zenith stromberg carbs

[rdssdi]

While running my +2 for the aforementioned temperature testing, it appears my ZS carbs perform poorly. Although the color tune revealed a blue flame I feel my carbs are running rich.

They were rebuilt during the restoration which has been years. At one point I added the adjustable needle / air pistons.

I wonder if a new rebuild with a bench test would improve performance?

I used Joe Curto to rebuild the carbs initially but I now use Jeff Palya at Paltech. I have been very impressed with his work on other carbs.

Has anyone gotten the ZS carbs to work well?

Bob

[Rob_LaMoreaux]

I got them to work pretty well even with the too long of duration cam. It took some time and I disabled the temperature compensator. I too went to adjustable needles but I can't remember which they were and I couldn't find the marking on them. I have an narrowband O2 sensor and at one point it was running rather lean which cause too mcu h heat inthe exhaust. Once I got it set up right it was much cooler and I got 42MPG on a cross country trip 1/2 55mph road 1/2 70 MPH freeway.

A wideband O2 sensor with logging would help a lot. The colortune is a nice idea, but to work right you really need four of them and a dyno so you can see what it does over temperature and load. Without the temperature compensator disable it could read great in the garage then be completely wrong on the road

I've got a weber head now and the car isn't all the way back together after a clutch job so I can't offer a whole lot more.

Personally I like the ZDs, but I wish they had been applied correctly on the engine. they should be paired to the correct cylinder pair (1-4 and 2-3) or one big one used for the whole engine. Pairing them to 1-2 and 3-4 means cylinders 2 and 3 will always be a little lean and 1 and 4 a little rich when everything is right.

Rob