[BakerFX4]

Ive been thinking about the 03/04 cobra shortblock (because they are cheaper) with my Livernois stage 2's as an option for my car and its mods. Questions i have are.... Is the cobra crank 8 bolt? How would the compression be? Would this be a good build for my mods?

 

[BakerFX4]

im thinking the compression will be to high. Heard someone say that i could just use really thick head gaskets?

 

[gray8188]

Cosmetic head gaskets.. And im wandering the same thing.. Seems like it will be the easiest and cheapest route to a built shortblock..

 

[mustanginky]

i'm pretty sure the 03 cobra's have a 17cc piston b/c they were 8.5 to 1. figure it'll be around stock with a set of PI heads.

 

[BakerFX4]

i think it will be 10 sumthing. Just a guess. Im not a pro at figuring this stuff out. I think the stage 2 heads and pistons are going to change things up.

 

[HBK_2007]

yes the crank is 8 bolt. i think all the forged modular cranks on the market are 8 bolt

 

[Boostang]

^^^ correct... i believe they are 18cc dished.. but 8.5 to 1 is correct also.. just get the cosmetic gaskets and evrything will be ok if your worried?

 

[Renegaderacer]

im not sure but i think with a good low compression 2v piston it shouldnt be much different?

 

[Boostang]

4v and 2v pistons are the same!

 

[BakerFX4]

yall have got me more confused now. So tell me this... Would the build still be good for boost?

 

[gray8188]

yall have got me more confused now. So tell me this... Would the build still be good for boost?

Wandering the same thing..

 

[BakerFX4]

im still wondering too.

 

[mustanginky]

stock PI pistons are 17cc, if the cobra pistons are 18cc and you're going with ported heads you're gonna have lower CR than stock. It'd be good for boost, but most engine builders like to keep CR around stock with built internals. i'd think you'd be around 9.1 with ported heads and stock 03 cobra short block.

 

[BakerFX4]

what is stock compression?

 

[neverfastenough1]

what is stock compression?

GT 9.4:1

Cobra 8.5:1

 

[mustanginky]

just go to diamond pistons website, they have a piston cc calculator on there. if stock 03 cobra's are 18cc just cross reference with our head CC, which i beleive is 42cc's if i'm not mistaken.

reason CR is so low on the cobra is it has a larger combustion chamber, i think 54 cc's or something like that.

 

[BakerFX4]

im not too sharp on all that. As long as it would still be good for boost thats enough info for me.

 

[gray8188]

Lol +1

 

[FOR U 2 3NVY]

Im not sure about an 03/04 but a 99/01 would be, with PI heads, your looking at a minimum of 11.4:1 CR - as high as 12.1:1 CR. The combustion chamber is bigger on the 4v causing the compression to be lower on the cobras. With the 2v it will INCREASE compression due to the smaller combustion chamber... Full of misinformation in here...

 

[BakerFX4]

well ****... lets get this **** straight! Thats what i was worried about. Too much back and forth.