Port taper and different shapes ?
Posted: December 16th, 2007, 1:09 am
Now we all have seen port taper where on some it bottle necks near the short side then expands again into the bowl area. I know some englarge in search of more flow and correctly done so . Some porters seem to enlarge the smallest section all the way around in a circle but recently i have seen some really wierd shapes being made there like leaving the taper in but making it larger at the upper sides of the roof only.
Have a look at this picture these barrells before the 4mm larger inlet valves were fitted were perfectly round.Look at the shape now.
My question is why has it been done this way ? Has it been done this way to preserve all the metal on the floor to make a superior short radius ?
I have seen the same head with the same size valves installed by other companys where the port in enlarged all the way around and has zero short side. Are the cuts in the upper corners either side of the guide there to gain the flow back to supply the valve.
Have a look at this picture these barrells before the 4mm larger inlet valves were fitted were perfectly round.Look at the shape now.
My question is why has it been done this way ? Has it been done this way to preserve all the metal on the floor to make a superior short radius ?
I have seen the same head with the same size valves installed by other companys where the port in enlarged all the way around and has zero short side. Are the cuts in the upper corners either side of the guide there to gain the flow back to supply the valve.