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#1
03-18-2004, 09:45 PM
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Whoever rebuilt the engine in my car put different heads on it...I think, they are sprayed a different shade of blue. How do I identify them and how do I figure out what the compression ratio is of my engine???
Its a 400 by the way. Thanks Mitch
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All the world is birthday cake, so take a piece but not too much. George Harrison |
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#2
03-18-2004, 09:45 PM
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Whoever rebuilt the engine in my car put different heads on it...I think, they are sprayed a different shade of blue. How do I identify them and how do I figure out what the compression ratio is of my engine???
Its a 400 by the way. Thanks Mitch
__________________
All the world is birthday cake, so take a piece but not too much. George Harrison |
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#3
03-18-2004, 09:47 PM
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Take a look at the code on the center exhaust ports and let us know what it is. Stock would be a 670 code.
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Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 Catalina Safari Wagon. |
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#4
03-19-2004, 07:39 PM
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670 is on the head, what compression ratio am I looking at?
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All the world is birthday cake, so take a piece but not too much. George Harrison |
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#5
03-19-2004, 07:55 PM
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I think I know this one....it's 13.75 to 1 isn't it?
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#6
03-19-2004, 09:25 PM
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could be 10:75to1
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Trying to be the person that my dog already thinks that I am!! |
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#7
03-19-2004, 11:59 PM
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<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by dogboy:
could be 10:75to1 <HR></BLOCKQUOTE> YOU WIN!! (if all is stock) |
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#8
03-20-2004, 12:08 AM
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The factory was always a little optomistic on their compression ratio estimates. They did state 10.75:1, but if you plug in the actual numbers you end up at something closer to 10.28:1. The good news is those are the correct heads for your goat. The bad news is anything over about 9.5:1 with todays gas is probably going to ping. Just keep your ears open for pre-ignition.
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Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 Catalina Safari Wagon. |
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#9
03-20-2004, 09:47 AM
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<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by urhere2:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by dogboy: could be 10:75to1 <HR></BLOCKQUOTE> YOU WIN!! (if all is stock) <HR></BLOCKQUOTE> Doh! That's right...I knew it was a .75 in there somewhere! Been a long time (12 years) since I've been in this game, I finally got a old Pontiac last week so I'm back in it!! Yeeehaaaaaaa! 
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