The Holley 1945 one barrel carburetor is used on six-cylinder engines. The Carter BBD two barrel is used on the "Super" six cylinder engine and on the 318 cu. in. V8. The Holley 2245 two barrel carburetor is used on the 360 V8. Both the 318 and 360 four barrel engines use the Carter Thermo-Quad carburetor.
REMOVAL & INSTALLATION
- Remove the air cleaner.
- Disconnect the fuel and vacuum lines.
It might be a good idea to tag them to avoid confusion when the time comes to put them back.
- Disconnect the choke rod.
- Disconnect the accelerator linkage.
- Disconnect the automatic transmission linkage.
- Unbolt and remove the carburetor.
- Remove the base gasket.
- Before installation, make sure that the carburetor and manifold sealing surfaces are clean.
- Install a new carburetor base gasket, making sure that the "top front" marking is correctly located on six-cylinder engines.
- Install the carburetor and start the fuel and vacuum lines.
- Bolt down the carburetor evenly.
- Tighten the fuel and vacuum lines.
- Connect the accelerator and automatic transmission linkage. If the transmission linkage was disturbed, it will have to be adjusted. The procedure is in this section.
- Connect the choke rod.
- Install the air cleaner. Adjust the idle speed and mixture as described in .
Whenever wear or dirt causes a carburetor to perform poorly, there are two possible solutions to the problem. The simplest is to trade in the old unit for a rebuilt one. The other, cheaper alternative is to buy an overhaul kit and rebuild the original unit. Some of the better overhaul kits contain complete step-by-step instructions along with exploded views and gauges. Other kits, intended for the professional, have only a few general overhaul hints. The second type can be confusing to the novice, especially since a kit may have extra parts so that one kit can cover several variations of the same carburetor. In any event, it is not a good idea to dismantle any carburetor without at least replacing all the gaskets. The carburetor adjustments should all be checked during or after overhaul.
Before you go to the parts store for a rebuilding kit, make sure that you know what make and model your carburetor is. Check for an identification tag or number stamped on the base.
Efficient carburetion depends greatly on careful cleaning and inspection during overhaul, since dirt, gum, water, or varnish in or on the carburetor parts are often responsible for poor performance.
Overhaul a carburetor in a clean, dust-free area. Carefully disassemble the carburetor, referring often to illustrations. Keep all similar and look-alike parts segregated during disassembly and cleaning to avoid accidental interchange during assembly. Make a note of all jet sizes.
When the carburetor is disassembled, wash all parts (except diaphragms, electric choke units, pump plunger, and any other plastic, leather, fiber, or rubber parts) in clean carburetor solvent. Do not leave parts in the solvent any longer than is necessary to sufficiently loosen the deposits. Excessive cleaning may remove the special finish from the float bowl and choke valve bodies, leaving these parts unfit for service. Rinse all parts in clean solvent and blow them dry with compressed air or allow them to air dry. Wipe clean all cork, plastic, leather, and fiber parts with a clean, lint-free cloth.
Blow out all passages and jets with compressed air and be sure that there are no restrictions or blockages. Never use wire or similar tools to clean jets, fuel passages, or air bleeds. Clean all jets and valves separately to avoid accidental interchange.
Check all parts for wear or damage. If wear or damage is found, replace the defective parts. Especially check the following:
- Check the float needle and seat for wear. If wear is found, replace the complete assembly.
- Check the float hinge pin for wear and the float(s) for dents or distortion. Replace the float if fuel has leaked into it.
- Check the throttle and choke shaft bores for wear or an out-of-round condition. Damage or wear to the throttle arm, shaft, or shaft bore will often require replacement of the throttle body. These parts require a close tolerance of fit; wear may allow air leakage, which could affect starting and idling.
Throttle shafts and bushings are not included in overhaul kits. They can be purchased separately.
- Inspect the idle mixture adjusting needles for burrs or grooves. Any such condition requires replacement of the needle, since you will not be able to obtain a satisfactory idle.
- Test the accelerator pump check valves. They should pass air one way but not the other. Test for proper seating by blowing and sucking on the valve. Replace the valve as necessary. If the valve is satisfactory, wash the valve again to remove breath moisture.
- Check the bowl cover for warped surfaces with a straightedge.
- Closely inspect the valves and seats for wear and damage, replacing as necessary.
- After the carburetor is assembled, check the choke valve for freedom of operation.
Carburetor overhaul kits are recommended for each overhaul. These kits contain all gaskets and new parts to replace those that deteriorate most rapidly. Failure to replace all parts supplied with the kit (especially gaskets) can result in poor performance later.
Some carburetor manufacturers supply overhaul kits of three basic types: minor repair; major repair; and gasket kits. Basically, they contain the following:
Minor Repair Kits:
Major Repair Kits:
After cleaning and checking all components, reassemble the carburetor, using new parts and referring to illustrations. When reassembling, make sure that all screws and jets are tight in their seats, but do not overtighten as the tips will be distorted. Tighten all screws gradually, in rotation. Do not tighten needle valves into their seats; uneven jetting will result. Always use new gaskets. Be sure to adjust the float level when reassembling.
THROTTLE LINKAGE ADJUSTMENTS
Throttle linkage adjustments are rarely required unless the transmission linkage has been disturbed. However, it is a good idea to check that the throttle valve(s) open all the way when the accelerator pedal is held all the way down. This is occasionally the source of poor performance on new cars.All Automatic Transmissions
- Lubricate the friction points of the linkage.
- Disconnect the choke at the carburetor or otherwise make sure that the throttle is off the fast idle cam.
- Loosen the adjustment swivel lockscrew at the transmission.
- The swivel must be free to slide along the flat end of the throttle rod.
- Hold the transmission lever firmly forward against its internal stop and tighten the swivel lockscrew. The adjustment is completed and linkage slack removed by the preload spring.
- Pull the transmission throttle rod slowly back and release it. It should go back forward slowly.
- Loosen the cable clamp nut. Adjust the position of the outer cable in the clamp so that all slack is removed. Move the outer cable away from the carburetor to do this. Move the outer cable back 1 / 4 in. to allow slack at idle.
- Lubricate the friction points of the throttle linkage.
- Disconnect the choke at the carburetor and make sure that the throttle is off the fast idle cam.
- Loosen the cable clamp nut. Adjust the cable by moving the cable housing so that there is about 1 / 4 in. of slack in the cable at idle.
- Tighten the cable clamp nut.
- Reconnect the choke and check the linkage for free movement.