First, the voltage getting to the starter solenoid is usually the main issue with an early GM product. The 40-plus-year-old wiring and switches have built up resistance over the years. The gauge for the energize wire is 12. The power on your truck comes from the battery across the core support to the voltage regulator. From there it travels from the regulator through the firewall bulkhead connector and then out of the fuse block to the ignition switch. Then, it goes through the neutral safety switch and back through the firewall bulkhead connector en route to the starter. The power for the starting circuit goes through no less than eight connections and two switches from the battery to the starter. The voltage that reaches the starter solenoid must be at least 9 volts for the electromagnet to pull in the plunger and make contact with the high-amperage connectors in the solenoid. If it can’t pull in the plunger, the starter won’t even try to turn. If it comes in slowly and just can’t make the connection, you will have a nice arc welding session in the solenoid. Exhaust header heat only magnifies the problem by increasing the resistance in the wires to transfer voltage. There are many helper solenoids on the market that use a full 12V shot going straight to the starter solenoid, which covers up most of the problems with the car, and they start. Check out the complete Start ’Em Up solenoid kit from MAD Enterprises, with the Ford-type remote starter solenoid to boost the energize voltage.
If the starter engages and cranks slowly, this can result from a number of situations, including undersized battery cables, overheated battery cables, or a poor ground loop back to the battery. On all of our projects, we upgrade the battery cables to 1- to 1/0-gauge wire to prevent any starting issues; with these cables, the starter will sing. A lot of the quickie auto parts store battery cables are undersized and will overheat in an instant when high loads are thrown at them. MAD can also help you with 1/0 battery cable and connectors to upgrade you entire starter power circuit.
Finally, we really like to dump the early, large electromagnet starters in favor of the late-model, permanent magnet-style gear-reduction starters. They give you increased clearance between headers and allow the starter to keep the motor cooler. They are not as susceptible to the heat because the poles of the starter are permanently magnetic and do not require voltage to create the magnetic field to drive the armature of the starter motor. All power is directed to the armature and creates a very strong magnetic field to rotate the starter. On small-blocks we’ve been very happy with the standard 153-tooth flywheel starter (GMPP PN10465143) that comes on the fourth-generation LT1-equipped Camaros. For big-block applications or anything with a 168-tooth flywheel, go with the starter (GMPP PN 12606096) off a ’96 L-29-equipped big-block Chevy truck.
Sources: mad-enterprises.com, gmperformanceparts.com
Do You Want To Compromise?
Q: I’m looking to build a 383ci stroker for my ’94 Camaro Z28 with an LT1. I want to build a separate short-block so I can still drive the car while I build it. I’m just extremely confused right now about what block I can use and still keep the LT1 intake, heads, and rest of the parts. Do I have to use another LT1 block, or is a Gen II Chevy small-block the same exact thing as an LT1 block, with no changes needed? Also, I’m building it forged because I will add a turbo down the road, but that could be a year after I finish the 383. So how low should my compression be, and would it be safe to have low compression and still have good power without the turbo on yet?
SW Ranches, FL