gave porting an old center iron that is blown out an attempt and I'm hoping to get some opinions on making it better or the overall shape. I learned my lesson and taped up around my scribed line so ignore the 2 obvious scratches, everything else on the outside of the port is just shavings that didnt blow away.

Please feel free to tell me what i can do to better the shape of the inside of the port, I didn't touch the rest of it yet, just the actual port and ground down the factory lines, I plan on smoothing out the runner a bit, but right now I am just concerned with overall port shape. The template I used was pineapples medium street port.

and the pictures








positive and negative welcome, and I know its not polished or anything yet.

 

I used the same port template as you, so far so good.. except I think you need to be more careful with your tool. I know when I was porting sometimes it jumps. could lead to problems.

 

yeah, I came up with a solution to that part after they happened, a few layers of masking tape lining the template line.....of course after I decided to do that I didnt have any more problems lol.

I was mainly curious about the bottom portion, a lot of material comes off there and I'm not positive what a good shape, or angle for it is

 

Anyone else there has to be some experts that can guide me lol

 

Put a 2mm bevel on the closing edge.

 

So bevel the closing edge beyond what the template I have goes? In doing that I guess the rest of that small lip would be ground away as well, I'm not shooting for anything crazy just yet, mild power gains as I still have stock twins and plan on autocross primarily. I haven't continued grinding yet otherwise I would have some more pictures, should have some later tonight of more progress. The iron is junk so im not too concerned, just getting practice for the ones going in the car

 

For a first effort it's not bad. The transitions can be smoother, and the bowl needs a lot of work still. I was porting a brand new engine for most of tonight, I can snap some pics tomorrow.

 

and yeah im Canadian Eh!

 

That'd be great , I know it still needs a lot of work, pressed for time latley, progress is slow, I ground a little more yesterday and have come to a point where I need the flex adapter for my dremel, can't reach into the runners lol.

I actually watch the whole series that you have on YouTube, very informative and its what actually convinced me to port it instead of just rebuilding. Looking forward to when she is finally back together, hopefully the pfc will have her running good enough to idle on the base map, then trailer her to somewhere in nc that can tune rotary!! I will post up more pictures after I'm back from harbor freight and finished working tonight for more opinions.

 

finally got some time to grind some more, took out a lot more material on the bottom to let the air flow in better, a little more up top as well, smoothed out the bowl some and work a lot on the runner, ground down the circular casting mark and took some material out all over, not much but I can tell the difference between the stock and one I'm working on. Probably try and hand sand it tomorrow with some 180 or so, not too sure how smooth it should be overall to promote good atomization, seems like people talk about that a lot, i thought modern fuel injectors did a good enough job themselves lol. cant wait to see what kind of pictures you put up goodfella!

here are pics of current progress....continue to ignore the grinder marks that are in bad places, i was intentionally testing the durability of the tape lining and then i got a little too rough with the tape, reminder this iron is trash already lol










^^^^think i will find a way to take out a little more material in the top left of the runner as viewed in this image, the shape of it looks a little off to me

 

no pics mr goodfella? you probably have the engine you were working on all put back together lol. Got my injector airbleeds in the mail today, and now its the time to decide, port the engine, find a place to tune it, and have decent amount of power, or leave it unported and just be able to enjoy the car. Polling the audience, if yall think I am doing an OK job with the shape and such, then I will be going for it! If not I will be putting it back together unported

 

Looks pretty good. I personally never "polish" my ports. A rough profile has its benefits, especially in the bowl. My only real recommendation is to "back cut" the opening edge a little more to offer smoother flow. Also more bevel on the closing edge never hurts.

 

well thats another person saying bevel the closing edge, looks like ill be opening it up a little more then the template to get the good bevel up there, i was planning on messing with the runner closest to the seals, not sure of the right term, but the portion opposite of where the bowl is lol, not sure how thin i can make the metal and it still have structural integrity.

 

finally got around to porting the rear iron, and all went well.....up until i took the masking tape on to add the infamous bevel to the closing edge. I am fairly sure its minor enough not to cause any problems as i cant even feel it with my fingers, but yea....I'll add the bevel with the tape on next time. Let me know what y'all thing, take off more metal in places or what not, throw it away and try again, whatever y'all think haha.

 

Its fine, that little mark will not cause any issues. The only time you really see any issue from "skipping the bit" across the face is when it gets into the oil control ring path causing low lying areas that oil can bypass the oil control rings and scrapers. Ports look great for someone who just started.

Hopefully you haven't ported the exhaust yet and you will take my advice and leave the exhaust ports stock.

Good job either way.

 

havent messed with the exhaust ports, why would you suggest leaving them stock? Any advice on making what i have done better, plan on hand sanding a little just to further smooth any grind marks and such, getting ready to start on the front iron, this is pretty nerve racking lol, dont want to ruin my engine.

 

You could remove a little more material on the opening edge where it meets the closing edge. You could back cut there a little more but that is being picky. The port will work just fine as is.


Exhaust ports: I used to port them as well and will still polish them slightly or even port them if a customer requests. The factory exhaust ports flow much more than most give them credit for. This is all in the design of the peripheral exhaust port as the port is fully open much longer than the intake ports during each rotor face revolution. It is pretty obvious to see if you take an iron, a housing and a rotor and play around in the garage. The intake port is fully open for a very small amount of time.


Either way, leaving the exhaust ports stock gives a nice idle and smoother running car. A lot of different experience people will have different views on this subject. I know of one car that trapped over 150mph in the 1/4 on stock exhaust ports and several others who have made gobs of power with the stock exhaust ports. Spool is very likely improved with stock ports as well but that is also debatable.

The guy who set the 1/4 record and horsepower records for stock twins also did so on stock exhaust ports(polished up but almost completely stock) and if you look at the build thread section for "Autox FD" with recent dyno sheets that was another one of my builds with almost completely stock exhaust ports.

The secret is in the intake ports for more power, just look at the semi p-port guys and the power they make. The stock exhaust ports offer plenty of flow in the Wankel 13Bs.

 

djseven whats your opinion on leaving the opening and closing times in the exhaust port stock but slightly opening the bottom two corners to give it more of a "D" shape?

 

That is exactly what I do. However I don't get carried away trying to create the "D" shape a lot of guys do. There is just some extra material in those lower corners that can be removed without effecting opening and closing times.

 

I agree the PP design of the exhaust port is great, The template i have only squares off the bottom a little and rounds off the top, hardly changes the timing at all. The 2 areas where i want to try and improve the rear iron are shown in the below image, just tricky getting the tool in the right area to take the metal i want off.



Im gonna start on the front iron and once i get the ports to look the same work getting them to be identical, and maybe try and take off the material in those spots.

edit: just saw the 2 posts above, thats what the template i have does, makes them a D shape.

 

The two areas you marked on the intake port are really the only areas I would have told you to improve. Be careful on the lower part you have marked towards the bottom(very beginning of opening edge). This is the area most make the mistake of porting too far into the oil control ring path.

Do you what you will on the exhast port but I would not port higher(closing edge) at all. The benefit is not there.

 

Well, now im at the part of matching the 2 ports, and they definitely are the same shape port wise, but the actual bowl and runner are tricky, trying figure out a method of getting them identical.....got any ideas besides eyeballing lol

 

Eyeballing is as good as it gets. Look at two factory primary or secondary ports, they are not close to the same.

 

you sir are a genius lol, they arent even close, thats pretty ridiculous, i decided to stick the front and rear face to face and feel around the port to see if i could feel any ledges, got them nice and even on that part, eyeballed the rest, tomorrow i will try and knock out the center iron, and then attempt to reassemble my first rotary. Wish me luck lol.

Next thing i have to figure out is who is gonna tune it for me, thats one area where i definitely dont want to go, id love to leard....but not on my budget lol. Should be safe to fire it up and idle it on the PFCs stock tune huh? so long as I dont get into any boost with all the extra air.

 

It should be fine to fire up and drive around on, just keep it below 6-7lbs of boost and you will be fine. Contact Allrotor93 on the forum and he will get you in touch with Steve Osley(not on the forum much) who is in Asheville and can tune the car for you. You also have the option of Rotorsports Racing somewhere in NC as well. If you are in North East NC you could drive up to Ray Wilson at Peter Farrell Supercars in MD>

David