Porting Head/Mani

[andrewjscott]

My engine is completely apart and it'll be a while before I can get it back together. I was wondering what would benefit me the most, porting the head or exhaust manifold or intake manifolds or a combination of all 3. I'm pretty handy with metal work but I've never done any porting work before but have all the tools that I'll need.

 

[bullettdsm]

My engine is completely apart and it'll be a while before I can get it back together. I was wondering what would benefit me the most, porting the head or exhaust manifold or intake manifolds or a combination of all 3. I'm pretty handy with metal work but I've never done any porting work before but have all the tools that I'll need.

I would recommend NOT porting the head. These heads are so well designed that unless your looking to play around near the low 11 second zone, I don't think it would be worth your while. If you want to do something to the head, fine polish the exhausts and quick polish the intakes. Look for any imperfections in casting and grind and smooth them down. You could even grind down your valve guides so they don't interfere with the airflow (though that will shorten the life expectancy of your valves). This is all about getting the most air to flow the most efficiently through your system.
Make sure that all your points of connections (i.e. intake to head, head to exhaust mani, mani to turbo etc...) are "matched" (that their openings are the same size and they line up to each other). These are all points of turbulance. Polish the s**t out of your exhaust mani (unless you have a tubular, of course). Make that mani baby smooth.

Just my .02 centavos.
MB

 

[andrewjscott]

ok, I've been reading some more posts on porting and I think i'll leave the head alone. I'm gonna follow all the instruction on porting the exhaust mani, turbo. Any suggestions on what to do with my intake?

 

[bjones18]

Before you give up without a try.... pull the hardware from your head and stick your fingers in the ports. Also, fit a piece of cardboard (or use a gasket) to your ports to compare the manifold ports to the head ports.

Do this and you will find all kinds of 1-3mm steps in your flow path. take for instance your valve seat to the head casting... feel the edge on some?

There is flow to be gained by matching and smoothing.