Does anyone have a link, or any info on some detailed porting instructions for LS1 heads.
There's not really anything in the search section

Thanks

 

Head porting is an art, not a science. I doubt if any two head porting shops use the exact same port and combustion chamber design. For example, look at the difference between the LS6 head and the new AFR head, or a set of Patriot heads.

Even though some porting techniques are pretty standard, there is room for a lot of variation. Also, the port size and shape needs to be matched to the cam profile. What might seem to be obvious improvements, like removing the swirl bump, can have negative consequences.

To answer your direct question, I have never seen detailed porting instructions for and LS1 or LS6 head. I have spent a few hours discussing porting techniques with Jay from Absolute Speed, enough to conclude that I would NOT want to try porting LS1 heads myself. Perhaps you have a lot more experience than I do, though.

 

I'm not an expert by any means or I wouldn't have posted the question, but I have done some porting on at least half a dozen pairs of heads for both my own cars, as well as for friends, both big block and small, but all cast iron Gen 1 heads.
The majority of the gains obviously come from smoothing and blending the bowls under the valves to promote smooth flow to the valve. It is of little benifit to bother with the ports other than polishing the exhaust and eliminating casting flaws from all ports. If I was planning on running a hugh cam and spending all my time at high RPM, (and money was no object) I would just order a set of the lastest AFR heads with monster ports and go racing, but that's not my goal with this car.
It is an art to pick up ever last cfm of airflow for a finely tuned race engines running open exhaust, but actually not that hard, if you take your time, to pick up some free hp with some pocket porting and polishing on a street engine, that runs less than optimum intake and exhaust, to be able to take advantage of those few last cfm.
Just like bolting on mods, some people like to do some of the work themselves instead of buying all of it.

 

go for it.

 

I m no expert head porter so take this as you may. I did my own and was worried about the same things you are. I studied pictures of many ls1 and ls6 heads that were ported and not ported for many hours. And the conclusion that I came up with was that all head porting shops say there heads flow ??? @ ???. BLAH BLAH BLAH. The size of the valves will have the single greatest influence on flow #s. If your willing to sit down for 80-100 hrs go ahead and do it. Take your time and make sure you maintain the same porting from runner to runner. Go to MTI's site and look at there porting about half way down the intake runners you will find a hole. They remove about a .5" of material from the bottom of one of the rocker arm bosses. I was affraid to burn threw it at first then I decided if they can do it so can I. I have had no problems with my heads. I do wish that I changed the cam at that time. I think that the porting would have been more noticable with a bigger cam. But I m glad I waited because now I have a S/C and will be getting a blower cam. Do it I would just recommend doing the cam also. Its alot easier to do the cam with the heads off. I also do all my own work! Heads, custom ATI P1sc FMIC to MY SPECS, computer programming to MY SPECS. Moral of the story break it down into steps of how you would do it.

 

Thanks Chris, I'll check out the site.
I am about to change the cam and springs, so I figured since I'll already have a lot of the same parts off, why not change out the heads, which I will mill for increase compression, do a 3 angle valve job, and some mild porting. Will I pick up as much hp as bolting on some professionaly ported aftermarket heads? No way. Will I pick up some noticable hp and have some money left over to go out for some nice dinners with my wife? OH YEA!!
And if I need a little more hp to take care of some off brand cars running some professionaly ported heads, I've got 150hp of nitrous to help off set the difference.
Thanks for the info and the website.

 

I believe that if you mill your heads you might also need to go to shorter push rods so make sure to check those when you intall them. There are several manufactures that make shorter LS1 push rods.