I have a stock starter on my engine and after the car has been running for a while and I shut it down, it is slow to crank if I try to start it again. Just plain wouldn't start the one day. It works fine when starting up initally.

Getting too much heat? Do those heat shields really work? Or is the starter just old and need to be replaced? I had it laying around so I am not sure how old it is.

To find out if you need a heat shield, pack some cheap fiberglass insulation up between the starter solenoid and your headers. If the problem disappears you can usually permanently alleviate the problem with the heat shield. If it doesn't go away with the fiberglass, then you have connection issues - battery cables with bad ends, etc.

By the way, if you use the stuff with the paper backing on it, remove the paper of course. We don't want you setting your car on fire.

Yeah...that's another job we need to line up first http://www.nastyz28.com/ubb/wink.gif

But honestly...with that motor you have I'd get a mini starter to start with (pun intended) and get a blanket to wrap it with.

Sounds like your timing might be a little too far advanced.

I have one of the aluminum heat shields that everyone seems to sell thesedays. Stock starter on a built 350 with headers. No problems, even on hot days. I put the shield on when I built the motor though, so I don't know if I ever would have had a problem, just didn't want to take the chance.
Installing the heat shielt is a pain though unless you are double-jointed!

I have about 10:1 compression and a stock starter. I have had fits with it, but if you wait about 30 minutes after shutdown it starts just fine. Added a blanket type heat shield and it did not help at all. Got a big 800+ cold cranking amps battery and it works just fine now.

Yeah, bigger battery can (sometimes) help. Don't forget to make sure you cables and connections are in good shape, including the neg. cable to engine ground. Heat shields in my experience are of very limited help (expect no miracles). "Hot start" kits do NOTHING unless your starter won't even "click" when you turn the key, which doesn't sound like your problem.

Headers are a pain for heat-soaking the starter and making it crank weak on a hot engine. The usual final fix for my engines is a high torque gear reduction mini starter. It's never failed to fully fix a hot start problem for me. I prefer the GMPP units, but there are much cheaper knock-off "clones" available on e-bay and elsewhere.

I discovered something a few years ago that might help here. When your engine is cold, you have live fuel atomized in the combustion chamber. With the kinds of advance we run in these engines, the combustion during cranking is more than the starter can overcome so when you crank it the starter has a heck of a time keeping the crank turning when the ignition system is lighting the fire so soon.

I realized that aircraft engines have the same problem, so they also have solved it for us. If you're running an aftermarket ignition system (like an MSD), add an extra switch in the keyswitch wire for the ignition system. In my car I did this and before hitting the starter I would shut off the extra switch and the starter had no problem spinning my 454. Once the starter has a little momentum, light up the ignition and it will fire easily.

IMO stock starters are underrated, but they are heavy! They are powerful, durable, and inexpensive. However, if you are extra weight conscious, you can save valuable pounds by going to a lightweight gear reduction type. Keep in mind that the weight you're removing is low to the ground and somewhat rearward (where you want the car's weight to be centered in the first place) so you're not helping weight distribution, but you are reducing total mass.