How to Set Points on a Small Block Chevyby Chris Stevenson
The older ignition point distributors for Chevy have survived until today. Many of the old classic and muscle cars used the mechanical ignition points, which still have to be set according to manufacturer's specifications. High-energy ignition has eventually replaced the old standard design, but for those who still own such vehicles, the need to replace the points and condenser remains one of the many necessary chores. A few simple tools and some knowledge can make the chore of replacing the points swift and easy.
Place the vehicle in park or neutral with the emergency brake set. Raise the hood and disconnect the negative battery terminal with an end wrench. Locate the distributor at the rear of the engine next to the firewall.
Use a slot screwdriver to turn the two distributor cap mounting screws 90 degrees out until they release. Pull the distributor cap off and set it aside in the engine compartment without removing the wires. Pull the distributor rotor straight up and off. In the case of a round rotor cap that has two screws, remove the screws with the slot screwdriver and lift off the rotor. Don't lose the rotor mounting screws.
Remove the small screws that hold the old points to the distributor base. Detach the points wire that connects to the small connector post. The points wire will either pull up from spring tension, or a screw will hold it in place. Only loosen the screw to remove the wire. Remove the condenser wire in the same fashion. Remove the screw holding the condenser to the distributor base. Discard the old points and condenser.
Place the new condenser and points on the distributor base, aligning their positions with their small mounting guides. The points will have a small pin that fits into a pivot hole in the distributor. Place the mounting screws on the points and condenser and tighten them down very lightly with the slot screwdriver. Tighten the condenser down fully; leave the points adjustment screw slightly loose. Push the points wire and the condenser wire back into their small, spring-loaded mount or tighten them with the screw, if so equipped.
Place the negative battery cable back onto the terminal. Instruct your assistant to "bump" the ignition key back and forth, turning the engine over in short bursts, until you see the high point on the distributor shaft---eight or six-sided cam---stop and rest directly under the small rubbing block on the points. This will be the correct adjustment position.
Disconnect the negative battery terminal. Use the proper width blade on the feeler gauge---refer to manufacturer's specifications---and place the blade between the two point contacts. Use a slot screwdriver to wedge the points open or closed by sticking the screwdriver blade into the small slot in the distributor base. Adjust the points closed over the feeler gauge until a slight drag can be felt when inserting it and pulling it out. Fully tighten the points' mounting screw after achieving the adjustment.
Use the distributor adjusting tool or the proper size Allen wrench to make the adjustment on the newer model Chevy distributor. Most gap points for Chevy small-block engines require .016 to .019 of an inch.
Reinstall the new or used rotor by pushing it down over the distributor shaft or secure it with the screws if equipped with them. Place the distributor cap back on in the same position you removed it and turn the mounting screws in the cap 90 degrees to secure into place. Reconnect the negative battery cable.
Hook up the positive lead of the dwell meter to the positive battery terminal. Hook up the dwell meter negative lead to the negative side of the distributor coil. Start the engine. Refer to your owner's manual for the correct dwell angle. On most small-block Chevy engines, the dwell will be 30 degrees. To adjust the dwell exactly, insert the distributor adjusting tool or the Allen wrench into the small adjusting window on the side of the distributor cap. Turn the wrench very carefully until you have reached the required dwell angle. Remove the dwell meter.
- Hot Rodders: Setting the Points on the SB Chevy
- "Auto Repair Shams and Scams"; Chris Stevenson; 1990
- When replacing or setting new points on any engine, a condenser and rotor should be included in the package for a complete tuneup. The cost is minimal.
Things You'll Need
- Slot screwdriver
- Dwell meter
- Feeler gauge
- Owner's manual
- End wrenches (small set)
- New points (condenser and rotor for complete tune-up)
- Don't adjust used points; replace them.
Chris Stevenson has been writing since 1988. His automotive vocation has spanned more than 35 years and he authored the auto repair manual "Auto Repair Shams and Scams" in 1990. Stevenson holds a P.D.S Toyota certificate, ASE brake certification, Clean Air Act certification and a California smog license.