hunt4cleanair

I'm curious what owners of pre-lead free fuel do about those cars that once ran on leaded fuel...how do you compensate now? Add lead additive? I'm interested to learn how various model years and engine RPOs handle this.

Racer16k

A friend of mine has a LT1, 70 I think. He uses some lead additive with his, but he only drives the thing about 1000 miles a year, so I'm not sure if he'll ever know if it makes a difference. It can't hurt.

A C

When I had my heads redone, I got hardened valve seats. I burn premium unleaded most of the time, and a 75/25 mix with 110 octane when it's hot outside to prevent pinging.

AC

Larry B.

Amoco 93 is the only fuel that works for me.. But I rercurved the distributor by changing the limit bushing to give me 28 deg total @3000rpm and I do not use the vacuum advance at all. I still run 6-8 deg. initial advance. Even set up this way I cannot use ANY other 93 octane fuel without pinging in the heat of the summer.


[Modified by silvervetteman, 6:27 PM 3/22/2003]

bence13_33

The heads on my big block are from 1966 and they have "soft seats" in them. Hardened exhaust seats are highly overrated. You can run lead addative if it makes you feel better (won't hurt anything) but it's not necessary. I don't run any lead addative but am forced to run 93 octane due to my compression ratio.

PRNDL

I do fine with amoco unleaded premium, but my compression ratio is 10.25:1. There are some higher compression engines from the era that need higher octane. I saw a 70 LT1 at the racetrack that was only there to fill up with race gas (100 octane leaded). MJ

norvalwilhelm

I never worry about it. My old 69 454 does not have hardened seats and it never had a problem. When I pulled the heads to refreshing and asked the machinist to install hardened seats he looked at the heads and asked why. My old seats were still fine. He told me unless I was towing alot and the car was pushed hard regularly for extended periods normal seats would be fine. I was not a matter of money, I wanted the best. I installed the best guides and all new stainless severe duty valves but kept the normal seats.

no_radio

Local airport, less then 5 miles away. I have hardened valve seats, but the compression ratio dictates higher octane. From what I understand this is still unleaded. Costs about $2 a gallon, which is cheaper than 93 in some parts fo the country right now.
Jeff

Schmucker

My dad's old plow truck was supposed to use leaded gas, but he didn't bother doing anthing to the fuel. That thing smoked like none other. Burned the seats right out I'm sure. But then it saw pretty hard duty for plowing snow.