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Location:
Brisbane
Registered:
October 2002
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 what can these low cylinder pressures do??????
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Mon, 20 October 2003 12:32
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i have just pressure tested my engine, its reading 130, 100, 100, 110, does this sound way too low, std it 153spi, would it even run with those pressures, its not a fast car but it aint really quick, but i held a zorsted vl till 3rd {he had auto, longer 2nd}
btw is there any direct correlation between psi and CR
btw i have a 8.7:1 and my 18RG book says 153 does that mean mine will be slightly lower, it has new rings and gasket kit thru it, no valve grind done tho
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Location:
Brisbane
Registered:
February 2003
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Re: what can these low cylinder pressures do??????
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Mon, 20 October 2003 13:01
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hi phil,
was there a big diff between the dry comp test and the wet comp test (squirt of oil in each pot to help seal big leaks)?
big differences (increases in wet) will help identify out leaking rings and/or dodgy valve seat grinds.
brand new ring should giv you high readings ;(
maybe valve job was in order while the top was off?
charles
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Location:
Melbourne
Registered:
October 2003
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Re: what can these low cylinder pressures do??????
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Mon, 20 October 2003 17:37
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how long has it been since the new rings have been in?
it's not uncommon for brand new rings to read low pressure (ie, leak) until they 'bed in'.
did you do the rings yourself? and if so when you started the car
did you let it idle or did you keep the revs changing (you should NOT idle new rings for long times..)
Otherwise do the wet comp check and see what happens.
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I supported Toymods
Location:
melbourne.victoria.austra...
Registered:
June 2002
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Re: what can these low cylinder pressures do??????
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Mon, 20 October 2003 21:34
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who shimmed the valves? wondering if they need re-shimming - ie: a valve may be slightly open if not shimmed correctly meaning wrong readings...
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Location:
Montrose, VIC
Registered:
May 2002
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Re: what can these low cylinder pressures do??????
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Tue, 21 October 2003 01:32
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If the engine has just been re-done, it will need a bit of time before you get meaningful readings. If you're in doubt still, go to a mechanic and get them to do a leakdown test.
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Location:
Brisbane
Registered:
October 2002
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Re: what can these low cylinder pressures do??????
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Tue, 21 October 2003 08:02
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well, i had sufficient cash to do the engine convo but it had to be rebuilt and i didn't have enuff cash to do a valve grind, the shims were ground down to spec, but are now .010 inch instead of .026, maybe Valve seat recession, i forgot to do a wet test, i'll do one soon when cars cool 
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Location:
Brisbane
Registered:
October 2002
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Location:
Brisbane
Registered:
February 2003
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Re: what can these low cylinder pressures do??????
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Wed, 22 October 2003 14:33
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Hi Phil,
at least the rings are OK.
you'll have to think about head gasket, valve seats or shims ;(
charles.
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Location:
Brisbane
Registered:
October 2002
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Re: what can these low cylinder pressures do??????
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Thu, 23 October 2003 11:13
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i let the mechanics at work have a listen and they said fucked valves/seats, FUUUUUUUUUUUUUUUCK, it aint too bad, it hasn't changed since i got it so its always been like that, imagine the power if i had full cmpression
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