I was just thinking, the Z SU's are commonly used on 2.8-3.0L L series engines, so would a single Z SU carb work on a 1.4L A series engine? Would duals be too much for a 1.4L? I don't know how the GX dual SU's compare to the Z SU's - are they smaller? I'm considering doing a custom intake to use my Z SU's on my A14 but I dont' know if I need one or 2.

If I were you I would keep my eyes open for a GX manifold that would be the simplest option.

If you were going to the trouble of making a custom manifold I would recommend using both SU's.

In this case, the GX model refered to is the twin carb Japan Domestic Model, [JDM] & not the US single carb model.
These are just the ticket.

Yeah I've been looking for the GX setup but they're hard to find in the US (and hard to find someone to ship it to the US from Oz). That's why I'm wondering if the size is different between the US Z model and the GX model. Maybe you only need one if it's a higher flow carb. ANyone got a spec sheet on the GX carbs? That could answer my question. I'll go look through the Tech articles to see what I can find there.

Oh yeah, and the reason I'm considering the US carbs is because I have a really nice set ready to use. Just don't have a manifold or know whether I need them both or not.
Michael

> I'm wondering if the size is different between the US Z model and the GX model

The answer is in the Which Carburetor article.

Two carbs don't have much more airflow than one due to the design of the intake manifold, so it doesn't matter much whether you use one or two. Just use whatever the manifold is designed for.

And no Datsuns came with SU carburetors. They are Hitachis.

Sorry dd - bad habit from hanging with Z folks. They all call the round-tops SU's.

I've looked at the carb link but still didn't find a solid answer about whether the carbs are the same or not. The P/N given doesn't lead to any Z car hits on google so they're probably different. I'll do some research. Thanks
Michael

Excellent, do the research then share your findings with us. The article shows which ones the A12GX engine uses. Keep in mind that Part Numbers will be different -- just as they are different between California and non-California cars and between years. Instead, focus on the carburetor type (HJE38W). As the article states, these were used on the GX engine and on the 240Z.

Real car guys know exact engine numbers and carburetor types. Maybe some of those Z-guys are just posers Not saying they aren't nice guys.

I think the reason the Z guys call the carbs SU's is because that's the best way to differentiate them from the flat top Hitachi's. Most Z owners wouldn't be caught dead with a set of flat tops - they generally refer to them as "boat anchors" so to avoid any confusion if they're talking about Hitachi's they shorten "SU style Hitachis" to "SU's". The one's who know their stuff know they're not really SU's. LOL Anyway, I'm getting off topic here. I'll post what I find out about the carbs.

Michael

A series Hitachi "SUs" are 1.5"
Z car Hitachi "SUs" are 1.75"

Right L18_B110. I've been doing some searching and I've found just that.

The early Roadsters (1.6L and smaller), the GX Hitachi's carbs and at least some of the 510 carbs were 38mm (1.5"). The Z's and 2.0L Roadsters are 46mm (1.75"). That number comes straight out of the part number: The Z's are HJG46W (46mm) and the early Roadsters are HJB38W (38mm). Still trying to figure out what the "B" and "G" mean - there is also an HJL which is a 510 "flat-top" Hitachi.

So in short, my 240Z carbs will not fit on a GX manifold unless I bore the manifold. I've also found an article arguing against putting the larger bore carbs on an engine smaller than 2.0L (http://www.jetlink.net/~okayfine/su/zsus.html).

Well, for now I'm looking for some more details on which 510s' used which carbs to widen the number of interchangable parts. But in any case, I still dont' have a GX manifold anyway... still looking for one. BUt when I finish my "research" I'll post a more comprehensive report here, if anyone is interested anyway.

Michael