Return-Path: Sender: (Marvin Kaye) To: lml Date: Mon, 14 Apr 2003 09:49:10 -0400 Message-ID: X-Original-Return-Path: Received: from imo-r03.mx.aol.com ([152.163.225.99] verified) by logan.com (CommuniGate Pro SMTP 4.1b3) with ESMTP id 2121964 for lml@lancaironline.net; Mon, 14 Apr 2003 09:35:21 -0400 Received: from RicArgente@cs.com by imo-r03.mx.aol.com (mail_out_v34.21.) id q.167.1ec00272 (3842) for ; Mon, 14 Apr 2003 09:35:09 -0400 (EDT) From: RicArgente@cs.com X-Original-Message-ID: <167.1ec00272.2bcc130d@cs.com> X-Original-Date: Mon, 14 Apr 2003 09:35:09 EDT Subject: Re: [LML] LNC2 speed "trick" X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_167.1ec00272.2bcc130d_boundary" X-Mailer: 6.0 sub 10511 --part1_167.1ec00272.2bcc130d_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 04/14/2003 12:38:14 AM Eastern Daylight Time, LHenney@dellepro.com writes: > I turn the Hartzell 68" prop at 2920 RPM Larry, Thanks for publishing your speed 'tricks'. It was very interesting reading. A few years ago, Lancair did compartive flight testing between the 68" and the 72" props (I have the 72") and various altitudes and power settings. For those interested in the results, here it is: 72-inch 68-inch Cruise@7,500 Ft (mph) (knots) (mph) (knots) 2500rpm/23.9" Hg 233 203 237 206 2500rpm/21.8" Hg 221 192 228 198 2500rpm/19.5" Hg 210 183 211 183 Cruise@12,500 Ft 2500rpm/19.5" Hg 227 197 233 203 2400rpm/19.5" Hg 223 194 227 197 2300rpm/19.5" Hg 221 192 228 198 2200rpm/19.5" Hg - 224 195 Climb: (1,000' climb from 4000 MSL) IAS 72-Inch 68-Inch (mph) (Knots) (fpm) 80 70 1670 1430 95 83 1760 1460 120 104 1880 1670 140 122 1765 1670 As the results above indicate, the 68-inch prop has a 3 to 6 knot advantage over the 72-inch, but shows a lower climb rate. Hmmm, let's see now, if I switch to the 68-inch prop (3 knots), run at 2,900 rpm (2 knots), get hi-comp pistons (3 knots), that make my speed number (209 to 217 knots) a bit less of a 'minimal' racer, eh? -grease PS Are the Sun 100 race results published anywhere on the internet? --part1_167.1ec00272.2bcc130d_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable In a message dated 04/14/= 2003 12:38:14 AM Eastern Daylight Time, LHenney@dellepro.com writes:

&n= bsp;I turn the Hartzell 68" prop at 2920 RPM

Larry,

Thanks for publishing your speed 'tricks'. It was very interesting= reading.

A few years ago, Lancair did compartive flight testing between the 68" a= nd the 72" props (I have the 72") and various altitudes and power settings.=20= For those interested in the results, here it is:
=20
           &= nbsp;            = ;    72-inch       = ;       68-inch =20
Cruise@7,500 Ft (mph) (knots) (mph) (knots)
2500rpm/23.9" Hg 233 203 237 2= 06
2500rpm/21.8" Hg 221 192 228 1= 98
2500rpm/19.5" Hg 210 183 211 1= 83

Cruise@12,500 Ft =20
2500rpm/19.5" Hg 227 197 233 2= 03
2400rpm/19.5" Hg 223 194 227 1= 97
2300rpm/19.5" Hg 221 192 228 1= 98
2200rpm/19.5" Hg -       &n= bsp;      224 195

Climb: (1,000' climb from 4000 MSL) =20
       IAS    &n= bsp;72-Inch 68-Inch
(mph) (Knots)          &= nbsp;  (fpm) =20
80 70        &nb= sp;   1670 1430
95 83        &nb= sp;   1760 1460
120 104           = ; 1880 1670
140 122           = ; 1765 1670

As the results above indicate, the 68-inch prop has a 3 to 6 knot advant= age over the 72-inch, but shows a lower climb rate.

Hmmm, let's see now, if I switch to the 68-inch prop (3 knots), run at 2= ,900 rpm (2 knots), get hi-comp pistons (3 knots), that make my=20= speed number (209 to 217 knots) a bit less of a 'minimal' racer, eh?

-grease

PS Are the Sun 100 race results published anywhere on the internet= ? --part1_167.1ec00272.2bcc130d_boundary--