Go Back  RCU Forums > RC Airplanes > RC Warbirds and Warplanes
Reload this Page >

Byron P51 w/Q42 prop drive

Notices
RC Warbirds and Warplanes Discuss rc warbirds and warplanes in this forum.

Byron P51 w/Q42 prop drive

Old 03-04-2012, 03:30 PM
  #1  
MarvinLoomis
Thread Starter
My Feedback: (20)
 
Join Date: Jan 2008
Location: Mankato, KS
Posts: 157
Likes: 0
Received 1 Like on 1 Post
Default Byron P51 w/Q42 prop drive

I am interested in knowing what rpms any of you might be getting with Quadra 42 with prop reduction and 4 blade prop on your Byron P51's. I'm using a Fromeco TNC tach and reading on the 2 blade setting is 12875, which I assume you need to divide by 2, about 6435 or there abouts. Any feed back would be appreciated!
Old 03-04-2012, 05:09 PM
  #2  
Ram-bro
My Feedback: (101)
 
Join Date: Jan 2002
Location: Bennington, NE
Posts: 5,805
Received 2 Likes on 2 Posts
Default RE: Byron P51 w/Q42 prop drive

Havent run mine yet so will waiting with baited ear. I am guessing hat you know that at fullrpm the blades flatten out . So full RPM is not necessary or probably required.
Old 03-04-2012, 05:29 PM
  #3  
Luft-Gangster
 
Join Date: Dec 2010
Location: Pinckney, MI
Posts: 425
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Byron P51 w/Q42 prop drive

Subscribed - This has my interest too. My 1985 edition one piece wing is still in the box, Prop drive included. Currently working on a clone of it.
Attached Thumbnails Click image for larger version

Name:	Da83109.jpg
Views:	9
Size:	96.0 KB
ID:	1735059  
Old 03-04-2012, 09:26 PM
  #4  
spitmad
Senior Member
 
Join Date: Jan 2005
Location: MentoneVictoria, AUSTRALIA
Posts: 855
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Byron P51 w/Q42 prop drive

My old Byron was getting around 2800 on the ground and around 18 lbs of thrust - but the old Q42 was getting tired - reduction was 2.5:1from memory

cheers

Al
Old 03-05-2012, 07:04 AM
  #5  
masteromodels
My Feedback: (11)
 
Join Date: Apr 2002
Location: north port, FL
Posts: 723
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Byron P51 w/Q42 prop drive

I was getting around 2900 with a Quadra 40 but Byron advertised that it should get around 3200. If you have the heavier 2 piece wing heavier version you will need to get the max. for a good flight, with the one piece wing it should be lighter and you can get a goog flight with approx. 2900. I have had approx. a dozen of the Byron P-51's over the years . Great airplane .

thanks bob
Old 03-05-2012, 08:54 AM
  #6  
JeffH
My Feedback: (43)
 
Join Date: Jan 2002
Location: Carrollton, VA
Posts: 2,284
Likes: 0
Received 1 Like on 1 Post
Default RE: Byron P51 w/Q42 prop drive

Something is off on your tach or settings. 6400ish RPM at the prop would mean 16,000 at the crankshaft if the reduction ratio is 2.5:1, and still 12,800 if its 2:1. Quadras are tough, but not sure they can hang on at 16,000 RPM
Old 03-05-2012, 09:59 AM
  #7  
Dick T.
My Feedback: (243)
 
Join Date: Feb 2002
Location: Visalia, CA
Posts: 1,564
Likes: 0
Received 6 Likes on 5 Posts
Default RE: Byron P51 w/Q42 prop drive

2900-3200 rpm is the correct number you should see with a properly tuned Quadra 42. Forget about the blade flattening comments as that does not occur. A model based four blade prop looses efficiency beyond a practical RPM.

Byron originally designed the prop drive around the readily available Quadra 35 to achieve the best rpm/thrust. The later Quadra 42 and Mustang 50 (A Fuji 46) provided a little more power at similar rpm.

A lot of fellows wanted more speed from the great flying P-51 so experimented with larger or higher RPM engines. Much to their chagrin the results were disappointing as the fixed prop diameter/pitch saw the tips cavitate at higher rpm which lost thrust efficiency.

My .02
Old 03-05-2012, 11:28 AM
  #8  
MarvinLoomis
Thread Starter
My Feedback: (20)
 
Join Date: Jan 2008
Location: Mankato, KS
Posts: 157
Likes: 0
Received 1 Like on 1 Post
Default RE: Byron P51 w/Q42 prop drive

Duh, I wasn't taking the reduction 2.5:1 into consideration when using the tach!! that should be around 2900 to 3100 rpm, guess I'm about right then! Thanks guys.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.