Redliner223

iTrader: (6)

Since I've been into rotaries (5 years now) I've always wanted to do something crazy.
I've been dreaming about doing a 13b 4 port that makes 220hp at the wheels with a side draft carb. With my little knowledge I don't know if a naturally aspirated rotary can make it with a simple carburetor, I've seen 163 and numbers around that area.
I'm just trying to get an idea what I'm in for if it is even possible.
No turbo for this build just carbs.

F1Pilot

PP and it should be no probs.

BP pretty much same, but you be better of with 2 side draughts and 4 runners.

As an EP? I've no idea.

Redliner223

iTrader: (6)

For the internals in the engine besides the 4 port housings what would be the best years for the other parts?
Would using say '95 rotors be better than using rotors from a '83?
I would like it to be as reliable as possible and money wouldn't be an issue with this build, in a perfect world.

j9fd3s

iTrader: (3)

do it! it'll be fun no matter what HP it makes. i'd expect something more like 170-180hp, more is possible, but you really need to have all your ducks in a row

Redliner223

iTrader: (6)

How accurate if this information?
Porting

peejay

Should be doable with a pair of DCOE 45s or 48s on a big street port, if you want the number. Not sure if dual DCOE manifolds are even still available (or if you'd have to do so much work to it that you'd be better off fabricating), and exhaust tuning goes from "important" to "critical".

We're talking about a 99.995th percentile engine, though. No screwing around - NEW housings, ceramic seals, 9.7 rotors, lots of time playing with exhaust lengths and intake trumpet lengths and tuning.

I've heard from a reputable engine builder of a similar engine making 260hp at the wheels with a non-streetable exhaust.

I'm shooting for similar numbers, but I'm exchanging ducks-in-a-row for bridge ports, and am going to be using a Holley 750 which can be thought of as a pair of 42mm carbs. Hoping that I won't need to go larger on the carb, since larger carbs are much more expensive used. People have far exceeded my power goals with the 650 so I think things will be fine.

And a lot of the info on that page is BS. You won't make 180hp with a stock ported 12A unless your "exhaust upgrade" includes a turbo in the manifold, and the info regarding the peripheral port is flat-out wrong.

Redliner223

iTrader: (6)

Well, rotary engineering produced a dual intake system and Atkins has a duel carb intake but it is directly side draft. I asked about it some time ago and it's only truly good for drag racing or super high rpm applications.

peejay

And that's what you'd want. The dual side draft setup is superior to everything else because the manifold is straight.

junito1

Wouldn't he want na rotors from an s5 6port engine? I think this would also help achieve your 220hp goal.

ArmyOfOne

iTrader: (12)

Definitely the 9.7s out of the S5 N/A

As for the exhaust, 2" i.d. tubing for the primaries joining somewhere under the seat collecting into a 3".

As for the carb I know a Holley 600 on the above setup, bridgeported will get you that number easily.

fidelity101

iTrader: (11)

all you need is money!

Redliner223

iTrader: (6)

This is looking good so far, thanks guys.
I've seen this come up before but is using the rx8 e-shaft any better or should I use the s5 e-shaft due to the rotors.

Sgt.Stinkfist

iTrader: (6)

the Rx-8 shaft is better in the tiniest amount, definitely not a cost effective part swap, just stick with a full S5 NA rotating assembly

Redliner223

iTrader: (6)

Can you guys post pictures of the direct side draft intake.
I'm trying to get an idea of how much clearance is available for an air box.

Thanks everyone.

Tanj!

iTrader: (5)

TWM originally made the manifold. They were bought by Borla. Borla has sold off the manifold portion of TWM's bussiness to Pierce Manifolds.

Their Mazda products can be found here.

Some user pics can be found in this thread at nopistons.

Redliner223

iTrader: (6)

Wow for a 1000$ ...... I guess I know what I'm getting for Christmas. LOL

Any pics installed on the car or a car? It doesn't have to be the double carb intake it can also be a single.
I was thinking short stacks with a mesh screen would be best, but if a box can be built so I can draw cold air coming from under the car that might be better.

peejay

The double is the best manifold for power, period. A single won't be able to keep up, AND have the drivability.

Redliner223

iTrader: (6)

No, I totally understand that and that's why I'm going with the double.
I just want a picture of how close a carburetor is brought to the fender wall.

jorx7

iTrader: (11)

220 is more than possible on a 4port. but bridge or semi pp would be needed. look up my build and youll see. putting 230 down. im running apexi pfc instead of carbed. just more easier to tune. post pics when you begin!!

Redliner223

iTrader: (6)

I've been keeping my eye out for 4 port 13b in Texas but so far I've had no luck.
This project will start as soon as I find a nice one near me.

Hopefully in a month or so I'll have an extra 12a to tear into to get some practice in before the real project.

peejay

Turbo II or FD engines are the best starting points. 13B-RE if you can find one.

I'm EXTREMELY happy with my 4-port 13B (12A end housings on GSL-SE block), but Turbo II secondary ports are larger than the 12A housings have, and all FC primary ports are MUCH larger than the GSL-SE ports. So I know that I'm leaving a lot of power on the table, but these are the parts I had, you know?

Next step is installing fuel injectors in the carburetor. GSL-SE injectors are going static at 7500 in cool weather. Extrapolate on that a bit...

fidelity101

iTrader: (11)

bump for rep for pierce manifolds, just picked up 4" air horns with new filters, great support, prices and shipping.

j9fd3s

iTrader: (3)

yes pierce is great, i get next day service from them, although they are like an hour away...