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Chevrolet Old Carter Carburetors : CHEVROLET PASSENGER & TRUCK G. M. C. TRUCK 1941 - 1948

Form 6522B—Canadian CHEVROLET & G.M.C. TRUCK 574S
November, 1945
Revised August, 194S

CHEVROLET PASSENGER & TRUCK G. M. C. TRUCK 1941 - 1948

Casting No. 421 on face of flange
W-I DOWN-DRAFT CARBURETER No. 574S—LIST PRICE $21.85
A $2.50 exchange allowance is deducted from the list price if buyer turns in old carbureter.
CARBURETER SPECIFICATIONS
574S
Passenger Cars
and
1/2 to 21/2 Ton Trucks
For Chevrolet Six Cylinder Engine:
Dimensions: Flange size, 11/4 inch S.A.E. Primary venturi, 11/32 inch I. D. Secondary venturi, 11/16 inch I. D. Main venturi, 11/4 inch I. D.
Float Level: Distance from float (at free end) to float chamber cover, when needle is seated, to be V2 inch plus or minus 1/64 inch.
Vents: Outside, none. Inside balance vent tube above choke valve 13/64 inch I. D.
Gasoline Intake: Square vertical needle. Size No. 48 drill hole in needle seat.
Gasoline Line Connection: 5/ 16 inch weatherhead nipple.
Low Speed Jet Tube: Vertical jet size, .035 inch diameter. By-pass in body, size No. 51 drill. Economizer jet, size .0545 to .0555 inch diameter.
Idle Ports: Upper port diameter, No. 44 drill. Lower port diameter, No. 54 drill.
Idle Port Opening: Top of lower port .044 to .048 inch above top edge of valve, with valve closed tight.
Idle Screw Seat: Size No. 52 drill.
3½ Inch Bore, 3i/4 Inch Stroke
Set Idle Adjustment Screw: 11/4 to 21/4 turns open. For richer mix we, turn screw out. Do not attempt to idle engine below 350 r.p.m.
Outer Nozzle: In primary venturi, angle 30°. Discharge size, .125 inch diameter.
Inner Nozzle: (Seats in outer nozzle) .120 inch I. D.
Nozzle Retainer Plug: Jet size No. 31 drill (early production), No. 29 drill (late production).
Metering Rod: Economy step .067 inch diameter. Second step
tapers to .062 inch diameter. Third step tapers to .060 inch
diameter. Power step .046 inch diameter. Length 33/8 inches. Metering Rod Jet: Size .093 inch diameter.
Metering Rod Setting: Use gauge, part No. TI09-25 (2.795 inches).
Accelerating Pump: Low pressure type with. non-adjustable stroke. Discharge jet, size No. 72 drill.
Intake disk check plug, size No. 62 drill.
Discharge disk check plug, size No. 40 drill.
Choke: Manual—butterfly type, offset valve.
Throttle Valve: Opens to within 0° to 3° from perpendicular. Vacuum Spark Port: Slot type: size, .041 to .125. Bottom of port .000 to .004 above top of valve.
Motor Tune-Up—Be Accurate! Always Use Feeler Gauges!
CAUTION: Change worn or leaky flange gaskets. Tighten manifold bolts and test compression before adjusting carbureter.
/V
Spark Plug Set Use Neon Timing Light Set Valves—Hot Correct Float Level Idle Adjustment
Gap Breaker Points or Timing Light (Remove Cork Gasket Screw Setting
and measure from
Intake .006"-.008"
.040" .020" to .022" Breaker Points to machined surface of 1¼ to 21/4
open 5° before top float cover) Turns Open
dead center I/2 Inch
Exhaust .0I3"-.015"
Copyright 1945
Copyright 1948