Looking to chat with other builders about experience and thoughts on rotor beveling.

I have been playing with this and sacrificing port timing changes and using the rotors to adjust the advance and or closing times to some degree.

The porting itself tends to be more time consuming and more costly doing this. But the results seem to be far more drastic then just adjusting the porting on the iron. I feel like I have been getting a more aggressive sounding and more responsive overlap by milling the rotors. Throttle response also seems good.

Does anyone have some input or experience perhaps learned information on this particular method.

 

I have a pair done by Carlos of CLR Motorsports has been doing this for years... his on this forum I think under G-1 20B? We call it Scallops not to sure if that's you mean but he has lots of infor....

 

I have been testing several styles over the past 8 months or so. I posted pics of the latest variance I am running right now. I have tried more of the RX8 and differing angles and so far this one is by far the most promonet I have assembled. They are not CNC'ed yet I have been doing them by hand. I have not figured out how far I can go yet but I also have not dug into a bad rotor to find out, also afraid of making the side seal support to thin.

 

They look real good almost like mine and only on the intake face good job....I'm running S4 rotors I will post pics later tonight...

 

re beveled rotors:

don't the bevels greatly reduce static compression? they look like a couple of new combustion chambers to me...

howard

 

Be careful not to get too close to the side seal as you are closer to the apex seal end of things. You WILL melt the side seal, been there, done that. Look at how close the seal is to the face in the center of the edge and use that as a guide.

The area you take removed towad the middle doesn't seem to need to go that far in. On the flow bench you are still dealing with a 'wall' that is moving(think about the direction of the air and how it is coming into the chamber from the port) The timing matters more than how far you fare it in.

 

what improvments did you see from the scalop rotor?

 

A little closer to bridgeport timing without the bridgport. I havn't done any back to back tear down tests so I don't know how much power it gets you.

 

When I had a bridge I use to get very low vacuum and my brakes would not work properly.
Do you get any of this?
Also what is your ideal quality like?

 

The greater the overlap the lower the vacume.
Depending on how the rotor is modified meaning earlier opening or later closing or a combination of both it will affect idle somewhat.

 

Thankyou very much Sir