The rebuild started right up.
It runs smoother than I expected. Almost no Idle lope.
The hardest part is keeping off boost during break-in.

The cause:


Template & layout:


Primaries - conservative to maintain high charge velocity:


Secondaries - your basic street port:


Exhaust - a little more clearance, a little earlier opening, same closing:


Rotor - bevels for earlier opening & later closing with the primary opening earlier than secondary:


Early opening:


Late closing:


I won't know about high end power until after the break-in.

 

picture's don't seem to be working for me.

 

I just finished cleaning up the typos.
Try again..

 

Who cut those rotors.. have you run them before....

 

Me & my little dremmel - with some careful templating.

And - yes - I did lighten the counterweights also.

 

With a Dremel? Wow, so I could pull something like this off as well.

 

i ask becuz I know the person who cuts them.. the right way and has proven them one the race track (GT-1 ) and on the street ..

 

is that plexiglass you used for the template of the rotor?

 

what yr are the rotors from? did you use the counterweight from a S5?

 

It's all S5.

I cut side & face templates for the rotor bevels.
Careful layout - stop at the line.
Side seal support ridge is .050"-.060"

The templates are made from some .020" plastic sheet.
Easy to cut with scissors & very little parallax transfer error.

 

I would love to see what it makes for power once it's broken in and boosting, keep us updated.

 

you guys are ballsy cutting rotors by the seat of your pants. i hope the bearings don't prematurely fail due to an out of balance rotating assembly.

i would only try it in an engine that would never see more than 8k and was only run at the track a few times a year and wouldn't mind if the engine blew.

i am interested in how much this port phasing helps though.

 

This is the origonal motor in my daily driver.
The temporary J-spec is now on the stand - in case this deal blows up.

So far - low end feels every bit as good as the J-spec.
Just a little torque vibration as it pulls up past 1200RPM.
I feel it only because my torque brace has very little cushion.

It's as smooth as glass up to 4K (well 5K once).

In a few weeks it will either look brilliant or stupid..

 

Hey, someone has to be the pioneer! Keep us updated man!

 

who wants to bet it blows up?



did you get them rebalanced? or did you just kinda do it and hope it all works?

 

On my budget - close has to be good enough.
I just took my time with the templates on all 6 faces, to make them exactly the same.

On initial startup I held various steady revs between 1K &3K with absolutely no vibration.
So it should be OK for at least a while.
The only vibration I get at all is a slight torque resonance at 1200 during acceleration.

 

even though it ran well, with min. vibration - how could you be sure wehen you put it back together?

did you wiegh the shavings you ground off?

just curious, this is some very in depth motor work for the setup you have...Im quite impressed. - nice work my you rotary playa

 

Awesome xperiment man,
Keep us updated,

I see you're in Jax, I have a buddy in north palm beach who works at a machinist shop. Maybe he can do some beveling for you (next time? will there be a next time?)

All he needs to know is what to change, he can program the machine, CAD and all..

I'll see if I can get his *** to post....

|M|

 

definetly excited to see the outcome of this. Keep us updated!

 

uh, i don''t know what the big deal is this mod has been around forever.

 

Even if it has been around "forever", it's poorly documented and the people who run the custom beveled rotors are few and far between. Any documentation or progress that's posted is valuable in helping the next man decide whether or not he wants to undertake this type of modification.

 

Looks like you did a nice job. I've been itchin to do a set myself. I'll be milling mine but there's nothing wrong with the way you did it.Guy's way over think these things. Why would you need to rebalance and all that ****? As long as you cut each one the same they'll be every bit as balanced as before you did the mods. Hope it stands the test of time. Will you be taking it to the dyno?

Brent

 

This is great. Jrats got it, someone has to test it for us :-D But anyhow I realy like how you showd the port opening and closing times with the rotors. Good work bro!

 

i want updates on this.

What math did you use to figure out how much weight to take off the counter weight?

What hp goals at what boost level using what turbo do you have planned for this motor?

 

thats some crazy stuff man.....how long do u think the engine will last with the rotors like that? normal life expetency?