BakedPotato65

I just recently pulled individual plug wires from the distributor while the car was running on my 1974 L48. The wires that go to cylinder 5 and 8 do not affect the idle quality or sound. With both 5 and and 8 unplugged, the engine sounds the same as it does with all wires plugged in. I believe there might be something going on with the valves because running on 6 cylinders would explain the ticking noise from the exhaust sound. I just changed the plug wires to see if that helped, I started the car with 5 and 8 unplugged then plugged 5 and 8 in one at a time hoping to hear the V8 come alive. I did not hear or feel any difference between having all wires plugged in or having 5 and 8 unplugged. The distributor was replaced about 7 years ago and appears to work fine with it visually sparking the wires when I unplug them. 1 month old spark plugs too, so I'm not sure if the engine just runs very good with 5 and 8 unplugged or if the cylinders aren't actually working. I took off a valve cover and the rockers wiggled a little side to side but none seemed to be loose.

Thanks

C3 4ME

If you have an infared thermometer, shoot it at the exhaust port on the cylinders you believe to be dead, and then compare the temp to a good cylinder. A poor man's way of doing the same it to poke a small hole in the top of a water bottle then shoot a stream of water at the exhaust port and compare the "sizzle" from a dead cylinder to a good one.

MelWff

do the spark plugs in cylinders 5 and 8 look different than the others in the area of the spark plug electrodes?
you gapped the plugs to .035 when your replaced them?
there are no cracks in the ceramic section of the plugs?
what do you mean by "the ticking noise from the exhaust sound"?
You cannt tell if a rocker arm is loose, assuming the nut hasnt backed off, unless you have that cylinder on TDC on the compression stroke.
Are you running an oil with sufficient zinc/phosphorus to prevent camshaft wear?

BakedPotato65

I believe that the problem has been solved. After timing the engine for the first time in probably over 20 years, the engine sounded much better than it ever has. The exhaust ticking disappeared, which was just the sound of the airflow through the exhaust, and sounds much more aggressive. I only set the total timing around 3000 rpm to TDC so I will have to do a complete timing some other time, but for now the engine runs great. Thanks for the suggestions to help me out, I tried the infrared thermometer first and it helped me to know if it was firing correctly

MelWff

your statement "I only set the total timing around 3000 rpm to TDC" isnt too clear.
does that mean you set the total timing at 3K rpm to 36 degrees before TDC?

BakedPotato65

Yes, and that's just for now since the engine runs a lot better since I've done that. Right now I need to work on a pretty big radiator leak and and power steering leak, once I get those fixed I'll start the more fine tuning