Sorry for the confusion. I said I never thought of that. Then I went and checked the car. It was a simple single exhaust car, but someone converted it to duals with glass packs. That's probably when the heat riser was eliminated. I checked it, after someone's suggestion that it may be the cause of my hot start. I then informed the group that my particular car didn't have a heat riser and therefore it wasn't causing the hot start issue. I in fact had removed the loud glass packs and had magnaflow mufflers installed. Does this clarify it for you?

 

Got it.

 

Actually, I was premature in my initial response - which was deleted after I realized I too was having some difficulty following.

 

Installed 1/4" phenolic spacer. Adjusted heat tubes because carb now up by same amount. Air cleaner pipe to left exhaust manifold now rattles because it is less inside the air cleaner. Will try to figure out something to make the fit tighter? So far, with just a couple of heat soaked engine restarts, the engine remains reluctant to start. It does seem to require about half the revolutions from before. Now about 5-8 revolutions. May just live with this. When cold, choke set, it is starts almost immediately. Idles at 1000 rpm. Blip throttle, drops rpm to 750. Thanks to everyone for their excellent suggestions.

George, in south Alabama

 

Check the heated air intake system for proper operation. Hot air flap in air cleaner snorkel open to exhaust manifold heat when engine is cold. Flap closed to manifold heat when engine has warmed up to operating temperature.

 

i'll check ove. May even prop it open temporarily to see what, if any, effect it has. Thanks.

 

Have you tried a different hot start procedure? Your older carburetored vehicle is not like modern fuel injection where you just crank it over and fire it up. Try pressing and holding the gas pedal to the floor while cranking the engine if you having tried this already.
It was suggested you check the float level. Any luck with that? Check the float for sinking. (Absorbing fuel)

 

Did the hold the gas to the floor. Unfortunately i think as soon as i pressed the pedal to the floor made the accelerator pump squirt more fuel into the intake. Negating most of the advantage of wide open throttle adding the maximum air into the intake and getting afr closer to 14.7 to 1. Removed carb to install a phenolic block (insulating carb from hot cast iron manifold), slight improvement. If it is boiling over, running fuel into the intake, causing this issue. If i let it sit over night, it cranks and fires with a revolution or two. I looked at the float level by the csm, was good. Linkages,and dashpot, choke linkages, all were a pain in the butt. Qjet much easier to me. Next. Per suggestion of this thread, i'll eliminate the air cleaner assy having any affect on the start issue. It is less of an issue to me with the improvement obtained so far. I hate to mention this, but gas mileage stinks for an extremely mild 350 with a 2 barrel carb. My mark remmel, 425 got way better gas mileage with a properly tune qjet. My next quest is afr with a wide band/o2. Don't hold much hope considering how well it idles and the plug colors i've found so far. Enjoy the tinkering. We'll get there. God bless.

 

Checking the float level is a basic procedure but if the float weight or buoyancy is wrong you will have a high fuel level. Checking the weight or buoyancy requires extra equipment and time. A better alternative is to simply replace the float with a high quality replacement. This even more critical with todays ethanol gasoline.

 

it was a brass float. Didn't have a way to weigh it even if i had that info. Shoke it by my ear didn't hear anything and it was awfully light in my hand. George

 

Gasoline may leak out or more likely evaporate before you get a chance to shake it. A better way to test it is to submerge it in very hot water and look for escaping air bubbles. If you need clarification on this there are many videos on you tube.
PS
If you want to eliminate the hot air intake system as a cause just remove the hot air pipe and test the heat soak hard starting with out it.

 

Installed a O2 fitting on exhaust down pipe. Plugged up my AEM afr guage and sensor. Lamda read: .96 at idle, on the road .98 at 2200 rpm, 1.05 at 2500 (85 mph) went right back to .95 when I came to a stop. Really pleased with factory fuel jetting. Probably just going to live with the starting as it is. Otherwise a great older car. Runs well, uses no oil, doesn't overheat "ever". 12/15 mpg accepted.

 

My 72 442 with a 455 with headers has always had issues starting after shutting down a hot engine. Engine tends to run hot and with the headers, the heat around the starter is substantial. Symptoms were characteristic of a bad solenoid, but replacing the solenoid AND starter along with a solenoid heat shield did not solve the problem. My mechanic (a FORD guy no less!), made and installed a 1? gauge battery to starter cable and installed a starter heat shield. This seems to have solved the problem. The factory and aftermarket positive battery cables are just not robust enough to overcome a hot solenoid/starter. Something to consider if owners are experiencing similar problems. I still have minor issues starting a cold engine with the factory Rochester 4V, but setting the choke (it actually works!) and pumping it several times to fill the bowls seems to work.

 

Thanks, my small block never has slow cranking issues. Spins at the same speed hot or cold.. Engine reluctant to fire when warmed up thoroughly and sits for 10 minutes or so. One of those DEI heat blankets and a mini sterter solved a hot starter issue I had on my 67/442. I'm good with this little 350/2v plan to drive her into the sunset. Have a blssed day, thanks for your response.

George

 

That is exactly the same as what my factory original 1970 Supreme 350-4bbl with duals and 2.56 rear gears got back in the '80s.

 

I’m following this as I have the same problem (stock 1970 rocket 350) it has hardly been run in the last 5 years so my current game plan is to run a lotta fuel through it and hope it fixes itself lmao

 

I recently tweaked the AFR readings using my AEM/O2 sensor . It had yielded .96-1.05 Lamda at idle/ 1/4, 1/2, wot. Had a pleasant, as always, chat with Mark Remmel. He suggested richening it slightly. Fiddled, tweaked, and cussed but she is now .90 to .95. Plugs look excellent, light brown. Mileage 13 to 16. Outside temp is now down from 95 to 75, probably helped the gas mileage a liitle? Also had a new Cloyes timing chain set installed. The old nylon set looked really good. I could not see any wear on either gear. Maybe the chain had a liitle stretch?

The starting issue. Cold: psh pedal slowly, fuel stream into throat, choke sets, turn key to start, fires within 1 or two turns. Idles at 1000 smoothly. Tap pedal, choke disengages, idles smoothly at 750. Drives normal with no stumble, miss, or bog. Parked for 5, 10, or 15 minutes and she take 5-7 turns and fires up. I tried the old hold pedal to floor while cranking and it helps it slightly (3-4 turns) to fire up. I'm satisfied. Now I'm on to an intermittant rattle. My sincerest thanks to all who responded and your suggestions. Love the car. She is a very pleasant 51+ year old lady. We call her "Penny". Felt right for a Sienna Cutlass.

George, in south Alabama

Any Olds breaks down near me and needs help, look me up on C.O.