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#31
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![]() Morgans wrote: "MrV" wrote in message oups.com... yes i did and that is why i posted it here asking for comments. if u notice a number of times i have stated this is just for info and if it is reasonable. I'm guessing you are just an idiot that doesn't bother to read complete post. from the replies i've received the only thing i can see wrong with my idea is 1 weight and 2 vibration everything else can be solved readily with some planning. instead of posting something stupid like this why not give reasons why i'm TOTALLY off base. The guy isn't completely on the ball but he did ask a question that has a simple and well-known answer. Car transmissions don't work in boats either. |
#32
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Hello Dan,
without saying so much i've already decided to sacrifice weight for familiarity. considering the goal is to build a 2 seat aircraft i'm pretty sure i can come in at an acceptable weight. no it will not be a feather but should be reasonable considering the engine is aluminum. i'm also trading weight for cost. the added cost of the approx equal hp engine is a multiple of the cost of my auto engine. now just quickly looking up a few things O-360-A1D 180 284 O-360-A3A 180 285 IO-360-A1A 200 320 IO-360-B1B 180 295 IMO-360-B1B 225 274 GO-480-B1D 270 432 GO-480-G1D6 295 437 IGO-480-A1B6 295 469 IGSO-480-A1F6 340 498 O-540-A1A5 250 396 O-540-B2B5 235 395 O-540-B4B5 235 395 O-540-B4B5 260 398 IO-540-A1A5 290 437 IO-540-C4B5 250 402 IO-540-D4A5 260 402 IO-540-E1A5 290 437 compared to the 200hp io360 i give up 120 lbs to a tweaked out 360 engine acutally weighs about the same as a 540 now that doesn't take into account, radiator,coolant, associated hardware, coils, alternators, etc. but some of that hardware is common and would add to the weight of either engine. i would estimate not giving up 200lbs at the same hp. I haven't started building buying or even plotting out a time frame for this project i'm jsut getting information at the moment formulating ideas, plans and such. You guys actually seem to get threatened maybe defensive what the hell. number 6 i totally agree with and well already decided i'm willing to take my risk. the thing i would fear more would be not trying. no i don't have lots of money but i have enough to do what i want. In reality the reason i chose the auto derivative is because i can INVEST loads of time equity. i can tear down and rebuild a car engine how much does that cost ? few hundred dollars in parts. now the lycoming I CAN NOT WORK ON and the parts would cost more than the auto engine probably. hell forget rebuilding i can buy a new engine for cheaper than the cost of rebuilding a lyc. I'm sorry bout the lycoming lawnmower comparison its not exactly true. the briggs and straton is cheaper to repair. hehe JUST KIDDING. the simple truth is I feel more comfortable with an auto engine. There has not been 1 airplane mechanic i've spoken too that has said any airplane piston engine is more reliable than a car engine. NOT ONE and i've spoken to atleast 2 dozen of them since before i got my license. that is not saying the car engine would be just as reliable in a plane its just saying in their respective environments the airplane engine has NOT shown any more reliability than the auto engine. also a few of the mechanics stated they may be less reliable. NOT TROLLING THAT IS WHAT THEY SAID now 1 thing i would have u know I'm not a troll i'm not trying **** anyone off just want ideas. I want to know WHY an engine with nice rubber motormounts, tranny with poly bushings between the tranny and SHORT drive shaft connected to a thrustbearing secured to the frame would not live. i'll state the conditions more clearly. engine and tranny will run at a MAX OF 65% rated power. more likely 60% they will not under any condition run above this power range. IN other words at FULL OUT throttle wide open thign will spin at 3500 rpm if that. truthfully the idea of using the tranny as reduction unit was just that an idea but now i want someone to explain to me where it will fail given proper mounting and isolation. |
#33
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![]() "MrV" wrote in message oups.com... yes i did and that is why i posted it here asking for comments. if u notice a number of times i have stated this is just for info and if it is reasonable. I'm guessing you are just an idiot that doesn't bother to read complete post. from the replies i've received the only thing i can see wrong with my idea is 1 weight and 2 vibration everything else can be solved readily with some planning. instead of posting something stupid like this why not give reasons why i'm TOTALLY off base. I guess you can't read a whole post, either. I said before, that there are so many problems, there is no good place to start the shooting down process. Why don't YOU start by doing your homework, and do some research about what is being done out there, and why some things are NOT being done. Hint: If you start _without_ vibration and WEIGHT being solved, you can't start. EVERYTHING will change, solving those problems. Still haven't found the "shift" key, I see. It makes you look like a child, or a lazy person. Maybe both. -- Jim in NC |
#34
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![]() MrV wrote: Hello Dan, no i don't have lots of money but i have enough to do what i want. In reality the reason i chose the auto derivative is because i can INVEST loads of time equity. i can tear down and rebuild a car engine how much does that cost ? few hundred dollars in parts. now the lycoming I CAN NOT WORK ON and the parts would cost more than the auto engine probably. hell forget rebuilding i can buy a new engine for cheaper than the cost of rebuilding a lyc. I'm sorry bout the lycoming lawnmower comparison its not exactly true. the briggs and straton is cheaper to repair. hehe JUST KIDDING. the simple truth is I feel more comfortable with an auto engine. There has not been 1 airplane mechanic i've spoken too that has said any airplane piston engine is more reliable than a car engine. NOT ONE and i've spoken to atleast 2 dozen of them since before i got my license. that is not saying the car engine would be just as reliable in a plane its just saying in their respective environments the airplane engine has NOT shown any more reliability than the auto engine. also a few of the mechanics stated they may be less reliable. NOT TROLLING THAT IS WHAT THEY SAID now 1 thing i would have u know I'm not a troll i'm not trying **** anyone off just want ideas. I want to know WHY an engine with nice rubber motormounts, tranny with poly bushings between the tranny and SHORT drive shaft connected to a thrustbearing secured to the frame would not live. i'll state the conditions more clearly. Of course you could work on a Lycoming. There's no high magic, you need a few tools like cylinder base wrenches and so forth, but if you have the brains to work on any engine you can work on a Lyc, a Ranger, a Menasco, a Napier Lion, an OXX-6, or any other museum piece. All these engines have a place, like antique airplane fly-ins and, umm, museums. (The last running Napier Lion is in a car. Go figure.) First off though, you haven't done your homework. You didn't study the available literature, and the successful projects that have flown. Second, you should build an existing design first with an existing engine setup. Several are available in varying states of compleness. After you succeed at that, the piece de resistance can come later. Third, you have a few Olde Pharts here. Some of them have advanced WSE and some have apparently died, like Backdoor BoB, or whatever his name was. Second, |
#35
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In article .com,
"MrV" wrote: now that doesn't take into account, radiator,coolant, You're going to put a radiator in a pusher? (Bret, wouldn't this qualify as "clean sheet of paper" engineering? Or has this been done already?) |
#36
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okay now from listening to u guys i've done just a bit of research.
check out http://www.epi-eng.com took a bit but i read most of this site. From reading the epi site i've come up a couple new ideas. instead of a single thrust bearing how about a double bearing system 1 for thrust and 1 to transfer gyro forces to frame and to isolate the prop from the engine vibs . kinda like prop-|-|-engine. Also consider the system will still have the flywheel in place. actually i'd prob just buy a psru from epi considering they've already created one specifically for the engine i plan to use. .. |
#37
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the simple truth is I feel more comfortable with an auto engine. There
has not been 1 airplane mechanic i've spoken too that has said any airplane piston engine is more reliable than a car engine. NOT ONE and i've spoken to atleast 2 dozen of them since before i got my license. that is not saying the car engine would be just as reliable in a plane its just saying in their respective environments the airplane engine has NOT shown any more reliability than the auto engine. I'm a mechanic, and I'll tell you: the engine/transmission setup you are proposing is far less reliable than an aircraft engine. Most direct-drive engine problems are electrical, and that means ignition failure. Many auto conversions are single-ignition, relying on the battery/alternator setup for power, and there have been problems. Adding a second similar system doesn't increse safety much, since it relies on the same power source and usually fires the same set of plugs. Aircraft magnetos are a little less reliable than the auto's system, but there are two of them, and two sets of spark plugs, making the engine MUCH more reliable from the ignition standpoint. That transmission will be heavy and will fail. It can't take the high power levels for extended periods. When I put a Chev 283 in my boat, I used a Warner marine transmission; it weighed about twice what the chevy car trans had, and had only forward-neutral-reverse. It also had a big oil cooler to keep it alive. Your weight will be higher than estimated. These things have a way of doing that. I have heard of several projects that came off way too heavy to ever fly. Even the standard kit or plans-built airplane usually ends up havier than forecast. Dan |
#38
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#39
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Hey Dan good info. Question what is considered "High Load"? My plan
is to run the system at a max of 65%. from personal exp i know running my auto at 5k rpm will shorten its life but i also know that it'll run damn near forever at 3500 rpm. One thing i had planned on was creating a duplicate electrical system atleast up to the engine managment comp maybe even duel comps with isolated elect buss. I would like to maintain the chevy ems but have contemplated an after market. one thing i really really like about the chevy ems is that when something goes bad say u lose a coil it adjust and keeps running. My car lost one of the coils at about 60k miles the only way i knew it was a loss of power and the service engine light being on. I drove around like that for about a month before the service guy told me the problem and replaced it. (side note -- never ever let midas do this 700$ repair for 10 mins of work and 100 bucks in parts) I guess it may be a possible to have duplicate coil packs but just from the examination of my auto that may be a bit difficult. |
#40
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MrV wrote:
Hey Dan good info. Question what is considered "High Load"? My plan is to run the system at a max of 65%. from personal exp i know running my auto at 5k rpm will shorten its life but i also know that it'll run damn near forever at 3500 rpm. Question for you: What torque/rpm setting do you use to arrive at 65%? Take a generic direct drive aero engine, and some ballpark figures for the sake of an example to explain my question: Let's say cruise flight is at 7,000 feet, wide open throttle, and near max rpm. Max power is at sea level, wide open throttle, max rpm. More numbers- let's say this cruise setting translates to 2,500rpm at 24". Max power is 2700rpm and 29". Use some simple math and simplifying assumptions (flat torque-rpm curve) about the engine to calculate "percent" power... 2500/2700 x 24/29 = 77% (pretty close to the popular definition of cruise power, 75%) Anyway, just curious what numbers you use to get 65%. Note I don't have any issue with the figure, I realize it's an arbitrary decision in performance/reliability tradeoff. By the way, the first hit on Google for keywords 'chevy ls2 rpm horspower' gives 400hp at 5200rpm. |
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