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Re: stock 440 pistons, how far down in the hole?
[Re: John_Kunkel]
#83451
07/04/08 12:33 AM
07/04/08 12:33 AM
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Anonymous
Unregistered
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Anonymous
Unregistered
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Quote:
Quote:
67, 70-72 ran a piston with a compression height of 1.991.
'72 was the first year of the really lowered compression (8.2 advertised), the compression height on those is 1.926" which puts it close to .150" down.
cept' for the 72 440+6. that big dog still had 9.5-10.0:1 cr.. depending on who you believe.
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Re: stock 440 pistons, how far down in the hole?
[Re: DaytonaTurbo]
#83452
07/04/08 02:54 AM
07/04/08 02:54 AM
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Joined: Oct 2003
Posts: 1,183
eganville ont
440beep
super stock
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super stock
Joined: Oct 2003
Posts: 1,183
eganville ont
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70 440 4bbl hp are 9.7l flat tops 71 440 4bbl hp are 9.5 l flat tops 71 440 4bbl lp are 8.8.1 flat tops 70 440 6bbl hp are 10.5 71 440 6bbl hp are 10.3  
Last edited by plymouth birdman; 07/04/08 03:06 AM.
Plymouth's gonna getcha!
There are 3 things that will live forever, cockroaches, Keith Richards, & slant 6 Dusters
71 gtx 440 4speed air grabber blue on blue with white vinyl roof
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Re: stock 440 pistons, how far down in the hole?
[Re: DaytonaTurbo]
#83455
07/04/08 10:21 AM
07/04/08 10:21 AM
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Joined: Jan 2003
Posts: 74,978
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,978
U.S.S.A.
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Quote:
Either way, at the end of the day, what does it really matter? Nobody builds a performance engine with stock pistons these days and no two engines were built exactly the same. Go with your aftermarket pistons, have your block decked to get zero deck and call it a day. 
what matters is there is some potential misinformation in this thread . too many times i have seen people that haven't researched the combo they want get STUCK with a low compression PIG because they either assumed that they were buying correct replacement parts when what they were really buying was the aftermarkets COMPROMISE to having to carry an EXACT replacement for every model year , at least thats how it works with big block MOPAR engines .
take the 383 for example , 2 or 3 basic compression ratios built over multiple years with first a closed chamber head then an open chamber head , dicounting a DOMED piston, both TRW/SPEEDPRO and KB carry ONE piston to cover ALL those variations 
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Re: stock 440 pistons, how far down in the hole?
[Re: VITC_GTX]
#83456
07/04/08 10:25 AM
07/04/08 10:25 AM
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Joined: Jan 2003
Posts: 74,978
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,978
U.S.S.A.
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Quote:
Trying to figure out the compression in my '70 GTX with original 440 (without tearing the motor apart). I'm getting tired of fighting pre-detonation and want to try and do something. First thing I want to do is figure out my CR.
I have ported 906's that are shaved .006" (assuming 78 cc's), .030" over bores, stock replacement forged pistons. If I can find what the average depth of the pistons are (and look at compression thickness of my head gaskets) I can closely estimate my CR.
What's the average depth in the hole for a '70 440?
Van lets try to actually ANSWER your question instead of GUESSING what you have .
heads shaved , by you ? if so what head gasket did you throw it back together with ?
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Re: stock 440 pistons, how far down in the hole?
[Re: JohnRR]
#83458
07/04/08 01:58 PM
07/04/08 01:58 PM
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Joined: Mar 2003
Posts: 4,924
Tri-Cities, Washington
VITC_GTX
OP
master
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OP
master
Joined: Mar 2003
Posts: 4,924
Tri-Cities, Washington
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Quote:
Quote:
Trying to figure out the compression in my '70 GTX with original 440 (without tearing the motor apart). I'm getting tired of fighting pre-detonation and want to try and do something. First thing I want to do is figure out my CR.
I have ported 906's that are shaved .006" (assuming 78 cc's), .030" over bores, stock replacement forged pistons. If I can find what the average depth of the pistons are (and look at compression thickness of my head gaskets) I can closely estimate my CR.
What's the average depth in the hole for a '70 440?
Van lets try to actually ANSWER your question instead of GUESSING what you have .
heads shaved , by you ? if so what head gasket did you throw it back together with ?
I did not put the motor together. I have all receipts showing parts and head machine work. The receipts shows that the heads were shaved .006". I know I can't count on everything I read (or believe everything Ma Mopar said) but I was just trying to see if I have a compression problem, quench problem, or another problem.
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Re: stock 440 pistons, how far down in the hole?
[Re: VITC_GTX]
#83460
07/04/08 03:52 PM
07/04/08 03:52 PM
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Joined: Jan 2003
Posts: 74,978
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 74,978
U.S.S.A.
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Quote:
Quote:
Quote:
Trying to figure out the compression in my '70 GTX with original 440 (without tearing the motor apart). I'm getting tired of fighting pre-detonation and want to try and do something. First thing I want to do is figure out my CR.
I have ported 906's that are shaved .006" (assuming 78 cc's), .030" over bores, stock replacement forged pistons. If I can find what the average depth of the pistons are (and look at compression thickness of my head gaskets) I can closely estimate my CR.
What's the average depth in the hole for a '70 440?
Van lets try to actually ANSWER your question instead of GUESSING what you have .
heads shaved , by you ? if so what head gasket did you throw it back together with ?
I did not put the motor together. I have all receipts showing parts and head machine work. The receipts shows that the heads were shaved .006". I know I can't count on everything I read (or believe everything Ma Mopar said) but I was just trying to see if I have a compression problem, quench problem, or another problem.
do the receipts show what pistons were used ? i just noticed you said its .030 and stock replacement pistons , which could be anything and will effect the compression ratio greatly .
unless its got KB step heads you can rest asuure that you have NO quench
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Re: stock 440 pistons, how far down in the hole?
[Re: JohnRR]
#83461
07/04/08 04:32 PM
07/04/08 04:32 PM
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Joined: Mar 2006
Posts: 1,611
Pataskala, Ohio
GTX70sixpack
top fuel
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top fuel
Joined: Mar 2006
Posts: 1,611
Pataskala, Ohio
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When I rebuilt my GTX engine I used TRW forged pistons for a 71 440 4 barrel application and Felpro head gaskets. It runs fine on pump gas but does have a noticable power loss, does not pull hard on the big end.
65 Belvedere II Station Wagon
69 Coronet R/T convertible
70 GTX
70'cuda
99 Dodge Diesel dually 4X4
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Re: stock 440 pistons, how far down in the hole?
[Re: JohnRR]
#83462
07/04/08 06:04 PM
07/04/08 06:04 PM
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Joined: Mar 2003
Posts: 4,924
Tri-Cities, Washington
VITC_GTX
OP
master
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OP
master
Joined: Mar 2003
Posts: 4,924
Tri-Cities, Washington
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Quote:
Van lets try to actually ANSWER your question instead of GUESSING what you have .
heads shaved , by you ? if so what head gasket did you throw it back together with ?
I did not put the motor together. I have all receipts showing parts and head machine work. The receipts shows that the heads were shaved .006". I know I can't count on everything I read (or believe everything Ma Mopar said) but I was just trying to see if I have a compression problem, quench problem, or another problem.
do the receipts show what pistons were used ? i just noticed you said its .030 and stock replacement pistons , which could be anything and will effect the compression ratio greatly .
unless its got KB step heads you can rest asuure that you have NO quench
The part number for the pistons is SPE 2286P .030. I was told these were Speed Pro forged replacements for the '70 440, but have nothing to back that up.
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