Any harm to vintage engines running unleaded fuels. Options

[914043]

Back in the day when they took lead out of gas there was a lot of concern that without the cushioning effect the lead had on the valve face there would be bent and broken valves. Since my car fits those criteria and will be driving soon what if any concerns should I be aware of?? Fairly technical but Thanks for any help that might save me a damaged engine. Best to Ya

[bbrock]

BTW, I've also read that all aluminum heads used hardened seats but I don't know if that is accurate. Anyone know?

[Superhawk996]

BTW, I've also read that all aluminum heads used hardened seats but I don't know if that is accurate. Anyone know?

True. I’m sure there is some exception somewhere. It would make little sense to go to the expense of using aluminum as a head material and then to try to thrift the valve seats with cast iron seats.

Another way to look at this: if VW was using steel seats (and they were) in their engines - why would Porsche cheap out and use cast iron? No way that was happening.

The whole topic of valve recession back in the day was largely spun up based on concern for turn of the century - 1970s domestic iron with cast iron heads and/or the even more archaic side valve engines that had the valve seats cut in a cast iron block.

[wonkipop]

BTW, I've also read that all aluminum heads used hardened seats but I don't know if that is accurate. Anyone know?

True. I’m sure there is some exception somewhere. It would make little sense to go to the expense of using aluminum as a head material and then to try to thrift the valve seats with cast iron seats.

Another way to look at this: if VW was using steel seats (and they were) in their engines - why would Porsche cheap out and use cast iron? No way that was happening.

The whole topic of valve recession back in the day was largely spun up based on concern for turn of the century - 1970s domestic iron with cast iron heads and/or the even more archaic side valve engines that had the valve seats cut in a cast iron block.

yes. that does make sense.

i think my mate down here was/is really using an octane boost additive that he has fallen into the habit of continueing to use since he has boxes of the stuff. he runs quite a few old 60s and 70s aussie fords. (IMG:style_emoticons/default/biggrin.gif)

unleaded until the late 90s early 2000s was not super high octane here. think it went up to 95. then we started getting 98 - opened the gates on more new import european models of cars being sold here. the 70s porsche 6 had higher compression than the VW 4 bangers - at least down here. so whatever people were doing it was just to boost the octane to make them run a bit sweeter during the 90s.

i'm sure when it came to the USA market that anything porsche or vw were doing was set up for unleaded from late 60s. it had to be. everyone knew unleaded was on the way from 1969 on. there was a timetable to get to 1974 set in 1969.

as an aside, apart from removing lead as a dangerous material from fuel, i believe the real reason was agreement among manufacturers and the EPA that catalytic converters were the technology to clean emissions to the standards the EPA wanted achieve. to use cats the fuel had to be lead free. lead kills a cat.