seawalkersee said:
If I am reading this correctly then you install larger seats and valves and you wont need to weld up the floors? I thiught it was to lengthen the short turn radius. Hmmmmmm....Is not lenghtening the STR better on almost all heads?
Chris
As I said in an earlier post,I can't write evey thing needed to do
a port in a post.There are more than just one or two or even three
reasons to weld the SC exhaust port floor.Keep in mind when I am
writeing that I may just be talking about an area of .300 x .075
inside of the port at a time.
With the seat standing to high at the beginning of the short side
radius.This is the number one problem to repair.
Port work is just like moding your motor for more power.You make
one change,you then will need to mod two other areas to take the
power from the first mod.Then you need to change onther part,
because of the last two changes.
Yes increasing the diameter of the seat can take care of some bad
castings of the short side radius.Were the seat is taller than the ports
floor.And some low bowl casting areas.This is just one way to help
improve this one problem,sometime 2 or 3.A good casting may not
need much if any welding,to get some good flow numbers.I run stock
heads.But I flow tested three sets to get the ones I use.And the
heads I chose was the heads that came with my SC.
But now that you have increased the seat diameter.And The larger
diameter valve that gos with this mod.And because the SC head
has a quash combustion chamber .You now will have even more valve shrouding.That now needs to be takin care of inside of the combustion chamber.Although the benifit of fixing the to tall seat on the short
side radius with the installation of a larger seat can out weigh the
extra valve shrouding.And some cases it will not.
The reason to lengthen the short side radius ,and what
other mods that should or may go with this mod.Is a hole other story.
For the ones that plan to do your own port work.I have payed for two
new houses that the eye doctor has lived in.So you might want to
give some thought about safty glasses to ware.
Randy