Racing Fuel Systems

Just some info and maybe some input on how this carb is set up.

Pro Systems 2.190 bores, 1/960" venturiis. Main body modified to relocate the transfers slots because of the bores being enlarged.3 circuit. Race Gas.

Here is how it is presently set up which matches the original build sheet. On a BBC 470" truck pull engine. 1000 HP approx. Big bore, short stroke.

Main jets. 101, .128"

Air bleeds. idle .046", intermediate .059", High .026"

Emulsions ..027", X, .027", X, .028" from top.

Kill bleed .026".

Idle fuel restrictor .040", low position.

Transfer slot drilled but not tapped, ,076".

Intermediate fuel restrictor. not sure where it is.

Boosters .500", stake pins .169". Has small skirts.

Angle channels .166".

Squirters .045". High flow screws.

Needle and seats .150" steel tips.

A/F idle screws 2 turns out.

Secondary linkage in #3 hole. Starts opening at half primary throttle position.

Carb # PS 33673.

Metering blocks 3046-2 with" Pro Systems" on them.

The owner has no complaints on the way it runs.

Just seems these calibrations could use some more tuning.

I have it rebuilt and back together for now as it was except I did leave out the jet extensions since it is not a drag application.

Picture of the metering blocks?

Mark, here are pictures of metering block.

Full shot of the backside of the metering block? The body by the way was BLP modified, t-slot plugged and cnc machined.

Mark W.

More pictures on the 1350 carb for metering block details and recommendations. Are there any intermediate restrictions on this carb? Where would they be?

Is there any advantage or disadvantage to using brass floats over composite ones? (Other than for jet extension clearance.) Do they weight the same?

Pro Systems used the 2 additional air bleed jets in the top of the body direct to the intake, on many of their carbs.is that so the idle speed can be controlled without opening the throttle plates too far exposing the transfer slot too far?. They use .059" orifices usually it seems

Those are standard 3 circuit blocks, I don't suggest you use them. You can get a wide body BLP block to replace them, that requires longer bowl screws but removes the idea feed tube from the mainwell that is restrictive to fuel flow. You can also use a 2 circuit metering block and eliminate the intermediate. Idle bypass bleeds on top I usually plug, rarely need them and especially with the t-slot plugged BLP bodies. With either metering block above I would ream the main wells to .170, angle channels to .170. And thread for lowered idle feed restrictions.

As far as those blocks the intermediate feed is next to the main jets, and the outlet is also threaded for secondary restrictions. Brass is fine for a primary float.