fuel requirement question

[entropy454]

Could someone point me to a link or tell me what the fuel requirements were for the 68-72 corvettes from the factory.
I.E. octane and leaded gas etc?
thanks

 

[Vettehead Mikey]

'70 and up were designed to run on unleaded gas, although field experience has shown that no Corvette ever really required it for valve seat protection.

With respect to octane levels, it's best to consult the owners manual. Keep in mind that the gasoline rating system changed.

By the early/mid 70's the cars were designed to run on regular 87 octane gas.

 

[Crimson Thunder]

I'd say 71 and up.My 70 base motor has 10.25:1 compression and the L46 and LT-1 had 11.00:1.

 

[6880 Mike]

...Could someone...tell me what the fuel requirements were for the 68-72 corvettes from the factory....I.E. octane and leaded gas etc?...

Leaded fuel. 92 or better octane where it was available. Pretty much a moot point these days since leaded fuels are long gone.

 

[entropy454]

So I assume you use whatever octane level the engine is built for and buy a bottle of lead addititive from a parts store?

 

[6880 Mike]

...So I assume you use whatever octane level the engine is built for and buy a bottle of lead addititive from a parts store?...

74 and up heads have hardened valve seats to run on no lead. You don't need lead additives/substitues for those. 68-73 do not have hardened valve seats from the factory, but there may be enough residual lead in the heads not to give you any problems. I've never had any problems with no lead in my '68 with stock heads. Every now and then I buy a can of the substitute and run through it.

She likes 92 octane, but she'll run all day on 87.

 

[Vettehead Mikey]

So I assume you use whatever octane level the engine is built for and buy a bottle of lead addititive from a parts store?[/QUOTE]


Absolutely not. There is no need (not now not ever ) to add lead. The 'big scare' of the 70s when we were converting over to unleaded was that the valve seats would burn away due to microwelding between the valve face and valve seats. Well, here we are 35+ years later and we're still waiting for the first case of valve seat burning to occur.

Apparently the sky is not falling.

Burning might be an issue on an engine run at full load for an extended period, but not on street driven cars.

BTW- I think the first hardened seats in Corvettes was '70 or '71.

 

[entropy454]

Good info, here is a link from the EPA about leaded gas and valves.
http://yosemite.epa.gov/R10/airpage.nsf/webpage/Leaded+Gas+Phaseout
Though Im guessing they have more of an interest in the enviroment than your car.