Hey, all. Some friends of mine and I are considering selling custom aluminum intakes at a very competetive price. Right now we're working on single and dual downdraft dell'orto DRLA/weber IDA manifolds. The dual-dellorto prototype is done and I will try and get some pics up within a couple days.
Also, is there any other type of manifold you'd like to see made that isn't available, or rare? I remember there is a very old dual carb mani that's good, but uses smaller carbs than drla for stock port motors. Or possibly a 2 barrell holley manifold? I've never seen one for a rotary.
Anyways, I wanted to post up and get a feel for the level of interest. So, how 'bout it?

 

the holly manifold would be very cool.

 

Here's a strange request. How about a square bore four barrel carb on a 20B? An Edelbrock 750 CFM to be exact.

I don't know much about manifold design, and I need a way to get the air fuel mix from my carb down into all six ports, so I drew up a little something in MS paint. I don't know how large the plenum needs to be, or if it should be shaped/angled differently than in the graphic. The primary and secondary ports will both flow simultaneously. The secondary ports are huge on this engine, and will get most of the incoming AF mixture. The primaries will ingest only as much as they can for their size, I suppose.

I didn't draw a top view, but I'd like all three runners to be as equal in length as possible. Is something like this anywhere close to a possibility for you to build? And if so, how much money would you need? Or am I off my rocker with no chance of climbing back on? What I'm asking is whether or not this style of manifold would even work? Thanks.

 

I/d be interested. BTW anyone know how hard it would be to use an Edelbrock? I really like them better than a holley.

 

elelbrocks are junkive had three new ones , and a used one, most tempremental carb ive ever seen, forreliability a slobberjet rules for flat out performancs holley, for fishing for swordfish eldebrock, just one opinion

 

Hmm, interesting.. I never thought about making custom 20b stuff. Well, it seems to me that you would need the finer tuning of fuel per port a weber or dell'orto would provide, and in that case I would recommend a triple downdraft dell'orto. I'd bet good money on it being a more effective setup than a big single 4bbl. Triple dells would be more difficult to tune, given their flexibility, but they look and sound VERY cool.
Having said that, however, I've got a 12a holley manifold and I'll take a look and see what it'd take to make a 4bbl mani for the 20b.
I believe we can do this, however the biggest hurdle we have is not having a 20b to test fit it to. Is there any way you can get me a flange template, like paint the bottom of your stock manifold and stamp it on a piece of cardboard/paper and mail it to me?
The mazdatrix 20b flange is $150, but we can make one for waaaaaaay cheaper.
http://www.mazdatrix.com/fabricators.htm
If we go with the 4bbl intake, I'm against using a plenum. I think it would take away your tunability. Seems like it would simply dump fuel into all the ports at once in a kind of random fashion, you just wouldn't be able to tune the ports as you like. Also, hood clearance might be an issue. That's my take on it anyways.
We're still debating on the cost of these, so I'm not sure yet, but it'll be much cheaper than a RB alternative.
And you're definitely not off your rocker. A very valid request and it was the kind of response I was loooking for.

 

Something for a Demon Might be nice.

 

A demon would be the same pattern as a holly, no?
Are eldebrocks and holly the same mount pattern
I was under the impression all v-8 stuff had very similar if not the same mount pattern in which case most any american 4-barrel would work.?.?.? There are adapters for all this stuff i know, so we can just make it ford or chevy stock pattern, then people can get adapter plates, and run whatever carb they like.

The single downdraft manifold may be complete tonight, if jay can round up a digital camera we may have some pics real soon.

 

also, for the 20B ... maybe try to adapt something for a single Porsche Weber unit instead of 3 Dells/Webers, since they have 3 throttle plates instead of the usual 2. i don't see why a modded 50 mm (or 55 mm, depending on if you're using a turbo) unit wouldn't do the trick.

 

that's a great idea, but from a "profit to time to demand ratio" i don't think it's worth it. We don't have a 20b to test with either. And of all the people with 20b's how many want carbs with no forced induction, and if you can afford a 20b you'd probably want something better/faster.

 

So are you a fabricator? Do you do your own casting? I'm asking cause I have a project working for a better intake manifold for the NIKKI.

 

I will be making my own Intake for the 6 rotor with two 770 holly avenger carbs, If I get the motor on time?

 

I will be making my own Intake for the 6 rotor with two 770 holly avenger carbs, If I get the motor on time?

 

"So are you a fabricator? Do you do your own casting? I'm asking cause I have a project working for a better intake manifold for the NIKKI."

We're not casting, tig welding aluminum plate and pipe. thus the low cost of production. The finished product will be nice, once trimmed and polished.

 

SCCA racing V8 RX7, are you going to feed three rotors per carb?

jayroc, I think for better tuneability, I might want to build two plenums. One for the primary barrels flowing into the primary ports, and one for the secondary barrels flowing intot he secondary ports. I'm not sure how much the carb will like this, but I think it will be ok.

It's either a custom manifold, or maybe a side draft weber or dellorto on a stock 20B upper manifold in place of the throttle body. Since I have my doubts that simply attaching a carb to the stock manifold will even work, the custom manifold may be the best way to go.

 

i can see what you mean about the economics and practicality of it, and i agree to some degree. although, my take is that if you can afford a 20B-conversion, an intake manifold should not be an issue that will keep you from completing it. i mean, think about it, you have a few choices of where to get the throttle bodies read-made - i know they're not cheap, but ...

anyway, i just want to clarify one thing. when i made the references to the Weber for Porsche Boxer 6's, i wasn't really thinking about carburetors. i was thinking more along the lines of a custom EFI system with a Weber or Weber-type throttle body.

 

The carb you're talking about is the Weber 40 IDA 3c. A triple barrell downdraft carb. I've never seen one in person, but I'm sure they're a bit on the expensive side, even used. If you can find one anyways.
It would be a cool intake to have, I do admit, though.

Yes, if you can afford a 20b, you may be able to afford a custom intake mani, or some sort of modified FI, but you may not necessarily want to. If there's a cheaper solution that will get you running with very decent tunability, I think people would go with it. I would, anyway. Save that money for tires, or suspension.
A good FI custom engine management with manifold and TBs could potentially cost the price of the engine itself. Granted, you could use the stock wiring and manifolds (assuming your harness wasn't cut) and go with just a standalone ECU, but you're still looking at $800 at least. Then you have to wire and tune it and if you don't know how to wire, or tune with independent engine management, you'll need help to get it anywhere close to 100%. And that help usually isn't cheap or easy to come by. The cost factor increases exponentially with FI, although it has some very solid advantages over carbs.
We want to make something for people that know (or want to learn) how to tune carbs, but not necessarily fabricate, or want to fabricate. And at the same time save a lot of money and time on it.

 

I spent all my money on other stuff.