Disassembly and Assembly
Carburetor
To make overhaul easier, and to help prevent damage to carburetor throttle plates, use the EGR spacer (if equipped) as a holding fixture. If a spacer is not available, use a carburetor stand with appropriate mounting bolt holes.
Holley Model 1946 1-V Carburetor Disassembled:
Disassembly
Air Horn
1. Remove the choke bimetal assembly:
Check rivets to determine if mandrel is well below the rivet head. If mandrel is within the rivet head thickness, drive it down or out with a 1/16 inch diameter tip punch.
Select a 1/8 inch diameter or No. 30 drill for drilling the rivet heads.
Proceed to drill into the rivet head and continue until the rivet head comes loose from the rivet body. NOTE: Excessive pressure on the drill bit at this point could cause the rivet to spin in the hole.
After the rivet head has been drilled off, drive the remaining rivet out of the hole with a 1/8 inch diameter punch. If this procedure is followed, the hole size is retained.
Repeat previous steps for the remaining rivet. Remove remaining standard screws. Remove choke cap. NOTE: Do not immerse the cover assembly in cleaner. Clean by wiping dirt from the cover and gently blowing out the inside with compressed air. If the assembly is corroded or damaged,it should be replaced.
2. Remove the two pulldown diaphragm bracket screws, disconnect the vacuum hose from the main body and remove the pulldown diaphragm and linkage assembly. NOTE: Do not immerse the pulldown diaphragm assembly in cleaner, as serious damage to the diaphragm could result.
3. Remove the bowl vent electric solenoid, spring and gasket. Remove the fast idle cam retainer and fast idle cam. Remove choke control lever retaining screw.
4. Remove the throttle return spring bracket attaching nut and lock washer. disengage the return spring from the throttle body and carefully remove the spring and bracket. (NOTE the slot in which the accelerator pump link is located for proper reassembly.)
5. Remove the accelerator pump link. Remove the gradient power enrichment valve assembly retaining screws and gasket. The gradient power enrichment valve is serviced as an assembly and should not be disassembled.
6. Remove the eight screws holding the air horn assembly to the main body and remove the air horn. NOTE: Do not pry air horn from the upper body, but tap it gently from side to side with a plastic hammer until it is loose. Invert air horn on clean working surface.
7. Remove air horn gasket. If any material remains on either air horn or main body gasket surface, remove it with a suitable cleaner. NOTE: Use a nylon or plastic scraper as a metal scraper may damage the gasket surface.
8. Remove the accelerator pump operating rod attaching screw and retainer clamp. Remove the accelerator pump spring retaining plate and attaching screw. Rotate the pump operating rod and disconnect the pump drive spring and accelerator pump assembly. NOTE: Do not immerse the pump plunger and cup assembly in cleaner as damage to the cup may result.
9. Rotate the pump operating rod and remove the rod and grommet from the bowl cover. The main well tube cannot be removed but must be cleaned carefully from both inside and outside the cover with compressed air. NOTE: It is not recommended that the choke plate and shaft be removed during normal disassembly unless they are damaged and are to be replaced. Use caution during handling of components so they will not be damaged. Always rest air horn upside down so that the gasket surface, pump assembly, main well tube and enrichment valve piston will not be damaged.
10. Remove the bowl vent valve seat by holding the valve seat against the internal vent tube with a thin screwdriver and pull the actuating pintle loose from the seat.
Throttle Body
1. Remove the tamper proof idle mixture concealment plug by center punching and drilling a 3/32 inch diameter hole through the hardened steel plug. Install an easy-out into the hole and remove the plug.
2. Turn mixture screw clockwise until it lightly seats, recording the number of turns required. The needle must be returned to the same position when the carburetor is reassembled in order to maintain proper calibration. Do not tighten needle against its seat as damage to the needle and/or seat may result. If the needle is bent or grooved where it seats, it must be replaced.
3. Remove the curb idle speed adjusting screw and spring, and the fast idle speed adjusting screw and spring. Inspect the throttle plate and shaft for nicks, burrs or wear. NOTE: Do not remove the throttle plate or shaft from the throttle body. If wear or damage is evident, the complete throttle body assembly must be replaced.
Assembly
Throttle Body
1. Reassemble the fast idle speed adjusting screw and the curb idle speed adjusting screw and springs to the throttle shaft and lever assembly.
2. Place the idle mixture adjusting needle through the spring, lubricate rubber O-ring and install in the throttle body. Lightly seat the needle, then back the needle out couterclockwise the number of turns recorded during disassembly, stopping with the screw in the tamperproof idle mixture concealment plug. Final idle mixture needle adjustment must be made after the carburetor is installed on the engine. Following adjustment, a new service concealment plug must be installed on the idle mixture needle.
Main Body
1. Install the low idle speed adjusting screw and spring. Position the throttle body and gasket on the inverted main body and install the three throttle body attaching screws. Tighten to 25 lb-in.
2. Snap the small diameter end of the enrichment valve spring over the shoulder on the large end of the pin and insert the pin into the valve body from the threaded end. Install the valve body, pin and spring in the main body. Tighten to 6 lb-in with the specially modified screwdriver described under Disassembly. NOTE: Valve must be installed carefully so that the spring is vertical and not misaligned against the side of the casting. Work the plunger up and down to insure freedom of movement.
3. Install the main metering jet using a jet wrench or suitable screwdriver. Tighten to 20 lb-in. Install the float hinge pin in the float arm and lower the float and hinge into position in the main body. Install the hinge retainer.
4. Install the fuel inlet valve assembly and gasket and check the dry float setting. Install the accelerator pump check ball and weight.
Air Horn
1. Install the pump operating rod and grommet in the air horn. Push the accelerator pump cup over the retaining tab on the end of the pump piston rod. Assemble the pump string and pump spring retainer plate to the piston rod by compressing the spring enough to let the plate slip over the piston rod. The larger diameter end of the pump spring should contact the retainer plate and seat over the shoulder.
2. While holding the assembly together, connect the pump operating rod through the slotted hole in the piston rod and rotate the rod so that the plate can be positioned and the screw inserted. Tighten the plate attaching screw to 6 lb-in. Install the pump operating clamp and attaching screw. Tighten to 15 lb-in.
3. Invert the air horn. Drop the bowl vent valve seat into place. Lube the end of the actuating rod and carefully insert the rod into the hole in the valve seat. Lightly push the rod until it snaps into the seat. Position the air horn gasket over the alignment pin and carefully lower the air horn into place on the main body. (Do not force) Guide the accelerator pump cup into the pump well and the main well tube into the main well. Align the air horn and lower it into place. Install eight air horn attaching screws. Tighten to 10 lb-in.
4. Install the gradient power enrichment valve assembly, gasket, valve and retaining screws. NOTE: Care must be taken to install the gradient power enrichment valve in a vertical position. Hook the accelerator pump link into the pump operating rod and into the correct slot in the throttle return spring bracket, noted during disassembly. With the pump link engaged in the proper slot, slide the throttle return spring bracket assembly over the throttle shaft and align it with the shoulders on the end of the shaft. NOTE: Depressing the pump operating rod against its spring pressure will provide sufficient clearance to permit assembly.
5. Install the attaching nut and lockwasher and engage the throttle return spring over the throttle body stop. Place the fast idle cam link in position so that the link engages the fast idle cam slot. Install the cam and retainer. Install the choke control lever and screw.
6. Install the electric bowl vent gasket, spring and solenoid. Tighten to specification. Connect the choke pulldown diaphragm linkage and install the two diaphragm bracket attaching screws. Reinstall the vacuum hose from the manifold vacuum tee to the diaphragm assembly.
7. Use Marson Rivet Gun HP-2 Ford Part No. D79P-53700-A with special nosepiece Tool D80P-53700-A or equivalent. Use Ford rivet Part No. 388299 (1/8 inch diameter).
8. Determine that choke bimetal assembly spacer is installed properly. Install choke bimetal assembly after engaging bimetal loop on choke housing shaft lever and rotate to engage plastic spacer index tab. Install choke bimetal assembly retainer over cap and loosely retain with the standard screw.
9. Rivet choke bimetal assembly as follows:
Place rivet in rivet gun and trigger lightly to retain rivet.
Press rivet fully into casting after passing through retaining clamp.
Trigger lightly the two rivets until sufficient pressure is obtained to hold assembly temporarily.
Reposition rivet gun on mandrel and trigger until rivet is popped (mandrel breaks off).
Repeat previous steps for remaining rivet.
Tighten the standard screws to 6 lb-in.
Reinstall carburetor.