Newbie owner - Is unleaded gas a problem for '74?

Discussion in 'Engine Topic' started by Rockmolsen, Nov 6, 2016.

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  1. Rockmolsen

    Rockmolsen New Member

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    A friend just asked me if running unleaded was an issue for my '74 Camaro 350 motor. I didn't know how to answer. Is it ok, should I be using an additive or using higher than 87 octane?

    Thanks
     
  2. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    Should be just fine. 75 was the first year for a cat which demanded unleaded, but 74 was prepped for it with hardened valve seats. It is a low compression engine so 87 regular should be just fine.

    Truth be told, most of these vintage engines don't get run that much to ever have serious valve seat erosion. The lead in the fuel was there to act as a "cushion" for the valves when they slammed against the seat.
     
  3. Rockmolsen

    Rockmolsen New Member

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    Dave, Thank you for your response. This is not an everyday driver. I've waited along time to find this car and wanted to be sure I was doing the right thing. Thanks
     
  4. cadillac_al

    cadillac_al Veteran Member

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    GM made all their cars unleaded fuel compatible in '71. A 74 will be fine.
     
  5. Z27LS3

    Z27LS3 Veteran Member

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    I would not worry about unleaded, but I steer away from standard ethanol gas. I use ethanol free and always have on my old cars and never have had fuel system issues. aside from valve seat concerns I'd be a little concerned with todays 10+% ethanol gas laying around in the fuel system. I run straight no ethanol gas as cheap insurance, these older fuel systems are not designed for ethanol. I manage to find ethanol free gas at ag coop gas pumps, truckstops and random stations advertising ethanol free.
     
  6. slayer021175666

    slayer021175666 Veteran Member

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    Don't worry about it no matter how old it is! We all thought we might F-Up our heads or valves or something when we could no longer buy leaded gas but, it never happened. The old thinking was that you had to have lead to cushion the blow of the valves when they seat but, when we were forced to try unleaded, it was fine. I been running unleaded gas for many years in a 1965 327. Never had hardened seats and all is WELL! :)
     
  7. ol' grouch

    ol' grouch Veteran Member

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    The fears of seat erosion were hysteria to protect market share. Tetraethylead was a cash cow for years and let higher compression engines be built. Other methods are available but the push was on to make money quick. The same push to protect market share led to the banning of Cyclamate (an artificial sweetener that competed with saccharine) and is also the reason why so many towns no longer have street cars and are looking to put them in. GM made a push in the early 50's to sell their buses.

    I've run 1950's cars hard over the years and if I tore one down, there wasn't ever any seat erosion. All of GM's engines for the 1972 model year had hardened valve seats. These went into production in early to mid 1971 for the '72 model year.
     
  8. Z28PILOT

    Z28PILOT Veteran Member Lifetime Gold Member

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    Use 100 % gas , not the blend ethanol and oil with LOTS of zinc in it.
     
  9. giggity

    giggity Veteran Member

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    where in the heck do you get 100% gas these days? I would bet I could do a pepsi challenge on gas, and no-one could tell a difference. Ive run just about everykind of gas and see, hear, feel no difference when comparing apples to apples. Now I have run AV gas before and I could tell a difference in the higher octane.
     
  10. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    Kind of interesting on this topic of gas, I have heard that the auto manufacturers are requesting higher octane fuels at the pump to meet the new gas mileage requirements. They say they are hitting a wall on efficiency and the higher cylinder pressures (from turbos on small displacement engines) can't be achieved with current 93 octane. They are pushing for 95-100 octane.

    This could be good news for the old high compression engines that have to run race gas if it really happens.

    http://www.autonews.com/article/201...press-for-higher-octane-gasoline-to-help-meet
     

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