Hi all, well - my motor swap time is here. I've pulled it and got all of the parts (i think) that I'm going to need for the rebuild but.. just about the one key part of this process that I have yet to address is the carburetor. I'm open to suggestions, and money is not such an important factor at the moment, but want to hear about some experiences for different options. The carb has never been touched, that's based on how the bolts felt taking it off and that the previous (2nd) owner didn't have any info on it.

1) Considering rat's nest delete and/or hogging out the carb. I've looked here and through google/YouTube for this process and cannot seem to find a process for this.
2) Atkins Rotary: Side draft 48 DCOE (weber) kit for $975 complete
3) Racing Beat: 48 IDA Down draft for $1200-1300 complete(ish)

Regardless of the approach, I would like the end result to be a clean look to the car. I do not plan on boosting the car at this point, if ever, but I do not want any drop in performance or...i know, i know, reliability.

Write-ups, pictures, or helpful responses are much appreciated.

 

I am in the same boat with a bridge port 12a. I have a hogged out nikki but can't seem to get it right. I have a cheap weber ida clone sitting on the shelf, the problem is the manifolds are so expensive and I am afraid the cheap carb will get me cheap results then I'm having to purchase a real weber to make it right. A street port should be easier for running the factory carb and save you some money.

 

What about the Dellorto DHLA? If you can afford to wait and find one that comes up for sale, I think it is a good option.

Back in the day, Racing Beat sold a modified DHLA 48 for 12A and 13B applications, and I think they sold enough of them that they are relatively easy to find.

I am running a ported 12A with the Dellorto and absolutely love it. I do think that the Nikki is probably the way to go, but something about the clean side draft look, foam filter socks, ease of tuning, and the unbelievable sound is worth it.

I am not sure what a ported 12A sounds like with a modified Nikki... but the sidedraft just has an induction sound that is 'motorsport'. Not sure how else to describe it. I'm running it with the RB full Streetport long primary exhaust.

I have an original Sterling Nikki in my parts collection but have not been tempted yet to run in.

And carbs are a bit controversial.. lets see what the gurus say. And remember, exhaust will be crucial for your ported build too.

Also don't forget the fuel delivery. I don't think the OEM pump is up to the task for a Ported engine. here is my thread outlining an aftermarket pump install and some things to look out for. You want a proper, return regulated setup.
https://www.rx7club.com/1st-generati...ation-1116260/

BTW, have your torn your 12A down yet? Curious to see what condition the housings are in. This could be a much bigger issue that carb decision.

 

I've played with every after market carb set up there is. My opinion the best performer and easiest to tune is the Ida. Looks good too. I'm also a big fan of the mikuni phh44. But those are hard to find. Far better carb than a dcoe Weber.

 

IDA. Easy to tune and, in my experience, they hold their tune. So things like float levels don't have to be set and reset over an over again like the Niki and Holley carbs I have used before. There is also allot of knowledge on this site regarding jets and e-tubes.

I have one on my 13B street port in a race car. Here are what I am using - 195 Main Jets, 125 Air Correctors, 60 Idle Jets, F11 E-tubes with the carb fitted with 42-44MM chokes.
I have no idea if these are the right jets for your engine because I don't know how aggressively your engine is ported, what your exhaust system is like, the intake you are using, etc. It could be a good baseline to start with, however. For sure, use the F11 E-tube

What ever you do for a carb, do your self a favor and get some form of an exhaust based tuning tool. I use a dual Pyrometer but others have successfully use A/F meters. Either way, that is best way to know if are getting close to optimum.

Last, if you want to make power, fit the carb with a cold air box that breathes air from outside the engine bay. Those tall air cleaners might look cool and sound cool but they are costing power. On the dyno my air box made 10+ HP over just having the carb open to the world. On track, at speed, the difference is even greater.

 

Last, if you want to make power, fit the carb with a cold air box that breathes air from outside the engine bay. Those tall air cleaners might look cool and sound cool but they are costing power. On the dyno my air box made 10+ HP over just having the carb open to the world. On track, at speed, the difference is even greater.[/QUOTE]
I definitely would recommend the air box also. I put one on top of my Ida throttle body EFI and saw a 100° difference in intake air temp. Never dyno without the air box. But it felt like alot more than 10hp. Dyno at 192rwhp on a hub Dyno with the air box .

 

@Mustanghammer - What class are you competing it? (SCCA, NASA?) Thank you.

 

Doing the same thing. Picked up a fb a few years ago, got it running. And then built a exhaust. Rebuilt the carb ran ok but not quite right. Said no big deal I want a Weber anyways. Want that old school look. Ya not going to make 500 horsepower but that’s not what I want anyways. Sense 12a housings are hard to find I decided to use 12a irons, gsl-se housings, s4 internals (because that what I found on Facebook for cheap), street port, ida carb, and racing beats aluminum flywheel. Going with 2 msd boxes, and the s4 transmission. And I forgot, got it balanced, rotors side clearanced and irons lapped. Machine work done by Mike at Rotary science.

 

SCCA - Super Touring U. Engine is basically an E Production Street Port