Charlotte\ said:
Nagging question. Not yet answered, even by HDR. Anyone care to take a stab at this?
:huh: Charlotte
2 issues.
First, lead acted as a 'lubricant' for the intake and exhaust valves...the sealing face of the valve where it meets with the 'valve seat'. Not too big an issue on the intake valve, but definitely a problem for the exhaust valve. The lack of lead allowed deterioration of the mating surfaces, resulting in what's known as a 'burnt valve'. The sealing surface would no longer seal which caused compression loss resulting in misfires. Continued driving and bits of the valve could actually break off, and having even the smallest bits of metal bouncing around in a cylinder is not a good thing $$$.
The solution is removing the cylinder heads and having a machine shop install new 'hardened' valves and seats. Basically at this point the heads should just be completely rebuilt...new valves, seats, springs and keepers. Would check for warpage and resurface if needed. In today's world it would be a rare find for an old motor not to have had this done already (unless it's a barn find and has not been running for 30 years).
Second, the alcohol in today's 'crap gas' is corrosive to rubber, aluminum and plastics. Older rubber fuel lines will degrade and clog the fuel filter. Some bits in older carburetors also don't like alcohol. These issues are actually easy to fix with more modern materials...replace the fuel lines, filters and rebuild the carb....again should already have been done on an old vehicle still on the road. Alcohol also absorbs water. Back in the day we in the colder winter areas would use 'dry gas' products to remove the water condensation that would form in the gas tanks. It was nothing more than a small bottle of alcohol. 10 or 12 ounces in a 20 gallon tank of gas every now and then would 'mix' with the water on the bottom of the tank and allow it to be burned thru the motor. (water and gas don't mix, water is heavier and sinks to the bottom)
Nowadays, with crap gas having a 10% mix of alcohol 'dry gas' products are obsolete.
However, a modern day 'hack' is that you can use water to remove the alcohol...but that's a different thread.
Hope this long winded diatribe helps.
(and of course in the time it took to write this, HDR and others have already chimed back in...but WTH, I wrote it, I'm posting it.
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