Another Compression Question!!!!
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Joined: Apr 2004
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From: Iron Station N.C.
Another Compression Question!!!!
I have tried using the compression programs recommended on this forum, but it seems that I get different results or the results seems like it cannot be right. Last time I tried I got a DR of over 11.0:1 and a static of around 7.1. Can this be right?
Bore: 4.030
Stroke: 3.75
Pist Vol -5
Pist Compression Height: 1.425
Cam:
Comp Cams 270 Magnum Hyd. Flat Tappet
Int. 224@ .050 Exh. 224@.050
Heads:
World S/R Torquer: 67cc Cast Iron
Head Gasket: .041 with 4.166 Bore
Advance: Hopefully 32-34 Degrees
Any help greatly appreciated. I just want to make sure I can run with premium fuel.
As always, Thanks in advance.
Bore: 4.030
Stroke: 3.75
Pist Vol -5
Pist Compression Height: 1.425
Cam:
Comp Cams 270 Magnum Hyd. Flat Tappet
Int. 224@ .050 Exh. 224@.050
Heads:
World S/R Torquer: 67cc Cast Iron
Head Gasket: .041 with 4.166 Bore
Advance: Hopefully 32-34 Degrees
Any help greatly appreciated. I just want to make sure I can run with premium fuel.
As always, Thanks in advance.
Melting Slicks
Joined: Aug 2004
Posts: 2,165
Likes: 950
From: Keizer Oregon
I feel your pain brother
I just went throught the same thing. The CR programs available all disagree with each other. I got anywhere from 10.2 to 11.8 SCR on my build....It is NOT 12.8 or 10.2. My best guess right now is about 10.7SCR.
BTW are you sure your DCR and SCR aren't backwards??
A DCR of 7.0 will run on pump gas.....If your DCR is really 11.0:1 then you better fill up on the 115 leaded
BTW DCR will always be lower than SCR
Good Luck
I just went throught the same thing. The CR programs available all disagree with each other. I got anywhere from 10.2 to 11.8 SCR on my build....It is NOT 12.8 or 10.2. My best guess right now is about 10.7SCR.BTW are you sure your DCR and SCR aren't backwards??
A DCR of 7.0 will run on pump gas.....If your DCR is really 11.0:1 then you better fill up on the 115 leaded
BTW DCR will always be lower than SCR
Good Luck
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Joined: Apr 2004
Posts: 74
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From: Iron Station N.C.
Yes I did get the static and dynamic backward. Even so it still would seem that a dynamic of around 7.1:1 and static of over 11.1:1 would not be right with a short cam like this one.
Thread Starter
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Joined: Apr 2004
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From: Iron Station N.C.
I almost forgot this spec. The deck is stock, which should be 9.025, right? I could not find a machine shop to deck the block without taking of the numbers. It was checked and found to be OK.
Melting Slicks
Joined: Aug 2004
Posts: 2,165
Likes: 950
From: Keizer Oregon
Thread Starter
Advanced
Joined: Apr 2004
Posts: 74
Likes: 0
From: Iron Station N.C.
I agree. The piston mft. states 10:1:1 for a 68cc head. I was just concerned about using pump fuel, and was trying to figure dynamic compression. Guess I was just putting the wrong figures somewhere.
Thanks anyway
Thanks anyway
Burning Brakes
Joined: Oct 2002
Posts: 971
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From: Rockwood TN
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