To the assembled rotary brain trust, would it be possible to get the overlap via scalloped/beveled rotors as apposed to working on the endplates? Or maybe a combination of the two?

 

its about time

 

well.. any new vids!

 

Below is one of my bridgeports on a Turbo II. The "bridgeport" is the second intake port that's been cut that's to the right of the main port and to the left of the water jacket square ring land. The "bridge" in bridgeport comes from having a bridge of iron leftover inbetween the stock port and the newly-cut bridgeport that allows the corner seal and side of the apex seal to ride across without falling into the port.

As Fred (RG) said already, the bridgeport for a Renesis iron would look a bit different but this is what it basically is.

B

 

The overlap is determined by the Apex Seal position in comparison to the intake and exhaust ports. If the Intake port is open in the same chamber (rotor face) as the exhaust port you obtain overlap.

 

Not quite true. Sort of. That's only completely accurate in an all peripheral port engine as only the apex seal opens and closes the ports. However in a side port engine it's the location of the ports to the side seals that determines when a port opens. A 13B with it's side intake and peripheral exhaust ports still has port overlap as the intake and exhaust ports are open at the same time. Briefly. In the all side port Renesis only the side seals control when the ports are open or not. They just so happen are never open at the same time as each other. There is 6 degrees of dwell. If you could open the intake port earlier or close the exhaust port later, you only have to make up 6 degrees of eccentric rotation before you get overlap.

Hold a rotor in a housing that has a side plate on it. Orient the rotor so that an apex is pointed exactly halfway between the spark plugs. Now look at the other side, specifically for the ports. You can move the rotor back and forth to see when the intake opens or the exhaust closes. Remember if you can see light through each one at the same time, and you can't on a stock Renesis, that means you have overlap. The rotor face is dished which is what allows the overlap to happen. Without a dish we wouldn't get overlap but we also wouldn't have a usable compression ratio!

 

Renesis rotors are already bevelled from the factory.

 

Hi

as RG said, the renesis rotors are beveled, but only on exhaust side, it might help to do same on intake side of rotor, but then you must strip motor for that only, then you can just as well cut a bridge in.


Here are another link for a clip i just did on you tube, i gave it some revs,

i do add approx 200ml of 2strooke oil to a tank of fuel as extra protection aspecially now.
I will send another clip which shows while i am driving, soon very soon

http://www.youtube.com/watch?v=ilkzok3CrWU


BDC that porting is done very nice, clean, good job.

mine is the same idea but the bridge itself a bit narrower and the port part is the same width as on there, all following the standard port shape, but we did make the port a bit longer, it is to the same place at top as yours but a bit down to bottom of port at bottom


NEMESIS8


my exhaust setup is as follow,

the small precilenser as on the standard exhaust is still there, but i removed the cat and just inserted a 2,5" pipe in its place, straight and i put the oxygen sensor back at same spot it used to be and it is connected as well.
to the back it is the same, but right at back close to diff, where the clamp is for the big standard box we took the big standard box of and made a new pipe to fit and split in Y shape, a long curve (no sharp curves) to one box with 2" in and exit on the left and exactly the same to the right, the boxes are approx 300mm (12")long and 170mm diameter (7") but a bit oval for space at bottom, it exits to the same standard exit pipes, thus looking standard from outside.
main differances is then the cat removed and 2 small boxes, 2" straight through, one on each side.
the middle section of exhaust is still standard, we didnt go to 3" we kept same size, but the split makes the 2 boxes at 2" each.

that is it.

other change i did was the relacement of standard air filter with a BMC F1 washable drop in filter, it flows better and are a bit thinner than standard, i wash / clean / oil it regularly.

I hope this helps,

it is a bit more noisier than before the porting


RG

true on the overlap as renesis ports are on side not peripheral, that is why the peripheral port is totally differant in overlap.


I will keep all posted,

will send more clips


Philip

 

Hi see above

i added one

Philip

 

[embed]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/ilkzok3CrWU&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/ilkzok3CrWU&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/embed]

 

Man you must have a long leg to press the gas all the way from the passenger side. ;-)

 

Ha

I am from South Africa,

our cars are right hand drive

 

What's the duty tax for importing a sense of humor?

 

/\ FAST AND FURIOUS FTMFW!

Good job, can't wait until you drive the car around and give it some gas

Oh and the dyno too. Expecting above 215whp

 

Brian: Nice car. What's the retail on one of those?


Douche in Ferrari: More than you can afford, pal. Ferrari.

 

Youtube is the best.

http://www.youtube.com/watch?v=4j5m2FuFC48

And no, this isn't considered street racing because it was in a movie

 

/\ So the moral is....???...the Supra is a better car than the Ferrari because it can go faster????...

What a load of

 

Considering the version of Supra that the movie car is modeled after has approx $120,000 worth of parts and work done to it...yeah I'd say so.

I'd take that Supra minus the graphics. Targa top FTW.

 

bridged rotary sounds better imo..... i would just like to see the reaction and looks from people while sitting at a stop light. probably the last sound people would expect out of a japan import

 

I hoped to get you guys clip when driving,

just cant get a quiet time to do it, will do it tomorrow, doesnt matter what,

so far no problems


and yes a bridged rotor sounds nicer, i had a lot of heads turn already, you can see they wonder what it is or what motor it is, but i love when i drive of with them behind me...



Philip

 

Have anyone ask you why the car isn't "running right" yet?

B

 

in theory could you just bridge port the aux ports to have a decent idle but better upper rpm flow?

 

As far as I can remember, all attempts at bridging just the aux ports (at least, on RX7's) were unsuccessful. Maybe someone from the 7club will come in and correct me.


Edit: Aha. A quick search on 7club came up with this post. Don't take it as fact, as I'm not sure on the references.

 

Yes,

well its not that it is not running right, it runs fine and runs better than before, but we are sure it will run much better to make better use of the porting if we have a other management system to fuel more at high rpm,

to be honest, my budget dont allow more spending at moment (the whole rebuild and new fuel pump and coils and clutch was a hard one!), although i want to, and i dont want to have a piggyback system on, thus rather wait a while, and do it properly with complete other system like microtech or so.

it is not running too lean to create problems, but needs more fuel from about 7000rpm, it is run in now and i will still take it for just simple test on oxygen readings, i was there today but the guy helping me normally want there,

i will keep all up to date,

one thing i saw was my traction control light on dash flashes more often and longer when changing gears, if it means something


Philip

 

Did you notice whether they cut into the housings at all when they did the porting ?