Today's Message Index:
----------------------
1. 12:24 AM - A Special Thank You - List of Contributors (Matt Dralle)
2. 05:22 AM - Re: Turbos vs. mechanical-drive superchargers (Archie)
3. 06:15 AM - Re: Turbos vs. mechanical-drive superchargers (Healy, Joseph)
4. 07:23 AM - superchargers (Gary Casey)
5. 08:01 AM - Re: Turbos vs. mechanical-drive superchargers (James R. Cunningham)
6. 08:04 AM - Re: Turbos vs. mechanical-drive superchargers (James R. Cunningham)
7. 09:22 AM - Re: Turbos vs. mechanical-drive superchargers (Nielsenbe@aol.com)
8. 09:34 AM - Re: Turbos vs. mechanical-drive superchargers (LessDragProd@aol.com)
9. 02:39 PM - Re: Turbos vs. mechanical-drive superchargers (AI Nut)
10. 02:43 PM - Re: Turbos vs. mechanical-drive superchargers (Archie)
11. 08:46 PM - turbo vs super (andrew manzo)
12. 08:50 PM - turbo vs. super (andrew manzo)
Message 1
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| Subject: | A Special Thank You - List of Contributors |
--> Engines-List message posted by: Matt Dralle <dralle@matronics.com>
Dear Listers,
This year's List Fund Raiser was pleasantly successful and I want to thank
everyone that so generously made a Contribution to support the continued
operation and upgrade of these Lists! Below you will find the complete
list of this year's Contributors. Its these great guys that make it all
possible! All of the List members owe these special people a debt of
gratitude.
I would also like to thank Andy Gold of the Builder Bookstore (
http://www.buildersbooks.com ) for again this year providing free and
substantially discounted merchandise in support of the Fund Raiser. Andy
is a great guy and I encourage you to check out his very nice web
site. Thanks again, Andy!!
For those of you that ordered gifts with your Contribution, I will be
shipping these out over the next few weeks as the merchandise arrives and
as I can get all of the orders processed. Its quite a job so I appreciate
your patience! I hope to have everything on its way by the end of the
month if not sooner.
If you would still like to make a Contribution to support the Lists, please
feel free to do so! If you'd like to receive one of the awesome free
gifts, they will be available on the web page though the end of the
month. The Contribution web page can be found here:
http://www.matronics.com/contribution
Finally, I would like to once again sincerely thank each and everyone of
you that took the time to make a Contribution to support the Lists this
year! Your kind support greatly appreciated!
THANK YOU!
Matt Dralle
Matronics Email List Administrator
------------------- 2003 List of Contributors #1 -----------------
Adamson, Arden
Akin, Thomas
Alber, John
Alexander, Don
Alexander, George
Allender, Pat
Allison, Steven
Amick, Michael
Amundsen, Blair
Anderson, Douglas
Anderson, Edward
Andrews, Myles
Anthony, Bruce
Applefeld, Gerald
Aronson, David
Aschliman, Jim
Atkinson, Harold
Austin, Peter
Avant, David
Ayers, Jim
Babb, Tony
Bahrns, Stan
Bailey, Rick
Baker, Gary
Baker, James
Baker, Owen
Baker, Roger
Bales, Robert
Ballenger, Jim
Balmer, G
Banus, Mark
Barnett, William
Barrie, Darwin
Barter, Thomas
Basiliere, Richard
Bataller, Gary
Batte, W.Granville
Bean, James
Bean, Robert
Beard, Harley
Becker, Charles
Bell, BruceB.
Belted, Air Power, Ltd
Benham, Dallas
Benjamin, Hal
Benson, Lonn
Benson, Lonnie
Berg, Wayne
Bergeron, Daniel
Bernard, William
Berner, Walter
Bernier, Jim
Berry, Bruce
Bertelli, John
Bertrand, Carl
Berube, Bob
Bezzard, Richar
Bidle, Jerry
Bieberdorf, Roger
Bish, Dan
Blackwell, Charles
Blake, Peter
Blank, Steven
Blomgren, Jack
Bohannon, Larry
Bond, Charles
Bonsell, Edward
Booze, Greg
Borne, Chuck
Bosomworth, David
Boucher, Michel
Boulet, Paul
Bourne, Larry
Bowen, Larry
Bowhay, Eustace
Brame, Charles
Branstrom, Dan
Brasch, Glenn
Breckenridge, Bruce
Brick, John
Brogley, Michael
Brooks, Chris
Brooks, John
Brooks, Ken
Brooks, William
Broomell, Glenn
Brown, Gerald R.
Bruce, L.B.
Bruch, Stein
Brunke, Judy
Buchanan, Sam
Buchmann, Kenneth
Buess, Alfred
Bullock, Jack
Bumhoffer, Al
Burke, James
Burks, Terrell
Burns, John
Burton, Charlie
Burton, James
Burton, Ron
Butcher, James
Butcher, Ron
Butler, Francis
Butterfield, John
Buyse, Lieven
Calhoun, Ron
Calloway, Terry
Campbell, Greg
Cann, Robert
Cantrell, Jimmy
Capen, Ralph
Capra, Salvatore
Cardell, William
Carden, Richard
CarillonSr., Paul
Carney, William
Carpenter, Kenneth
Carr, David
Carroll, Randy
Carson, Rowland
Carter, David
Cary, William
Challgren, Stanley
Chambers, Ken
Champ, Nicolas
Chandler, Charles
Chandler, John
Ciolino, John
Clark, James
Clark, John
Clarkson, Scott
Clayton, James
Cliff, John
Cloud, Ralph
Clyma, Frank
Cochran, Jerry
Coffey, John
Coggins, Michael
Cole, Gary
Cole, Gerry
Colley, Larry
Colucci, Tony
Combined, Merchants
Combs, Doyle
Comer, Dave
Comfort, Gordon
Compton, Scott
Conaway, James
Condrey, Bob
Cone, James
Connell, Joseph
Conrad, Gerald
Conti, Richard
Cook, Craig
Cooley, John
Cooper, James
Corbalis, Leo
Corbette, Claude
Corder, Michael
Corner, Jim
Cotter, Tim
Cotton, David
Cottrell, Larry
Coulter, Carlin
Coursey, William
Courtney, Dean
Courtney, James
Couture, Wayne
Cribb, William
Croke, Jon
Crook, Tracy
Crosby, Harry
Crosley, Richard
Cruikshank, Bruce
D'Onofrio, John
Dalstrom, Douglas
Dalton, Bob
Daniel, Karie
Danielsen, HansJurgen
Darby, Frank
Daudt, Larry
Davenport, Jimmy
Davidson, Adam And Janet
Davidson, Jeff
Davies, Brian
Davis, Charles
Davis, Chris
Davis, Nathan
Davis, Peter
Davis, Terry
Dawson , Clif
Dawson, Garth
DeJong, Jan
Dearinger, William
Decramer, Dick
Deford, David
Denham, Bob
Dennis, Chris
Derouchey, Bill
Desmond, Richard
Devaney, Bob
Devere, Al
Diehl, Don
Diffenbaugh, Scott
Disher, John
Dixon, Thomas (Steve)
Dominy, Ken
Donaldson, Norman
Doran, Thomas
Dresden, Robert
Driscoll, Patrick
Dube, Bill
Dudley, Richard
Duffy, Russell
Dukerich, Thomas
Dumoret, Paul
Eagleston, Ron
Eckel, John
Edwards, Garland
Edwards, Joseph
Eginton, William
Eli, Robert
Ellenberger, Mike
Elliott, Andrew
Ellison, Craig
Enga, Wallace
Engh, Duncan
Enns, Dennis
Erb, Bob
Erickson, Alan
Erickson, Gerald
Erikson, Donald
Ervin, Tom
Erwin, Chip
Esterhuizen, Deon
Etherington, Al
Evans, Walt
Evenson, Roger
Fackler, Ken
Faris, Kevin
Farmer, Daniel
Fasching, John
Feldmann, StephenW.
Ferrer, Gabriel
Finley, John
Finley, Jon
Fischer, Doug
Fishe, JF
Fisher, Dru
Fisher, Michael
Fisher, Tom
Fitzpatrick, Robert
Flamini, Dennis
Flavin, John
Fleck, Joe
Foerster, James
Fogerson, Richard
Forrest, Gerald
Fox, Byron
Franz, Carl
Frazier, Ford
Frazier, Vince
Friedland, Thomas
Frizzell, Alex
Frye, Dwight
Fulgham, W.R.
Fulmer, JosephA
Fux, Franz
Gagnon, Laurent
Gagnon, Tim
Galati, Rick
Gallagher, Noel
Galley, Cy
Gantzer, Charles
Gardner, Albert
Gardner, Terrence
Garner, Mitchell
Gates, Leo
Gawronski, Brian
Gaylen Lerohl, Terminaltown
Geldermann, Dan
Genzlinger, Reade
George, William
Gerken, James
German, Mark
Gernetzke-hays, Jill
Gherardini, Don
Giacona, William
Giddens, Gerald
Gillespie, Dick
Giusti, Roberto
Glass, Roy
Golden, Shane
Gonzalez, Jorge
Goode, Richard
Goodings, John
Goodman, David
Goolsby, JamesE.
Gordon, Keith
Gott, Shelby
Goudinoff, Peter
Gowing, John
Grabb, Gary
Graber, Joel
Graham, Gary
Graham, Jim
Graham, W.Doyce
Grant, Jordan
Grebe, David
Green, Luther
Green, Roger
Greenough, Jim
Gregory, Michael
Griffin, Bill
Griffin, James
Griffin, Robert
Grosse, John
Gustafson, Aaron
Haertlein, Frank
Hagar, Steve
Haley, Gary
Hallsten, Keith
Hamer, Steve
Hamilton, William J
Hand, Chris
Hankins, Roger
Hankinson, Jimmy
Harbour, Keith
Hardaway, Mike
Harding, Joel
Harmon, John
Harrison, Nigel
Hartwig, Richard
Harvey, Dale
Hasper, Jim
Hatch, Pat
Hatcher, Edmund
Hatfield, Cecil Jr.
Hauck, JohnR
Haynes, Joel
Heath, Donald
Hefner, Jim
Heindl, Karl
Heitman, Christopher
Helming, Larry
Heritch, Ian
Herminghaus, John
Herren, Bill
Hetrick, Dale
Heykoop, John
Hibbing, William
Hill, Jeff
Hill, Ken
Hill, Stanley A
Himes, Joe
Hinrichsen, Jim
Hodgson, Mark
Hodgson, Robert
Hoffman, Carl
Hoffman, Curtis
Hoffmann, Thomas
Hohos, Charles
Holifield, Steve
Holland, Mike
Holland, Rick
Holmes, Tom
Hood, Bill
Hooper, Gerald
Hooper, Randy
Horton, Kevin
Hostetler, Donald
Howell, Pete
Howerton, Bill
Hubbard, Eugene
Hudson, Jeff
Hueltz, Wolfgang
Huff, Scott
Huft, John
Hughes, Robert
Hulen, Fred
Humbert, Robert
Humes, Hubert
Humes, Hugh
Humphrey, Roger
Hunt, Peter
Hunt, Wallace G
Hurd, James
Hurst, Kingsley
Hutchison, Tom
Hyde, David
Ice, Michael
Iddon, Richard
Irvin, Robert
Isler, Jerry
Jackson, Kevin
Jacobson, Marshall
Jannakos, Gregory
Jaussi, Curtis
Jenkins, John
Jensen, Jerry
Jewell, James
Johannsson, Johann G.
John Allen Hurn, Hurns Aircraft
Johnsen, Svein
Johnson, Bruce
Johnson, Dale
Johnson, Dennis
Johnson, Les
Johnson, Murray
Johnson, Robert
Johnston, Stephen
Jones, Eric
Joosten, Craig
Jordan, JR
Joyce, David
Jurotich, Matthew
Kahn, Steve
Kaluza, Charles
Karmy, Andrew
Kaser, Jim
Kayner, Dennis
Kellum, Mark
Kempthorne, Hal
Kent, John
Kerr, John
Kerr, Joseph
Kesterton, Donald
Kilburg, Larry
Killion, Clay
Kimsey, Thomas
Kinney, Kevin
Kirby, Graham
Kirk, Tony
Knepper, Harold
Knoll, Lynn
Kohn, Carl
Koonce, R.L.
Kosta, Michael
Kottke, Dwight
Kovac, Harold
Kramer, Ed
Krasinski, Jerzy
Krok, Peter
Krueger, Grant
Kunkel, Fred
Kuntz, Paul
Kyle, Fergus
Lahey, Jim
Laird, Dave
Laishes, Jeff
Lally, Sean
Lalonde, Bart
Landucci, Larry
Lannon, W.
Lasecki, Robert
Laurie, Kip
Laverty, Charles
Lavigne, Pat
Lawliss, James
Lawrence, Derek
Lawton, John
Ledbetter, Gene
Ledoux, Paul
Lee, Terrence
Lefler, Fabian
Lekven, Carl
Lemen, Ted
Lenton, Dennis
Leonard, Nicolas
Leslie, George
Lewis, Terry
Lewis, Tim
Licking, Larry
Lifer, Craig
Liming, Gary
Linebaugh, Jeff
Linse, Michael
Lloyd, Brian
Long, Charles
Long, Eugene
Long, Patrick
Loubert, Gary
Mack, Don
Mackay, Alex
Madden, Peter
Magsam, Del
Mahr, Egon
Mains, Ralph
Malich, Gunter
Markle, Jim
Markwell, Cleone
Marshall, F.R.
Marshall, Nigel
Marson, Thomas
Martin, Bryan
Martin, Clifford
Martin, Richard
Mason, Ron
Matteson, Robert
Maxson, Phillip
Maynor, Troy
Mcallister, Paul
Mcbride, Duncan
Mccallister, Donald
Mccallum, Bob
Mccutchan, Bruce
Mcfarland, Larry
Mcfarland, Randy
Mcfarlane, Lloyd
Mcgregor, Bruce
Mcintosh, Wayne
Mcintyre, Jay
Mckervey, Joseph
Mcleod, Neil
Mcmanus, Jim
Medeiros, Joel
Meehan, Don
Mekeel, DonaldE
Melenyzer, Charles IV
Merchant, Dean
Merrill, Dj
Messinger, Paul
Meyette, Brian
Michel, Riazuelo
Miller, David
Miller, Mark
Miller, Robert
Miller, Warren
Mills, Moe
Mills, William
Milner, Gregory
Milner, Red
Mineart, Stephen
Mitchell, HD
Moak, Ken
Montagne, Raymond
Montgomery, Dale
Moore, David
Moore, Glenn
Moore, Marbert
Moore, Warren
Morawski, Brett
Morelli, William
Morin, Mauri
Morrison, Douglas
Morrison, Malcolm
Morrow, Dan
Mosher, Doc
Mosier, Colby
Mrotzek, Dan
Muegge, James
Murphy, George
Murray, Ronald
Murrill, Robert
Myers, John
Myhra, Donald
Nascimento, Marcio
Nash, Simon
Neilsen, Richard
Nelson, William
Nicely, Vincent
Nickless, Jim
Nickson, Dennis
Nolan, Jim
North, Wheeler
Noyer, Robert
Nyman, Stephen
O'Brien, Dan
O'Donnell, David
O'Reilly, Colm
Oberst, James
Oconnor, Edward
Ohlinger, Judith
Ohlinger, Mark & Judy
Okeefe, Lawrence
Oldford, David
Olendorf, James
Orear, Jeff
Otaola, Ricardo
Ouellette, Will
Overall, Dana
Owens, Duane
Owens, Phil
Packard, Tom
Parker, Dennis
Parks, Dann
Partyka, LeeM
Patsey, Kevin
Patterson, Ron
Payne, Craig
Payne, Ron
Pelletier, Dave
Perez, M. Domenic
Perkins, Stan
Perry, John
Petaccia, Ettore
Peterson, Alex
Peterson, David
Peterson, Paul
Petri, David
Pettey, Don
Petty, Paul
Pflimlin, Paul
Pfundt, Jan
Phillips, Mark
Phillips, Russell
Pierce, Tony
Pike, Richard
Pilling, Kevin
Pinkston, Gordon
Plecenik, Michael
Pocock, Graham
Point, Jeff
Porter, Richard
Potter, Lee
Powell, Jim
Powell, Ken
Preston, Douglas
Pritchard, Roger
Proctor, Joe
Puckett, Greg
Puglise, James
Rabaut, Charles
Raby, Ron
Randolph, George
Ray, Rick
Ray, Rob
Reading, Thomas Sr
Red Dragon Aviation
Reeck, Kris And Art
Reel, David
Reese, Wayne
Reeves, William
Reimer, Curt
Render, James
Repucci, William
Reuschle, Jeffrey
Reusser, Hans-Peter
Reynolds, Richard
Rice, James
Richards, Stephen
Richardson, Colin
Richardson, Scott
Richter, Randall
Rickard, Ian
Rickman, Loy
Rigby, David
Riley, Stuart
Ringrose, Andrew
Robert, Nuckolls
Roberts, Gary
Roberts, Jeffrey
Roberts, John
Rodebush, James
Rodriguez, Paul
Roehr, Mike
Romine, Chris
Ross, Chris
Ross, William
Rourke, John
Rozendaal, Doug
Russell, E.Frank
Russell, Jack
Russell, Keith
Ryan, Mike
Sa, Carlos
Saffold, Michael
Sager, Truman
Salter, Phillip
Sanders, Andrew
Sapp, Doug
Sargent, Thomas
Satterlee, Robert
Sax, Samuel
Schaefer, Steven
Schertz, William
Schieber, Cedrdic
Schilling, Karl
Schlafly, Fred
Schlatterer, Bill
Schmidt, Gregory
Schmidt, John & Patty
Schneider, Werner
Schnitzlein, C.E.
Schoenberger, H.Robert
Schrimmer, Mark
Schroeder, Fire
Schroeder, John
Schumacher, Roger
Scott, James
Scott, Troy
Scroggs, Ross
Seaford, Jack
Seal, John
Selby, Jim, Sr. & Jr.
Selinger, Carsten
Selix, Richard
Setser, David
Settlemyer, Art
Shank, William
Shaw, Cliff
Shepherd, Dallas
Shepherd, Stanislaus
Shipley, Rob
Shipley, Walt
Shipp, Garry
Shumaker, Robert
Siegfried, Bob
Sigmon, Harvey
Silvanic, Ed
Simmons, Kendall
Simpkins, Shaun
Simpson, Randy
Sinclair, Michael
Sipp, Richard
Skelly, Brian
Sletten, Mark
Sloan, Alex
Smith, Danny L
Smith, David
Smith, Edmond
Smith, Gene
Smith, Kirk
Smith, Lloyd
Smith, Rodney
Smith, Ronald
Smith, Simon
Snedaker, Robert
Sobel, Martin
Solecki, John
Sorensen, Kent
Sorensen, Lance
Spainhower, Craig
Sparks, Timothy
Spence, Stephen
Spencer, Russell
Springer, Jerry
Staley, Dick
Starn, John H. "kabong"
Stewart, Michael
Stewart, Paul
Stewart, Shannon
Stone, Christopher
Stout, Randall
Strawn, David
Strong, Gary
Strong, Tom
Stuart, Clay
Sutterfield, Stan
Swaney, Mark
Swanson, Ronald
Swartzendruber, David
Sweeney, Timothy
Swinford, George
Szantho, JohnB.
Szarafinski, Roy
Szentmiklosi, Mark
Tarmar, Brian
Tasker, Richard
Textor, Jack
Thesee, Gilles
Thomas, Bruce
Thomas, Gummo
Thomas, Lee
Thomason, Michael
Thompson, Scott
Thomure, Randall
Thwing, Randy
Titcomb, Edward
Tomlin, Thomas
Tower, John
Tracy, Roger
Trainer, Dave
Trombley, Erich
Trost, Sebastian
Trumpfheller, Bob
Tuton, Beauford
Twigg, Alan
Tyler, George
Unruh, Brian
Unternaehrer, Rolf
Utter, Bob
Van Winkle, Dean
VanHeeswijk, Jack
VanHeuveln, Lemar
VanSchoonhoven, Peter
Vanartsdalen, Scott
Vandenbroek, Martin
Vangrunsven, Stan
Vaughan, Cye
Vaughn, John
Verdev, Victor
Vervoort-Woestenburg, Jef
Vincent, Bill
Vogt, Gary
VonRuden, Dennis
Vormbaum, John
Voss, Richard
Vranken, Karel
Wagoner, Richard
Waldal, Art B.
Walker, Dale
Walker, Tommy
Walker, Weston
Walrath, Howard
Walsh, Denis
Ward, Timothy
Washburn, Oliver
Watson, Richard
Watson, Terrence
Watters, Daniel
Weaver, Erich
Weaver, Fred
Webb, Randol
Weber, Edward
Webster, Tom
Weese, Brian
Weiler, Douglas
Whelan, Thomas
Whiteley, Kenneth
Whiteside, Eric
Whittier, Lavoy (aka Bucky)
Wigney, John
Wiley, Robert
Williams , John
Williams, Hildred
Williams, Jeff
Williams, Lawrence
Williams, Terry
Williamson, John
Willig, Louis
Wilson, Christopher
Wilson, Kelly
Wimmer, Thomas
Wingard, David
Winings, James
Winne, Edward
Woboril, David
Wood, Frank
Wood, Larry
Woods, Donald
Woods, Harold
Wright, Roy
Wsiaki, Michael
Wymer, Jerry
Yager, Jack
Yamokoski, William
Young, Rollin
Zaric, Radomir
Zheng, Andrew
Zilik, Gary
Zinkham, Ralph
Zollinger, Duane
Zuniga, Oscar
------------------- 2003 List of Contributors #1 -----------------
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email
http://www.matronics.com/ WWW | Featuring Products For Aircraft
do not archive
Message 2
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| Subject: | Re: Turbos vs. mechanical-drive superchargers |
--> Engines-List message posted by: "Archie" <archie97@earthlink.net>
> --> Engines-List message posted by: "Randy" <rnvcrothers@comcast.net>
>
> Archie,
> First I want to thank you for sharing your knowledge. This kind of
> information is not easy to come by without considerable research. I am
> going to be installing an Eggenfellner Subaru firewall forward package in
my
> RV7A, and it will have a belt driven supercharger. Testing by the
developer
> indicates that tossing a belt allows the blower to freewheel, driven by
> vacuum, and still allowing enough remaining power to maintain altitude and
> make your way to an airport and safely land. Comments?
Jan is using a small belt driven blower, and viewed it at OSH this year.
If it is loose enough, the power loss of a thrown belt may
be tolerable. (Remember, this severely constricts intake flow by losing
vacuum
in attempting to drive the rotors). I do not recall what drive belt he
incorporates,
but under low boost, should not be a problem.
Perhaps dual belts if space allows, if that would make you more comfortable.
Check with Jan on this, and if you have not spoken to him, mention my name,
it may help, inasmuch as I taught at the college he attended.
The big race engines utilize a metric Kevlar timing belt which is 5" to 6"
wide.
> I don't know what type of supercharger this one is but it comes as
> standard equip. on some Mercedes cars. It obviously has two shafts that
> rotate and they seem to turn pretty easily.
> I am hoping you might have a few minutes to take a quick look at the
web
> site, http://www.eggenfellneraircraft.com/ and take a look at the unit.
> Click on the supercharger button and you can scroll down to the pics.
> One flyer had an engine quite from a belt toss that resulted in it
being
> pushed into the housing and interfering with the cam timing belt. This
was
> an alignment and belt guide problem that has reportedly been remedied.
> Otherwise, the initial flight testing of this unit has been very positive
> with the RV7 getting speeds at altitude to make it very comparable to the
> 180-200 hp Lycoming installations. Pretty impressive given that this is an
> engine that has less than half the displacement of the Lycs.
> This particular unit has a waste gate valve that is operated by a
servo
> with a programmable controller to automatically control the amount of
boost.
> In theory it will maintain a pre-set boost limit up to it's altitude
limit,
> around 17K, via operation of a 1 1/2" butterfly valve.
> I would be very interested in your comments regarding this system.
> Thanks
> Randy
I have no personal experience with this system, so cannot honestly comment.
It does, however, sound theoretically decent.
Wonder how Jan would feel about incorporating a bypass system
in case of drive/belt failure? .........Just conjecture.
Archie
>
>
> ----- Original Message -----
> From: "Archie" <archie97@earthlink.net>
> To: <engines-list@matronics.com>
> Subject: Re: Engines-List: Turbos vs. mechanical-drive superchargers
>
>
> > --> Engines-List message posted by: "Archie" <archie97@earthlink.net>
> >
> >
> > > --> Engines-List message posted by: "Healy, Joseph" <WJH@BRPLUSA.COM>
> > >
> > > What happens if the belt breaks or the impeller seizes? Do you revert
> > > to the same capability as normally aspirated? Or, does the impeller
> > > restrict the airflow somewhat?
> > >
> > > Another question, does the supercharger operate all the time? Or, only
> > > on demand, like a turbo charger?
> > >
> > > Joe
> > Blowers,(superchargers), are positively driven. either belt or direct.
> > Drive ratio, however, is easily controlled through the belt drive.
> > Of all the turbos and rootes-type blowers we have rebuilt, or modified,
> > never had a siezure of any kind.
> > If a blower belt lets go, the engine will still continue running, but
due
> to
> > the
> > fact that now the impellers are being driven by vacuum, power loss is,
> > perhaps, in the area of 80%. Standard use blowers have clearances
> > of around .002/.004 between rotor and case, as well as end play,
> > and perhaps around .003 /.005 between rotors. (dependent on size &
mfg).
> > Racing blowers have these clearances zero'd with the use of Nylatron,
> > and Teflon. (we cannot have ANY efficiency loss).
> > Remember, the air is forced around the periphery of the housing,
> > not through it.
> > I believe that the hp loss would not be as great with the loss of a
turbo.
> > Might be an interesting test next time I have one on the dyno.
> > Archie-again
> >
> >
>
>
Message 3
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| Subject: | Turbos vs. mechanical-drive superchargers |
--> Engines-List message posted by: "Healy, Joseph" <WJH@BRPLUSA.COM>
Good job on research.
What about the first question?
What happens if the supercharger belt breaks, or the impeller bearings
seize up? Does the engine revert to the operational capability of a
normally aspirated engine? Or, does the impeller restrict the airflow
somewhat, causing the engine to quit?
Joe
-----Original Message-----
From: Gordon and Marge [mailto:gcomfo@tc3net.com]
Subject: RE: Engines-List: Turbos vs. mechanical-drive superchargers
--> Engines-List message posted by: "Gordon and Marge"
--> <gcomfo@tc3net.com>
Subject: RE: Engines-List: Turbos vs. mechanical-drive superchargers
--> Engines-List message posted by: "Healy, Joseph" <WJH@BRPLUSA.COM>
What happens if the belt breaks or the impeller seizes? Do you revert
to the same capability as normally aspirated? Or, does the impeller
restrict the airflow somewhat?
Another question, does the supercharger operate all the time? Or, only
on demand, like a turbo charger?
Joe
Listers: I know just about enough about supercharging to be dangerous,
but in reading the references from elsewhere on the list a couple of
things come to mind. Superchargers (however driven) that have internal
compression are generally more efficient than those that don't. Roots
types do not. The Lysholm does have internal compression. Centrifugals
have internal compression. The vane type, not mentioned but typified by
the Shorrock of years gone by has internal compression. Positive
displacement blowers (Roots, Lysholm, Shorrock) have output more nearly
linear in nature. Centrifugals at low rpm's have proportionately less
output than at higher. Sizeing a centrifugal would need to account for
this. As has been said, changing pulleys would match the positive
displacement unit so sizeing would perhaps be less critical. From the
operational standpoint, turbochargers require some considerations. If
the wastegate is adjustable it becomes a significant maintenance item.
If it is automatic, more so. If it is manual it must be handled with
care and skill. Polen removed the turbo setup from his special because
he couldn't solve the stability problem with the system. I believe Dick
Keyt has reestablished it using newer components. Any type of
compression heats the induction system air. The lower efficiency types
heat it more. I can't be sure, but suspect that the turbo system
transfers more heat to the charge air by conduction and radiation than
the others do because the turbine housings are close and can run red
hot.
This is a good discussion. There is undoubtedly a lot more that can be
said.
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--> Engines-List message posted by: "Gary Casey" <glcasey@adelphia.net>
Lots of good comments and questions on the subject:
<<Don't forget that a supercharger heats the incoming air considerably more
than a turbo will, according to Hugh McInness in his book,
"Turbochargers.".>>
<<I know just about enough about supercharging to be dangerous,
but in reading the references from elsewhere on the list a couple of
things come to mind. Superchargers (however driven) that have internal
compression are generally more efficient than those that don't. Roots
types do not.>>
As I think Archie mentioned, you have to separate supercharging systems that
compress the air (like centrifugal) compared to those that just "pump"
it(like the Rootes). The power required for centrifugal devices is perhaps
70% of that required for Rootes blowers and the waste all goes into heating
the inlet air. The compressor of mechanically-driven centrifugal units is
almost certainly less efficient than the compressor in turbine-driven units.
This is because the turbo's are able to run faster, in the neighborhood of
100,000 rpm, allowing a smaller diameter wheel, which has less leakage path
area. To intercool or not to intercool (actually called "after-cooling")
depends on the pressure ratio and how much heat can be extracted at what
pressure loss. Generally the dividing line is at a pressure ratio between
1.5 and 2.0. A turbonormalized engine generally flown below 20,000 feet
will usually not require an intercooler although it might be desirable.
<<Btw, is there a good source for a wastegate that will turbonormalize
versus
constant boost that is on mine now?>>
The hydraulically-actuated aircraft units will hold a constant manifold
pressure and that is what one would usually like. However, they require
even more plumbing and they weigh more and cost more. I don't know of any
that hold a "constant boost" except those in passenger cars.
<<I favor supercharger applications over turbochargers primarily due
problems
with exhaust systems and turbochargers.>>
Exactly. The two things that make turbocharging very difficult in passenger
cars are the lag (not a factor in an aircraft) and exhaust heat management.
The heat problem, though, is primarily one of getting early light-off in the
catalyst, not a factor in aircraft applications. I think the problem is all
the bend, twists and joints in the exhaust system and how to keep them
leak-tight over time. A non-trivial problem.
<<What happens if the belt breaks or the impeller seizes? Do you revert
to the same capability as normally aspirated? Or, does the impeller
restrict the airflow somewhat?>>
Good question. I think you would have to assume that the power would be
considerably less than without the restriction. You might want to install a
check valve that would allow outside air to be brought in just for that
possibility. I don't think I will, though.
<<The areo supercharger system is about 17k and 28lbs. I remember when
they were talking weight for the TSIO 550 that it was about a 100lbs
over the standard 550.>>
Most of the added weight is not in the turbo itself - I estimate that the
weight penalty is about 25 pounds for the turbo and associated plumbing.
This assumes that a muffler is required for a non-turbo application - not
always a good assumption for homebuilders, it seems.
As for the power requirement to drive a supercharger, it depends entirely on
the efficiency of the system. Also, it can't be said that a turbocharger
doesn't take power to drive it. One "free" power source, though, is the
blow-down energy in the exhaust. This is from the residual pressure of
something like 100 psi in the cylinder when the exhaust valve opens. This
pulse of energy can be harness by the turbo is there is a small enough
volume in the exhaust manifold. A 6-cylinder twin-turbo system can get
close to 50% of the power required from this pulse energy. Almost all the
inline 6-cylinder diesel engines separate the front and back sets of
cylinders and use a twin-scroll turbo housing to do the same thing. As for
the residual back pressure, it is not "minimal" as someone suggested, but is
typically close to the boost pressure generated. If you want 5 psi boost
you will have about 5 psi back pressure, less in a well-matched system.
Does the engine suffer from running with constant back pressure? They don't
seem to.
Gary Casey
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| Subject: | Re: Turbos vs. mechanical-drive superchargers |
--> Engines-List message posted by: "James R. Cunningham" <jrccea@bellsouth.net>
Gary Casey wrote:
>
>
> 1. Better overall efficiency. Turbo generally spin faster and hence are
> smaller in diameter and inherently more efficient.
Why does being smaller in diameter make them more efficient?
JimC
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| Subject: | Re: Turbos vs. mechanical-drive superchargers |
--> Engines-List message posted by: "James R. Cunningham" <jrccea@bellsouth.net>
Thereby increasing the backpressure on the engine?
AI Nut wrote:
>
> while the turbo uses only exhaust pressue.
Message 7
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| Subject: | Re: Turbos vs. mechanical-drive superchargers |
--> Engines-List message posted by: Nielsenbe@aol.com
It seems you could put a valve sort of like a wastegate between the output of
the supercharger and the motor. It would be closed when there is positive
pressure(supercharger working) then open to normal air flow if there was a
vacuum. That would at least give you normal HP if the supercharger had a
catastrophic failure.
Brad
Message 8
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| Subject: | Re: Turbos vs. mechanical-drive superchargers |
--> Engines-List message posted by: LessDragProd@aol.com
Hi All,
Since I've been flying with a supercharged aircraft engine for the last 8
years, I thought I might add to this discussion.
This supercharger is a radial compressor driven by a 7.4:1 gearbox from the
crankshaft.
It includes a clutch on the gearbox to engaged, or disengage, the
supercharger.
At 2700 RPM at sea level, I get 5 inches of boost. I didn't write down any
numbers, but I believe I get 2" of boost at 2400 RPM at 17,500'. I'll have
complete numbers when I've finished getting the performance data.
There is a 5 horsepower difference between the non supercharged engine
rating, and the supercharged engine rating with the supercharger disengaged.
So there is a 5 horsepower lose with the supercharger "disconnected", or not
pumping, or acting as a flow restrictor.
Jim Ayers
RV-3 N47RV LOM M332A engine
Message 9
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| Subject: | Re: Turbos vs. mechanical-drive superchargers |
--> Engines-List message posted by: "AI Nut" <ainut@earthlink.net>
Yes, backpressure is increased, but the effects are almost negligible in a
well designed system, as in you won't notice it due to the large increase in
available power.
AI Nut
----- Original Message -----
From: "James R. Cunningham" <jrccea@bellsouth.net>
Subject: Re: Engines-List: Turbos vs. mechanical-drive superchargers
> --> Engines-List message posted by: "James R. Cunningham"
<jrccea@bellsouth.net>
>
> Thereby increasing the backpressure on the engine?
>
> AI Nut wrote:
> >
> > while the turbo uses only exhaust pressue.
>
>
Message 10
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| Subject: | Re: Turbos vs. mechanical-drive superchargers |
--> Engines-List message posted by: "Archie" <archie97@earthlink.net>
> Gary Casey wrote:
> >
> >
> > 1. Better overall efficiency. Turbo generally spin faster and hence
are
> > smaller in diameter and inherently more efficient.
>
> Why does being smaller in diameter make them more efficient?
> JimC
One of the advantages of turbo'd engines is the fact that you can change the
characteristics and curve by mixing and matching compressor or turbine
housings. I had one fellow who did not care what I did, he insisted on
immediate boost just over idle. I gave it to him, and it was impressive,
but he was warned that it would overspeed at higher rpm.
Well, it did. And while it did not sieze, the compressor wheel rubbed
on the housing, made metal, and killed both the engine and the turbo.
BTW, the piston tops showed signs of detonation.
Archie
Message 11
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--> Engines-List message posted by: andrew manzo <andrewmanzo@yahoo.com>
This is my understanding, please inform if I am
mistaken.
I believe the turbo generates power from the exhaust
gas, while the super generates power directly from the
crankshaft.
Either one can generate significant boost, thereby
increasing engine power.
However, because the turbo is "free" power, there is
no inherent loss of fuel efficiency (at the same power
level as a normally aspirated engine). There ain't no
free lunch, so if you get more horsepower, it will
take more power, but it is not intrinsicly more
inefficient.
Because a supercharger is driven off the power output
of the engine, at the same power levels the
supercharged engine will drink more fuel (to drive the
supercharger).
With a turbocharger, damage to the exhaust system can
cascade to the intake system much more easily than
with a supercharger, since the supercharger isn't
connected to the exhaust system.
Those are the only differences that I know of that you
haven't covered...
--Andrew
__________________________________
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--> Engines-List message posted by: andrew manzo <andrewmanzo@yahoo.com>
My understanding is that the temperature increase is
proportional to the boost (boyle's law).
Therefore, at the same compression, a supercharger and
turbocharger will heat the intake air to the same
degree... with perhaps some conductive heating in the
case of the turbocharger.
However, to get the same power increase, the
supercharger will have to generate more boost (as
described in my last post), and the increased boost
means more heating of the intake air.
Does this sound right to y'all?
--Andrew
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