QuestionHello, I have a 60 F-100 with a 223 inline 6 with a question regarding fuel usage. I understand that typical unleaded won't cut it for the old leaded engines and that a fuel additive or modification/part replacement is needed. I would prefer to make it so that it ran run straight unleaded. I read a few articles, but they all varied a bit as what needs done to the valves. What exactly needs done to the engine to make it run on unleaded gasoline?
AnswerHello Sam,
Beg to differ from your sources but the research I've seen shows unleaded fuel does not hurt valve seats in normal operation. If your truck is used for heavy duty towing for example, deterioation of the valve seats by unleaded fuel could be a problem in this case (heavy load) only.
Regardless, when you rebuild the engine, put hardened valve seats in at that time, it's cheap insurance!
The second area unleaded can hurt is your carb. seals and such. The fuel has such active cleaners that they can deteriorate these components. Solution: be prepared to rebuild the carb.
Third, modern motor oil may no longer contain additives giving sufficient valve train lubrication. Solution: Switch to older formulation oils like Shell Rotella.
Hope this helps,
Bob
