The Stovebolt Site Forums The Shop Area Engine Shop Still a pining?

Been a while since I have been on my favorite sight. Hate to complain here but trying to find out why my 235' is a pining more and more, for about the last year or so she has been just running its best. About the only thing I have done is retard the timing to about 2 degrees and advanced it all the way up to 6 in 2 degreese increments. I run Mobil regular fuel monthly. What could it be? new plugs maybe, points, condenser, let me know gang, thanks...........

"Pinging" could be timing. You say you have tried different settings. That should have had some results that you could hear. It's called spark knock also. It can be timing related or spark plug related.
Also the sound is called detonation/preignition caused by lean fuel mixture (carburetor) ........ or overheating/exhaust leak.
Tune it up with points, plugs, condenser, cap and rotor, and plug wires (all the cheap and easy stuff). Tune ups don't waste money. If a person has tried and can't find it and does not have equipment/Hot Rod Jerry type experience, the first thing is a tune up so as to start with a baseline of good electrics. If you can't install and set point gap accurately, find someone who can. Tripple check the gap after tightening screw by moving rotor on and off the lobe.

Then time it per the book. With slight tweaking. Then move to other causes mentioned.

Be Aware: Sometimes the sound you hear is NOT pinging. Especially if it runs good and does not overheat. Especially if you didn't get any results from turning dizzy back and forth. The sound can be an exhaust manifold leak/exhaust connection leak, a heat riser flapper, tappets, rod knock...........coins in your pocket, false teeth.

GET A STETHOSCOPE...or a broom handle. Listen at valve cover, all around on the block, each exhaust port, the pan, the dizzy, the draft tube, water pump, fuel pump.....

Good luck and let us know what you need or find out.

Yeah sorry about the mis spell. So basically it does run pretty good, I'll start messing around with the distributer components and whatever you mentioned, its funny though I'll be going to my home after work up this fairly long hill and punch it in High gear and here comes some pinging again. Thank you

The only thing I would add is to check your engine for vacuum leaks. Vacuum lines, intake manifold, carburetor base gasket (loose nuts / bolts). Use a can of carburetor cleaner and spray the components; if you get an increase in engine RPMs you have found your vacuum leak that is causing the lean mixture. A leak at any of those locations would usually get worse over time.

I used to run a 216 in a '52 3100. It would ping under load up a hill no matter where you set the timing. I could certainly make it happen earlier with the wrong timing.
I have a '53 235 with hydraulic lifters which I cannot make ping by adjusting the distributor.
I am going to suggest that mechanical lifter engines are going to ping under heavy load. I am not convinced that this "ping" is the dreaded detonation we are often warned about, but rather the nature of theses beasts.

Here is a quote from the Chevrolet Truck Operators Manual for 1952. (the little book what goes in the glove box.)
"Road test. For best performance and economy the the octane selector should be set to produce a slight ping upon acceleration at wide open throttle."
Carl

If the engine has high miles, there might be enough carbon deposits in the combustion chambers to cause detonation regardless of where the ignition timing is set. Once carbon deposits get hot enough to glow (just a few minutes' warmup) as soon as the engine lugs a little on an uphill pull the glowing carbon will light off the fuel/air mixture. The spark plug comes along later and tries to light a fire that's already burning.

Fill a 1-liter soft drink bottle with HOT water, take the air cleaner off, set the idle up to around 1500 RPM, and slowly dribble the whole bottle down the carb throat. The engine will buck and shudder, and clouds of steam and possibly huge gobs of carbon will get blown out of the tailpipe. Don't pour fast enough to stall or hydraulic-lock the engine, just give the combustion chambers a good steam cleaning. Then set the timing to factory specs and take a test drive at full throttle up a long hill. You'll either fix it or you won't, but you won't do any harm.
Jerry

Years ago my 216 would ping going up a long hill also. Found the heat riser flap stuck in the closed position. Got it moved to the open position and pinging went away.

Try this:
Remove the distributor cap.
Grasp the rotor and turn it until it stops, then release it. It should return to a solid stop without assistance. What you will be feeling is the counter weight springs functioning. If the rotor does not return to a hard stop, you will need to take the distributor apart and inspect the counterweights and springs for excessive wear.
Carl