Hot restart issues.

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FABO diagnostic procedure.
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hoping someone on here can offer advice or a solution to to my quandary. - Rubuilt my 360 sb some time ago…..030 over; speed pro hypereutectic pistons ; Clvite bearings; Hastings rings; 11.2 :1 static compression mild cam and re graphed ignition initial 16BTDC. Recently ran the camshaft in using an engine test stand . Ran it for 20 mins varying revs etc as per proper run in procedure. Engine is now in the car and starts up perfectly runs solid, crisp sound response on throttle is brilliant and oil pressure sits on 60PSI. Problem is, if I run it and bring up to temperature and then try and restart it, the battery struggles to turn it over. Battery showing 12.2 volts so I’m sure it’s ok. Engine was very tight whe turning by hand before initial run in of the cam. Any thoughts??! TIA
Been doing this for 45 years. Set your static timing to 10BTDC, fire it up and tune the carb for the best idle you can get then, with the engine running, start pulling the timing advanced until you notice it stumble a bit, go back a touch before that point and lock it down. Should run good then. Let us know.
 
Crackedback. The diagnosis was a discharged battery, 12.2 v, which if you knew anything about electrics is a discharged battery. SO YOU START THE FIXING PROCESS BY GETTING A FULLY CHARGED BATTERY, WHICH IS WHAT I SUGGESTED.
 
I have seen 12.2 volts make an MSD box not happy to the point the car wouldn’t start
Crank, maybe not fire. If it struggles to crank, likely has something happening with ignition in the chamber.

Funny that the guy saying this stuff also says that MSD aren't sensitive to voltage. I'm out.

Simple diagnosis stuff, pull coil wire, try it, add a jumper try it. Hillbilly stuff to narrow the issue without any conclusions.
 
A general rule of thumb: Every tenth of a volt is a 10% reduction is battery capacity. Pick a number for your fully charged lead/acid battery (not AGM, not LiFe, not Li-Ion, not etc.), say 12.8V. If you measure it next week and it shows 12.7V, that is a 10% reduction in capacity.

IF you started at a 12.8V number and you now measure 12.2V, that is .6V difference which translates to a 60% discharged battery.

A ways back in this thread, the battery voltage in this situation was said to be 12.2V. That is close enough to being 'dead' to not consider calling it anything else. Low. Ineffective. Wrong. Discharged.

...or...FIX IT.

Batteries and the systems they are used in CAN be a headache if you don't follow some basic rules. ...like, why fuss with a 12.2V measured system to try to 'start' ANYthing?

Realizing that what the battery 'reads' on its posts may well have not a thing to do with what the measurement is at the other end of the cable connection (maybe 1/2" away) is the sort of thing learned over time.

Whether the system is hot or cold isn't really the question if you are STARTING with a 12.2V source.

...and the measured charged FLOAT number of a lead/acid battery (say...maybe 13.2V) doesn't mean anything.

Don't lose sight of the 'rule of thumb' as stated above. One can find many lists/charts that show different numbers.


IF 'your mileage' does NOT ever vary, you probably are NOT normal.


Google's AI attempt at 'splaining the matter does say:

Lead-acid battery
A 12-volt lead-acid battery is 100% charged at 12.7 volts, 90% charged at 12.6 volts, 80% charged at 12.5 volts, and so on.



I have fussed with 'won't crank right and does NOT start...' complaints with other folks over email and the phone many times. I have asked repeatedly that the 'owner' check the battery terminals and connections. I have heard...repeatedly...'I checked that. It's all good.' But the problem persists, sometimes for MONTHS.

Finally I drive over to 'the place' 30 miles a way. I look at the battery cable/connection. I wiggle the cable and see the end wires (through the connector) move. I say, 'See that!?' I 'fix' that problem.

The engine cranks fine, starts fine, the problem has been, at least for the short term, resolved.

Trying to get an engine to run with a measured voltage of 12.2V is NO place to START. har har dee har
 
Crank, maybe not fire. If it struggles to crank, likely has something happening with ignition in the chamber.

Funny that the guy saying this stuff also says that MSD aren't sensitive to voltage. I'm out.

Simple diagnosis stuff, pull coil wire, try it, add a jumper try it. Hillbilly stuff to narrow the issue without any conclusions.

Good points!
 
C'back still not getting it........
THE BATTERY IS DISCHRGED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Yes, 12.2v might be enough to crank the engine when cold. Factors such as the CCA rating of the battery, how old it is, etc play a part in how much reserve the bat has left. And yes, too much timing might make it slow to crank when hot.

BUT YOU TRY A FULLY CHARGED BATTERY FIRST BEFORE PULLING OUT TIMING BECAUSE THAT IS THE LOGICAL THING TO DO.
 
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