Okay, I bought some bare heads that I had planned on having ported by a buddy. Since I've never really had the oppurtunity to port anything, I decided to give it a shot on these heads (since they were only a $225). Anyways, I've been looking over issues of GMHTP and the web for pictures that show how "the big dogs" perform their magic. Most of the pictures that I have seen show the intake / exhaust ports ported to a smooth finish. I've talked to several people, and they have said that you don't want to make them like glass, but yet leave them a little rough. Also, do I need to worry about increasing the size of the intake / exhaust port, or just concentrate on removing the slag? I'm basically looking to throw these heads on the car with a decent cam and be running 400+ rwhp (with tuning, intake, and exhaust etc). I know that many guys are making this power with a cam alone, but I'd like to say that I did these heads myself.

 

You're wasting your time without a flow bench.
And you're wasting your time asking for advice, because the people who know what to do to those heads aren't talking.

If you can find someone with a flow bench, port... flow, port.. flow. Find out what works for you and what doesn't. But be prepared to waste time.

 

don't worry about getting them very smooth, it doesn't make much difference at all on the bench. I may gain a couple cfm going from a grinder that leaves pits to an 80 grit finish.

Spend your time blending the bowls and short side in, open up the seat back to the bottom cut of the valvejob. And narrow the guide boss. Don't worry about opening up the port, it won't help. It's all in the bowl.

Good luck

 

I heard you can use a dremel tool also, but how the hell? I mean, is there a special kit for this? All the dremel bits I've seen are an inch away from the dremel, and the dremel wont fit into the intake ports or exhaust ports. Someone help me out a litle here! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

dremel will not put up with the abuse of doing a whole set of heads, you will burn it out.

They make a flex shaft, that could be used to port heads, and it would work good. BUT you really need a 1/4" shank tool, air powered prefered to do any serious head porting.

Ryan.

 

Chris,

Thanks for the input. I'm not trying to reproduce / fabricate what an "ARE" or "Cartek" cylinder head can do because it's just not possible with a dremel! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> I'm simply interested in whether the ports and bowls should be smoothed. To me, this seems to be common knowledge, especially for anyone who has purchased a set of these high dollar heads. I don't want to know the intricacies of porting, I would just like someone to let me in on the basics... that's all. These heads will be flowbenched, but without input from people who have firsthand experience (buying, installing, porting etc) with LS1 heads, I'm basically in the dark.

Thanks

 

If you tried to use a dremel to port you would quickly grow frustrated and bored. A $20 rotary air tool from any parts store will work fine... just be sure to lower the pressure to 30-40 PSI to make the tool controlable. Use two hands and extra care when opening up the valve seat, as you can easily slip and nick the seat... if you nick it too bad you will need a new seat installed.

If you are doing a set to install on your car. I highly reccomend you work on a junk set first so you can work the ports in different manners and flow them to see the results.

Good luck!

 

Thanks everyone! Those are the types of responses that I was looking for! I'll let you know how my endeavor pays off...