How not to make HP with a 427 BBC

Discussion in 'High Performance Modifications' started by 1980RS, Feb 14, 2020.

  1. camaro71/holland

    camaro71/holland Veteran Member

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    So, basically the lesson you learned back then was that it's better to use a less than optimal tool than not to bring the right tool for the job, right? ;)
     
  2. badazz81z28

    badazz81z28 Veteran Member

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    You can use calipers to check a bore size. A dial bore gauge will check bore wear and taper, but the simple calipers will give you an indication if its been over bored.
     
  3. Rdobbs1977

    Rdobbs1977 Huge Guns N Roses Fan

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    Guess i did...still playing the same note on that lesson too...
     
  4. roeville

    roeville Veteran Member

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    It is a 1970. Agree, it’s a beautiful car.
     
  5. Rdobbs1977

    Rdobbs1977 Huge Guns N Roses Fan

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    Agree and disagree. Calipers are good enough to distinguish a sizable variance in bore size. But that's it and in my opinion not the best tool when measuring bore size. You said the dial bore will check bore wear and taper, but in order to do that, it's got to be able to also check bore size based upon what you set it to, in order to account for variances..? Bottom line: Dial bore or telescopic gauges w/mic beat a caliper any day when measuring cylinder size, period.
     
  6. badazz81z28

    badazz81z28 Veteran Member

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    But if all you want to know if it’s been over bored...a caliper will tell you if it’s 4.001 or 4.030...
     
  7. G72Zed

    G72Zed Veteran Member

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    Well, 366HP is not too bad for 7.63 CR. But the .85 HP per CI is the true indicator LOL
     
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  8. Rdobbs1977

    Rdobbs1977 Huge Guns N Roses Fan

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    I'm not going to use a caliper to tell me if i'm within 1 thousandth of a measurement on a cylinder. like i said, it can give a good ball park on notable differences but it ain't that precise.
    lol i said i agreed and disagreed...for me, in most cases (me, ok), i like to know how many thousandths i'm within. yes, a caliper will get you close to a .00, .030, .060 number but it loses credibility when looking at .001, .002, .003 variances from that main mark mentioned above. Next time you take a block to a machinest for work done, see which tool he busts out to take measurements. comes down to how precise i guy wants to be on something,
     
  9. 1980RS

    1980RS Veteran Member

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    I know I made more than that with my 7.9 comp 461 Peanut Port BBC engine. Did the same thing at the track, slapped a Chevelle around with a 468 Sq. port aluminium head engine big time which had 9 to 1 compression. Big port heads do have their place, but not on a low compression engine unless you are going to turbo or put a blower on it.
     
  10. G72Zed

    G72Zed Veteran Member

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    I hear ya, did you use the larger oval port intake on that peanut port? Much the same thinking of a square port on an oval port?
     
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