redbstd

what the big differnce between the two. from what ive seen the six ports arnt as good as the four ports, or am i mistaken. i want to built a nice ported engine but am a little confused when it comes to the port designs. will it be better to scrap my six port in favor of a four port?

trochoid

iTrader: (6)

6-port NAs offer great driveability and low end torque. 4-ports offer more high end due to being able to be ported more.

84stock

iTrader: (5)

Full performance application=4 port, great daily driver with economy in mind=6port, great combination=6 port with 5-7 psi of boost.

dbragg

iTrader: (7)

what do you want to use the car for?

im in the stages of trying to design the power plant for my SA. im looking at many different rotarie designs as well aspiston engine..yeah i know. for now ive decided to stay rotary. so i to am debating between 4 or 6 port and what rotors. mine will be boosted though.

locopr1

Does anyone know where to get the adaptor to run a 6-port 13B using a 12a manifold and carb? Has anyone tried it and how does it work? I imagine you bypass two ports?

Blake

Beware conventional wisdom. You can make just as much power with a 6-port as you can with a 4-port. The conventional wisdom was formed in the mid-80s when the 6-port engines were brand new and 4-port engines were old familiar friends. The comparrison was not apples-to-apples but "built" 4-ports vs. stock block 6-ports with bolt-ons. Like now with the RENESIS, the engines were too new to be pulled apart and modified by a large number of people, trying a large number of different things. What you had were a large number of 4-port gurus making a lot of power and a lot of 6-port shmoes feeling inferior because they just added a Weber or Holley and a Racing Beat exhaust and didn't keep up. The 4-port gurus, like all gurus, are resistant to accept a new learning curve with a new engine, so most either stuck with what they knew or dipped their tow into the 6-port engine and quickly gave up. The few who persisted were too small of a sample to see consistent results. Also there has been nowhere to competitively race ported 6-port motors, the street cars they came in are all in the era of emissions control (fewer potential customers), and factory turbo 13Bs became the hot ticket. Overall, the 6-port motors have gotten a bad rap because all of the above came to formulate the conventional wisdom that 6-port motors had less power potential than 4-port motors when the reality is that they never had a chance to show their potential before the world made up its collective mind as to the perception of potential.

I have posted this dyno sheet before but the response has been underwhelming. It does not agree with conventional wisdom so ignoring it seems to be the only rational reaction. It shows a ported S5 13B-6PI with factory fuel injection, a S-AFC piggyback, stock induction with a cone filter and a full exhaust making 189.9 rwhp. I am not saying you can't make that kind of power with a ported 4-port, but I would love to see the dyno sheets from people advocating the conventional wisdom that the 6-port engines don't have the potential of a 4-port engine. Show me your dyno sheets. No nitrous, no turbos, no bridge- or peripheral-ports. Just a full-effort streetported 4-port with any conventional intake and exhaust combo. If what you say is true, there will be all sorts of 200+ RWHP 4-port engines out there. Perhaps there are. I wanna see 'em.

glewsRx

iTrader: (1)

Yeah, what he said.
And let this be a lesson to you all.

84stock

iTrader: (5)

Great feedback Blake. My ideal daily driver would be a GSLSE with a streeported 6 port & s5 vdi intake.

diabolical1

iTrader: (3)

well, there's credence in what Blake said. it brought a new train of thought to me, not on the potential of 6-ports, but on why they are met with a cold shoulder by so many. i always believed that they had hidden potential, but i felt (and still feel) their shortcomings are their intake setups and (lack of) engine management. a few years ago, Kahren's results supported my "feelings". the bottomline is that now there is proof that significant power can be made with them. in addition to Blake's dynosheet, there are a handful for others floating around.

with that said, the 4-vs.-6-thing is going to totally depend on your goals and the budget supporting them. however, i think you could probably use your 6-port for any goals you have for a street car though.

Blake

Actually, I believe their intake setups are a strong point of those motors, particularly the latter ones. The Auxiliary ports are open so late that the revertion is utilized to help charge the corresponding port on the other rotor. That is a very hard thing to phase correctly without a gaggle of engineers designing and testing until it works. Aftermarket manifolds may be better in other ways, but as far as utilizing reversion goes, they miss this freebie entirely. The S5 intake was the pinnicle. Those motors have three distinct torque curves (pre-auxiliary, auxiliary, VDI) and you end up with a composite torque curve that is virtually flat. But, of course, the downside is complexity. Nothing is prettier than the stark simplicity of a 4-port with an IDA...I just don't necessarily think that is the only way to make good power.

wallyrx7

iTrader: (1)

when people talk about 6-port motors are they referring to the 13b that came in the gsl-se ? or does no-one use that motor for projects?

Rogue_Wulff

6 port engines were used in the SE and non-turbo 2nd gens. The SE engine had the lowest power, and heaviest rotors, while the 89-92 N/A had the most power and lightest rotors. The rotor weight difference between 84/85 and 89-92 is around 2LBS each. Huge difference in rotating wieght.

Latin270

Thats why once I dropped in my current s5 motor I never looked back. My next project involves a street ported s5 motor. Aside from Blake, Judge Ito also has done great things w/ the 6port n/a motors. Check out his crazy youtube vids.
http://www.youtube.com/user/JudgeItoRx3Sp

Slammed_GSL

iTrader: (14)

What ECU are you running? I got a s3 13b and a s5 UIM&LIM and a Megasuirt to run it. Don't think the -se ECU is going to cut it.
Let me know on the ECU question.

diabolical1

iTrader: (3)

i don't think you and i really disagree on this so much as we may simply place a premium on different qualities/results. i totally see the merits of the stock intake system and i agree that "improving" the Mazda design would be, at best, ridiculously difficult. however, i, personally, would prefer to have some more power even if it's at the expense of a flat torque curve. i mean, i understand that this is just my taste and i'm not arguing your points at all, really. your results speak loud enough for you. likewise, stock ports running within 10 whp of a streetport by simply changing the intake setup and adding a decent EMS speak pretty loud, too.

bugman1973

i am using an s4 6-port in my 85 gs project that engine is much stronger than any engine before it tried the so called gsl-se engine. i blew up that sucker in like 3 months the six ports are where they are at though so much potential. when i get done i should be close to 250-300hp and yes still s4 but some port changes will be used. intakes will be changed and i will be contacting pineapple racing and and some other companies about porting the intake runners and dynamic chambers and some other thing i been thinking up. you'll will know when its done and i will be a one of the seven stocks to debut it.

Blake

I see where you are coming from and don't disagree in theory. I would question if there really were an additional 10 rwhp to be picked up with another manifold and EMS, however. Have you seen any dyno sheets of 200 rwhp on a streetported 6PI? Not saying it can't be done, just that I haven't seen it personally. I do think we could pick up more peak power from the one on the dyno sheet above by removing the actuating mechanism and pinning the sleeves open (because the sleeves with inserts flow better than no sleeves at all). Probably not anywhere near 10 rwhp, though.

Blake

Good luck on the project. I too have recently built an all-out 4-port 13B for myself that I can't wait to try out. Fairly modest porting but with S5 internals, lapped and renitrided plates, RX-8 stationary gears, oil mods, etc. I plan to use a TEC III to control it.

Jeff20B

iTrader: (13)

That sounds like some fun.

I'm probably going to build a J-spec RE-SI engine (6 port 13B from an HB Cosmo) for the GLC in a few months. I'll probably swap out the super tiny ported intermediate plate in favor of a US-spec GSL-SE intermediate plate, and port out the end plates to GSL-SE spec as well. The RE-SI spec has very small ports for some reason.

Blake, I'll probably send a set of 6 port sleeves down to you guys for some inserts at that point.

diabolical1

iTrader: (3)

i don't know if you've seen these already, but there are some links in this thread. some are more insightful than others, but it's one of my favorites though. i think it's post 21 where i link to the stockport that Kahren made 179-ish. the pics of the motor and dynosheet are X'd out now, but i did post a pic of the motor and you can see a little bit of the manifold he made. it's been like 3+ years, but as you can see it's not forgotten. you made 190 with a streetport and the stock setup, now imagine if you added a similar manifold setup and a truly tunable EMS. add a good tune and imagine ...

Thread on N/A Power

diabolical1

iTrader: (3)

i will be looking out for this one. i've been curious about the TEC III in non-turbo applications. sounds like it's going to be a firecracker.

redbstd

im tired of god d**m turbo hondas kicking my ***. they get me on power alone. im thinking about carbing my engine because this is the fourth time ive heard that the se ecm is a puss. im hoping for 200 horse or so. will porting and direct fire do this or should i just get a second gen na and use it?

redbstd

im willing to put 5k into this power train by the way

Latin270

Swap a T2 in there or NOS that badboy!

bugman1973

i have an s4 and it kill hondas all day with my 6 port