[the82elco]

Ok i'm having problems with my car starting. It fires right up when its cold but when its hot it cranks over real slow like the battery is dead & ill have to wait a few mins to start it back up. (WHAT COULD IT BE)

(I improved my grounds)

(wrapped my starter solenoid)

[vinniekq2]

check starter draw and load test battery,chech static timing

[MouseFink]

You need a fresh rebuilt starter with new cables. When the armature (windings) in a starter gets hot, the resistance increases and it takes more battery power to turn it. . If the starter commutator (where the brushes wear) is worn out, the temperature and resistance of the starter armature becomes critical.

What is the displacement and compression ratio of the engine? Many modern batteries are not powerful enough to start our old high compression, large displacement engines of the 1960s, especially if they have a radical, long duration camshaft with a lot of initial timing advance. . In the mid-1990s, I had difficulty finding a battery that would start my 455 Pontiac engine with 12:1 static compression ratio. I tried those New Castle repro AC Delco DC12 tar-top batteries. After the second AC Delco DC12 battery failed, New Castle Battery Co. told me their repro AC Delco DC12 tar--top battery would not start a 455 Pontiac engine but two or three times on a hot day. EPA compliant batteries have antimony plates and do not use lead plates anymore. I installed an Interstate 1100 CCA battery that fit the battery tray, and did not have any further problems.

I always keep a Deltran 800ma water proof battery charger (or equal) on my battery 24/7. especially if i was not going to drive the street machine for a few days. You should especially use one of those if it is a modern car with all the sensors, alarms, clocks, relays, computers, amps, bells and whistles that can have up to a 50 ma constant parasitic discharge when the engine is not running. . Your battery will last twice as long.

[the82elco]

Originally Posted by MouseFink

You need a fresh rebuilt starter with new cables. When the armature (windings) in a starter gets hot, the resistance increases and it takes more battery power to turn it. . If the starter commutator (where the brushes wear) is worn out, the temperature and resistance of the starter armature becomes critical.

What is the displacement and compression ratio of the engine? Many modern batteries are not powerful enough to start our old high compression, large displacement engines of the 1960s, especially if they have a radical, long duration camshaft with a lot of initial timing advance. . In the mid-1990s, I had difficulty finding a battery that would start my 455 Pontiac engine with 12:1 static compression ratio. I tried those New Castle repro AC Delco DC12 tar-top batteries. After the second AC Delco DC12 battery failed, New Castle Battery Co. told me their repro AC Delco DC12 tar--top battery would not start a 455 Pontiac engine but two or three times on a hot day. EPA compliant batteries have antimony plates and do not use lead plates anymore. I installed an Interstate 1100 CCA battery that fit the battery tray, and did not have any further problems.

I always keep a Deltran 800ma water proof battery charger (or equal) on my battery 24/7. especially if i was not going to drive the street machine for a few days. You should especially use one of those if it is a modern car with all the sensors, alarms, clocks, relays, computers, amps, bells and whistles that can have up to a 50 ma constant parasitic discharge when the engine is not running. . Your battery will last twice as long.

350 bore 40 over 10.1 CR

[MouseFink]

Any engine with 10:1 compression ratio should start if it has a GOOD battery and starter. That means any engine with less than 10.3:1 static compression ratio or 8.5:1 dynamic compression ratio.

I have never had a problem starting my 455 Pontiac engines with Interstate 1100 CCA batteries and both had 12:1 compression ratio using 100% VP 108 octane C-12 racing fuel. One of the 455 engines had a NAPA fresh rebuilt starter and I rebuilt the other starter myself using a NOS GM heavy duty armature. You may need a fresh starter and a fresh battery with new cables. If the engine initial advance is 12 or more degrees BTDC and sound like it is trying to start an ignited mixture, back the initial timing advance down to about 8 to 10 degrees BTDC. The engine will run hotter and will not have as much power at 8 to 10 degrees BTDC , but your engine will start and you can use 93 octane pump gas.

[cdminter59]

What do you have your initiaal timing set at? If your timing at idle is above 12* back off 2* at a time to see if starting improves.

[hcompton]

Get a gear mini starter or GM high tq starter both are easy to find and work. The gear starters are best they just work every time. The GM starters go bad if they turn slow. The more it does it the faster they wear out.

My poncho would not start with stock gm starter when hot. Not sure how mouse fink got his to work with 12:1 but I never had any luck with the stock starters on larger high compression engines. Maybe mouse will help us both out on that one. Once i get the timing where the engine makes power with a big pontiac they always start slow.

[MouseFink]

The reason it is difficult to find a Pontiac GM high torque starter today is because they all have worn out armatures and have been rebuilt to death. You can only resurface the commutator on a armature a few times, then the armature must be replaced with a new one. New starter armatures have been discontinued from GM since the mid-1970s. That is why new aftermarket starters have become available from Chinese manufacturers. My 455 engines were 1963 421 blocks which used a bell housing mounted starter and all of those were high torque starters. The low torque starters were first introduced with the Pontiac 350 and 326 V8 engines but starting in 1973 through 1979, all Pontiac V8 engines received a high torque starter. You had to be careful when you purchased a 1964-1973 Pontiac starter because you may get a low torque starter. The 1964-1979 Pontiac high torque is about 2" longer.

My 455 CI (1963 421 blocks) Pontiac engines used a bell housing mounted starter and they were discontinued from the local parts stores in the mid-1980s. I had to locate a new armature from NOS parts vendors and rebuild my 1963 starter. All the the parts needed to rebuild a GM starter are still available from aftermarket suppliers except for the 1955-1963 starter drives. I managed to obtain several starter drives, commonly called a "bendix", and three NOS Delco-Remy armatures for 1962-1964 Pontiac engines. I also used AC Delco starter solenoids with the brown cap. Those HD solenoids were first introduced in 1970 for the 455 Pontiac engines.

As I wrote before, my starting problems with Pontiac 455 engines, 12:1 compression ratio, 9.8:1 dynamic compression ratio and 220 PSI cranking cylinder pressure was caused by modern batteries that are designed for engines with less than 9:1 compression ratio and less than 350 CI displacement.

I use a starter on my 1991 4.3L V6 Chevy engine with 10.13:1 compression ratio (8.4:1 dynamic compression ratio) that is designed for a 7.4L V8 Chevrolet truck.

[vinniekq2]

I just bought a starter for a pro stock engine

[MouseFink]

That is what you must do if you want a new starter...all others are rebuilt to death.

[cobalt327]

Originally Posted by the82elco

Ok i'm having problems with my car starting. It fires right up when its cold but when its hot it cranks over real slow like the battery is dead & ill have to wait a few mins to start it back up. (WHAT COULD IT BE)

(I improved my grounds)

(wrapped my starter solenoid)

It could be a lot of things. Some common problems are bad grounds, bad battery cables- especially if they have replacement terminals on them. These can look and feel tight, yet have a ton of resistance that only rears its ugly head when there's a higher draw on them. If the terminals feel hot after a hot restart, that's a good indicator.

The starter solenoid can get worn internally after a while. This can be remedied by taking the solenoid apart and swapping the terminal lugs. More on renewing the solenoid can be seen here.

A remote solenoid may help. Info on that and where the following was taken is here:

The wiring has to be in good condition or nothing will help. That means no frayed wiring, no wires of insufficient size, no parts store clamp-on replacement battery terminals (the #1 cause of "bad starters").

Throughout the electrical system there needs to be tight connections, a properly working charging system including the battery, and a good starting system. Grounds have to have direct contact with bare metal and be of a sufficient gauge for the job.

If the problem remains even after the remote Ford relay/solenoid is installed, a starter heat shield may help. Another option is a "permanent magnet" starter. They're less inclined to suffer from heat soak. Then there's the heavy duty "high torque" mini starters- also permanent magnet type starters.

If the initial timing is advanced far enough, the engine will turn over slowly when it's hot regardless of what is done. This often happens when there is a big cam that needs a lot of initial advance or needs the timing locked at full advance.

The solution for this is to use a remote ignition interrupter switch. Generally the switch is a momentary on-type switch that allows the engine to be turned over by the starter, without the ignition being armed. Once the engine is spinning over, the switch is released to energize the ignition, and the engine fires up.