Zenith 32 NDIX single on type 1

[chrswlsn]

Working on a 1300 with a single zenith 32NDIX for a customer. I’ve been having major difficulty with idle. After doing much analyzing, I realize that there are no holes drilled in the throttle plates. Does anyone have any info on the transformation required from dual 32NDIX carburetors from a 356 Porsche to a single 32NDIX on a type one engine. There is absolutely zero idling capable due to the suffocating of the engine When the throttle is dropped below about 2000 RPM. What size hole needs to be drilled in each butterfly and the exact location. This has been done many times before. The old-school techniques are fading away.

[alanhall]

What is the type number of the carb? PO2, PO3 and PO131 were the versions used on 356 motors and PO10 versions were used on Porsche industrial engines with a single carb and is the version typically used on VW engines with a single carb. The PO10 has a large balance passage between the throats in the carb base. There is no balance passage in the 356 versions. The PO10 also was typically fitted with a choke while the 356 versions had the choke area blocked off.