The way you speak it sounds as though more intake duration is a bad thing. Could you explain to an amateur like myself please?

 

Grizzly, if by tracking you are referring to road courses and such instead of drag strips I would be interested in the answer to your question as well. Would making the hole higher tend to produce a better "track" engine?

 

Yes you could do that. Keep in mind that would possibly eliminate the oil injection depending on how high you went. If it did you would need to either premix your gas or else you could drill a tiny hole going through oil injector port and the hole would actually come out in the pport tube.
I would spend the extra time during build to recreate the the injector system to avoid dealing with mixing.

 

I ask becouse i am going to get some made very soon.

How i would like to do it is reduce the size of the port and get the hole lot as far up the Housing as possable (as you say to reduce the Overlap etc) the other reason i would reduce the ID or Port size is to keep the Gas speed up whilst its not on Boost (Basicly low revs).

Your Oiler Coment has started mew thinking as i thought it was alot higher and i would'nt have to bother with it?

I am still going to be staying withing the same two stud holes, so without having a Housing here in frount of me would i still have the Oiler Problem?

Chris

 

Or how does this sound to keep the Overlap down.

If you get the Port Tube then find a bar that fits tight inside the sleve then mill it end to end at about 45% (roughly) so at one end its half covering the tube and the other is open, then fit and weld in as usal, triming the end etc so it fits nicly and does'nt catch the Apex (on your new Port) and hey presto you have a D shape port.

Do you get where i'm coming from?

Its just an idea i've been dreaming up to keep my engine's over lap down. I would have to Play with the idea a bit but you should get the basic idea.

Do you think it would work?

Chris

 

The problem with that is by creating the D port you significantly cut the flow and what you lose from that is more than what you would gain from the reduced overlap. You would also get a reverberation effect at the point of restriction that would add to the problem.
You would be better off running a smaller tube without restictions.

 

Has anyone ever thought of making a pp housing with a bridge in the middle of the port? This would allow the port to be made wider to get rid of the stagnant areas normally left on either side of the port without apex seal "bowing".

 

There are links of guys making 380bhp from a 13BPP at revs below 10k rpm over 5 years ago. Much more efficient than the revs you need from a Bridge to get near that power level.

I would like to see the VE% of any bridge that can better a PP ?

In regards to your or Rohans Idea of making a bridge on a PP, it has been done by John Dear in 1987! (PM me and I will scan you some pics of it)
The VE% drops when you do this style of porting on a PP, it does not increase. But if you apply 4 seperate runners on a 2 rotor together with staged throttles you could get a good increase in air speed in mid rpm ranges and improve output for sure, though it would be at the expense of ultimate power.

Easiest way to tell is put it on a flow bench, there is no way ANY bridge will out do a PP in flow.

 

I would be really careful with placing the port too high because as you move higher you start to leave the bounds of maximum intake expansion. Basically, move too high and the motor wont have any vacume to bring the intake in. This is why the ports need to be kept somewhat low.

CJG

 

Even if its a Turbo?

Chris

 

Would this sort of thing be possable as a P/P on its own without the Side ports or would it be too small?

https://www.rx7club.com/forum/showth...hreadid=189780

Scalliwag, Have you run one of your P/P engines yet? i am intrested how it feels (Low end) I have had some Bridge experiance but the P/P seems smoother at lower revs which tends to Imply its got less over lap?

Also i am sure it says hear somewhere but are you running a Turbo or is this NA?

Chris

 

A turbo motor has no forced induction until the turbo spools. If you create the problem that Rotortuner described you may go from a stumbling low RPM with almost no torque to a monster when and if the turbo actually spools.
It would not be a very pretty site.

 

Here is a history of my pport experience.
The only pport housings I built was for Ken Scheepers NHRA Import All motor car. Out of 4 races this year, 3 NHRA and one NOPI he made first place in 3 of the 4 races. The one he lost had a great deal to do with breaking the ring and pinion gears in his rearend. His best time was 10.25. Ken dyno'ed the car at Rotary Performance (his sponsor) and as expected it ran the same numbers as the Padilla motor dyno'ed.
The motor running the housings I built is an exact replica of the one Jesus Padilla built for him so I cannot take credit for the design.
This car is not setup for low-end torque and I never asked Ken how it feels at low-end because of that.
The throttle body is setup as a downdraft real close to the rotor housing so the runner is incredibly short.
If a wraparound intake was built and it was setup like the Racing Beat sidedraft it would gain alot more throttle range and with a custom header tuned to optimize the intake setup.

I think with that type of setup that the torque range would be pretty good. Some of our Aussie friends down under seem to have made more effort to build streetable pport than here in the states. I know a shitload of rotorheads here in Texas and none of them have ever tried it.
My rotary T-Bucket project will be pported so I really hope my theory works as I plan to street drive as well as drag race it. The nice thing is that with everything so easily accesible I can make changes very easily.

 

Here is a sneak preview of my peripheral port components I am working on. For my roadster I could not see using a large rubber hose coupling to attach my manifold system so I made a coupling system that looks much better in my opinion at least.
For 1st, 2nd, and 3rd gen's I am making modular elbow fittings in 45/90/180 degrees for routing. I am also building the throttle bodies that will get your full attention.
The tube with the o-ring is actually the tube that mounts into the rotor housing. I will be making some retrofit fittings (retrofittings? ) for the Racing Beat housings. The o-ring grooves will be internal on those couplings.
Also being worked in to my project list are aluminum modular intake systems for 4 port as well as pports.
I think you guys will really like them as well as what you see (when I let you see ) the throttle bodies.
With a modular intake system and a programmable ECU you could change your intake setup with a few hand tools and load seperate maps for each setup. You could have an optimal setup for street,strip, and road race by changing the length of the intake system and adding or removing chokes. Using different combinations and being careful to remember to change the maps you should be able to get the significant performance in a wide variety of driving.
Microtech's dash unit will store 3 maps that can be changed on the fly. So that looks very promising. Well at least in "Scalliwag theory"

BTW the elbow below is unmodified. It will have a welded collar for the application it will be used for. There will be flanged and other elbow configurations..... yakyakyak... I will shutup for now

 

Here is a mock housing to show the way I want to setup the components and the change as far as a short inlet tube with the o-ring. The tube may come in just a little higher because I am building my housings to the timing specs Paul Yaw published on his website.
But overall this is a good mockup.
Think of the straight coupling as a throttle body. I turned a short coupling and welded it to the elbow. The couplings are secured using set screws. I will be using 180 degree elbows for my street setup so it will wrap around over the top of the housing and the throttle bodies will be slightly toward the drivers side.
I am planning on running a turbo at some point and all the plumbing will be setup like this. I am not ready to divulge the injector rail setup at this point.
The first two pictures are from Paul Yaw's website so you can see the way all the pports I have seen have had the manifolds attached.
Let me know what you think about this phase of my project list

 

Just thought I'd post this; just made a practice PPort on a dead 12A housing. Yeah, it's a lot smaller than the ones for Ken's motor, as it's going to be a secondary port, *and* on a street motor. Also, port timing's pretty approximate, as I was just seeing how well the holesaw would cut mainly.

 

Describe how you setup. Equipment, etc.
How did you like the holesaw? It works slick as hell for me. Did you make a 1/4" pilot hole and then a smooth 1/4" shaft in the actual holesaw? That was how I was able to get a real clean round hole.
I am glad to see more people posting their projects. Thanks Kenku!

 

*coughs* *looks embarrased*

Uh... actually... I mean, that was just to see what it'd take to go through. I didn't expect it to actually come out that well.

Er... well... I moved the drill press tray thing to the bottom stop and braced the housing against it, then I lined the hole saw up with the water hole and drilled the sucker. It's an old drill press, so it took maybe 20 minutes to go through the last bit.

Yeah, I know, I know. No guide or pilot hole, or jig or any of the rest. I don't know *how* it came out looking as good as it did. I'm *NOT* chancing it when I do it with my 13B later on.

Though I think with how I'm planning on doing the port, an absolutely straight hole is less essential. I'm going with the idea of filling it in with epoxy beforehand and using a die grinder to change the port timing a bit after the inch hole's drilled.

 

If you use a jig and make a 1/4" pilot hole and use a smooth shaft in the holesaw I can promise you you will have an absolutely straight hole.
Are you talking about just boring a hole through the hardened epoxy and not using any tube? That would be different. I would use a tube but if you do not have a lathe to turn the tube this may work.

 

the smaller hole is a great idea.. at least that is what i'm in the middle of doing also. leave the side ports open way open. tha tway you still retain some torque and is streetable....
hey scalliwag where did you get those short 90's and how much i need to pick up a few...
also good pic's on the mani.
I'm going the custom intake also

 

Interesting pics of the modular manifold looks good. My only thought is what type of transition exists in the interior of the piping when you go between couplings? Is it smooth or is there a stair step, which will create turbulence? Also how well do you think an o-ring will seal against boost?

 

I got it (as in one) from a local supply called Cohn & Gregory in Fort Worth. They are $21 each so I am trying to source out a better price. I have not had time to do that though with all the other caca I have going.
They are not the easiest thing to come up with local to Fort Worth. It took about 20 phone calls before someone told me to try them.
Stainless is plentiful but harder to work and higher priced.

 

All the transitions are the same ID and centered. All the ID tubes are flush on the ends and butt together for a continuous and flush fit ID. You butt the joints together as far as they go and lock down the set screws.
The only exception to the ID is the throttle body which is slightly larger but it has graduated transitions to reduce turbulence. Overall it is the only intake system I have seen that maintains as close a diameter throughout.
The o-ring and tube diameters are made to a very tight tolerance and the four set screws at each collar keep everything where they should stay. I believe the o-rings will handle more boost than the motors can.

 

Yup, that's exactly what I'm talking. Because, as it happens, I don't have a lathe. Actually, doing it that way also lets me play with the interior port shape a lot more than I think the tube'd let me; the PPort's going to be there to provide overlap at high RPM more than anything else.

Also, another consideration is that I'm going to be fabbing a custom manifold for *all* of the intake system. So the PPorts are actually going to be connected via a gasket, just like they would be stock.

Ambitious perhaps, especially given my resources but... hey, if it works.

... I really should save up for a Microtech though.

 

You can still use a tube and cut it off flush to the surface if you went that route. I would be concerned for any air pockets. I would make a setup to put the epoxy in the water passage under pressure possibly if I was to try that.