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Eileens 79 Corvette resurrection. It survived 1450miles on Power Tour

Had 30 minutes in the middle of the day to mess with it. 1.5 hours later I was late for a meeting. Set my alert to the wrong time. I hate being late.

Welded an adapter to my balancer turning tool so I could turn the crank with the plugs in. Bolted it on and proceeded to turn the engine over 4 revolutions. Was smooth with each compression stroke felt. Nothing stopped it. So no plug interference. Did this with my bad arm and the 10" ratchet. It's got to be the starter.
 
has to be something between the battery and starter. Hard to believe you have two bad starters but weirder stuff has happened.
 
Yep. Wade and I had a conversation about that this morning. Put two starters on a car in two days.

Third one I rebuilt on the tailgate at the racetrack and never messed with it again
 
campfire said:
It could be any part of the electrical system.

Have you considered using a voltmeter to pinpoint the problem?
Click to expand...
He bypassed everything on the car including the trigger point. Even built different leads to an external battery
 
Bent77 said:
He bypassed everything on the car including the trigger point. Even built different leads to an external battery
Click to expand...

I understand that. And yet, it still does not work. Having ruled out the easy sources, it's time to check the less likely things. His test leads may not be passing sufficient current. Or the motors could both be toast. Or something else. Either way, an ounce of testing is worth several pounds of speculation...
 
Zero loss in the test leads. New 1/0 wire with copper ends that I installed yesterday to try it. 5urned over identical to running through the car system.

No time until Saturday to work on it.
 
Only other thing that comes to mind is if the wiring to the starter is grounding out on the engine. I had a small block that had a cracked starter bolt hole and when you would hit the starter it would shift and the bendix gear would hit the flywheel. But if you stuck a screwdriver in and moved the bendix gear out every thing looked good.
 
Got home after having an epiphany about trying something to eliminate one more thing.

How much torque does it take to turn over a SBC with the plugs in. I had remembered from decades ago that it was about 40 feet pounds. could not find anything on the interweb. Then a light came on. I have the 5.7L I recently pulled. Checked it. Between 40 and 45 feet pounds. Checked the Corvette. Same. So the engine dragging is not it. The volt meter on my power probe shows 12.7 volts. Drops to 10.5 volts when cranking. Comes back to 12.5 after a 5 second crank attempt. Rotates the engine a 1/4 of a turn.

I am leaning towards a bad starter. I have the car battery with a semi battery and a jump box connected.
 
ktmoutfront said:
Got home after having an epiphany about trying something to eliminate one more thing.

How much torque does it take to turn over a SBC with the plugs in. I had remembered from decades ago that it was about 40 feet pounds. could not find anything on the interweb. Then a light came on. I have the 5.7L I recently pulled. Checked it. Between 40 and 45 feet pounds. Checked the Corvette. Same. So the engine dragging is not it. The volt meter on my power probe shows 12.7 volts. Drops to 10.5 volts when cranking. Comes back to 12.5 after a 5 second crank attempt. Rotates the engine a 1/4 of a turn.

I am leaning towards a bad starter. I have the car battery with a semi battery and a jump box connected.
Click to expand...

If that's 10.5 volts on the input terminal of the motor, you are definitely needing a new motor.

If that's at the battery it's still probably the motor, but could also be resistance upstream of there (particularly look at the solenoid).

You're getting close.

:popcorn:
 
campfire said:
If that's 10.5 volts on the input terminal of the motor, you are definitely needing a new motor.

If that's at the battery it's still probably the motor, but could also be resistance upstream of there (particularly look at the solenoid).

You're getting close.

:popcorn:
Click to expand...

Are you talking about the starter motor? Or are you speculating the engine may be bad, but calling it a "motor"?

engine = a device that uses combustion or heat to produce motion
motor = a device that converts electric (or hydraulic) energy into motion
 
tRustyK5 said:
Are you talking about the starter motor? Or are you speculating the engine may be bad, but calling it a "motor"?

engine = a device that uses combustion or heat to produce motion
motor = a device that converts electric (or hydraulic) energy into motion
Click to expand...

One of my biggest pet peeves. And I have many.

I took it as the starter motor.

Won't get to mess with it until tomorrow.
 
tRustyK5 said:
Are you talking about the starter motor? Or are you speculating the engine may be bad, but calling it a "motor"?

engine = a device that uses combustion or heat to produce motion
motor = a device that converts electric (or hydraulic) energy into motion
Click to expand...

I'm talking about the starter motor. Motor is motor, engine is engine, and never the two shall mix. :waytogo:

If the motor is getting good voltage and not delivering good torque, it is not functioning properly.
 
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