Modifying chambers for boost

[396monteSS]

Backstory; I am working on a rear wheel drive 2007 Cadillac Northstar in a STS. I have had the car for quite some time, right after I bought it I installed a supercharger from a STS-V. After a couple years running it developed a slight coolant leak. Sure enough a couple head bolts had lost tension and were letting the head gaskets seep under load. I already have a plan to remedy the head bolt problem, my question is the combustion chambers.

The question; since I'm planning on running boost should I remove the quench pads and smooth out the chambers, especially the point between exhaust valves, while I have the heads off? R&R heads on this car is not an easy task so I dont plan to have them off again.

Pics of the chamber in question below

[396monteSS]

The image above is of my non supercharged head, this is what GM did when they added the supercharger in factory form. Should I just copy their work?

[mt-engines]

Softening them sure won't hurt. Have you thought about regrinding the cams? And are you studding the heads?

[396monteSS]

I havnt really given cam grinding any thought, I'm pretty happy with power though. My biggest concern is the high compression ~10:1 and boost. It is intercooled and runing methanol injection. I'd like to be able to remove the meth system completely. I have the timing pulled back a good bit under boost to eliminate knock. The plan is to open up the chambers to drop compression as much as possible. E85 is non existant where I live so thats no option either.

For the dreaded northstar head bolt situation I am using the NS3000l inserts from Huhn solutions, I have used them previously and had good luck so I'm going with what I know.

[panic]

What does a prepped 2JZ-GTE chamber look like?

[396monteSS]

I was able to google search a factory 2jz gte head and came up with this, looks like I could do something similar by cutting out the small quench pads on the sides of the chamber as well as removing the peaks between valves.

[panic]

My 2JZ 3 liter makes about 520 hp at 17 psi with the stock head.

[mag2555]

I would only remove the beak on the exh valve side of the head.
That looks like a 3 to 4 CC gain right there.

I would also get all the valves heat coated .

To get the longest service life out of any head gasket you want the finish to be so fine that it’s mirror like.

[396monteSS]

Why do you recommend only removing the exhaust valve side? Is it because there is little volume to gain from also doing the intake side, or do you think it would benefit from keeping that quench area? From what I have read it seems like some recommend no quench in a boosted application and others recommend keeping some quench area.

[396monteSS]

This is where I am right now, I think I'm ready to clean them up and put them back on. Are there any obvious mistakes I made or things I should change? I didnt want to do any more grinding around the valves because I was concerned I'd get too close to where the fire ring of the gasket seals, tight now I did not grind the chamber any closer to the fire ring than the factory head was. The sharp contrast between the carbon and the bare aluminum makes the edges look much sharper than they actually are.

[mag2555]

Keeping the Heart shape on the intake side helps with pressure recovery factor for the times when there’s no boost being made.