Just wire in a "hot start solenoid" and forget the rest of the advice. I've had two SBC powered rods that did the exact thing. Added the solenoid and the things would start if you looked at them crosseyed. Oh and they work on other engines. Two years ago while driving a VW Thing from Portland, Ore. to the Arctic Circle north of Fairbanks we had a problem with the ignition switch not activating the starter, I found a NAPA and added the solenoid, no more problems. http://www.oldengine.org/unfaq/solenoid.htm
Sounds like timing if everything else checks out. Just cause it's "set" dosen't mean anything. Every motor is diffirent. Next time try moving the dizzy just a tad and see if it helps or gets worse. That's the ony way to rule out timing. If that don't work fix it for good and put a ford motor in it...
If you are running a standard starter, make sure you have one with the shunt coil fields. The way to tell is look on the top of the starter where the copper strap come through from the fields and a screw goes through it into the front of the solenoid. If there is no spacer on the screw, then you don't have enough starter. If it is a shunt coil with the longer fields it will have a spacer a little over an inch long and a longer screw holding it to the solenoid. Will look like a piece of 1/4 copper tubing.
i AGREE WITH ZOMBIE. ALMOST EVERY SBC I HAVE OWNED HEAT AND STARTER SOLENOIDS CAUS PROBLEMD UNTIL I DISCOVERED ADDING THE SOLENOID THEN IT WAS PORBLEM SOLVED. THEY USED TO CALL IT VAPOR LOCK BACK IN THE DAY, BUT THEN NOW WITH THAT REMARK I DATE MYSELF.
I wire in Ford solenoids on my GM cars, I started doing it on my stock cars and I never had a hot-start issue at the track, even at 230 degrees. I also recommend over-size battery cables, make sure you have an engine ground to the firewall. Can't have too many grounds. Vapor lock is related to a hot fuel delivery problem. But the sedan looks like it should have enough air flow around the engine. I did have one SBC that gave me fits with hot-starting. It was a combo of too much timing and a ****py starter. Bob
All of the above plus , replace your coil . I had the same problem twice , start perfect cold and hot just crank and crank . Buddy said change the coil , no more problems !
I had the same problem using OE starters on my SBC......both new and rebuilt. I finally got a Nippondenso-style starter from Summit that's the NUTZ! It draws less amperage (80-90 amps) which is easier on the Odyssey battery I have up under the dash, never exhibits 'heat-soak' and there's no anxiety when re-starting in public. It just whirs for a second and "vrooom!" If it doesn't solve your problem easily you can return it.
When in doubt, replace the coil. They can break down due to heat. I always keep a "golden coil" on the shelf. If I have doubts about a coil, I pop in the golden one, study its habits and go from there. I worked in a shop where a real old timer used to do exactly that. Bob
solenoid,solenoid, solenoid, its getting heat soak! they have a ton of kits to make it like a ford set up everywhere. i did it on my caprice, i ran shorty headers on my small block. i had the same problem you had. mounted the solenoid on my fender well, and the problem was fixed. heat shields ****! they never worked for me!
Yep, I'd say from experience that the bushings are getting worn. Napa usually has them in stock and along with a set of brushes you can have a fresh starter for under ten bucks. But the heat shields, making sure that the battery cables have good grounds and all connections in that system are good goes along with that too. The Ford Solenoid setup isn't a bad idea either. I'm thinking about doing that on my daily driver 71 GMC. But if it kicks right in and turns slow when it is hot it is the bushings being worn enough to let the armature drag a bit when it is hot and expanded a bit from the heat.
+1 on wiring a remote Ford solenoid. Just did one last weekend to fix a nagging hot start problem. Here is a link to a nice wiring diagram: http://www.chevelles.com/techref/tecref4.html
I had this problem with my SBF. It turned out the cable to the starter was shot and the battery was charged fully but had a bad cell. Replaced both and it was fine.
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