4A-F TwinCam?

[lgene10]

hi guys i just want to ask if this engine is a twincam or not?.. i know it got two cam but it seems like its not officially known as twincam

[eage8]

yeah, it has 2 cams. It's DOHC.

twincam doesn't really officially mean anything except that it has 2 cams :P originally it was to differential the 4age from the 4a-c which was sohc. and they carried it over after the normal cars became dohc as well. the heads are still different though. the 4age has a much wider valve angle.

[toyotaspeed90]

Toyota uses the term Twin Cam in engines that are DOHC and both cams are driven off the timing belt directly, in the same direction. 4age, 3sge, 3sgte, 7mgte, 2zzge, etc.

Toyota used DOHC on the slave cam designs (like 4af, 4afe, 7afe, 4efe, 1zzfe.... you get the point). One cam is directly driven by the timing belt and then each cam has gears under the valve cover in which the cam on the timing belt physically drives the other.