Sir Head On My B16a2

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Pewble

Senior Member
Yo I got a 99 Civic Si and im swapping a JDM Civic SiR Cylinder Head that has:

3 angle valve job , swirl marked valves , shaved valve guides both intake and exhaust ports ,

intake ports were opened up 3mm all the way around, intake ports are sand blasted , knife edged

intake and exhaust ports, fully polished combustion chambers , cylinder head is CFM'c and CC'ed

to make sure all combustion chambers are even and exact. I am wondering a few things about

this swap. The cylinder head is also milled. Can replacing the head raise compression, and/or can a head

gasket raise compression? I am also assuming raising the compression of the pistons and/or boring

them out can provide an enormous power increase especially with this head.. is this true?
 

B16

Super Moderator
VIP
god is the only one who knows what you will run by putting that head on, people must realize there is much more to it, than saying "with x and x mod, how fast will my 1/4 be?" put it on and find out, only way. to raise compression you can get a 1ply head gasket, which will bump you up .3-.4 or you can mill the head. the better way to raise your CR is to replace the pistons, if you mill the head, you can't go back :)
 

Pewble

Senior Member
How about a Multi layer head gasket? Im guessing I want single ply to lower the clearance from stock for higher compression. Is there a "best" head gasket or a good one for my application (Norimally Aspirated Power) . .. WAIT!!! ... If the Head is milled that means it will provide higher compression than stock without the need of a gasket?
 

B16

Super Moderator
VIP
OEM head gaskets are fine for NA (3 ply), for a thin one for higher CR get a mugen or spoon. i would recommend getting pistons before milling the head. milling the head would have the same effect as a thin gasket, but you can get higher CR's from milling the head. i would us milling the head as a last resort.
 
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