An engine needs a certain minimum rotation speed to start. It has to suck in air and be able to compress it, so the mixture can ignite and the piston can generate the power to drive the crankshaft fast enough to get the next piston over top dead centre. It is all up to the starter motor to get the engine up to the minimum starting speed.
The starter doesn't have an easy job. It has to accelerate all the heavy steel parts of the engine, like the flywheel, the crankshaft and the connecting rods. It has to overcome all the friction of the bearings, the valve drive and the pistons inside the cylinder and it has to overcome the compression in the cylinders. Even if temperatures are well below zero and the thick, cold motor oil acts like glue rather than a lubricant.
To provide enough torque, the starter motor usually connects to a large toothed ring around the biggest turning part of the engine, the flywheel. The starter uses a very tiny gear itself. That means there's a huge ratio, creating torque, but decreasing speed. That's why starter motors have to turn at very high rotation speeds and use huge currents, sometimes up to 90 Amps.
Considering the high ratio, most starter motors would wear down rapidly if the engine would be revved up. That's why the drive gear isn't permanently connected to the starter ring gear. A strong electromagnetic servo or solenoid slides the gear onto the starter ring gear when starting. A freewheel makes sure the drive gear can turn faster than the starter motor itself to protect the electric motor when the engine fires up. A special return mechanism will pull back the gear from the starter ring when the engine is running and the driver lets go of the ignition key or starter button.
It isn't easy to create a durable starter motor. The gear shapes, the material strength the tolerances and the steel hardness are important factors, as are the constructions of the solenoid, the coils and the collector/carbon brush unit. Savings on material or production quality will result in a reduced life span. As it is Nipparts policy to deliver value for money, durability is a key factor in Nipparts production plan. Therefore, Nipparts starters are always of OE matching quality, despite the fact that they are usually more affordable than the manufacturer's item.
Nipparts offers an extensive range of starter motors for Japanese and Korean cars. Check our free catalogue for all of our references:
Nipparts Starter Motors:
- High power starter motors
- Durable constructions
- Extensive range
- OE Matching quality
- High value for money ratio