Starter question
April 14th, 2020, 07:28 AM
#1
Registered User
Thread Starter
Join Date: Jan 2010
Posts: 147
Starter question
Hello, need advice on best way to prevent starter heat soak. Which is better, shield vs blanket? What are your thoughts? Also can anyone advise if it would be worth it to install mini starter in order to reduce distance from exhaust manifold/pipe? I have a 72 supreme with stock 350
April 14th, 2020, 08:03 AM
#2
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,661
First, there is no insulation or heat shield that is 100% effective. Eventually, the temperature will be the same on both sides of the shield or insulation. Worse, once the starter does heat up, the insulation delays cool down.
The real reason for the GM hot start problem is too much resistance in the start circuit. The purple wire runs from the battery to the firewall connector to the ignition switch to the NSS to the firewall connector to the starter solenoid. In addition, any pitting on the disc or contacts inside the starter, or worn brushes in the starter, will further increase resistance. Finally, the ground path is as important as the power path. If you are missing the starter support strap, the return now has to go from the steel starter case to the aluminum nose piece to the iron block. Galvanic corrosion between the steel and aluminum also increase resistance. The right answer is to ensure that everything in that circuit is clean and making good contact to minimize voltage drop. That includes the firewall connector. This is free but time consuming. Most people would rather buy a new starter or band-aid a F**d starter solenoid.
The real reason for the GM hot start problem is too much resistance in the start circuit. The purple wire runs from the battery to the firewall connector to the ignition switch to the NSS to the firewall connector to the starter solenoid. In addition, any pitting on the disc or contacts inside the starter, or worn brushes in the starter, will further increase resistance. Finally, the ground path is as important as the power path. If you are missing the starter support strap, the return now has to go from the steel starter case to the aluminum nose piece to the iron block. Galvanic corrosion between the steel and aluminum also increase resistance. The right answer is to ensure that everything in that circuit is clean and making good contact to minimize voltage drop. That includes the firewall connector. This is free but time consuming. Most people would rather buy a new starter or band-aid a F**d starter solenoid.
April 14th, 2020, 09:15 AM
#3
Running On Empty
Join Date: Jul 2018
Location: Earth
Posts: 18,846
First, there is no insulation or heat shield that is 100% effective. Eventually, the temperature will be the same on both sides of the shield or insulation. Worse, once the starter does heat up, the insulation delays cool down.
The real reason for the GM hot start problem is too much resistance in the start circuit. The purple wire runs from the battery to the firewall connector to the ignition switch to the NSS to the firewall connector to the starter solenoid. In addition, any pitting on the disc or contacts inside the starter, or worn brushes in the starter, will further increase resistance. Finally, the ground path is as important as the power path. If you are missing the starter support strap, the return now has to go from the steel starter case to the aluminum nose piece to the iron block. Galvanic corrosion between the steel and aluminum also increase resistance. The right answer is to ensure that everything in that circuit is clean and making good contact to minimize voltage drop. That includes the firewall connector. This is free but time consuming. Most people would rather buy a new starter or band-aid a F**d starter solenoid.
The real reason for the GM hot start problem is too much resistance in the start circuit. The purple wire runs from the battery to the firewall connector to the ignition switch to the NSS to the firewall connector to the starter solenoid. In addition, any pitting on the disc or contacts inside the starter, or worn brushes in the starter, will further increase resistance. Finally, the ground path is as important as the power path. If you are missing the starter support strap, the return now has to go from the steel starter case to the aluminum nose piece to the iron block. Galvanic corrosion between the steel and aluminum also increase resistance. The right answer is to ensure that everything in that circuit is clean and making good contact to minimize voltage drop. That includes the firewall connector. This is free but time consuming. Most people would rather buy a new starter or band-aid a F**d starter solenoid.
April 14th, 2020, 09:27 AM
#4
Registered User
Join Date: Feb 2009
Posts: 2,257
My Recipe
I always install oversize battery cables.
Be sure the grounds everywhere are clean and tight.
Battery must be 100%.
Starter should be a high torque version with a high heat solenoid.
Timing must be set to specs.
With this recipe, I have never had a hot start issue on any car I have owned.
PS - Listen to Joe, he knows!
Be sure the grounds everywhere are clean and tight.
Battery must be 100%.
Starter should be a high torque version with a high heat solenoid.
Timing must be set to specs.
With this recipe, I have never had a hot start issue on any car I have owned.
PS - Listen to Joe, he knows!
April 14th, 2020, 11:11 AM
#7
CH3NO2 LEARN IT BURN IT
Join Date: Jul 2010
Location: Land of Taxes
Posts: 4,924
Check column D, all the above.
These vehicles were engineered to operate within specified ambient and underhood temps.
Heat mitigation helps but its a bandaid. Remember these cars worked just fine when new through their average life expectancy of 3-5 years. So at 50, these systems will need your attention.
As a vehicle ages so do all of its electrical components and electrical connections.
This degradation increases resistance which requires everything to work harder or beyond its designed specifications.
The additive recipe is simple....Apply normal degradation, bad connections, add high ambient and engine heat, what you get is a poorly operating starting and charging system.
Solenoid discs build carbon each time the starter is engaged. The brushes wear the commutator down and expel carbon dust. All can be considered wear items. The bearing lubrication breaks down making the component harder to rotate.
As mentioned clean all connections. Test starters and alternators. Open them up, clean, inspect, regrease, rebuild as needed.
Test (Ohm) and visually inspect battery cables. If they are original and brittle they should be replaced with OEM or equivalent. Wire insulation and the copper conductor ages and has a shelf life. The same goes for rotating components in the starter and alternator(and the VR if it's mechanical).
The first thing everyone likes to replace without testing is the battery. Load test your battery step 1! A 3000CCA battery will not be able to overcome high resistance(insert smoke show).
Starter blankets never made sense to me. They hold in the heat soak. A heat shield works for reflecting radiant exhaust heat until heat soak saturation happens.
I mitigated my hot start problems by freshening up all the above components.
I eliminated/plugged the exhaust gas crossover in the intake and removed the thermal flap in the driver's ex mani.
I also added a 20" exhaust pipe heat blanket around the head pipe from the pipe flange down past the bend past the starter. This will at least keep the exhaust radiant heat at bay.
These vehicles were engineered to operate within specified ambient and underhood temps.
Heat mitigation helps but its a bandaid. Remember these cars worked just fine when new through their average life expectancy of 3-5 years. So at 50, these systems will need your attention.
As a vehicle ages so do all of its electrical components and electrical connections.
This degradation increases resistance which requires everything to work harder or beyond its designed specifications.
The additive recipe is simple....Apply normal degradation, bad connections, add high ambient and engine heat, what you get is a poorly operating starting and charging system.
Solenoid discs build carbon each time the starter is engaged. The brushes wear the commutator down and expel carbon dust. All can be considered wear items. The bearing lubrication breaks down making the component harder to rotate.
As mentioned clean all connections. Test starters and alternators. Open them up, clean, inspect, regrease, rebuild as needed.
Test (Ohm) and visually inspect battery cables. If they are original and brittle they should be replaced with OEM or equivalent. Wire insulation and the copper conductor ages and has a shelf life. The same goes for rotating components in the starter and alternator(and the VR if it's mechanical).
The first thing everyone likes to replace without testing is the battery. Load test your battery step 1! A 3000CCA battery will not be able to overcome high resistance(insert smoke show).
Starter blankets never made sense to me. They hold in the heat soak. A heat shield works for reflecting radiant exhaust heat until heat soak saturation happens.
I mitigated my hot start problems by freshening up all the above components.
I eliminated/plugged the exhaust gas crossover in the intake and removed the thermal flap in the driver's ex mani.
I also added a 20" exhaust pipe heat blanket around the head pipe from the pipe flange down past the bend past the starter. This will at least keep the exhaust radiant heat at bay.
April 14th, 2020, 02:46 PM
#8
Registered User
Thread Starter
Join Date: Jan 2010
Posts: 147
Not sure what you were getting at with” of course you will” but I understand what you are saying. I have had the car about 15 yrs and have never replaced the starter/alternator for all I know they are original or at least very old. Battery terminals/battery/ ground wire to block are all new, will keep going and see what happens.
April 14th, 2020, 02:58 PM
#9
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,661
Not sure what you were getting at with” of course you will” but I understand what you are saying. I have had the car about 15 yrs and have never replaced the starter/alternator for all I know they are original or at least very old. Battery terminals/battery/ ground wire to block are all new, will keep going and see what happens.
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