What is the use of the
Quote:
: scratch awl for? And other than that all I
: have to
: do is get a carbide tip and begin?
O.k. there's a good article on how to port the head on the internet, but I can't find the book mark...
pretty easy, you dope up the ports with the marking compound to make them off color (usually purple), let the stuff dry, then use your gasket as a template and use the scratch awl to mark around the inside of the gasket cut outs of the ports...this gives you a baseline of how much could be hogged out of the mouths, you have to go easy on the throats, and around the valve seats.
If you are doing a drag port job, then by all means get a set of different grit wheels to finish polish the ports.
In a street port (since mine is soon to be a daily driver), the polished ports don't help much since most driving is at lower RPM, to a rougher/unfinished port job would be good enough (some differences of opinions will occur here).
This job can just be done with the rasp and is quicker that way. It just chews off the rough edges and can hog out the material pretty fast.
In this porting you just want to take away any excess material, smooth out any rough spots and casting flash (dingleberries?), and "round" out and sharp curves and corners (smoooooth...not glass though)
I was lucky to have a friend who has done loads of heads for his own rides, and other projects, to guide me on what to expect, and even ran his fingers over spots and told me what to do...
hope these ramblings are helping out...
Just watch out around the roof of the runners it can get thin in some cases (then you'll need another head), but if you just smooth it out and don't hog out a trench you should be o.k.
-D.Idiot