Dual zenith NDIX32 carbs maximum engine size?

[volkswagenman]

Hello,

I have a nice vintage TDE tuning set with dual Zenith NDIX32 carbs and I am building a engine for this set.

I have original dual port cilinderheads flowed and a AS41 engine case. Both are already machined to 92mm cilinders. I would like to use a counterweight crank and I don't know if it is possible to make a stroker engine? With 69 stroke it is a 1835cc and I was wondering if it is possible to make a 76mm stroke? So it would be a 2021cc. But I don't know if the carbs are to small for this setup (dual 28mm Venturi's and 32mm throttles each carb). And would the crank be to big for the case. (I know I have to make clearance) I have a new set longer cilinders 92x82 and have to machine them to the calculated length so I don't have to use shims between the case and the cilinders. These carbs were also used on a Porsche 356 1600 super engine with 75 HP. I also have a engle W110 camshaft, Bosch 010 ignition, stage 1 valve setup for max 6500 RPM and sidewinder exhaust.

I hope someone can tell me the maximum flow/powerband of these carbs.

sorry for my bad English😬

[Alstrup]

Hello.
With the 32 NDIX there is no idea in going larger than 1835 because the carbs cannot support more. From our experience with Porshe 356 engines we see that with 1720 cc displacement and varius cams the power plateau´s at around 53-5400 rpm and 95ish hp at best. Typically more like 90-92 hp.
You can modify the 32´s to 36 mm butterfly and go to 30 mm venturies along with modifying the carb top and add stacks (Stacks do not aid much in power, but the torque pattern gets a surpringly good boost. This all together can make them support uyp to about 115 hp with more cam and compression. This modification is a little costly and are generally not recommended unless it "has to look right"
In your case, with 1835 displacement and W110 cam I would expect the classic, around 90 hp.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[volkswagenman]

[Vanapplebomb]

There are at least two other NDIX carb sizes out there, 36mm and 38mm. Unfortunately, they are not getting any easier to find these days. L

There are a fair number of 36NDIX carbs out there, but prices are getting pretty stupid for cores. They almost always require a complete tear down and rebuild given their age.

The 38NDIX carbs darn near may as well be unobtainable these days. I haven’t seen one in a number of years.

But, if you ever happen across one...
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1800 Type 4 Berrien 295

http://www.thesamba.com/vw/forum/viewtopic.php?t=487021

[Alstrup]

Both the 36 & 38 NDIX have fixed venturies. That makes them less interesting for the average tuner. I can get them CNC machined to 29, - even 30 mm venturi size. We have the program developed. But still.
38´s are very rare.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[Frederik]

I have two NDIX 38 and one "39" (modified/rebuilt 38?). But they are for single carb use, most probably used on some sort of military veicle as they came from a army parts warehouse, one is probably NOS, but the two others look used. I don't know if they can be used as a dual setup or single carb only.

https://www.thesamba.com/vw/forum/viewtopic.php?t=729416&highlight=38+ndix

I ended up just buying a set of porsche 32NDIX that suited my plans better and still have no idea what to do with them. Can they be used for something fun and what would a fair price be on them (if so)?