When going to a carburetor can the port valves be removed on a 13b with injection ?? I want to use the stock intake back to where the throttle body bolts on ..

 

I'm confused...If you are going to a carb, you will need a whole new intake setup. You can't just bolt the carb to the throttle body flange unless you are talking about something like a Weber side draft. And if you make that approach, you will need to make a custom adapter and have huge problems with fuel pooling in the VERY long intake runners.

I believe that all of the 13B carb intake manifolds eliminate the aux port system because they don't have the castings.

Why someone would go to a carb on an EFI 6 port 13B is a bit of a mystery to me because it'sa downgrade on all fronts.

 

Aaron Cakes The reason I ask is I would like to use the fuel injected system but I don,t know exactly what components I need to run the system for a out of car use . .. The engine will be used in a two wheeled drag bike for the dirt track. The ign and fuel injection system seem to both use some the same components,,, like the angle sensor and so on. I need help to sort out all the right components and make them work ... I am not interested in using any emission parts unless they are absolutely necessary. I do have two 86 sle to take parts from... So anyone that is up to a long drawn out challenge your help would be appreciated ... Rotary engines are totally new to me I have built these machines from Harley to v8 chevy engines .. The reason I want the rotary is they have the same cubic inches as a 1300 cc Harley Davidson close to 80 cubic inches and those are the boys I want to race .. I also have a small self contained private shop mill machine ,, Lathe etc. I just need a little guidance and patience .. correction A Lot Of Guidance and patience .. This is not as extreme as some would think if you google dirt drags or dirt drag bikes you will find that they have them all the way past 1000 hp. I will be the only one that I know of that has used one of these beautiful little engines for this purpose.. Thanks Boogie

 

You can use a side draft carb and have the Aux ports work if you buy the right intake. The S4 intake consists of 3 major parts. Dynamic chamber and lower/upper intake manifolds, (LIM/UIM). You'll keep the LIM along with all the attached parts for the Aux ports, then find a Racing Beat UIM for a 2 barrel side draft carb, Mikuni, Weber or Dellorto.

You then need a way to activate the Aux ports from the exhaust pressure. In the photo album under my user name there's a pic of a 1/8" copper tube that I use on my 87. The elbow is 3/8" NPT X 1/8" compression. Parts can be found in the plumbing section of your local hardware store.

 

Look into a full standalone.

 

Thank-you for steering me in the right direction.. What I have decided to try is using only the intake manifold with port actuators intact I am going to make a manifold adapter to accept a 500 holly ... Instead of using the pressure side of the port actuators I will machine a piece to shrink over the bottom of the actuator and put a 1/8 spout on it then use one of the ports on the base of the holly that has vacume ON PARTIAL THROTTLE and use that to open the ports .. I know I can make the tower to mount the carb on as I have made many for large v8 engines ( when we were oval racing sometimes we only used a carb for one or two runs and then would try something else so instead of buying different towers we simply made our own throwaways .. Has anyone ever tried this and with what kind of success.. ??

 

That's an interesting approach. I think you're over thinking the aux port activation, but give it a shot. Fwiw, the aux ports should open around 3600-3800 rpm.

 

If you mean that they might open to fast I think I can make something to control that or do you mean that they are not as important as I think ? Also when I look into the exhaust ports is it normal for the( insert ,,I can't find a name for them )to move a bit ? one moves and one seems firm or does the header and gasket hold them from moving when tight ??

 

It only takes 2-4 psi to begin opening the Aux ports. The solution shown in my pic is elegantly simple. Converting it to vacuum operation is overthinking/overworking it. The exhaust inserts should not be loose. But there is little you can do unless you're willing to tear the engine down and replace the roll pins that hold them in through the side of the housings.

 

I really appreciate you taking the time to help me through this I have read quite a few of your threads and I know that the guys keep you busy and that tells me you know your stuff... I will do the pipe and see what happens I guess my only concern was getting enough pressure with just short headers with no mufflers but if needed I will make something to trap the exhaust where my fitting goes into the exhaust pipe ...[LIST]
If the insert wont do any harm being a tad loose then it can stay like that until there is a reason to pull the engine apart .. I will give you a break for a few days while I see what I can come up with for the carb mount and so on and then I will be back to pick your brain about the ignition side of things ...And won't that be fun [LIST=1]

 

Just a few more hours and I should have my air box made ... I will take a few pics and post when I get it finished .. I will make both ends from shatter proof plexiglass machine them to fit,, use threaded rod to run through and bolt ends together.. That way I will be able to see if there are droplets going into the intake from the carb or if it is just vapor .. Also cleaned and polished the lower intake ports,, it actually opened up very nice .. The pin in the one port valve was wore out and the other one the actuator was stuck .. I'm thinking that there must be a large number of 6 port rotary's out there with inoperable port valves...

 

It is safe to say that most of the 6 port 2nd gens don't have functional aux port at this point. Either from wear and tear, or idiots who defeat the system because they think it will make the car faster.

I'm very curious about your setup. Looking forward to those pictures.

 

I have made a few different shapes of air boxes and to be honest I don't see much difference ( but this is the first on a rotary ) all I know is that when the throttle plates open on the 500 there will be a good flow of air and if jetted down a bit should have good low end power and when the auxiliary ports open there should be ample for them too.. It might pool a bit but remember it is for only three hundred feet as hard as it can take .. I just hope it doesn't surge at the end ..I don't need that ... Going to try it in line to start with if the engine creates too much side-draft i will need to cross mount and that gets complicated and expensive ,, All comments are welcome so long as there positive no just kidding I'm use to negativity ... All I know is if I can keep it going in a straight line it will win every time .. Will I need a vac line going to the transmission modulator valve to keep it from shifting prematurely . Any way here is a couple pics I will take more as soon as I get everything rounded out and cleaned up

 

opened the ports and shined them up a tad ..

 

Ah, I see what you are going now. I had thought you would be keeping the entire upper intake, but replacing the throttle body with the carburetor. This makes much more sense and it is unlikely you will need to worry much about fuel pooling.

 

Actually Arron that was my original plan but after the comments from yourself and Trochoid and thinking about it it didn't take long to see the problems associated with the long horizontal tubes . I would like to make that work though I think it would look good .. I tried a little experiment on the subject of pooling .. I noticed quite a few beads of oil on the inside of the end of the vac hose while the vac was still running after cleaning off the top of my mill.. with the vac running I placed my thumb and forefinger round the hose and slowly slid my hand up, as soon as my fingers were above the edge of the hose end the oil beads were sucked down the pipe .. That is what I thought might happen in the air box but with the rounded edges that problem is gone .. so I don't think there will be any problem with engine surging when the throttle closes .. It will be interesting to look into the end of the air box when the engine is running to see what actually goes on in there .. I can hardly wait to get it running Man I feel like a kid just before Christmas

 

Just a couple more pics of air box ends being made from plexi-glass ..

 

That's a cool setup. I love the idea of the clear intake manifold. Actually, I did something similar on a plenum I helped with on a 12A PP engine. The idea was to be able to see the injectors spraying fuel into the engine. There was to be a camera mounted near the intake and a display on the dash.

 

Thanks Aaron When I finally get it up and running I will take a short movie of what's happening in there and either post it or mail it to you. Making things comes easy to me but this dam Electronic Ignition stuff is killing me as you know I am building this with the bare necessities and all the other things I have read include components that I don't want ... I have my coils and wires, the connectors for the coil wiring is there somewhere , I take it that the control box is under the dash, drivers side against the kick panel ,, What else should I need .. If you help me through this I promise to be a good boy-- if you don't I will get my ex-wife to cast a terrible spell on you ..

 

Are you running a dizzy or the 2nd gen ECU and CAS? If the ECU, I'd recommend downgrading to the dizzy, because the ECU won't advance timing without the AFM connected and working.

If using the dizzy, then you don't need the control box as that is just part of the emissions setup. Check the 1st gen FSM for the wiring diagram. All the coils need is 12V on one side, the ignitors on the other side, and then the ignitors need their ground and 12V supply. Page 289 of the 1st gen Haynes manual.

 

No dizzy here ,,Do I need a special one or will any for the 13b work ? I will check the local auto wreckers but I would sooner buy one from someone here ..I will check and see if there is anyone close to Saskatchewan that might have one .. So all I need to do is swap my angle sensor for a first gen. dizzy and use the same coils and ignitors that I have .. huummm this seems to easy I must be missing something ..

 

Well found a dizzy just waiting for it to come .. The more I look the more blue I see so while I am waiting I took it apart and repainted it green I haven't seen any green ones .. Need to find some nice big O rings for the ends of the air box , I try to find clear automotive silicone But I can't find any so for now I am stuck with the ugly blue **** I wonder If I can Get Green.. Took the starter apart just to have a look see and of course the brushes were hooped so ordered new ones from NAPA and they had them in 3 days.. Took a few thou. of the armature , just to shinny it up a bit .. I used the Holley 500 racing carb ( I love them you can change everything in them for performance right through from idle right to the top.. ) Next time if I use a carb I think I will go with a nice set of side drafts and I think I know who to talk to about that when the time comes.. When I take this engine apart to rebuild I will do a proper job on the paint but it seems good right now ..

 

like the message says more pics of Mr Green

 

nice work. i'm curious to see how this runs with all that open air under the carb.

 

My theory behind the tower is that with the large area with negative pressure I should be able to lean the machine out on idle to keep it from loading up and then the over sized acc. pump will supply a extra good shot all the way up to full throttle without hesitation .. I have a coffee cup half full of power valves and jets to play with. I will use trochoids little pat. for the operation of the port valves but I might put a electric solonoid in the line to control the port valves and have them open whenever I want with a switch on the throttle linkage ( just a thought ) .. I uploaded the wrong set of pics in # 23 so if someone wants to delete them that would be nice ..