JokkVahl

OK, im thinking about buying a SK racing 48 dcoe for my stock port 12A.
Here is a truck load of questions


I have open headers so what will be my powergain over the nikki ?
And will my stock gearbox and stock 12A handle the extra power ??

Im also wondering what fuel pump and regulator i should use, and at what pressure.



Would i need to go over to premix and block off the OMP system ?
Would my accelerator cable linkage fit without modifications.


Thanks in advance, for answers

Latin270

Well as far as stock linkage goes your going to have to make one. I used the linkage from a stock Nikki and modified it a bit to fit. Looks good but havent tried it yet.

RX7Elmo

from reading here....poewrgain over the nikki will be very noticeable. Possibly 20+hp or so with the right tuning.

I'd run premix.

Stock gearbox and the stock 12a can more than handle the power.

Hyper4mance2k

iTrader: (40)

looks good those short full radius velocity stacks are beautiful and a hard find! get that kit and put it on a 13b ummmmmm....

Boswoj

I had the SK carbs you are contemplating on my 13b conversion for many years, on a short Lake City manifold. Be absolutely sure you know what you are getting into! Mine made tons of power and worked fine within the parameters of what they were designed for. The downside was that they are loud (lots of induction noise), they are really not well supported any more and don't have a lot of parts available, and have a tendancy to be either ON or OFF. The "binary" nature of the throttle works pretty well with race cars, but gets a little old on a street car. On cold and humid days it will also form ice in the carb throat pretty easily - then you don't go anywhere for a few minutes while it thaws out and works again. Face it - carbs with at least a rudimentary choke are kind of a nice for a car that needs to take you to work every day.

All that being said, the car that I had with those carbs on it was nothing but fun. It was loud, fast, obnoxious, and had too much horsepower for its outdated brakes and suspension - just right for a kid out looking to have some fun burning up a ridiculous amount of fossil fuels. It was like the kind of crazy-assed girl that makes the perfect mistress, but that you wouldn't even CONSIDER marrying! Great for making memories in the short term, but not useful for making a future at all.

(as a matter of fact - that carb and manifold ihas been sitting on my workbench gathering dust since I parted out that mistress, um , I mean Rx-7 several years ago.)

JokkVahl

interesting information there boswoj, so in other words the carb isnt that streetable?

Midwest 7's

iTrader: (4)

I have a stockport 12a with 48 dhla dellortos and it is fun as hell to drive. definitly street -able. rb header so it is a little loud but who cares. i say buy it and enjoy!

Rotor13B

That's all fine and dandy but those aren't Dells . I know what you mean though, i have the 48 dhla on my 13B and it perfectly streetable.

Boswoj

Jokk -

It's not that it isn't streetable per se, it's just what you are willing to put up with in terms of compromise. I had mine set up well enough that always started and got me where I was going for several years. I had it jetted too rich for most of it's life, and made the common mistake of not making sure that I got it to full operating temperature EVERY time I started it, so eventually it carbon locked and gave up on me. I also had RB headers on it and it was loud enough that all my neighbors always knew every time I started it. It accelerated like a motorcycle which was really cool at the time. It sucked down huge amounts of fuel, even dipping into the single digits if really flailed hard. I t was serious ticket bait as well, drawing interest from Johnny Law on a regular basis. It required constant maintenence from a mechanically inclines and diligent owner to remain reliable. Streetable? I drove it on the street every day for years. At that age I would have considered it streetable - but I would have a completely different opinion today with my accumulated "age and wisdom". Now I have a nice boring Ranger pickup that takes me back and forth to work with zero drama, an E30 BMW to use as a track day / instructor car, and a 1st gen Rx-7 E-production race car that I don't have to worry about being civilized at all. Streetable is in the eye of the beholder, but I just wanted to point out the strengths and shortcomings of the SK setup.

(edit: Don't Dellortos, Mikunis, and DCOE's have choke circuits? I've run the SK, heavily modified Nikki's, and now run a modified IDA but have to admit some ignorance about the others. I have an original pair of italian Weber DCOE 45's sitting on the same shelf as the SK's gathering dust, so I guess I could go out to the garage and take a look.............)

Midwest 7's

iTrader: (4)

yea, i guess if by streetable you include gas mileage, it is not.

680RWHP12A

sk is a great carb, get it, try it ,,you'll love it!!!

japanese copy of a weber



fbII... where are you?eating cheese?

680RWHP12A

p.s. it also has externally adjustable float level too!!
excellent carb for boost prepping

JokkVahl

I got a very nice offer on a Weber 48 DCOE yesterday.

So whats better, weber or SK when you think about powergain and streetability?

perfect_circle

i hve a questin(sorry for the hi-jack, but its about SK's) do i need to use phenolic spacers, or any kind of nylon spacer between my carb and intake? its a 48 sk, and a racing beat one piece intake mani.

cpa7man

iTrader: (2)

Anyone have a link to SK racing? Also since were thread jacking here, anyone know of a source for intake manifolds for DCOE (Weber) type carbs? Racing Beat does not carry them anymore nor can they tell me a supplier. I'm trying to decide if I should dump my DCO and go to IDA......I'll start a thread later.

cpa7man

iTrader: (2)

I don't use one in my sidedraft Weber DCO. I know the IDA type (downdraft) do use them.

perfect_circle

i was told that i had to

JoseReyes

Have you tried Mazdatrix http://www.mazdatrix.com

the racing section

cpa7man

iTrader: (2)

Thanks Jose, they have them on the web site. I should have known they would have them. I just like the beefey look of the Racing Beat. I'm also going to check Mazdamotorsports.

perfect_circle

bump for my question

JokkVahl

so ?
What carb suits a pretty dumb person when it comes to carbs like me ?

Sk racing 48 dcoe or weber dcoe ?

JokkVahl

*bump*

mortenf

Hei igjen Joachim! (sorry, its Norwegian )

I can give you a simple and straight answer, Does the SK use Weber jets? Or do you have to buy special SK ones? Dellortos for instance, is a bitch to get parts for..

I`ll list my opinions.
Buy the new SK, filter, manifold. If its not jetted right, you will have to buy these jets. If the SK ones are different from the Webers, i would say NO. You would have to start fine tuning it, and that requires an investment in numerous different jets to find out what suits your engine. This would be costly.. Dont forget that you also will have to pay customs when importing.

Buy the Weber package. There is still a lot of these around, jets are easy to come by, and they are used (aka cheap) For instance, old VW that has been modded usually uses Webers. The same does old Fords, Lotus etc. These carbs are well known in the rotary community in Norway and you can easily find out what jets to use, so there is no need for buying a lot of jets and fine tuning. Plus, if you buy the package you got an offer for, its most likely already tuned pretty good for a 12A. I know 7000 kroner sounds expencive, but think about it. What you get is basically a bolt on package that will take you 30 minutes to install, and you are ready to race. Did Mindor say that you would also get a pump and regulator? If not, the rotary guru Totte recommends two black Biltema pumps, paralell coupled. The Webers doesn`t need a lot of fuel pressure. (remember, its not the pressure thats important, its the mass of fuel going in to the carb)

Basically, it all comes down to what parts fit the SK. If weber parts, especially jets fits, then buy the SK. If they dont, buy the Weber!

MVH
Morten

fitzwarryne

You have a stockport. A modified Nikki will easily cope with the fuel requirements.

Fitting the SK will result in very poor streetability, extremely lumpy, poor starting, extremely noisy, and a very high fuel consumption. At the top end output will be the same as a well modified Nikki [Sterling style], low to medium rpm less power. But at least it will look cool and a cheap imitation of a Weber should be cheaper Can you still get spares, factory service?. To even be serious you need a lond inlet manifold to go with it.

If you are into performance and trackwork, get a decent port job done and then think of a SK. But think longer of getting an IDA. By then noise, pollution and fuel costs will not be relevant.

There are good books on tuning a Weber, and plenty of tuning parts available if you streetport and they might be useful on a SK

JokkVahl

Hei morten
Thanks for the information there, you have been a great source for information on my "carb hunt"
I came across an auction on ebay with lots of information regarding the SK carb.
http://cgi.ebay.com/ebaymotors/ws/eB...965192745&rd=1

Looks like they do use weber jets !!
And a cable operated choke compared to weber, perfect !
Remember 3600 SEK is like 3200 NOK, for a new carb, upper manifold, pump, and FPR.
Thats cheap !
But the negative thing with the SK`s is the lack of parts, i doubt you find an overhaul kit for these carbs anymore.
And i have to order a new lower manifold

And ! with a DCOE i can finally close my hood with my UFO (powerpulse box) the air intakes on the hood blocks me for closing my hood

My brain says weber, my wallet says SK racing.
hmm...