084273lz

I'm having my heads done, the shop said he could cnc them further, aren't they already done at the factory? He claims an additional 30hp.

SHovV

Yes.

Tech

More knowledgable people than me have said there isn't much room for improvement on the intake but there is plenty on the exhaust side.

jayyyw

I'd take the supposed HP gains with a grain of salt. Consensus is, you gain more power with a mill, than with further porting.

There's more to it than just opening up the chamber.

LS7Solstice

Here is the before/after dyno sheet of my Z06 when I had the WCCH heads installed.

Before dyno was when my car had cam, intake, headers, Fast intake. Only change for the after dyno pull was the WCCH heads. Gains are definitely believable if you have the right cylinder heads.

jayyyw

Milled at all?

Apocolipse

Milled would have shown gains across the powerband not just up top.

LS7Solstice

No milling.

In hindsight I should have had them milled .030 but I'm happy with the gains and knowing the guide issue was addressed.

amlarson2001

Solstice - what valves did you go with?

LS7Solstice

Katech Ti/Mo intake. OEM exhaust.

silvrhand

Just call Tony Mamo @ mamomotorsports and tell him what you want to do with the car and then just listen.. Get the MSD, heads, and ported TB from him and a good cam suggestion..

Then go have fun..

Michael_D

There is a set of OEM heads that have been recently ported and rebuilt by Tony Mamo on the C6 for sale board. New PAC 1205x springs and solid stemmed exh valves. The guy decided to not use them. He also has a Mamy ported MSD, shaved and painted. I'd buy the heads just to have on hand, but I already have two sets.....

Someone should jump on those pretty quick.

Unreal

I've seen 50+rwhp gains just swapping one brand of ported heads to another.
I've seen heads lose 20-30rwhp. I've seen heads gain 30-40rwhp. All stock casting LS7 heads. So yes, there is a lot of power to gain or lose.

DanMan35

On average, how much HP TQ gains could one expect to see on a set of stock LS7 heads if they are race ported and milled .010" from a very reputable shop that has tons of experience with LS7's?

Unreal

Its an overall thing, not just heads.

Anywhere from 20-50rwhp I would say. Depends on cam, intake, etc. If it is a small cam, stock intake, etc. compared to a large cam, high compression, ported MSD.

DanMan35

Let's say a car has stock heads and has intake, headers, exhaust and tune.

Now that same car with intake, headers, exhaust and tune has the heads race ported and milled .010" how much increase over stock heads?

Unreal

5-35rwhp depending on a ton of things, dyno, etc.

Why only a 10 mill?

DanMan35

Because all I have here in Las Vegas is 91 octane gas.

Unreal

So?

Cali, Utah, etc etc all run 91 and I wouldn't go below a 30 mill (depending on cam of course). Seen 20rwhp on 91 octane just from a 30 mill.

DanMan35

The shop I'm taking it to said if you mill too much (over .010") with only 91 octane gas you could potentially run into issues with engine knock and then the engine pulling timing.

He said they usually only mill to .010 in shop to avoid any knock issues from using 91 octane gas since milling raises compression and milling too much with 91 will cause knock.