Alright, so my early '70s 460 is a pretty mild build but the stock starter (Lester 3152) has a lot of problems turning it over when slow. It barely cranks (feels like a dead battery) for 5-6 turns and then finally kicks it over. Researching online it looked like the solution was to upgrade to a PMGR unit out of a 90s truck (Lester 3226.) Bought a brand new chinese unit. This seemed to solve all my problems but the bendix on the new starter went out. Took it into my local shop and the guy rebuilt it and assured me that "this time he used american parts." Worked for a few weeks and then the starter stuck, roached my flexplate, burned up something inside the starter and wrecked the bendix drive gear. Back to the rebuild shop. Motor and tranny out. New OEM 164-tooth flexplate back in. Checked and double-checked my clearances. Started it up, starter stuck on immediately. I wanted to be sure the metal on metal sound was the starter so I pulled it out with the engine running. Bendix was shot again, starter was hot as hell. Metal on metal sound stopped. I'm 99% sure my wiring is correct for the PMGR (battery to left side of fender mounted solenoid to big starter terminal, right side of solenoid to small starter terminal.) I know the flexplate is good and has the right tooth count. I'm back to the OEM starter and my embarrassing slow whrrrr...whrrr....whrrr...... before it cranks over. What's next?
Sounds like a bad ground problem to me. Low voltage due to a bad ground can cause all of these problems you have had. The low voltage causes arcing which causes sticking which takes it's toll on everything.
Starter grounds through the mounting bolts. Hard for that to be bad. Battery terminal and ring are clean but I'll check the block end and see what might be up.
Yes, but do you have a ground strap going from your motor to the chassis, or is the ground side of the battery grounded directly to the motor??? Rubber engine mounts don't do a good job of conducting electricity. Also, what gauge of battery cables are you using? Are they getting hot as well?
x2 on the grounded engine with large cables. I have a 429 and the starter does the "slow roll" but it always starts.
There have been times when I have run a ground cable from the starter mounting bolt all the way to the battery. This was on a car with a battery in the trunk. It was the only way I could bet the danged thing to start consistently.
All my stuff is grounded from the battery to the block, the closer to the starter the better. Ground engine to battery, engine to frame, engine to body, body to frame, that should handle the ground situation.
Tried playing around with a section of 0-gauge ground wire and wasn't able to make anything work better (or worse.) Was at my starter rebuilders today and asked them and they said that the 460s can be really hard to start if there's too much timing in them. I haven't checked mine (timed it by feel) but sure enough, unplugging my dizzy caused it to fire up faster than a hurricane toupee. I'd had to retard it out just so it starts but what are the chances that's the real problem? Why would unplugging my dizzy magically make the starter spin faster? Just two things drawing voltage at the same time? Does this help or hurt the idea that I need bigger cables?
Or put a button to crank the starter then turn the key on. Timing by ear usually gets you too much advance. Check the vacuum advance. You won't have much vacuum when cranking so the timing will be backed off. Once the engine starts the vacuum advances the timing also,the mechanical advance kicks in as the engine speeds up. If the vacuum advance doesn't work, you will have set the timing very advanced when timing by ear. If you have one of the dual diaphragm distributors you might want to find a single diaphragm unit.