As the title reads, i am thinking of modding this manifold to fit with a sterling modified nikki carb. anyone try this before? i like the simplicity of the manifold, and the nice flow of the ports. i know i will have to relocate the studs, and modify the ports slightly. i'm thinking of using a phenolic spacer as an adapter plate. i have to look into it a little more. any opinions? am i just wasting my time and ruining a good manifold?

 

No idea if you would be ruining it or not, but if you get it going please make sure and post pics and even possibly a write up on what you did.

 

I've always thought about that as well.
I'd be willing to bet someone could fab an adaptor that would use the RB Holley intake manifold stud locations and account for the port differences (kinda on the same lines as the adaptors available to mate a 12A dog leg intake manifolds to a 13B block) but in this case the adaptor would have studs affixed to the top to accept the Nikki carb.

Trick is- Carl or someone would have to flow bench the set-up to see how it performs against the stock manifold to see if it's really worthwhile..

Could be a little out of pocket coin for very little gain (or vice-versa).

 

well, i got the manifold used for a good price, and the spacer isn't too expensive. i'll see what i can come up with.

 

I don't think the ports will work out too well I was looking at mine to do the same and I think the ports on the inside were too close together and the mounting flange on the nikki was too close to the runners in the manifold. Then there is the issue of the drop in velocity as the air/fuel hits the large runner and slows down and the fuel falls out of atomization from the lower velocity.
There is 1 potential benefit of the smaller carb on the big runners and that's anti-reversion but unless your running a monster port at low speeds on a rotary it shouldn't be an issue.

FWIW for the last few months I have been running a zenith RX4 carb on my 1/2 bridge 12A on the holley intake and I can tell you the low end seems a bit doggy I'm in the process of getting the Carter/performer 600 ready to go back on it again.

 

The nikki will perform better on it's own manifold. Adapter plates are **** for flow. My guess is a loss of power, but i wouldn't mind being proven wrong

Marques

 

allright, thanks. maybe i'll just modify the stock manifold and sell the holley manifold.

 

I have had a similar thought, but with my experience after the thought. A Holley creates much more power than a nikki ever could imagine! So why waste the time and money, buy a used Holley and learn how to tune it, their is Not much to Holley's at all . . .

 

what i am thinking about doing is looking for a used holley 4 barrell throttle body fuel injection setup. i have seen some on ebay, and they aren't too bad price-wise, and would give full tunability. this is for a csp autocross car, and the engine will be stock ports (have to follow the rules)

 

Is that the setup on most early 90s chevy trucks? If it is I would think it woudl be very easy to snag one from a junkyard for cheap.

 

yeah, but this is fully programmable with a laptop

 

ooh nice

 

yeah, new at summit its like $1200, which ain't cheap, but if i could find a used setup for a better price, it might be worth it. fuel injection is soooo nice, especially when it is fully programmable.

 

any new feedback on this?

 

The Nikki carb is very tall. It may not fit under the hood with an air cleaner assembly if you use a Racing Beat manifold.

 

i sold the manifold. gonna mod a stock one, and use sterling carb

 

Very well said. Youd have to make inserts to fit in the runners.










That could be an issue as well.

 

I made a few custom intake manifolds and the difference was minimal on a dyno with a stock nikki, and a lightly modded nikki.

I never had the pleasure of testing with a sterling carb though.

 

You must have missed Carl's recent post where he mentioned that he and Sterling have topped out their nikkis at 465cfm, the same as the racingbeat 12a Holley!

Now, if you're on anything bigger than a large street port, you'd go with a Holley 600cfm instead, which the Nikki can't hope to match. But slapping the same 600cfm on a stockport won't yield "much more power than a nikki...". It's simply TOO much. And if you're on something bigger than a large streetport, chances are you're going to spend the money on the intake upgrade anyway.

Jon

 

Interesting V8kilir, I assume this was a stockport engine?

Exactly Jon, youd be over car'b and velocity would suffer, killing the low end. There are times when too much is just TOO much.

 

One thing I do remember was that the Holley manifold really flowed well compared to the stock one.

 

yeah stockport
More people have stockports so I wanted to dyno test on a stockport.
had some light mods, my ignition system, rb header with straight through 2.5" exhaust etc...