Correct fue pressure for carb engine
 

What is the correct fuel pressure for 40 mm PMO carbs? My engine is a 2.2 Liter rebuilt with 911e cams and mild cylinder head work.

3 to 3.5 lb.

I had a set of Dellorto 40 DRLA Carbs on a 2.8L VW motor. The webers and the dels don’t like much pressure. Not like an American V8 of the carb era. I bought a specific Dellorto regulator as they recommend.

3.5 psi on Webers.

The PMO needle and seat will handle 4-4.5 psi. I set the pressure there for track cars and hotrod motors to prevent the float level dropping at high rpm.
But if your float levels come in right in the middle of the sight glass at 3-3.5 then that’s just fine for your small displacement street car.

I have run 2 -3 psi on several 356's, 914's, Alfa spiders with Webers. Never ran short of fuel. I would much rather be under pressured than over pressured