New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

Best rotary for a dirt bike

Thread Tools
 
Search this Thread
 
Old 01-05-10, 11:11 PM
  #1  
Junior Member
Thread Starter
 
bobbrain's Avatar
 
Join Date: Jan 2010
Location: I'm not sure
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Best rotary for a dirt bike

I'm toying with the idea of forcing a rotary into a dirt bike frame. Any idea what engine I should go for?
Yes i know it will take a lot of fabrication.
Old 01-06-10, 10:08 AM
  #2  
Engine, Not Motor

iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes on 91 Posts
Well, most of the dirt bikes I have seen weigh under 200 LBs, so by putting in a rotary you are basically doubling its weight. That is probably the most important thing to consider.

Another issue is that the rotary is dimensionally basically a box, while the frame is designed to hold an engine which is much flatter.

Keeping those two things in mind, I think the "best" rotary for a dirt bike application would be a custom single rotor unit made from 13B parts. Atkins sells a single rotor eccentric shaft should you want to do this.
Old 01-06-10, 05:07 PM
  #3  
Rotary Freak

iTrader: (7)
 
Go48's Avatar
 
Join Date: Feb 2005
Location: Mont Alto, PA
Posts: 1,608
Likes: 0
Received 2 Likes on 2 Posts
If you have deep pockets, try these people: http://www.rotamax.net/
Old 01-06-10, 09:26 PM
  #4  
Junior Member

 
tak209's Avatar
 
Join Date: Jan 2010
Location: stockton ca
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
on a dirt bike huh? thats new lol post pics if you get it up and running
Old 01-07-10, 04:05 AM
  #5  
Junior Member
Thread Starter
 
bobbrain's Avatar
 
Join Date: Jan 2010
Location: I'm not sure
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Well between rotomax and a few other companies I'm now toying with the very real possibility of a sub 200lb dirt bike with at least that much power. I'm just trying to figure out how i'd ever be able to repay the bank loans I'd need to build them....

http://www.aixro.de/

http://www.italsistem.com/saetta-eng.htm

http://thekneeslider.com/archives/20...r-motorcycles/
Old 01-11-10, 12:11 AM
  #6  
Junior Member
 
rx7420's Avatar
 
Join Date: Mar 2009
Location: connecticut
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
arctic cat made a rotary powered snowmobile i think its a 303 cc maybe u can fit that into a dirtbike
Old 01-11-10, 03:45 PM
  #7  
Engine, Not Motor

iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes on 91 Posts
Yeah, I forgot about those. Sachs made several small rotary engines for snowmobiles, lawnmowers, etc.
Old 01-11-10, 07:56 PM
  #8  
Full Member
 
baldguy's Avatar
 
Join Date: Jan 2010
Location: ohio
Posts: 48
Likes: 0
Received 0 Likes on 0 Posts
Hey how about a re5 suzuki you can pick up the hole bike at a swap meet pretty cheap. I could have bought 3 last year for 700 they needed a lot of work but motors were complete.
Old 01-11-10, 11:20 PM
  #9  
Junior Member
Thread Starter
 
bobbrain's Avatar
 
Join Date: Jan 2010
Location: I'm not sure
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Hmmm how do the power to weight ratios on either of those stack up against a 125cc two stroke?

edit: i saw that the sachs is pushing about 17 hp and the re5 has 63 but im having trouble finding the weight of the motors. anybody have any info?

Last edited by bobbrain; 01-11-10 at 11:28 PM.
Old 01-13-10, 07:07 PM
  #10  
Can Post Only in New Member Section
 
DRIFTERS14's Avatar
 
Join Date: Jan 2010
Location: SFL
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
i would love to see a rotary bike
Old 01-13-10, 07:28 PM
  #11  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,339
Received 369 Likes on 223 Posts
whats wrong with a regular two stroke 250cc bike engine? ts ts

u may aswell get a ktm 380sx engine if you want some crazy power
Old 01-13-10, 11:59 PM
  #12  
Rotary Fan

 
FC Zach's Avatar
 
Join Date: Nov 2006
Location: Eagleville, TN
Posts: 159
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by DRIFTERS14
i would love to see a rotary bike
Here's two for you.

My RE5 and a Hercules I've been cleaning up.
Attached Thumbnails Best rotary for a dirt bike-re5.jpg   Best rotary for a dirt bike-nsu.jpg  
Old 01-14-10, 06:12 PM
  #13  
Junior Member
Thread Starter
 
bobbrain's Avatar
 
Join Date: Jan 2010
Location: I'm not sure
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by R-R-Rx7
whats wrong with a regular two stroke 250cc bike engine? ts ts

u may aswell get a ktm 380sx engine if you want some crazy power
Too heavy and too physically bulky for a bike that'd fit me well.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
datfast1
Old School and Other Rotary
18
06-20-19 10:53 PM
Under PSI
3rd Generation Specific (1993-2002)
19
09-23-15 11:47 PM
datfast1
West RX-7 Forum
3
09-14-15 06:58 PM
andyvideopro
SE RX-7 Forum
0
09-05-15 06:56 PM
Murilli
Midwest RX-7 Forum
0
09-03-15 09:10 AM



Quick Reply: Best rotary for a dirt bike



All times are GMT -5. The time now is 06:39 PM.