need help with my 440
#374160
07/13/09 04:58 PM
07/13/09 04:58 PM
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Joined: Jan 2008
Posts: 894
Connecticut, USA
sixty7gtx
OP
super stock
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OP
super stock
Joined: Jan 2008
Posts: 894
Connecticut, USA
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I have 69 dodge charger with a 440 motor. Im doing a compression test. how much compression should a stock 69 440 motor have ?
1967 Plymouth GTX,
1968 HEMI, 4 Spd. Super Bee,
2010 Chrysler 300 Touring,
MOPAR = Machines Of Performance And Racing!!
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Re: need help with my 440
[Re: sixty7gtx]
#374164
07/13/09 06:31 PM
07/13/09 06:31 PM
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Joined: Dec 2007
Posts: 7,759
So Cal
HealthServices
Why would you even post that?
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Why would you even post that?
Joined: Dec 2007
Posts: 7,759
So Cal
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Try again with a strong battery, then like robert says afterwards try again with a couple squirts of oil. But make sure the battery is strong thru out the test.
If it is that worn out the motor should be easy to turn over with the battery.
And it just may need extensive work. But good test results require a good battery and starter.
Allen
Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first.
Life was a little easier when I was just a wrench.
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Re: need help with my 440
[Re: RodStRace]
#374166
07/13/09 08:14 PM
07/13/09 08:14 PM
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Joined: Jan 2003
Posts: 5,906
Athens, Greece
Pyper70
master
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master
Joined: Jan 2003
Posts: 5,906
Athens, Greece
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Should be at least 110....And they should all be within 10% of each other.....so if you are racking 100 on each cylinder and one is lower than 90, you have a problem....Thats how I was taught
Family owned 1969 Charger R/T DualQuad 440/727/GVO/3.55s
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Re: need help with my 440
[Re: Pyper70]
#374167
07/13/09 11:08 PM
07/13/09 11:08 PM
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Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
dave571
master
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master
Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
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How does the motor run? If it ran strong, and the comp all comes out even as low as 80, its' probably OK. Reality is, a comrpession test looks for varience, not a total number. The test is properly used for evaluating whether a motor can be tuned properly, NOT to find if it burns oil, or if it's due for a rebuild(although it may iondicate that if a varience does exist) If there is no problem with the running condition of the motor, a comp test will tell you very little. As for performing the test, I will add that it should be done as close to warmed up as possible, but this is very difficult with headers, or even hp manifolds. The numbers posted only show an incomplete test done with a dead battery. 
Last edited by dave571; 07/13/09 11:10 PM.
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Re: need help with my 440
[Re: Mopar Grandpa]
#374170
07/14/09 08:20 AM
07/14/09 08:20 AM
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Joined: May 2003
Posts: 15,487
Florida
scratchnfotraction
I Live Here
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I Live Here
Joined: May 2003
Posts: 15,487
Florida
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I thinking most were in the 7s for ratio on compression and 80 sounds close to right IMO cam can raise the the # up by closeing early to build cyl pressure I wet the cyl after removing all the plugs and chok the carb open wide,charge batt and do all the cyl...only takes a couple turns for each cyl IMO,sound like I would run it 
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Re: need help with my 440
[Re: dave571]
#374171
07/14/09 05:39 PM
07/14/09 05:39 PM
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Joined: Jan 2008
Posts: 894
Connecticut, USA
sixty7gtx
OP
super stock
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OP
super stock
Joined: Jan 2008
Posts: 894
Connecticut, USA
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Quote:
How does the motor run?
If it ran strong, and the comp all comes out even as low as 80, its' probably OK.
Reality is, a comrpession test looks for varience, not a total number. The test is properly used for evaluating whether a motor can be tuned properly, NOT to find if it burns oil, or if it's due for a rebuild(although it may iondicate that if a varience does exist) If there is no problem with the running condition of the motor, a comp test will tell you very little.
As for performing the test, I will add that it should be done as close to warmed up as possible, but this is very difficult with headers, or even hp manifolds.
The numbers posted only show an incomplete test done with a dead battery.
Thanks for all your help . the motor ran fine. I took it apart to paint the motor. i put it all back together started run for about 20mins and air started to go threw were you put the oil in and the air blew off the oil cover. and that it , maybe jumped a tooth on the timing chain????
1967 Plymouth GTX,
1968 HEMI, 4 Spd. Super Bee,
2010 Chrysler 300 Touring,
MOPAR = Machines Of Performance And Racing!!
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Re: need help with my 440
[Re: sixty7gtx]
#374178
07/15/09 12:35 AM
07/15/09 12:35 AM
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Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
dave571
master
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master
Joined: Dec 2003
Posts: 5,314
Carstairs, Alberta, Canada
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Quote:
Thanks for all your help . the motor ran fine. I took it apart to paint the motor. i put it all back together started run for about 20mins and air started to go threw were you put the oil in and the air blew off the oil cover. and that it , maybe jumped a tooth on the timing chain????
Is the pcv valve hooked up(sorry if repeat question)
You should verify that the crankcase is being evactuated properly.
If it is, it would seem the engine is tired, it's just how tired is the question.
As for the leakdown test, it's pointless, and good luck finding a pro who even knows how to do one anymore. They are never done in the trade anymore.
If you've got blow by into the crankcase, you've got a sealing problem in the rings. . The leakdown test may verify it, and it may not, but it doesn't really matter.
You've checked the dot's and they line up, so it's not the tc.
If it's blowing the breather off, it's something youa re going to have to deal with.
On the cheap side, if the taper isn't bad, you may be able to get away with a scratch hone,a nd a rering 
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