i was searching n asking around bout 7a, no one tell me 7a is reliable, theres 1 mech in kajang told me if u want turboing later, its better to bore 82mm only, unless, u want to play na, then, u can actually bore it to 83mm.
ok, when i ask him how is the reliability,
he answer me, u cant abuse it the way u drive 4age, if u always hirevving, it tend to break, bcoz, water "hole" r too close to the piston wall.
2. 7a will tend to burn the engine oil slightly higher compare 4a.
3. without hicam, it cant rev >8.5k, the power lost after 7k+ rpm.
4. with 7a, the timing will slightly not accurate.
5. save fuel compare 4a
6. 7a flywheel is weak compare 4a flywheel, another drifter told me, they had experienced flywheel broken while drifting. unless you have stroker kit, the crank can use 4a flywheel.
7. in zth, theres a old timer share his experience, saying that, if u have same performance parts on 4age, it can eat 7age within 400m.
8. 7afe block is not like 4age, if you r not lucky enough, when you bore it to 83mm, sometime, the block surface have small hole, so, you have to use another block.
after gather all the information, im not dare to convert to 7a. just share
