Hey anyone out there have the GM ported and polished head or just had the stock one ported and polished? I am thinking about saving up to buy the GM head but just wanted to get some info from anyone that is running one.

 

the GM head is just poted a little bit on the exhaust side. Build by GM performance engineers. if you don't want to spend over 1000, thats the best way to go.

 

I personally have not heard of anyone running it, just a handful of guys are running our head.

 

Once i get enough money and have my valve springs and new valve im getting my head port and polished

 

ls1fbody: Over $1000 for p&p'ing a head? Where are you getting your quotes from because you need a new shop man. Unless some of that cost is an upgraded valvetrain

Easier to just have your head ported if you can find a local shop and have your car down a couple days

 

Ok I just took a look at your head that you offer what kind of HP number am I looking at with it? Got any shops in mind Tom?

 

What are the "no-kidding" gains from a well done head with upgraded valvetrain on a supercharged Cobalt? I am so used to the V8 world and am not familiar with the Ecotecs that much yet. Sounds kind of costly to me. You can get a nice set of LS1 heads CNC'd with all valvetrain for .650 lift for around $1200.

What deficiences does the stock head have? Where are the best improvements made if I were to P&P one myself?

 

i was referring to CNC'ing a head. if you just want to open up some ports, fine, that won't be anywhere close to 1000.

i'm sure sean knows a hell of a lot more about it than i do, haha

from what i've heard, the exhaust ports are the most restrictive part of the head. Apparently GM has even said that our head is a bottleneck.

 

go with OTTP. Yes for sure GM say and we all agree the exhaust is the cork in this OEM LSJ motor, and for sure a CNC programmed job (providing the program is good) is far better than when god was a baby and i ported heads with a electric drill and a steel cutter, to earn gas money in high school. The days of just smoothing out the port bumps and unshrouding the valve port are long gone. Modern engines are better flowing, better balanced than even race engines were back in the day.

IN V8 land you can buy L92 CNC ported heads from GM as a production item with valves and springs for less $592.00 thats less than an LS1 CNC port job, or a set of LS6 heads, (1200 each) these days. Oh and L92 heads wont fit the LS1 or LS6so too bad, that makes the old engines more expensive to rebuild...

Once the port shape is determined, and the tests are done, the CNC pattern is relatively cheap to execute...for LSJ heads go with OTTP thats my 2 cents....