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#21
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RobertR237 wrote:
With all this talk of using a gas powered blower would someone please explain how that blower is going to overcome the effects of altitude and maintain the same velocity of air. It is going to drop off in power just as the engine will and at altitude its effect will be nil. Bob, they've told you already. They're going to put a turbo on the blower. Sheesh! 8*) -- ----Because I can---- http://www.ernest.isa-geek.org/ ------------------------ |
#22
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In article ,
Morgans jisumorgan@charterdotjunkdotnet wrote: "RJ Cook" wrote in message . .. If your blower has an exhaust velocity of 200 MPH the maximum pressure recovery in a diffuser would be about .7 pounds/in2, realistically about .5 lbs/in2. RJ Sounds like a good swag. How does lbs/sq.-in relate to inches of mercury (as in manifold pressure)? 30" of mercury is nominally 14.7 psi. For rough approximations just use a factor of 2 |
#23
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In article , Ernest Christley
writes: RobertR237 wrote: With all this talk of using a gas powered blower would someone please explain how that blower is going to overcome the effects of altitude and maintain the same velocity of air. It is going to drop off in power just as the engine will and at altitude its effect will be nil. Bob, they've told you already. They're going to put a turbo on the blower. Sheesh! 8*) OK, and they are going to power the turbo with what? Bob Reed www.kisbuild.r-a-reed-assoc.com (KIS Builders Site) KIS Cruiser in progress...Slow but steady progress.... "Ladies and Gentlemen, take my advice, pull down your pants and Slide on the Ice!" (M.A.S.H. Sidney Freedman) |
#24
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A teeny tiny leaf blower from the Barbie Collection.
" OK, and they are going to power the turbo with what? Bob Reed www.kisbuild.r-a-reed-assoc.com (KIS Builders Site) KIS Cruiser in progress...Slow but steady progress.... "Ladies and Gentlemen, take my advice, pull down your pants and Slide on the Ice!" (M.A.S.H. Sidney Freedman) |
#25
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" With all this talk of using a gas powered blower would someone please explain how that blower is going to overcome the effects of altitude and maintain the same velocity of air. It is going to drop off in power just as the engine will and at altitude its effect will be nil. Bob Reed "IF" you hook a leaf blower to pressurize the carb, and IF the carb was the type that could deal with the pressure without building an airtight box around it, and IF the CFM of the blower was high enough to be greater than the CFM of the engine at WOT, and IF the blower had a carb that could adjust to the altitude without going lean, and IF the blower still had a few inches of mercury pressure left over after all of that, it would supply a sensation of boost to the engine to raise the manifold pressure back up to what it was at sea level while it was buzzing along at, say, 8,000 feet. Yes, the blower wooould have lost some of its power compared to sea level, but what I would propose is turbo normalizing, so the increased power is of no use at sea level. Of course, it could be used to provide a boost for take off and such. Now, for all of the "IF"s !!! Not that many induction systems would take the added pressure without modification. Then there is the regulating valve for the turbonormalizing to deal with. I don't believe the CFM would be enough to keep up with more than a small (40 -50 HP ?) engine. No one has taken a pressure measurement from the home depot blower yet, so "I" doubt that it could produce more than one or two inches of additional pressure. (if that much) More reasons why I doubt the validity of such a Rube Goldberg setup. The superchargers that can do a good job of increasing manifold pressure use more HP than a 31 cc motor could ever produce. There is a reason the superchargers turn 80,000 RPM (some less, some more) They have to, to produce enough boost pressure. The superchargers also have very sophisticated impellers to deal with airflow at these speed, and the home depot blower does not have any sophistication. Now I put out a disclaimer. This was not any of my idea, nor would I do such a thing, but it is a semi-interesting mental exercise! How's that? :-) -- Jim in NC |
#26
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"Morgans" jisumorgan@charterdotjunkdotnet wrote in message
... snip Yes, the blower wooould have lost some of its power compared to sea level, but what I would propose is turbo normalizing, so the increased power is of no use at sea level. Of course, it could be used to provide a boost for take off and such. Now, for all of the "IF"s !!! Not that many induction systems would take the added pressure without modification. resnip But Jim. . . If the engine is just returned to sea level conditions, where is the pressure? At your given example of 8000', the manifold pressure would still be less than atmospheric pressure, would it not? Rich S. |
#27
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In article , "Morgans"
jisumorgan@charterdotjunkdotnet writes: ANOTHER leaf blower, silly! :-) -- Jim in NC And another to help that one and another to help that one and....... Bob Reed www.kisbuild.r-a-reed-assoc.com (KIS Builders Site) KIS Cruiser in progress...Slow but steady progress.... "Ladies and Gentlemen, take my advice, pull down your pants and Slide on the Ice!" (M.A.S.H. Sidney Freedman) |
#28
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In article , "Morgans"
jisumorgan@charterdotjunkdotnet writes: Now I put out a disclaimer. This was not any of my idea, nor would I do such a thing, but it is a semi-interesting mental exercise! How's that? :-) -- Jim in NC I think you hit it with the Rube Goldberg comment. Like going around the world to get across the street. Bob Reed www.kisbuild.r-a-reed-assoc.com (KIS Builders Site) KIS Cruiser in progress...Slow but steady progress.... "Ladies and Gentlemen, take my advice, pull down your pants and Slide on the Ice!" (M.A.S.H. Sidney Freedman) |
#30
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Rich
Let me try to talk in lay terms (close enough for Government work as they say) for the great unwashed masses G 1. Engine does not suck mixture into cylinder. 2. Piston comes up on exhaust stroke with exhaust valve open. At top, exhaust valve closeses and intake valve opens. As piston descends it creates a volume in the cylinder and ambient air pressure pushes mixture into cylinder to fill that volume. 3. At sea level the air pressure is 14+ psi and puts 'X' amount of mixture into cylinder. 4. At 18,000 ft (used because I remember from my Air Force altitude training) the air pressure is 7.5 psi (half the sea level pressure). 5. With half the amount of mixture pushed into cylinder you get reduced power out. 6. If you put a mechanical or turbo blower in system you can bring the amount of (fuel-air) mixture back up to the same amount in cylinder you get at sea level and will get sea level horse power. A normally aspirated engine, not designed for a blower, has a higher compression ratio than a engine designed for a blower. So if you add a blower (mech or turbo) you are limited to 30 inches of MP (sea level MP) to maintain engine longevity. How does this fit in this thread? No way will a leaf blower provide enough 'boost' to even offset the weight of installation. As some posts have said, "been a diverting subject to kick around". If anyone can make it work they can make a fortune. Big John Pilot, ROC Air Force On Mon, 7 Jul 2003 19:59:53 -0700, "Rich S." wrote: "Morgans" jisumorgan@charterdotjunkdotnet wrote in message ... snip Yes, the blower wooould have lost some of its power compared to sea level, but what I would propose is turbo normalizing, so the increased power is of no use at sea level. Of course, it could be used to provide a boost for take off and such. Now, for all of the "IF"s !!! Not that many induction systems would take the added pressure without modification. resnip But Jim. . . If the engine is just returned to sea level conditions, where is the pressure? At your given example of 8000', the manifold pressure would still be less than atmospheric pressure, would it not? Rich S. |
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