ohk bismillah
@saadzae i have a question.. is vti engine different from vvti? which one is better? and is Z-gen engine better then the Honda city idsi walla engine?
bro first of all which VTi are you talking about
i'll try to make it as simple as possible
if you are talking about 96-05 VTi's they have a valve control system, think of it as using two camshafts
now camshafts as we know are used to control the opening and closing of your valves , your valves let in air and let out burnt exhaust gases , now Hondas legendary VTEC system (Variable valve Timing and Electronic lift Control) uses two cam profiles, why does it use two cam profiles
well the answer is simple
1 cam profile is made for daily driving , like fuel efficent and economic , but that cam isnt very good at producing power (why is it so this profile opens and closes the valves quickly, and the valves open just a little bit so they take in less fuel , in turn burn less fuel, so low on performance but easy on the pocket)
the 2nd cam profile is very good at producing high end power and is very agressive , but is very bad at economy and daily driving (why is this so, this type of high radical cam profile keeps the valves open for a long time, and the valves are opened further , so the engine can take in alot more air/fuel mixture and burn it thus producing more power.
so honda adressed this problem by using two cam profiles
1 for low speed cruising,slow normal day to day driving
and the 2nd one for when you want to fast and get excited
now VVTi is basically the same thing but toyota makes it , except you dont have valve lift control , that only comes in VVTLi
VVTi technology is much simpler yet just as effective , VVTi uses a retard and advance type mechanism , in low speed driving the valve timing is reatarded to save fuel, and in high rpm mode the timing is advanced to give performance(not getting into too much detail)
and now the Z-gen question , Z-gen means alot of engine so i dont know what you are comparing that with
1SZ-FE (1.0l 4 cyl DOHC)
2NZ-FE (1.3l 4 cyl DOHC)
1NZ-FE (1.5l 4 cyl DOHC)
3ZZ-FE (1.6l 4 cyl DOHC)
1ZZ-FE (1.8l 4 cyl DOHC)
2ZZ-GE (1.8l 4 cyl pure racing DOHC)
these are all Z-GEN engines , pretty robust, aluminuim construction, with cast iron cylinder liners, timing chain equipped , and a retrurnless fuel injection system
very good engines
as far as i-Dsi is concerned (Intelligence-Dual and Sequential Ignition)
this sort of engine is most commonly a honda City/fit L13/L12 engine
it uses 2 spark plugs per cylinder as opposed to conventional 1 plug per cylinder
uses an old fashioned 8 Valve head, this sort of technology uses the spark plug to burn fuel more efficently, and use less fuel and give a cleaner enviroment
but i personally dont like the torque less L12/L13 engine , because lets face it , we in pakistan care about other things than Eco friendlyness green cars , that use 1950's technology , and some borrowed technology from Alfa romeo to make cars better and if it wasn't a failure , why did it get replaced by the i-VTEC system in the 2009 City/Fit models
thank you:)