---------------------------------------------------------- Rocket-List Digest Archive --- Total Messages Posted Mon 12/06/10: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:41 AM - Cowling intake and exit (Ernest Hale) 2. 08:11 AM - Re: Cowling intake and exit (Rob Ray) 3. 03:43 PM - Re: Cowling intake and exit (Ernest Hale) ________________________________ Message 1 _____________________________________ Time: 03:41:05 AM PST US Subject: Rocket-List: Cowling intake and exit From: Ernest Hale Is there a certain ratio that is optimum for cooling and reduction of drag between the intake and outlet for airflow over the engine? Also, any certain dimensions to the inlets and outlet? Thanks, Ernest Hale N540HB On 12/5/10 6:46 PM, "Jim Ayers" wrote: > Hi John, > > I didn't know that you've flown one of these Rocket 4 blade MT Propellers. > :-) > > Rainer, in Germany, is likely going to be limited to 2500 RPM maximum. > > An F-1 customer with the 3 blade Rocket propeller says the 4 blade MT Rocket > propeller is 2 knots sower at 4,000'. > But faster at 9,500' and 10,500'. > > John. I know this doesn't work for your typical flight. The highest altitude > you reach being when you climb to pattern altitude. :-) > > Jim Ayers > > > -----Original Message----- > From: John Harmon > To: rocket-list > Sent: Sat, Dec 4, 2010 9:32 pm > Subject: Re: Rocket-List: Best Prop for HR 2 > > But it sucks for performans > > Sent from my iPhone > > On Dec 4, 2010, at 8:31 PM, Jim Ayers wrote: > >> Hello Rainer, >> >> The quietest propeller is probably the 4 blade propeller, >> MTV-14-B/190-59b >> with a 76" diameter (190cm diameter). >> >> Regards, >> Jim Ayers >> >> >> -----Original Message----- >> From: Rainair >> To: rocket-list >> Sent: Sat, Dec 4, 2010 11:41 am >> Subject: Rocket-List: Best Prop for HR 2 >> >> > >> >> Hello, >> >> what the best prop for HR2 ? >> >> [F3YR-1ARF7693DF*1] Hartzell 3-Blade Propeller (D Twist) >> >> [M2YR-1BF/8475D4] Hartzell 2-blade Propeller >> >> [MTV-9-B/198-52] MT 3-bladed propeller >> >> [MTV-9-B-C/C-198-52] MT 3-Bladed Propeller >> >> Maybe important is the noise. Which db are the propellers ? >> >> At germany i need 75 decibel >> >> Which Prob to quiet down ? >> >> Thanks, >> Rainer >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=322285#322285 >> >> >> >> >> >> Attachments: >> >> http://forums.matronics.com//files/2010_11_19_2040_klein_205.jpg >> >> >> >> >> >> _blank>www.aeroelectric.com >> /" target=_blank>www.buildersbooks.com >> =_blank>www.homebuilthelp.com >> blank>http://www.matronics.com/contribution >> arget=_blank>http://www.matronics.com/Navigator?Rocket-List >> p://forums.matronics.com >> >> >> >> >> >> > > > _blank>www.aeroelectric.com > /" target=_blank>www.buildersbooks.com > > =_blank>www.homebuilthelp.com > blank>http://www.matronics.com/contribution > > arget=_blank>http://www.matronics.com/Navigator?Rocket-List > > p://forums.matronics.com > > > > ________________________________ Message 2 _____________________________________ Time: 08:11:38 AM PST US From: Rob Ray Subject: Re: Rocket-List: Cowling intake and exit Ernest, Johns stock HR2 cowling works extremely well for cooling and efficiency rig ht out of the box. I have always used 1:1.2 for entry/exit ratio. Remember w hen you measure the exit to consider the exhaust pipes using some of the are a. Most of my flying is in hot weather so I cut a large U in my lower cowlin g lowering my CHTs in climb below 350 and 300 in cruise and no noticeable sp eed loss. I estimate my current ratio at 1:1.5 entry/exit. I normally cruise at 20"/2350 RPM 180 knots true at 10.5 GPH using electronic ignition, GAMI i njectors 2 blade Hartzell D twist and swept wing tips. I use a larger tire f or my rough home strip yet can reach 220 knots in level flight. A truly wond erful airplane! Smokey Sent from my iPhone On Dec 6, 2010, at 6:37, Ernest Hale wrote: > Is there a certain ratio that is optimum for cooling and reduction of drag between the intake and outlet for airflow over the engine? Also, any certa in dimensions to the inlets and outlet? > > Thanks, > > Ernest Hale > N540HB > > > On 12/5/10 6:46 PM, "Jim Ayers" wrote: > > Hi John, > > I didn't know that you've flown one of these Rocket 4 blade MT Propellers. :-) > > Rainer, in Germany, is likely going to be limited to 2500 RPM maximum. > > An F-1 customer with the 3 blade Rocket propeller says the 4 blade MT Rock et propeller is 2 knots sower at 4,000'. > But faster at 9,500' and 10,500'. > > John. I know this doesn't work for your typical flight. The highest alti tude you reach being when you climb to pattern altitude. :-) > > Jim Ayers > > > -----Original Message----- > From: John Harmon > To: rocket-list > Sent: Sat, Dec 4, 2010 9:32 pm > Subject: Re: Rocket-List: Best Prop for HR 2 > > But it sucks for performans > > Sent from my iPhone > > On Dec 4, 2010, at 8:31 PM, Jim Ayers wrote: > > Hello Rainer, > > The quietest propeller is probably the 4 blade propeller, > MTV-14-B/190-59b > with a 76" diameter (190cm diameter). > > Regards, > Jim Ayers > > > -----Original Message----- > From: Rainair > To: rocket-list > Sent: Sat, Dec 4, 2010 11:41 am > Subject: Rocket-List: Best Prop for HR 2 > Reubelt@aol.com> > > > Hello, > > what the best prop for HR2 ? > > [F3YR-1ARF7693DF*1] Hartzell 3-Blade Propeller (D Twist) > > [M2YR-1BF/8475D4] Hartzell 2-blade Propeller > > [MTV-9-B/198-52] MT 3-bladed propeller > > [MTV-9-B-C/C-198-52] MT 3-Bladed Propeller > > Maybe important is the noise. Which db are the propellers ? > > At germany i need 75 decibel > > Which Prob to quiet down ? > > Thanks, > Rainer > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=322285#322285 > > > > > Attachments: > > http://forums.matronics.com//files/2010_11_19_2040_klein_205.jpg > > > > > _blank>www.aeroelectric.com > /" target=_blank>www.buildersbooks.com > =_blank>www.homebuilthelp.com > blank>http://www.matronics.com/contribution > arget=_blank>http://www.matronics.com/Navigator?Rocket-List > p://forums.matronics.com > > > > > > > > > _blank>www.aeroelectric.com > /" target=_blank>www.buildersbooks.com > =_blank>www.homebuilthelp.com > blank>http://www.matronics.com/contribution > arget=_blank>http://www.matronics.com/Navigator?Rocket-List > p://forums.matronics.com > > > onth -- > me AWESOME FREE Gifts!) > ="http://www.aeroelectric.com">http://www.aeroelectric.com> > > ef="http://www.homebuilthelp.com">http://www.homebuilthelp.com> > ://www.matronics.com/contribution > ; -Matt Dralle, List Admin. > Email Forum - > ist">http://www.matronics.com/Navigator?Rocket-List > ; - MATRONICS WEB FORUMS - > matronics.com > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= ________________________________ Message 3 _____________________________________ Time: 03:43:31 PM PST US Subject: Re: Rocket-List: Cowling intake and exit From: Ernest Hale Thanks, great information. On 12/6/10 11:08 AM, "Rob Ray" wrote: > Ernest, > > Johns stock HR2 cowling works extremely well for cooling and efficiency right > out of the box. I have always used 1:1.2 for entry/exit ratio. Remember when > you measure the exit to consider the exhaust pipes using some of the area. > Most of my flying is in hot weather so I cut a large U in my lower cowling > lowering my CHTs in climb below 350 and 300 in cruise and no noticeable speed > loss. I estimate my current ratio at 1:1.5 entry/exit. I normally cruise at > 20"/2350 RPM 180 knots true at 10.5 GPH using electronic ignition, GAMI > injectors 2 blade Hartzell D twist and swept wing tips. I use a larger tire > for my rough home strip yet can reach 220 knots in level flight. A truly > wonderful airplane! > Smokey > > Sent from my iPhone > > On Dec 6, 2010, at 6:37, Ernest Hale wrote: > >> Is there a certain ratio that is optimum for cooling and reduction of drag >> between the intake and outlet for airflow over the engine? Also, any certain >> dimensions to the inlets and outlet? >> >> Thanks, >> >> Ernest Hale >> N540HB >> >> >> On 12/5/10 6:46 PM, "Jim Ayers" > > wrote: >> >>> Hi John, >>> >>> I didn't know that you've flown one of these Rocket 4 blade MT Propellers. >>> :-) >>> >>> Rainer, in Germany, is likely going to be limited to 2500 RPM maximum. >>> >>> An F-1 customer with the 3 blade Rocket propeller says the 4 blade MT Rocket >>> propeller is 2 knots sower at 4,000'. >>> But faster at 9,500' and 10,500'. >>> >>> John. I know this doesn't work for your typical flight. The highest >>> altitude you reach being when you climb to pattern altitude. :-) >>> >>> Jim Ayers >>> >>> >>> -----Original Message----- >>> From: John Harmon > >>> To: rocket-list >> > >>> Sent: Sat, Dec 4, 2010 9:32 pm >>> Subject: Re: Rocket-List: Best Prop for HR 2 >>> >>> But it sucks for performans >>> >>> Sent from my iPhone >>> >>> On Dec 4, 2010, at 8:31 PM, Jim Ayers >> > wrote: >>> >>>> Hello Rainer, >>>> >>>> The quietest propeller is probably the 4 blade propeller, >>>> MTV-14-B/190-59b >>>> with a 76" diameter (190cm diameter). >>>> >>>> Regards, >>>> Jim Ayers >>>> >>>> >>>> -----Original Message----- >>>> From: Rainair > >>>> To: rocket-list >>> > >>>> Sent: Sat, Dec 4, 2010 11:41 am >>>> Subject: Rocket-List: Best Prop for HR 2 >>>> >>>> >>> > > >>>> >>>> Hello, >>>> >>>> what the best prop for HR2 ? >>>> >>>> [F3YR-1ARF7693DF*1] Hartzell 3-Blade Propeller (D Twist) >>>> >>>> [M2YR-1BF/8475D4] Hartzell 2-blade Propeller >>>> >>>> [MTV-9-B/198-52] MT 3-bladed propeller >>>> >>>> [MTV-9-B-C/C-198-52] MT 3-Bladed Propeller >>>> >>>> Maybe important is the noise. Which db are the propellers ? >>>> >>>> At germany i need 75 decibel >>>> >>>> Which Prob to quiet down ? >>>> >>>> Thanks, >>>> Rainer >>>> >>>> >>>> >>>> >>>> Read this topic online here: >>>> >>>> http://forums.matronics.com/viewtopic.php?p=322285#322285 >>>> >>>> >>> > >>>> >>>> >>>> >>>> >>>> Attachments: >>>> >>>> http://forums.matronics.com//files/2010_11_19_2040_klein_205.jpg >>>> >>>> >>> > >>>> >>>> >>>> >>>> >>>> _blank>www.aeroelectric.com >>> > >>>> /" target=_blank>www.buildersbooks.com >>> > >>>> =_blank>www.homebuilthelp.com >>> > >>>> blank>http://www.matronics.com/contribution >>>> >>>> arget=_blank>http://www.matronics.com/Navigator?Rocket-List >>>> >>>> p://forums.matronics.com >>>> >>>> >>>> >>>> >>>> >>>> >>> >>> >>> _blank>www.aeroelectric.com >> > >>> /" target=_blank>www.buildersbooks.com >>> >> > >>> =_blank>www.homebuilthelp.com >>> >> > >>> blank>http://www.matronics.com/contribution >>> >>> >> > >>> arget=_blank>http://www.matronics.com/Navigator?Rocket-List >>> >>> >> > >>> p://forums.matronics.com >> > >>> >>> >>> onth -- >>> me AWESOME FREE Gifts!) >>> ="http://www.aeroelectric.com">http://www.aeroelectric.com> >>> > >>> ef="http://www.homebuilthelp.com">http://www.homebuilthelp.com> >>> ://www.matronics.com/contribution >>> ; -Matt Dralle, List Admin. >>> Email Forum - >>> ist">http://www.matronics.com/Navigator?Rocket-List >>> >>> ; - MATRONICS WEB FORUMS - >>> matronics.com >>> >> >> >> ================================== >> http://www.aeroelectric.com">www.aeroelectric.com >> >>> >www.buildersbooks.com >>> > "http://www.homebuilthelp.com">www.homebuilthelp.com > > http://www.matronics.com/contribution">http://www.matronics.com/contribution > > ================================== > > href="http://www.matronics.com/Navigator?Rocket-List">http://www.matronics.com > /Navigator?Rocket-List > > ================================== > ums.matronics.com">http://forums.matronics.com > > ================================== > > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rocket-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Rocket-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rocket-list Browse Digests http://www.matronics.com/digest/rocket-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.