Instructables

Is there anything I can do to make a car starter run for longer periods of time?

I was looking into using a modified car starter on a go cart and from what I've read they'll burn out if they're ran too long. Is there anything I could do to make them run longer without breaking? Or even why they burn out from continuous use?

frollard5 years ago
The motor itself with proper heat dissipation can run for quite a while - trouble is it doesnt have any default way of dissipating heat. On a normal starter theres the motor, and the solenoid that makes the starter cog interface with the engine - when its off the gear retracts so the engine can run. Disabling or removing the solenoid - the part which is really not designed for continuous use - should elongate the life, but a starter motor is still not a very good choice for a go-kart.
rob_fed1 year ago
http://www.evalbum.com/251

This is my electric go cart that I made many years ago. I still have it and it is over 10 years old. The best starter to use is a gear reduction type, my common on import Japanese cars/trucks. This is because it is easier to mount a drive sprocket to replace the pinion gear. To answer the question, yes, you can modify a starter to run at 30 minutes at a time.

a. remove all off the original grease used in the gear reduction assembly, this grease is almost gummy and was designed to lessen the impact of intermittent full power when starting a car. Replace with some very light grease, I used some Mobil 1 pink synthetic wheel bearing grease.

b. Drill cooling holes around the motor brush housing. Do this carefully and as not take too much metal away making it too weak to hold the brushes.

c. Sand the outer motor housing and attach cooling fins made of aluminum. I used JB Weld, it does conduct heat, but if you access to PC CPU heat sink adhesive, this would be best but significantly more expensive. I used what I had, 1/2" by 1/2" "L" shaped aluminum strip, could go with tall fins if you want.

d. I run a 12volt fan directly on the case, you can experiment with the placement, but mine shoots air from bottom to top at about a 60 degree angle. I also cut off the solenoid from the start as it was just in the way. The starter shaft is permanently pushed out from the housing using Loctite Red. It has never dislodged.

After bench testing the stock Honda Civic starter, I found in stock form the motor gets very hot quickly when running for only a few seconds. When I removed all of the thick gummy grease, the motor spun significantly more free and there is much less heat created.

I let me nephew loose with the go cart, he ran it into the ground running up and the street. After about the 1/2 hour, the motor is hot, but the windings are not burning up with the typical smell of a overheated starter. I am sure that everything could be more optimized, but many people have tried the go cart and it has not given out.

Pictured the go kart only has on/off via a continuous duty 12v solenoid. I do have a homemade PWM speed control going through 6 vintage MOSFET's. The PWM controller helps mainly with initial jolt of taking off from a dead stop. For fully power, the continuous duty solenoid is wired to kick in and disengage the PWM controller.

skunkbait5 years ago
They can run pretty long without burning up while not under load. But if you want to run one under load, you might look into a different style of brushes.
If you put ball bearings in a v8 starter motor and use enough batteries, can you power a geo metro to 55 mph?
Hi, I am thinking if you did a couple of things, then perhaps you could do it. first, I would think that the starter should be made mechanically sound I.e. cleaned of any grease and grime, new brushes, bearings, armature contacts cleaned and polished, etc. As you want to start with the best opportunity for success. Heat is a big issue., so if you constructed an aluminum "shell" to fit around the starter case that might be a good start. I was thinking something like a long strip of aluminum heat sink and wrapping it around the starter case, or more likely, A series of aluminum angles perpendicular to the axis of rotation with small slits in the end to accommodate a hose clamp to secure them around the outer casing of the starter motor on each end. Once I had a good heat sink identified or fabricated and fit snugly around the starter. After getting a very snug fit, disassemble and add a thin layer of heat transfer paste around the starter to maximize heat transfer from the motor to the sink. I'd find some way to place a fan of some sort on the output shaft of the starter (or an electric fan) to blow air around the fins to transfer heat away. The use of a Pulse width modulated controller (like an electronic speed controller for a golf cart) would tend to reduce the operating temperature. As the PWM delivers power to the motor in a series of Pulses rather than continuous DC current, this may also result in lower heat buildup. PWMs are somewhat expensive. A cheaper alternative might be to build your own using 12V mechanical starter relays and resistance wire as used in older golf carts. All you'd need besides that is a control switch from a golf cart to "ease the transition" between the relays and away you go. Idea behind the resistance controller is that by creating a resistance coil, and tapping at different points, more current or less current is supplied to the motor. Check this link for a good description of how to build it. It is for a "golf cart" but the same idea. download the PDFs and enjoy. http://www.vintageprojects.com/go-kart/golf-cart-plans.html Just a couple of ideas, hope this might help.
lets take a look: //www.youtube.com/watch?v=t5GOhyvCxRU&feature=related
Hansj35 years ago
not really. from an engineering standpoint starters are designed to take a large amount of amperage for a short amount of time. in fact before the starter was invented people said that it would be impossible becouse the size of the motor would be the limiting factor.
NachoMahma5 years ago
. Not much you can do. They are designed to be run for short periods of time (~5-10 sec) only, not continuous operation. Heat is the main problem.