Twin IDF 40 & Malpassi Fuel King 67mm OR 85mm

[dutchspiderrider]

Hi All,

In my ongoing adventure to keep my Spider (built in 1970) running and to upgrade it I have a question: I want to install a Malpassi Filter King in my FIAT, which one should I get, the 67mm or the 85mm? My car has a 1608cc block with two double Weber IDF40, 4-2-1 exhaust manifold, 123ignition, Facet Red Top Gold-Flo fuel pump.

Thanks for your help! And tips, tricks are always welcome

Thanks,

Ralph

[Elosky]

The only difference is the filter capacity; the final adjustment is the same, no more than 3 psi.
Could you show me what ignition curve you're running? I have a very similar setup to yours and I'm running tests.

Thanks,
Oscar.

[dutchspiderrider]

Hi Oscar,

Thanks for the clear answer. Will keep my 85mm Filter King.

For the 123ignition I’m currently running curve #1 (basic version). I switched out a Marelli S144 dizzy. Curve #0, indicated for a 1608, just didn’t work.
We have it running now and sounds ok, although from time to time still flames coming out of the carbs and it backfires very occasionally.
Next stop: measure fuel pressure.

Ralph