cylinder head/valves questions

[Siral3x]

I have a spare 96GST head now, and I'm planning to rebuild it.
I did some porting intake/exhaust , but I just noticed that 2 intake valves on the 3rd cyl, and 2 exhaust valves on the 4th don't sit (close/leak) properly..it's like 1-2mm gap behind them.
My question is, what did it cause that?? are those bent valves, or what else could it be??
I'm planning on replacing them anyway, but I just want to know.
Also should I resurface the head ?? send it and get it hot tanked after i strip it down? any other suggestions??
What HG you guys chose/use?

Pics of the head/valves: (how bad is it?)

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I think pic 1 and 3 speak say it all..you can tell there is a pretty big gap behing the valves.
Any coments/suggestions will be apreciated.
Thank you,

 

[92DSMErdrick]

I have a spare 96GST head now, and I'm planning to rebuild it.
I did some porting intake/exhaust , but I just noticed that 2 intake valves on the 3rd cyl, and 2 exhaust valves on the 4th don't sit (close/leak) properly..it's like 1-2mm gap behind them.
My question is, what did it cause that?? are those bent valves, or what else could it be??
I'm planning on replacing them anyway, but I just want to know.
Also should I resurface the head ?? send it and get it hot tanked after i strip it down? any other suggestions??
What HG you guys chose/use?

Most likely bent valves, i have a head laying around with 2 valves that i can see light passing through, the person i bought it off of told me previously that it had bent valves. Def get it resurfaced especially if your going to go with a metal HG. Good idea to get it hot tanked, pressure tested with new valves and valve seals. Make sure the shop does a valve job so the valves are seated right. Im not gonna suggest a HG b/c i've heard too many things about them. The HKS metal HG is suppose to be extremely well but extremely expensive. Cometic i've read good things, and heard they are crap from other people. I'm running a Nippon racing 4 layer metal HG and it serves its purpose. All depends on which route you wanna go dude.

By the way those pictures didn't show up for me

 

[prplhz96]

If you have bent valves, get new valve guides installed as well while it is at the machine shop.

 

[GTM]

I have a spare 96GST head now, and I'm planning to rebuild it.
I did some porting intake/exhaust , but I just noticed that 2 intake valves on the 3rd cyl, and 2 exhaust valves on the 4th don't sit (close/leak) properly..it's like 1-2mm gap behind them.
...
Any coments/suggestions will be apreciated.
Thank you,

If you think about it the firing order is 1,3,4,2. Thus with valves damage on 3 & 4 it could have been someone didn't get the timing right and then starter cranked it over. Alternately, leaving the cams in the head and then rough careless handling setting it down on the bench could have bent them for they will extend beyond the level of the gasket face.

You don't have to replace the guides if they are not damaged. A quick check is to put a new or unworn valve in the guide (no springs), then with the valve open to maximum lift try to wiggle it. If you can feel it click against the side of the guide or it has excess movement then you should or have a machine shop check them with the proper reamer or bore gauge. Guides can be knurled and reamed to reduce the hole diameter, this also can reduce drag (possible valve float) and provide better lube.

Cheers,
GTM