Quote Originally Posted by EGGIRL View Post
ganun po sir, di ibig sabihin sir yung PH15 eh parehas din sa D15? bkit hindi pare-parehas ang mga variations ng mga engines dito sa pinas? sorry po, kasi curious lang at 1st time ko lang to have car.sabi nila malakas daw D15B ah. totoo po ba ito? nasabi din ng pinsan ko na malakas ang SiR?anu po mayron dun, at lahat ata ng mga lalake na gusto magkakotse eh yun ang pinipili?magkanu po yun ngayun?hehehe sakaling makayanan...

thanks again guys!
Yes ph15 and d15 are the same. honda sir have dohc engine while honda civic (ek/eg) are sohc engine, SOHC stands for Single Overhead Camshaft. That means that there is only one camshaft per header. Inline engines will contain one camshaft. V-type and/or flat will contain 2 camshafts. For a SOHC engine there are usually 2 valves per cylinder but there can be more with the addition of cams for each valve.

DOHC stands for Double Overhead Camshaft. Now there are 2 camshafts per header. So in an inline there are 2 camshafts because there is only one header, but there is 4 in a V-type or flat engine. These DOHC engines usually have 4 valves. One camshaft for the exhaust valves and the other for the intake valves.

Advantages to having a DOHC engine over a SOHC is that the engine has twice as many intake and exhaust valves as a SOHC motor. This makes the engine run cooler and more smoothly, quietly, and efficiently. But the downfall is that DOHC engines cost more for repairs.

check also this link, i hope it will help, http://en.wikipedia.org/wiki/Honda_Civic