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Have my eyes on a 1970 Imperial

Discussion in 'All other classic cars' started by Tori G., May 22, 2015.

  1. Tori G.

    Tori G. New Member

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    It does have the Holley Carb and I do have a good friend of mine that is very good working on them.He has worked on this carburetor before with good results.
     
  2. Scrounge

    Scrounge Got parts?

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    Remembered another problem that I hope you don't have; each of the taillight lenses were cracked in two places. I had to be very careful when changing rear light bulbs. A better design would have been to remove the sockets from inside the trunk. The few replacement lenses I found were in worse shape. This was a Texas vehicle; the lenses may have become brittle due to the heat.
     
  3. Tori G.

    Tori G. New Member

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    I drove it to work this morning,plated and insured now.Lot of lookers had their eyes on it.It drives good still like I mentioned.I did fill it up and did pour in a bottle of lead additive knowing it has the soft valve seats
     
  4. thedriver

    thedriver Active Member

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  5. dana44

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    From my own experience, like 250,000+ miles on a set of heads (actually 1963 big block heads), the lead additive isn't needed. Mopars built the big blocks with better metal (higher chromoly content) to start with, and the valves (near stainless) are higher quality to start with, and they just don't sink like the Ford and Chevy heads of the same era.
     
    patricklynch likes this.
  6. Scrounge

    Scrounge Got parts?

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    Lead substitute (I doubt that Real Lead still exists) will be helpful for higher rpm driving. If you only drive it on local roads at 40 mph or slower, it might not be an issue, but if you give it the freeway miles it's made for, it's a very good idea.
     
  7. dana44

    Ad-Free Member

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    Don't get me wrong, it won't do any harm to add the stuff, it is just a waste of money overall. These heads were in my 68 Charger, most highway driving back and forth from Washington State to San Diego, always the cheapest gas possible, and when the heads were pulled off for guides (which turned out to be valve stem guides DOOH!), all the valves were reground a third time in their lives and none, not one single valve, had to be replaced and no seats were replaced or installed. I never put any additives in the tank, just wasn't/isn't needed, save the money, just make sure the carb is tuned so as not to run lean. I say this because I did burn up a small block Chevy by running lean (and higher compression than stock), pre-1968 heads. I burned 8 intake valves in 17,500 miles.
     
  8. Scrounge

    Scrounge Got parts?

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    By "cheapest gas possible", I hope you're not advising that she use regular in an engine that's made for premium (10.1:1 compression ratio). I once put 92 octane in my Imperial; the resulting pinging made me use 93 octane in it from then on.

    In her vintage, some valve lubrication is better than none. One older guy put half a quart of motor oil in his tank whenever he filled up his '68 Imperial. It smoked a bit, but it never needed a valve job. I personally prefer lead substitute.

    Tori has our recommendations; she'll decide. Maybe she gets a deal on lead substitute. Or maybe she stocked up for cheap long ago.
     
  9. dana44

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    That's fine, and yes, I use 87 octane even with 10:1 compression all the time. If it isn't going to ping at idle, it will run on the lower octane, just have to slow the advance in the distributor down to counter too much advance. No, she can add the lead additive even though there is something in the gas to lubricate them (I honestly can't remember what they added to prevent/slow valve damage, but there is something added). When was the last time you heard of an engine having valve sink problems on an older car the way they were in the late 70s? I haven't for years and years.
     
  10. Scrounge

    Scrounge Got parts?

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    Does anyone know what the additive is, and when it started being added? I heard of valve sink into the '90s; by then, most owners of pre-'71 vehicles had converted to hard seats.
     
  11. ka9yhd

    ka9yhd Well-Known Member

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    According to the spec sheets from Chrysler that a friend had found. Regular leaded gas was 91 octane.
     
  12. valiant67

    valiant67 ...

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    Gasoline now is the average of MON and RON, also called pump octane in the US (not all countries do this). Gas used to be sold with the higher RON rating. Gasoline that is around 87 on the pump octane scale is roughly equivalent to 91 RON. So today's regular 87 octane is about the same octane wise as yesteryear's 91 octane regular.
     
  13. Scrounge

    Scrounge Got parts?

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    When this Imperial was new, most regular was 93 octane and most premium (or hi-test, or ethyl, depending on who was selling it) was 97 octane. Sunoco had "custom blending", with 7 or 8 different octane levels. Octane ratings were recalculated some time during the 1970s to where most regular was 91 octane (lower for unleaded), and later recalculated again to what we have today.
     
  14. valiant67

    valiant67 ...

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    Again what I said, the old 91 octane regular gas is the same* as today's 87 octane regular gas. The apparent reduction in octane won't cause pinging.
    * same as in anti-knock capabilities, not the same as in the current fuel has no lead and contains alcohol in most cases.

    It's a change much like the change from gross to net HP. The engines appear to have lost a lot of horsepower, but really did not.
    Gasoline appears to have lost octane but really did not.

    91 or 93 regular was the Research Octane Number rating (RON). There was also a Motor Octane Number (MON) which is much lower. If you look at today's pump octane, you should see it is (RON+MON)/2. This is almost always displayed somewhere on the gas pump.
     
  15. Tori G.

    Tori G. New Member

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    Luckily the auto parts store I go has the lead additive.I talked to the owner of the machine shop I have my engine machine work done at and said I better pour it in.He has a pair of 1964 Ford heads in replacing the valve seats,lead additive was not used and ate the valve seats and guides up.My boss and co workers could not believe it has 24,000 original miles on it at first seeing the odometer
     
  16. ka9yhd

    ka9yhd Well-Known Member

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    I am happy that you are driving and enjoying the Imperial.
     
  17. DC-93

    DC-93 Well-Known Member

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    Photos ?????????????????????????
     
  18. ka9yhd

    ka9yhd Well-Known Member

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    Yes I agree................. Photos please or are you going to keep us guessing? :D
     
  19. DC-93

    DC-93 Well-Known Member

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    Maybe it's invisible??? o_O
     
  20. peterjon1

    peterjon1 Well-Known Member

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    She has a few vehicles I would love to see. In another thread, she posted that she is going through chemo - so I hope all is well with her.
     

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