can anyone pls let me know which part in the head needs porting and polishing and how much meat should be shaved off or diameter of inlet. should inlet manifold be ported too? to which length and what diameter? iam from, sri lanka and so i need to give exact figures since not many machinists know about them.
Thanks alot
will be repped
you do NOT want polishing,
and you dont want the intake smoothed, maybe remove the casting marks but not smooth it,
other than that completly agree with skalabala,
from experience, the exhaust throats can be enlarged by 2mm using the stock valves, and the inlets 1mm using the stock valves, if you dont enlarge the valve throats it will be completely pointless porting.
also try and find a good reputable engine builder who knows what there doing, not an engineering shop must be someone who local race boys know and stuff as there workmanship is the best and they dont charge obscene ammounts of money
removing casting marks is smoothing it
and from my experience, smoothing and swirling a intake manifold makes good power.
In fact a huge amount of power lies with the piece before the head
If you don't understand it, don't do it yourself. It can completely change the shape of your engine.
ok, so i smooth/polish the intake manifold. i can get the 4 ends increased in diameter but how abouth the length? surely nothing can be poked along the curved lines on the intake manifold.
then i have to increase diameter in the 4 head ports where the intake manifold fits?
what about the 4 ports on the otherside of the head where the exhaust manifold fits?
Am i getting this all wrong or should i port only the intake and exhaust ports on the valve area? would that make a difference since i will be using stock valves and i wont be expanding valve seat area so it will still be squeezing the same amounts of air and exhaust at the valve seats.
Any pics so that i can get an idea?
(Im running a Garret BB GT28r on a 5E)