Rotary Car Performance General Rotary Car and Engine modification discussions.

High Compression Rotors?

Thread Tools
 
Search this Thread
 
Old 12-03-02, 12:01 PM
  #1  
RIP Icemark

Thread Starter
iTrader: (4)
 
j200pruf's Avatar
 
Join Date: Oct 2002
Location: Aloha OR
Posts: 1,481
Likes: 0
Received 0 Likes on 0 Posts
High Compression Rotors?

Hey all, I was wondering if there are any companies out thier that make high compression rotors for the 13B. Or do you just have to use the S5 rotors?
Old 12-03-02, 12:20 PM
  #2  
Full Member

 
Logo's Avatar
 
Join Date: Feb 2002
Location: Georgia
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
I believe pineappleracing.com may offer them. I know they offer lightened rotors. The S5 rotors would be a cheaper solution.
Old 12-03-02, 12:52 PM
  #3  
Eats, Sleeps, Dreams Rotary
iTrader: (1)
 
Node's Avatar
 
Join Date: Jul 2001
Location: Stinson Beach, Ca
Posts: 3,383
Likes: 0
Received 2 Likes on 2 Posts
no, no one really makes them. When the RX-8 comes out it should have 10:1 compression rotors, hopefully theyll be compatible with other 13B engines.
Old 12-03-02, 01:47 PM
  #4  
r71's daddy

 
David88vert's Avatar
 
Join Date: Feb 2001
Location: Atlanta, GA
Posts: 935
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by Node
no, no one really makes them. When the RX-8 comes out it should have 10:1 compression rotors, hopefully theyll be compatible with other 13B engines.
Sorry Node, but your wrong. They are made.
Downing Atlanta runs 12:1 rotors in their 4 rotor. Custom made. They will sell them to you - but you won't be able to afford it. I asked Jim Downing what he would sell a used 4 rotor for. His answer - $50,000.
Old 12-03-02, 02:35 PM
  #5  
Full Member

 
Logo's Avatar
 
Join Date: Feb 2002
Location: Georgia
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
David, are the rotors machined from scratch or are they modified stock rotors?
Old 12-03-02, 03:10 PM
  #6  
r71's daddy

 
David88vert's Avatar
 
Join Date: Feb 2001
Location: Atlanta, GA
Posts: 935
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by Logo
David, are the rotors machined from scratch or are they modified stock rotors?
Not sure. They have the facility to do either, and Mr. Downing didn't say. (I didn't ask.)
Old 12-03-02, 03:51 PM
  #7  
Full Member

 
Logo's Avatar
 
Join Date: Feb 2002
Location: Georgia
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
I wouldn't be suprised if they created them from scratch. My guess is that the only way to modify stock rotors to run 12:1 compression would be to fill in the combustion recessions on the rotor. I don't think that would be the best or even easiest way to go.
Old 12-03-02, 07:32 PM
  #8  
Senior Member

 
Join Date: Jan 2002
Location: Castle Rock Washignton
Posts: 596
Likes: 0
Received 0 Likes on 0 Posts
I wonder if any of the guys in the na class are running the high comp rotors... It would be funny if there not... 9.7:1 and still kicking every one elses A$$
Old 12-03-02, 08:05 PM
  #9  
Senior Member

 
turbostreetfighter's Avatar
 
Join Date: Aug 2001
Location: houston
Posts: 445
Likes: 0
Received 0 Likes on 0 Posts
you can fill the stock ones in and then CNC machine the pocket out for any ratio you want!!!!


MWW
Old 12-03-02, 10:23 PM
  #10  
Eats, Sleeps, Dreams Rotary
iTrader: (1)
 
Node's Avatar
 
Join Date: Jul 2001
Location: Stinson Beach, Ca
Posts: 3,383
Likes: 0
Received 2 Likes on 2 Posts
Really? Never heard of custom rotors.
Interesting.
Do you have any more information on them?
Old 12-03-02, 10:27 PM
  #11  
Moderator

iTrader: (3)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,827
Received 2,595 Likes on 1,843 Posts
are they not just 787b rotors?

mike
Old 12-04-02, 08:45 AM
  #12  
r71's daddy

 
David88vert's Avatar
 
Join Date: Feb 2001
Location: Atlanta, GA
Posts: 935
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by Node
Really? Never heard of custom rotors.
Interesting.
Do you have any more information on them?
Nope. I could go by there and ask though sometime. His shop is 5 min from my house.
Old 12-04-02, 12:15 PM
  #13  
Moderator

iTrader: (3)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,827
Received 2,595 Likes on 1,843 Posts
Originally posted by David88vert


Nope. I could go by there and ask though sometime. His shop is 5 min from my house.
lucky

mike
Old 12-04-02, 04:34 PM
  #14  
Senior Member

 
Lasse wankel's Avatar
 
Join Date: Aug 2002
Location: Sundbyberg,Sweden
Posts: 419
Likes: 0
Received 1 Like on 1 Post
I am planning to fill the combustion chamber with a trick alu insert to get a higher c:r. Plan to go all out PP and methanol. What kind of c:r should i use for a NA 13B?
Any inputs?
Old 12-04-02, 04:53 PM
  #15  
Full Member

 
Logo's Avatar
 
Join Date: Feb 2002
Location: Georgia
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
Stock rotors are steel right? Don't steel and aluminum have different expansion characteristics under high heat? If so, then your aluminum inserts would crack off. I'm probably waaay off on that one though.
Old 12-04-02, 07:07 PM
  #16  
Rotary Enthusiast

 
Bridgeported's Avatar
 
Join Date: Nov 2002
Location: -
Posts: 1,021
Likes: 0
Received 1 Like on 1 Post
That's what I was thinking (aluminum / steel)

I always wanted to compare a series5 na engine with the same compression as a renesis (10.0?) and streetported intake and enlarged exhaust ports to a stock renesis engine in terms of power output and shape of power curve.

Fun Dream: NA 13B in go-kart with 12.5:1 rotors and peripherial ports.
Old 12-04-02, 08:09 PM
  #17  
Full Member

 
Logo's Avatar
 
Join Date: Feb 2002
Location: Georgia
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
Bridgeported's Fun Dream = Grim Reaper on wheels!
Old 12-04-02, 11:12 PM
  #18  
Senior Member

 
Join Date: Jan 2002
Location: Castle Rock Washignton
Posts: 596
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by Lasse wankel
I am planning to fill the combustion chamber with a trick alu insert to get a higher c:r. Plan to go all out PP and methanol. What kind of c:r should i use for a NA 13B?
Any inputs?
Sounds like a expensive way to blow up a motor go to a machine shop have them make you new rotors and fill the dish in a little....
Old 12-05-02, 02:52 AM
  #19  
Senior Member

 
Rs4Racer's Avatar
 
Join Date: Sep 2002
Location: Washington
Posts: 422
Likes: 0
Received 0 Likes on 0 Posts
Wouldnt you have to get them heat treated so they dont fail? Or is that even done?

Can you simply just fill them in and how do you fill them in?
Old 12-05-02, 07:08 AM
  #20  
Senior Member

 
Lasse wankel's Avatar
 
Join Date: Aug 2002
Location: Sundbyberg,Sweden
Posts: 419
Likes: 0
Received 1 Like on 1 Post
I am gonna use 7075T6 heat treated alluminium block which i think gonna cope with the heat in the combustion when it occurs,it's only a very little time when the alu maybe expands a little. I also gonna use some paint on heat barrier from Powerhouse. I have plans to dyno this engine this winter with lot of power tricks for a N/A PP, hoping for 350hp or more!
Old 12-05-02, 07:26 AM
  #21  
Full Member

 
Logo's Avatar
 
Join Date: Feb 2002
Location: Georgia
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
Good luck! In the in it might be better/cheaper to go with completely custom rotors machined from a block of heat treated aluminum--or whatever other material your heart desires. It might also give you the potential to make even more power.
Old 12-06-02, 08:49 AM
  #22  
13B N/A POWA!

 
KiyoKix's Avatar
 
Join Date: Apr 2002
Location: Everywhere, WRLD
Posts: 1,013
Likes: 0
Received 0 Likes on 0 Posts
I was thinking the samething...how much do you guys think it would actually cost to get to brand new machined rotors???
Old 12-06-02, 12:39 PM
  #23  
Undercover

 
Rotortuner's Avatar
 
Join Date: Aug 2001
Location: Ohio
Posts: 1,983
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by Logo
David, are the rotors machined from scratch or are they modified stock rotors?
He used to own his own foundery. So i am pretty sure they were actualy cast. He casted his own AL housings also.

CJG
Old 12-06-02, 07:15 PM
  #24  
Senior Member

 
turbostreetfighter's Avatar
 
Join Date: Aug 2001
Location: houston
Posts: 445
Likes: 0
Received 0 Likes on 0 Posts
i am a machinist and i can tell you that it would not be cheap to make new rotors. at a quantity of two it would be around 1200.00 each. dont forget that all of the apex,side,corner seal slots are wire EDM'd and that is not cheap!! as far as using aluminum inserts go, there is no way that is going to work you have 1700+ degrees in the cumbustion chamber and the rate of expansion and the cast rotors is way off the mark. you would be better of plasma spraying the CC and CNC grinding the surface to a specific compression. i have access to all of the equipment to do this but it would have to be a SERIOUS group effort to make it affordable. i run methanol and would like to have 10:1 and i bet 12:1 on a NA would be beastly!!


MWW
Old 12-06-02, 07:34 PM
  #25  
Senior Member

 
Rs4Racer's Avatar
 
Join Date: Sep 2002
Location: Washington
Posts: 422
Likes: 0
Received 0 Likes on 0 Posts
In piston engines... does anyone have an example of how much power rasing the compression makes?


Quick Reply: High Compression Rotors?



All times are GMT -5. The time now is 11:04 AM.