Sorry but the guy sounds like an idiot,Kris. Engines ran for a long time on leaded fuel tend to have a pretty good cushion of hard deposits built up around the valve seats. Switching to unleaded fuel might take a long time to wear them away. When I was doing a lot of flying,I would occasionly add five gallons or so of 100-LL Avgas to my 57 Nomad's 327. I drove that car for over ten years without any signs of valve procession. Clint Hooper H&H Custom,owner LT5 Registry Director http://www.LT5Registry.net/ ACES #1650 http://dalesplace.com/misc/friends/clint/clint_hooper.htm ----- Original Message ----- From: "Krister Meister" <[EMAIL PROTECTED]>
> I guy asked me what fuel I used in my '66 Chevelle (stock 396 with mild > cam) while we were waiting for our step off time in the local July 4th > Parade. I told him regular 89 octane right now, but have used 91 and 93 > octane and noticed now real difference in how the car ran. He got all over > me for not using a "lead additive". I told him I am under the theory that > the engine has been heated up and cold down so many times over the years > that the valve guides are hardened by now (I do plan on rebuilding the > engine with hardened guides in a few years when doing my restoration). His > point was that without having a lead additive that damage would be caused > to the pistons by blowing holes in them if the car back fires or pings > especially under hard acceleration. My hardly occasional back fire comes > through my carb and the car is timed that it never ping's. I do get an > occasional engine run on for a half a second which I could blame on the > lower octane. Any one using "lead additive" and any thoughts supporting > this guys comments? > > Thanks, > > Krister Meister > '66 SS #'s > >
