The starter bolted on the bottom of your engine performs an amazing feat time and time again. Just think of the mass of weight tied to the crankshaft, plus the valvetrain, not to mention fighting against the compression in each cylinder. All of those parts are expected to go from standing still to over 200 rpm within a moment. It’s a brutal proposition which is why it’s so important to select the proper starter for your application.
There are many starters to choose from but first and foremost is the importance of setting up and feeding the starter what it needs to function to its full potential. This means the electrical system, battery, switches, and cables must all be up to the task. One weak link and you could be stuck in the pits or missing your turn on the autocross. We’ll cover those needs in short order but for now, let’s focus on the starter itself.
The obvious first step in choosing a starter is finding one that physically fits your application. Does your Chevy block accommodate a straight mount starter or a diagonal pattern? For Ford applications, is the ring gear 3/8” from the engine plate – indicating a typical manual transmission starter – or is it closer to a 3/4” requiring a typical auto transmission unit? Do you have an oil pan or exhaust system that will affect the starter mounting position? If you’re working with a confined space, a more compact gear reduction starter will be necessary.
Besides the smaller size being a bonus, gear reduction starters (commonly called mini starters) are generally lighter plus they provide increased torque over standard starter motors. In fact, when it comes to gear reduction starters versus the large, conventional direct-drive starters from the ‘80s and back, there is just no reason to stick with convention (unless you’re going for a 100-point restoration). Gear reduction starters are more efficient, deliver more torque, and are so much lighter. For performance builds, a compact gear reduction starter is truly the only way to go.
After considering the size and any obstacles in mounting the starter, you need to consider your engine and its compression ratio. The starter is going to be working against the compression to get the engine spinning to speed and it takes a lot more oomph to crank a 14:1 engine versus a 9:1 cruiser. The cubic inches also should be considered as larger displacement engines have bigger bores filled with larger, heavier pistons and moving parts – it all adds up!
We reached out to Powermaster for a few tips on selecting a starter and they provided a rule of thumb to consider when it comes to compression. Though you can’t really have too much torque, Powermaster recommends a starter rated with at least 160 lb-ft of torque for engines under 10.5:1 compression, 180 lb-ft for up to 12:1, and for anything over that, go with a 200 lb-ft rating. For serious race engines, they recommend their Ultra Torque series starter that produces up to 250 lb-ft stump-pulling grunt.
One Powermaster starter that falls squarely into our world of street machines and muscle cars is their popular XS Torque model. The XS Torque delivers 200 lb-ft of torque through a 4.4:1 gear reduction with a 1.8 horsepower motor. A billet mounting block provides a solid mounting foundation while a blue-printed solenoid handles high heat and is extremely durable. They also offer a similar line, the Master Torque model which is rated at 180 lb-ft, but for the few extra bucks, it’s worth stepping up to the XS in our opinion.
Another aspect of XS Torque is its unique ability to be clocked 360-degrees to clear oil pans, headers, and tight spaces. The mounting block features their Infi-CLOCK technology which provides the ability to rotate the motor and solenoid assembly to fit nearly any application. The Infi-CLOCK is simple to adjust by loosening two Torx-style screws to allow the motor assembly to be rotated to the best position for your application. Then simply tighten the screws and the assembly is secured in place.
Thanks to its universal mounting capabilities coupled with the power and torque to crank over nearly any street engine, the XS Torque is ideal for pro-touring, restomod muscle builds, and even the stoutest street engines. Powermaster offers their High-Speed Ultra-Torque series for drag cars running magnetos or alcohol and if you are working on more of a restoration project, they offer Original Look direct-drive models that deliver improved cranking performance.
Once you select your starter, it is imperative to follow a checklist of proper installation tips. As with any performance part, if it’s not installed properly, it likely will not deliver the performance and longevity that you expect. Powermaster gets calls every day that can be traced to poor grounding, small or damaged cables, bent ring gears, and more. Following are some tips for proper installation.
Mounting and Hardware
One of the first things to consider is the mount location for the starter as this serves as the ground for all of the current rushing into the motor. The mounting pad must be clean of paint and grime so there is a solid ground path and be sure to have a ground cable from the block to the battery negative terminal. Also, if your block-mounted starter came with new bolts – use them! Powermaster supplies special retainers with knurled shafts which help keep the starter from moving while they’re cranking. Smooth shaft bolts will allow the starter to flex or move a tiny amount, which will grow over time until there are issues. Always use the correct hardware!
Check Ring Gear Clearance and Pinion Depth: Before checking pinion depth, make sure there is at least .100” – .125” between the pinion gear and the ring gear (in three or four locations). Once confirmed, move on to checking the pinion depth which is the distance that the pinion gear teeth engage into the ring gear teeth. A rule of thumb is for the pinion gear to be about ½ -2/3 engaged with the ring gear. It can be checked by pulling the pinion gear out of the starter and engaging it into the ring gear. It is best to check the depth in at least three positions on the ring gear to ensure a straight flexplate. If the depth is too much, the starter gear could hang up, grind and spin far faster than it’s designed to before coming disengaged. Powermaster supplies a shim that goes behind the mounting block of the starter to help achieve the proper gear depth.
Check Pinion Gear Mesh: Gear mesh is the relationship between the ring gear and the pinion gear teeth. There should be .020-.035 of area (the size of a paperclip) between the gear teeth when engaged. If the clearance is too tight, shims can easily be added between the engine block and starter mounting block.
Cable Gauge and Length: If you’re working on a performance application, there is absolutely no reason to use the stock starter cables. Consider that a starter can pull up to 500 amps during cranking which stresses every component of the starter system including the cable, terminals, and disconnect switches. If the cable and terminals are not up to the task, the voltage will drop, amperage draw will increase adding more heat to the system, and eventual failure. Powermaster offers different gauge multi-strand copper wires to ensure you have the best connection to the starter.
Cranking Voltage: The wire that connects to the S terminal should also be inspected and likely replaced if it’s the original old wiring. This is the wire from the ignition switch that activates the solenoid and it can draw up to 15 amps. Powermaster recommends at least 11 volts on this terminal during cranking, anything south of that will introduce higher current and heat in the solenoid – and heat is not good! If the voltage drops below 11 during cranking, inspect the battery as well as the starter circuit.