USA New Member

[jamiemirror]

But banpei, if your goal is 170hp from 1.6 displacement - you can achieve it with SOHC 8V also - the DOHC 16V is not requirement. You can obtain very hight VE values even for such SOHC head with extensive P&P job, big valves, good cam etc. Stock 4AC is weak over 4500 RPM due to poor head/intake/exhaust header design but all these can be improved. I don't know exactly are 4AC internals good for continuos 6000+RPM or not (mine was "tested" over 7000RPM and survived, 100% stock engine).
4AC suffer also from low CR (~9).
PS: This is not easy modification and definitely is more expensive than 4AGE engine swap (at least in Bulgaria).