Upgrade Your Ride with a Mini Starter!
The Gear Reduction Starter: Mini Size with Maximum Power
Automotive components continue to advance as innovative technologies cross the horizon. These technologies often reduce costs, make components more efficient, and provide more power output. The 30 amp output of the typical generator found on 1950s and earlier cars has given way to alternators that are smaller with upwards of 200 plus amps of output! The same is true of starter motors.
Early in the 20th century cars were started with hand cranks. This cranking motion rotated the engine fast enough to start the combustion process, but it was a mixed bag. You had to have the strength to turn the crank, and if the fuel and timing weren’t set exactly right you either wore your arm out or could very possibly be hurt by engine kickback smacking you in the face or breaking a thumb with the hand crank! It wasn’t until 1911 that Charles Kettering and Henry Leland were granted a patent for the first electric starter, providing the driver a way to easily start the engine from within the cabin. The first electric starter in a domestic vehicle was the 1912 Cadillac, but today even your lawn mower most likely has an electric starter motor.
These starters were large, bulky affairs that were heavy and required higher current requirements to operate. A direct drive starter requires a lot of power to operate, often overheat easily, and were usually affected by exhaust manifold/header temperatures, or simply would be in the way of installing aftermarket tube headers. Couple these grievances with a hot, high-compression big block with a trunk mounted battery in the typical 60s muscle car and you weren’t going anywhere until things cooled off.
Enter the Gear Reduction Starter
Credit where it is due, it was our friends at Ma Mopar that introduced the gear reduction starter drive in 1962. This starter used a high-speed, low current starter motor with a gear reduction unit that made the starter more compact while increasing the available cranking torque for those Chrysler big blocks and Hemis. Soon that distinctive gear reduction starter sound became intimately associated with the Dodge, Plymouth, and Chrysler products of the 1960s.
Today, permanent magnet gear reduction (PMGR) starters, or mini starters, are used almost exclusively across all automotive manufacturers to reduce overall vehicle weight, increase cranking ability, and reduce load on the battery and starting systems. The aftermarket has taken the gear reduction starter technology and adapted it to a multitude of popular muscle car and hot rod applications, allowing the enthusiast to upgrade from their bulky direct drive starter unit to the popular and efficient gear reduction starter Chevy 350 application with nothing more than minor wiring changes in a few cases.
What Is the Benefit of a High Torque Mini Starter?
While we have covered some of the benefits of the mini starter upgrade in our opening copy, there are several additional advantages that you should be aware of when considering fitting a gear reduction starter vs direct drive starter to your engine. Besides the potential weight reduction and smaller, more compact body, many aftermarket gear reduction mini starters are fitted with special nose pieces that provide clocking ability to the starter body. This provides the installer with the option of rotating the complete starter body inboard or outboard of the engine block as needed to clear headers, block casting protrusions, and more.
Furthermore, the high torque mini starter places the starter solenoid directly on the starter body, which can provide for a cleaner look under the hood by eliminating the fender mounted starter solenoid and additional wiring in some applications (looking at you Blue Oval fans). While not mandatory, if you’re building something from the ground up this is a nice consideration for your wiring routing and eliminating the fender mount solenoid frees up space for ignition boxes or other electronics and reduces wiring connection points which can come loose or corrode, causing problems down the road.
How Are Mini Starters Rated?
Electric motors are rated in kilowatts, and starter motors are the same. The higher the kilowatts, the more output the electric motor. Where some confusion enters the picture is with gear reduction units, as the gear reduction ratio will affect final output numbers. Therefore, you’ll see some starters with lower kilowatt ratings able to crank higher compression engines. So, you must look at the total picture, the kilowatt rating, and the gear ratio of the reduction unit.
You will see most starters listing a horsepower rating as well, which for some is a more relatable power output. While the power output is important, the starter’s torque output rating should be a major consideration as well. Rated in the common ft/lbs of torque, it is a great way to determine what starter will work best for your engine’s needs. Obviously, like the starter’s kilowatt/horsepower output, the starter’s torque output improves as the value goes up. Knowing this you can choose the high torque mini starter for small block Chevy or other application with the best power and torque output for your application and within your budget.
Are Mini Starters Affected by Heat?
There are untold millions of stories of how a heat soaked starting system has ruined someone’s day, stranding them at the worst time. While a gear reduction mini starter is far less susceptible to thermal issues reducing the starter’s power output, they are not invincible to heat. Some applications like custom hot side turbo plumbing, big block engines with long transition cross over headers, and the like are thermal management nightmares. In these cases, we recommend some form of heat shield or thermal barrier for the starter body and the last foot or two of starter wiring/battery cable routing. Generally, your typical small block Ford or GM with standard headers or manifolds will not need a heat shield, but for the small additional cost it is always good insurance. Learn more in our Toolbox guide on starter heat shields.
It is easy to focus on the starter as the issue in these cases, but the starter is only a one part of the starting system. From the battery, battery cables, and even the ignition switch, everything in the circuit needs to be considered to prevent starting issues. Using quality battery cables properly sized for their current load and routing distance, using a battery with sufficient cold cranking amps (learn more in our battery guide) and of course having solid ground straps on the engine, chassis, and body with tight, clean connections on all wiring is critical to lighting off that engine without issue.
Do Mini Starters Require Any Special Mounting Hardware to Install?
One of the best features of the Chevy mini starter upgrade is that even with their smaller overall body dimensions, they are designed with cast or CNC machined mounting flange (many of which provide options for clocking the starter body for clearance) that bolts right in place of their older big brothers. High torque mini starter Chey 350 starter shims, Ford and GM mounting bolts, etc. are all able to be reused when upgrading to a high torque mini starter. If your mounting hardware has seen better days, or you simply don’t have mounting bolts, starter shims, and the like, we have what you need in stock.
Often the worst part of the installation is removing your original direct-drive starter. Depending upon your engine size, header or manifold routing, and other factors you might be in for a good bit of work on your garage creeper this Saturday. Worst case scenarios can often require removal of the header pipes, lifting the engine off its mounts, and more for full access to remove the old starter. That said, we do suggest refitting all components removed before trying to fit the new SBC mini starter. This will confirm if your new mini starter can be easily removed without any additional work in the future if you need to access it.
How Do You Wire a Mini Starter?
If there is any aspect of installing a mini starter that might give an enthusiast a pause is the wiring. Wiring is often the most troublesome aspect of any project, so many enthusiasts go into any upgrade that involves wiring with some trepidation. For many applications, upgrading to a gear reduction mini starter is a direct wire swap, but there are a few applications where you will have to perform some minor wiring relocation or additions to ensure everything works as it should to reap the benefits of these mini starters.
For classic GM applications that still use a points triggered ignition and resistance wire or ballast resistor in their ignition the “R” terminal from the factory starter solenoid mounted on the starter is what feeds the ignition 12-volts during engine starting. On a modern Chevy 350 mini starter this terminal is not usually present. To solve that issue you can feed your ignition 12 volts directly from the starter’s battery terminal (not the solenoid’s battery terminal) using a simple inline diode harness to prevent power back feeding to the starter.
We also offer a nifty quick disconnect harness for mini starters if you the confines of your installation make accessing the wiring terminals difficult for starter removal. Lastly, if your GM application’s mini starter doesn’t completely solve your hot starting issues you may want to consider a remote solenoid solution, such as Tuff Stuff’s Hot Start Starter Kit. The nice thing about using this “Ford” style solenoid on the fender is that it provides an easy connection for your “R” wire without the need for a diode harness too. Now you know how to wire a Chevy starter.
On Mopar applications you have a few options depending upon your chassis wiring situation. If you’re using the stock wiring and starter relay you can simply connect the factory wiring right up in place of the old starter unit. If your Chrysler product has been rewired with a universal chassis harness often the factory starter relay is no longer used, and you can direct wire the starter like in a GM application. Be sure to read any starter circuit notes/tips in your wiring harness instructions, as many provide the option of retaining the stock starter relay, or direct wiring the starter if you wish to do so.
Lastly, the Ford fans have it pretty easy. Ford used a fender mounted starter solenoid to provide battery power to the original direct drive starter only when the key was in “Start” and as the main wiring system’s battery and alternator connection point. To update the wiring for use with a Ford mini starter all it takes is moving the main starter cable to the battery, or “hot” side, of the solenoid (so it is hot all the time) and running a new length of 10 gauge wire from the old starter side of the solenoid down to the “S” terminal on the solenoid of the Ford mini starter (see Option 1 below). Alternatively, if you are installing a new chassis harness you can eliminate the fender mounted solenoid and use the terminals on the Ford mini starter directly to hide/clean up the wiring with the help of a standard automotive 12-volt relay (see Option 2 below).
Option 1
Option 2
One quirk about Ford starters is that Ford used different nose depths for manual vs automatic transmissions. We have a Ford starter drive tech sheet that will help ensure you order the right starter. Also, ensure your fender mounted solenoid is installed tightly, as the mounting bracket is the ground for the unit to function properly. One last word on Ford wiring; do not use a jumper wire between the original large starter cable and the mini starter’s solenoid terminal on the starter itself. This can create a run on issue and damage the starter.
So, there you have it. Everything you need to know about gear reduction mini starters and how to properly install and wire one in your classic truck, muscle car, or hot rod. Your 13:1 big block with lots of initial timing will no doubt be a lot happier with one of these mini wonders bolted up, so what are you waiting for?
