I was quoted MYR800 for all the above..i knew that it can be DIYed n since i got another 4agze lying around i ges its worth a try
1st step was to gather the necessities
tools of the trade
rotomatic rechargeable rotary tool set - MYR40.00
10piece mounted stone - MYR4.80
Flap wheels - MYR1.80 x 3
Wire brush, brush - MYR2.00/piece
G-Clamp - MYR14.00
Safety goggle - MYR1.80 (safety is always a priority right..)
so MYR70.00 investment for now all items can purchased at 100% superstore and your local hardware
the specific steps that i followed can be found here http://www.pirate4x4.com/tech/billavista/PDFs/Head%20Porting%20DIY%20by%20Standard%20Abrasives.pdf
since i dont have a proper flowbench or any means to measure flow before and after this process i wont try to do more than clearing the casting mark, smoothen the edge especially in the area below the valve seat..
this is the head i'll be trying to work on..its from 4agze bigport as u can see it has already been cleaned n 3 valve already been opened
the shims are cleaned and numbered so valve setting can be reduced at assembly later
big port..u can see the casting mark which need to be smoothen..i cant wait
according to toyota mr2 servis manual we need SST (Special Service Tools) worth MYR1xx.xx to disassemble the valve assembly..but with some creativity 8inch G-clamp and a slotted half inch tubing will do
tada!!! got the retainer, valve spring, valve seal, valve spring seat and valve out..
the valve sets are also numbered so every piece will go back to where it from later in assembly part..note that the valve spring have specific upper n lower part differentiated by 1st n 2nd coil distance..the upper/retainer part 1st n 2nd coil are closer than other coils..this act as a harmonic balancer to reduce vibration n floating at high rpms
note how ugly this head was..black and yellowish carbon deposit near the valve seat..
i know the DIY head p n p guide said to do the intake 1st but i just cant wait to try the diamond cutting tools and da#n this things can cut!! 4age uses aluminum head which is very easy to cut AND OVERcut..u have to be very gentle with these otherwise be ready to look for a new head
cleaning the seats using wire brush
i manage to almost finish a valve before the battery is dead..i think i can hear horses fleeing oredi the casting mark under the seat (left) almost vanish compared to the unwork valve (right)
to be continued again tonight, part 2, port matching