Chevrolet Old Carter Carburetors : CHEVROLET PASSENGER & TRUCK G. M. C. TRUCK 1941 - 1948Previous | Home | Next
Form 6522B—Canadian CHEVROLET & G.M.C. TRUCK 574S
Revised August, 194S
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.
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.
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
.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