Originally posted by THREE40SEVEN
With ivtec, how is the valve timing, lift, and or duration changed? Since cam profiles are fixed(machined) how are valve events changed? The only thing i can think of is no camshaft, and the valve are controlled through an electric solenoid. Saw that once as a prototype on a ford V8.
32 valve cobra engines(96-8) have a secondary rpm controlled runners(IMRC) like you had mentioned on the GSR.. The were dropped in 99 for a much improved tumble (single)port.
Sorry for the thread hijack....
ivtec, is some what similiar to normal vtec motors.
At a predetermined rpm a solenoids slams pins in to the rocker arms joing the arms together forceing them to ride on the high lobe of the camshaft.
However in ivtec the computer senses when you need this, by your driving style, load on motor and so on. Then it triggers the solenoid. Not always on a certain rpm, like the original vtec motors.
2004 Toyota 4 Runner V8 Sport
2001 Prelude SE- Sold
Speed Kills...Drive a Ford...Live Forever!!!