Need help please
 

hello all..

i a bit confuse, because i've just finished a top overhaul of my jazz (i've done a porting and polishing to the engine too), it's all fine
until i had a very bad traffic jam.. for example, this night i stuck for about 4 hours..

and after i free from that mess, i just want to go a bit faster, u push my jazz to 6000 rpm using 2nd gear, and i hear a pre-igniton or knocking sound at 5000 to 6000 rpm, i'm not sure which one.. but it just makes 2 mild knocks.. (when i did this i turn the aircon off)

after i go further i stopped for a while to buy something in a convinient store near to my house, than i try to push my car again just a bit after that short break (but now with the aircon on)..

and i didn't hear any knock sound anymore..

my big question, is that normal ??

can the heat off the engine causing the knocking or pre-igniton ?:(

How was the intake and head from the factory? Did you remove alot of metal to match up? And of course what was the power like after, any improvment? Gas usage/MPG better or the same? and did you find out about the pre-ignition knock
Big Mike :D

al normal just like any other jazz, my jazz uses the plastic intake from the factory so i just porting the intake on the head only.. i'm not removing a lot, what i did is just remove the roughness of the intake port, and that's it.. the power and torque is much better than stock, even my dad who didn't interest in car can feel it.. hahaha, and my gas usage is even better i can manage 15 km/L in a jammed city like jakarta, i found out that the spark plug is a bit weary, but i've chage the plugs, i can still hear a bit of pinging.. but it much much better.. ^^

Thanks Pinkz for the updated info.
Big Mike :D

you are welcome mike.. do you have any more suggestion for gaining more performance cheaply ? hahaha