Q-500 Racing Discuss AMA 428, AMA 424, and any other variants of Quickie 500 racing

OS .25 FX Turning 22,500 RPM

Reply

Old 04-01-2009, 03:22 PM
  #1  
BobHH
Thread Starter
My Feedback: (18)
 
Join Date: Jan 2002
Location: Holly Springs, NC
Posts: 1,861
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default OS .25 FX Turning 22,500 RPM

Well, I’ve seen it all. Had a guy at the field this weekend doing some testing on his combat plane. He’s running a stock OS .25FX with a APC 8x6 prop. He was turning around 17,500 when I approached him. Then he pulled out a rare earth magnet and bolted it across the bottom of the crankcase using the same mounting bolts from the engine lugs. I thought he was adding some nose weight. Upon re-cranking his engine and leaning it out his RPM had jumped to 21,750 and he could pinch 22,500!!! I was a bit skeptical so I picked up my digital tach and was reading the same as his.

Amazing! I asked him what he did and his reply was he was balancing the crankshaft lob reciprocating motion with the magnet thus making the piston appear lighter and increasing the RPM. What do you guys think?[sm=72_72.gif]


Bob Harris
BobHH is offline  
Reply With Quote
Old 04-01-2009, 03:38 PM
  #2  
s. wallace
Senior Member
My Feedback: (24)
 
Join Date: Feb 2002
Location: Endicott, NY
Posts: 782
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: OS .25 FX Turning 22,500 RPM

I think the date of this post says it all
s. wallace is offline  
Reply With Quote
Old 04-01-2009, 08:19 PM
  #3  
daven
Senior Member
My Feedback: (1)
 
Join Date: Dec 2001
Location: Waseca, MN
Posts: 8,455
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: OS .25 FX Turning 22,500 RPM

I agree, but good try
daven is offline  
Reply With Quote
Old 04-01-2009, 08:48 PM
  #4  
BarryReade
My Feedback: (1)
 
Join Date: Dec 2004
Location: Powder Springs, GA
Posts: 1,495
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: OS .25 FX Turning 22,500 RPM


ORIGINAL: BobHH What do you guys think?[sm=72_72.gif] Bob Harris
Can't say, it would be censored!!!
BarryReade is offline  
Reply With Quote
Old 04-01-2009, 08:48 PM
  #5  
BobHH
Thread Starter
My Feedback: (18)
 
Join Date: Jan 2002
Location: Holly Springs, NC
Posts: 1,861
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: OS .25 FX Turning 22,500 RPM

Oh well, I tried[:-] We will discuss about degreeing in the crankshaft tomorrow!!

Bob Harris
BobHH is offline  
Reply With Quote
Old 04-01-2009, 09:12 PM
  #6  
vicman
My Feedback: (10)
 
vicman's Avatar
 
Join Date: Dec 2002
Location: Valdese, NC
Posts: 9,910
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: OS .25 FX Turning 22,500 RPM

I got that trick down. The hard part at the moment is deciding if I want to try to hide the evidence by discoloring the surface I cut. Shhh.

Back to work on my BS...er BuckShot.
vicman is offline  
Reply With Quote
Old 04-01-2009, 09:21 PM
  #7  
daven
Senior Member
My Feedback: (1)
 
Join Date: Dec 2001
Location: Waseca, MN
Posts: 8,455
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: OS .25 FX Turning 22,500 RPM

Bob,

If you get the angle correct to offset the balance of the crank, you will see an increase in RPM.
daven is offline  
Reply With Quote
Old 04-01-2009, 09:28 PM
  #8  
vicman
My Feedback: (10)
 
vicman's Avatar
 
Join Date: Dec 2002
Location: Valdese, NC
Posts: 9,910
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: OS .25 FX Turning 22,500 RPM

Dangit Dave!
I race against that guy, quit giving these NC boys any tricks.
vicman is offline  
Reply With Quote
Old 04-01-2009, 10:22 PM
  #9  
j.gibson
Senior Member
 
Join Date: Jul 2008
Location: char, NC
Posts: 126
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: OS .25 FX Turning 22,500 RPM

DAMMIT Bobby, I told you to stop eating those mushrooms !!!!!!!!!

jmg
j.gibson is offline  
Reply With Quote

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