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#21
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The engine is going to be considerably hotter running at 65% at 15,000' than
at 5,000'. Mike MU-2 "Big John" wrote in message ... Peter Let me pose some what if's. I have a turbo normalized engine. Going cross country I cruise at 5K and 65% power. Turbo is off. I then go on another XC and cruise at 15K and use turbo to pull 65%. Are you saying that cruising at 65% with turbo on will do more damage to engine than pulling 65% with turbo off?????? I'll agree that the turbo will require more maintenance it used but engine no if run within engine manufacturers specs. Big John `````````````````````````````````````````````````` ```````````````````````````````` On Mon, 16 May 2005 14:36:27 -0700, "Peter Duniho" wrote: "Robert M. Gary" wrote in message groups.com... [...] In the Mooney community is mostly agreed that a 201 (non turbo) will give you twice the cylinder life as a 231 (turbo). Other wear factors (heat, less air over the cylinders) are the same for turbo-norm vs. regular turbo. The only difference I can see is the "idiot" difference of accidently over boosting. Exactly what Mike said. Any kind of turbocharging will shorten the lifespan of a given engine. The whole point of a turbocharger, even turbo-normalizing, is to allow the engine to produce more power in certain situations than it otherwise would have. More power means more wear and tear. Turbo-normalizing isn't as hard on an engine as "non-normalized" turbocharging, but it still makes more power some of the time than the same engine without a turbocharger would (and on top of that, the increase in power is in situations when the air is less dense, making cooling more difficult...again, more heat, more wear). That time spent making more power results in more wear and tear. Pete |
#22
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Big John wrote:
Peter Let me pose some what if's. I have a turbo normalized engine. Going cross country I cruise at 5K and 65% power. Turbo is off. I then go on another XC and cruise at 15K and use turbo to pull 65%. Are you saying that cruising at 65% with turbo on will do more damage to engine than pulling 65% with turbo off?????? I'll agree that the turbo will require more maintenance it used but engine no if run within engine manufacturers specs. Possibly, because the air is much thinner at 15K than 5K and thus pulling the same power from the engine will cause it to run much hotter. Depending on how much hotter it runs, wear can be accelerated and you would certainly want to change your oil more often and run a semi-syn oil. Matt |
#23
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That is my point. There does not appear to be any reason for anyone to
ever buy a turbo norm system. The engine runs just as hot/hard, etc at altitude with a turbo norm vs. a regular turbo. The turbo norm companies try to trick people into thinking that putting a turbo norm on your engine will not wear your engine any more than normal asp because you never get over 30". However, the argument appears to be worthless, in truth a turbo norm wears out your engine just as fast as a regular turbo. -Robert |
#24
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But runnnig your engine at 30" at 15,000 feet is MUCH harder on the
engine than running 30" at 5,000 feet. The engine runs hotter and harder. -Robert |
#25
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"Robert M. Gary" wrote in message
oups.com... That is my point. Huh? There does not appear to be any reason for anyone to ever buy a turbo norm system. Why not? The engine runs just as hot/hard, etc at altitude with a turbo norm vs. a regular turbo. No, it does not. With a regular turbo, the engine would run even hotter and harder at altitude. The turbo norm companies try to trick people into thinking that putting a turbo norm on your engine will not wear your engine any more than normal asp because you never get over 30". Which "turbo norm company" has made that statement? However, the argument appears to be worthless, in truth a turbo norm wears out your engine just as fast as a regular turbo. No, it doesn't. I find it bizarre that you are complaining about statements made regarding turbo-normalization compared to normally aspirated, but keep insisting on making (incorrect) comparisons between turbo-normalization and regular turbo-charging. The two are not relevant to each other. If there's a specific statement from a "turbo norm company" that you take issue with, let's see that statement and we can talk about it. Until then, your inability to express your own discontent with any sort of consistency makes it hard to even understand what your complaint is, never mind help you understand what's wrong about it (assuming there is something wrong with it). Pete |
#26
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Mike
Have you ever seen a flat 4/6 run hot at any altitude at 65% power? If your at 15K and engine is running 'hot' what do you do? Increase IAS, open cowel flaps or reduce power. My Mooney was as tightly coweled as anything I ever saw. On climb out after TO I used 120 mph to keep engine cool. It took longer to get to altitude but I made up for it by a long shallow descent at max IAS at destination. No shock cooling doing this. Block time was the same as Tech Order climb and dump for descent. When are you going to get out of that widow maker ) Big John `````````````````````````````````````````````````` `````````````` On Wed, 18 May 2005 19:22:04 GMT, "Mike Rapoport" wrote: The engine is going to be considerably hotter running at 65% at 15,000' than at 5,000'. Mike MU-2 "Big John" wrote in message .. . Peter Let me pose some what if's. I have a turbo normalized engine. Going cross country I cruise at 5K and 65% power. Turbo is off. I then go on another XC and cruise at 15K and use turbo to pull 65%. Are you saying that cruising at 65% with turbo on will do more damage to engine than pulling 65% with turbo off?????? I'll agree that the turbo will require more maintenance it used but engine no if run within engine manufacturers specs. Big John `````````````````````````````````````````````````` ```````````````````````````````` On Mon, 16 May 2005 14:36:27 -0700, "Peter Duniho" wrote: "Robert M. Gary" wrote in message egroups.com... [...] In the Mooney community is mostly agreed that a 201 (non turbo) will give you twice the cylinder life as a 231 (turbo). Other wear factors (heat, less air over the cylinders) are the same for turbo-norm vs. regular turbo. The only difference I can see is the "idiot" difference of accidently over boosting. Exactly what Mike said. Any kind of turbocharging will shorten the lifespan of a given engine. The whole point of a turbocharger, even turbo-normalizing, is to allow the engine to produce more power in certain situations than it otherwise would have. More power means more wear and tear. Turbo-normalizing isn't as hard on an engine as "non-normalized" turbocharging, but it still makes more power some of the time than the same engine without a turbocharger would (and on top of that, the increase in power is in situations when the air is less dense, making cooling more difficult...again, more heat, more wear). That time spent making more power results in more wear and tear. Pete |
#27
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"Big John" wrote in message
... [...] I have a turbo normalized engine. Going cross country I cruise at 5K and 65% power. Turbo is off. I then go on another XC and cruise at 15K and use turbo to pull 65%. Are you saying that cruising at 65% with turbo on will do more damage to engine than pulling 65% with turbo off?????? You'll have to define "more damage". Yes, as Mike said there are at least a couple of issues that cause the same power to result in hotter operating temperatures at higher altitudes than at lower. However, the increased temperatures may or may not result in damage, or even increased wear. There's just the *potential* for increase in wear. However, as far as I know, increased operating temperatures almost always translate into decreased lifetime. I'll agree that the turbo will require more maintenance it used but engine no if run within engine manufacturers specs. I'm having a hard time parsing that sentence. IMHO, the bottom line here is that no one ought to expect a turbocharged engine, turbonormalized or not, to require just as little maintenance as a normally aspirated engine. But that's not an indictment of turbocharging. It just means that with the significant benefit of turbo-charging, there comes a cost. As it happens, I feel that turbonormalization strikes a pretty good compromise. Even more so when the installation isn't strictly "normalization". Again, looking at my airplane as an example, the turbocharged installation has 20hp more than the normally-aspirated version. This isn't a lot of extra power, but it's enough to help compensate for the extra weight of the turbocharger and give a little extra "oomph", without significantly increasing the wear on the engine due to the power the engine is making. Yes, at altitude the engine runs hotter. It runs hotter than it would at the same power setting down low, and it certainly runs hotter than a normally-aspirated engine would at that altitude. But guess what? I go a lot faster too, to the tune of about 20 knots compared to what my best cruise speed at 8000' would be without a turbo. It's really nice being able to maintain cruise power up into the oxygen altitudes, and I get a nice true-airspeed boost as a result. As long as I'm not bucking a big headwind, it's all good. In addition, mountain flying is less dangerous. Ground speeds are still higher, and the prop can't convert the horsepower to quite as much thrust as it would at sea-level. But it's not nearly as much a reduction as I'd get without the turbocharger. Acceleration, even at max gross, is good as is the climb rate (handy when you are surrounded by high terrain ). What's the cost? Well, I can't speak for the average. But in my own case, I have had a "mini top overhaul" (replaced one piston, due to leaking rings on that piston, causing erosion of the piston head), and have had to replace all of the exhaust valves and guides. I don't even know that this was due to the turbo-charger, but certainly it seems that the extra heat may have accelerated the wear, if not caused it entirely. The turbo-charger itself has been remarkably maintenance free, especially considering it uses an automatic wastegate. As an added bonus, it acts as a muffler, so my airplane is somewhat quieter than similar-powered airplanes, and noticeably quieter than the normally-aspirated version. Since it's a seaplane, and since I do often operate in "well-habited" areas, this is a nice side-benefit. There is, of course, the acquisition cost too. Turbocharged airplanes seem to run anywhere from $20-50K more than the normally-aspirated equivalent. But given that airplanes are intentionally operated at above-sea-level altitudes on a regular basis, I can't imagine owning another airplane without turbocharging. Turbonormalized or otherwise. IMHO, it's much more important to look at the maintenance history for a given installation, than to try to paint all turbocharged aircraft with the same brush. The effects of turbocharging have as much to do with how the manufacturer recommends the engine is operated and the design of the installation (especially with respect to cooling), as they do with generalities about all turbochargers broadly. Pete |
#28
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"Robert M. Gary" wrote in message oups.com... That is my point. There does not appear to be any reason for anyone to ever buy a turbo norm system. The engine runs just as hot/hard, etc at altitude with a turbo norm vs. a regular turbo. The turbo norm companies try to trick people into thinking that putting a turbo norm on your engine will not wear your engine any more than normal asp because you never get over 30". However, the argument appears to be worthless, in truth a turbo norm wears out your engine just as fast as a regular turbo. -Robert Not true, if the engine is cooled with adequite airflow. If you have an instalation that is marginal at cooling a non turbo instalation at altitude, and you put a turbo norm engine in it, yes, it will overheat and wear out. Put enough air across it, and it will stay cool at 65%. There are all kinds of flying examples to support this. What is the difference at flying a well cooled turbo norm engine at 12,000ft at 65%, and at flying it at sea level and 65%, if you keep it cool ? -- Jim in NC |
#29
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"Robert M. Gary" wrote in message oups.com... That is my point. There does not appear to be any reason for anyone to ever buy a turbo norm system. The engine runs just as hot/hard, etc at altitude with a turbo norm vs. a regular turbo. True, but you don't kick a turbo norm's ass running it at 40 inches at sea level, like you run a regular turbo. Ultimate HP production is the killer, if they both are kept cool. -- Jim in NC |
#30
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"Robert M. Gary" wrote in message ups.com... But runnnig your engine at 30" at 15,000 feet is MUCH harder on the engine than running 30" at 5,000 feet. The engine runs hotter and harder. -Robert 65% is 65%, is 65%. All equal, no harder. That is the point of turbo norm. The engine has not got a clue how high it is. MP is the same at sea level or 15 thousand. The only argument is the temp. Keep it cool. it is not that hard, nor is it rocket science. -- Jim in NC |
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