive AD's and pick up and delivery. It is not to "within" limits but to new limits. I have a O-235-L2C and the price was $11,700 Even if you get to TBO, the rebuild can be anything within limits, not always new limits. If you shop you can get a certified engine O-320 or O-360 from 10K to 13K with 1000 hours on it. If you fly 100 hours per year you get 10 years out of it if was in decent shape in the first place. The O 360 rebuild at PGA was about 13K. That means you would have to put $108/month away for the impending cost of the rebuild. http://www.poplargroveairmotive.com/Overhaul/facts.html http://www.poplargroveairmotive.com/...aoverhaul.html If my memory serves correctly either way the TBO is now in the experimental catagory and can be whatever makes you feel safe. I could be mistaken on the last point but that is another discussion. Another thing. My engine was out of a storm damaged 1978 Cessna 152. 27 years later I could still get parts for it. |
#8
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![]() Quote:
Turbines, Part 121, 135, etc have different requirements that have to be met.
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~Nathan |
#9
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![]() Quote:
I think rings and cylinders will take more of a beating due to the long term, high continuous gas loads driving an aircraft along at high power settings. My Subaru EJ22T had 26,000 miles on it when I got it. Everything was mint inside. No detectable wear on anything. I reused the bearings in their original locations. I installed new forged JE pistons built to my specs and rebored the cylinders for the correct clearance. Ring end gaps were carefully set to my specs. Reground the valve faces and seats. Exhaust seats on turbo engines, I make wider than stock for higher heat transfer rates. Other than that, all stock. All engines have some weak link in racing. Once this is known and either checked frequently or fixed with a design or part change, reliability can be expected within a given lifespan. There really is no excuse for failures if this is so in a race engine. I told a couple of customers when they'd have to do teardowns and checks on certain components. Both ignored my advice and both eventually suffered catastrophic failures at 1.5 to 2.5 times the projected lifespan. No surprise there. It's not if, it's when. On any rebuild, all parts have to be measured. If they are close to being out of spec, they should be replaced. Typically on turbocharged engines, the top piston ring lands take a beating from the high temps and gas loading. A good piston and ring choice can mitigate this as does Mobil 1 oil. I've gone up to 6 rebuilds on the same pistons and bearings on one very high output engine before the block was beyond specs. The trick is, that all these parts are pennies compared to cert engine parts so the rebuilds are usually less than $2000 even with new pistons if you DIY. ![]() The EJ Subes seem to easily go 1000-1200 hours between overhauls. Some of the Egg units are over 1500 now with zero oil consumption and good compression. It would seem than many of these will easily exceed 2000 hours and judging by wear trends may even exceed 3000 hours. Only time will tell. |
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