Lots of threads ask "Can I run Unleaded in my old engine with stock valve seats?" What I'd like to know is what are you running, not what can you run.

Please don't answer if you know you have hardened valve seats.

 

1964 262 - Unleaded is all she gets and the seats looked good when we put rings and bearings in it a couple years ago.

 

I hear a lot of this, and wonder what sort of testing or experience made this "conventional wisdom" come around. That's why I thought this poll might be interesting.

 

So here's question for you: why did they start adding lead to gasoline in the first place? Was it solely for lubrication? Or for some other reason?

 

 

My 66 gets plain old unleaded. I have driven it 33,000 miles since last august, so if a problem were to arise I would know about it.

 

I think most of the, "unleaded destroys exhaust seats" came about in the 1970's before the refiners got a handle on how to make the stuff. Remember the petroleum industry resisted the switch to unleaded more than the auto industry did. I've taken apart a bunch of Ford engines mostly Cleveland's and 429's. I've only ran across one engine that had severely recessed exhaust seats and that was a 429 SCJ that had been driven by a teenager putting in the cheapest gas he could find. I run unleaded 91 octane in my Cleveland without hard seats with no problems but I built it with 7.73-1 dynamic compression ratio. It's 10-1 static. And that 7.73-1 is assuming 100% VE "which it isn't" so in reality it's lower than that.

 

Lead also increased the octane rating or, more specifically, resistance to detonation. Alcohol (ethanol or methanol) does also , but in my opinion that is not why it is in our fuel.
I drive several miles past my local gas station to get ethanol-free fuel. It is expensive (because it is 92 octane, which my truck doesn't need), but it doesn't damage the rubber parts in the fuel system.
Eric

 

Glad I'm not the only one that hangs on to the old "conspiracies"...

 

I've seen a couple of FE's with significant exhaust seat erosion. I put hardened seats in mine so no worries. There was no, "I have hardened seats so I burn anything I want", option in your poll.

 

LoL that's a good one.

 

Here's the Wikipedia on him... interesting. https://en.wikipedia.org/wiki/Charles_Nelson_Pogue

 

 

 

How'd that go? Did you win?