need help pls b20 vtec setup

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drey

New Member
hello guys i am building a b20 vtec with gsr head but the problem is will my piston CP carillo SC7121x with 11.9 to 12.8 compression , (piston too pointy) (pic below) will work on my gsr head without detonating it ?? im worried about the compression being too high and risky.. although 100 octane is available in my country..what do you suggest guys i really need your help guys thanks :)
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thanks mate do you mean its ok to use Gsr head on this piston? and use pump gas or should i go for e85
 
you can go way higher on e85
people have ran 14:1 and higher on e85
if it is readily available in your area and anywhere you might end up being then it may be worth it to tune for that
 
also - i have no idea if your head clearance will work with these... i am only speaking tot he compression
 
yes that one thing to consider the head clearance... were planning to add 1 layer of gasket what do you suggest?
 
Make sure you clay the motor to check for tolerances/clearance. It's the only way to know if it will hit or not.
 
ok yes we will clay , the only thing that concerns me is the compression, detonation , clearance with gsr head and if its ok with 100 octane but i can do e 85 but not to accessible in my place have to drive 15 to 20 kms... i recently lost my b18 engine due to detonating i dont want to happen it again hehehe.. thank you guys for your replies =)
 
guys do you think it can rev past 8k.. if not do you have suggestions regarding parts to consider.? i have replace the rods, bolts etc.. with aftermarket parts.
 
bottom end is probably good, whats your valve train made up of? the springs/retainers need to be upgraded to handle it, and a larger cam that actually makes power up there is probably a good idea.
 
here is my set up mate:
Gsr (b18c head)
b20z block
CP 11.8 - 12.8 comp. forged piston (when they say 12.8 compression does this mean this is the maximum compression?) or depending on the head?
skunk pro 2 cams
toda camgears
skunk 2 valvespring
skunk2 titanium retainers
ferrea flat valves
skunk 2 intake manifold
74mm skunk throttle
500 plus cc injectors
eagle rods
arp head studs

im currently looking for a good header =)
 
Yeah, compression depends on several things-- piston dome, head gasket thickness, combustion chamber of the head design... so alone, they aren't a "ratio".

sounds like you got the goods to go 9-9200 all day long on a proper tune.
 
Went to 9500 daily on an h22 with hi comp set up and a nice set of Crower N/A cams springs and retainters... Just make sure everything is seated right, and also give the motor time to break in and what not... don't need to over rev her on her 1st date.... :)
 
any suggestion for the header? should i go pump gas (100 octane) or e 85? just finished the block today tomorrow will start porting the head :thumbup: ill post some pics when finished.. thanks guys
 
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