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Want to increase DCR

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Old Mar 17, 2012 | 12:04 AM
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Default Want to increase DCR

I currently have a LS1 with 241 heads and a TTP Equalizer v3 cam. I need to replace the heads due to a snapped valve cover bolt, and would like to go with a set of ported, milled heads. What I am trying to achieve is more torque and, more importantly, a quicker revving motor with snappier throttle response. Although I was originally planning on going with a smaller cam, I would like to make do with this current cam for now and do as well as I can to increase these attributes with new heads. It is my understanding that I would need to increase the DCR of the motor to do that.

Can I order a set of milled heads without knowing the complete cam specs? Is all I need even a set of milled and ported heads? Thanks in advance.

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Old Mar 17, 2012 | 12:48 AM
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What cam specs do you know? What is your dcr now? If. you know, or can find your intake valve closing point you can know what static compression to shoot for.... I am running 12.5:1 scr on pump gas, but my dcr is 8.22.

8.5dcr from what I have found and read is about max for pump gas
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Old Mar 17, 2012 | 09:16 AM
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I don't know the cam specs, I only have approximations, which I think is 234/238 .595/.598 112lsa. Is it possible to simply mill the heads and increase the DCR over what I had?
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Old Mar 17, 2012 | 09:22 AM
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Yes you can, but remember the more you mill off the heads the closer you piston to valve clearance will be
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Old Mar 17, 2012 | 06:26 PM
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I doubt I'll be able to check my PtoV clearance without knowing the cam specs either. Alright, thanks Mark.
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Old Mar 20, 2012 | 03:07 AM
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Originally Posted by mark21742
What cam specs do you know? What is your dcr now? If. you know, or can find your intake valve closing point you can know what static compression to shoot for.... I am running 12.5:1 scr on pump gas, but my dcr is 8.22.

8.5dcr from what I have found and read is about max for pump gas
so 8.5 dcr is max for pump 93,, i am going to shoot for maybe 8.3 or 8.4

i am getting forged pistons to fix the ptv clearance also milling heads 243s



so if i go with a 11.8:1 static and a 8.4 dynamic should i be good with pump 93 ?
i also think i am going to need a custom cam to help me reach that valve closing point and proper overlap to get me that dynamic compression ratio,,
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Old Mar 20, 2012 | 05:10 AM
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Just to be on the safe side I'd shoot for 8.2-8.3:1 dcr,to be safe on a street car, that way a bad tank of gas won't kill your motor.

Quikz28, if you take some time with a dial indicator and a degree wheel you can find your exact cam specs....it might even be worth taking it to a speed shop that knows what they ate doing to find it. If you have any aftermarket cam and and plan on getting milled heads you should plan on the possibility of needing to flycut valve reliefs in your pistons, and the best way to do that is to have the new heads and your old gasket, and clay to be sure...might not need to do any cutting, but this is too important of a step to skip.
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