Which would be the better core?

[bpk1337]

My GSX overheated over 2 years ago, and it was so bad that the plug wires melted to the head. Had to torch it up, and dig like hell with some pliers just to get all the hardened melted plastic out. Since then I've been hoarding parts, and picked up another head off Craigslist. I wanted to seek some advice before deciding which of the two would be the over-all best core. (Which would cost more to repair, and what problems I'll face with each, etc..)

Head 1 has detonation damage. It's a (G6S) off my 1997 GSX (measured out at 5.1985").:

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Head 2 is the Craigslist Head (G6K) has damage, (dings and scratches) on the cam caps, and where the cam sits on the head. Mostly on the outer areas. This head has been decked, and it measured out at 5.1835"

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Sorry about the crap cell phone quality videos.. Thanks in advance guys!

 

[boost97gst]

I'd prefer the first one. Simply cause its thicker to begin with.

 

[bpk1337]

I'd prefer the first one. Simply cause its thicker to begin with.

Thanks for the response! I forgot to mention that the Craigslist G6K head passes the flatness test, so it won't need to be resurfaced again unless I decide to go with a MLS gasket. Not sure what the roughness average is but it just doesn't look smooth enough.

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[boost97gst]

Well, since you're building either one it would be beneficial to get it mirror smoothed/decked for an MLS. Who are you sending it off to? Port/polish work? Look up jafromobiles videos on youtube for polishing the combustion chamber. A shop will charge a LOT of money to do this and you could pull everything before you send it off and polish the hell out of it. Save ya some money and perform quite a bit better. I guess if the 2nd one is flat it just depends on HOW flat. If they take too much more off then you might not be able to use it. I thought ~ 5.185 was the limit but i could be mistaken.

If you choose a composite then that could factor in a little and save ya some money. I would just want to be 100% sure the thickness is ok to run. GL bro!

 

[athlete3344]

5.185" is the service limit but you can use a thicker gasket to make up for any extra material that would need to be removed. I would suggest using Jafro's head porting video also. If you want some after results, search the newbie forums for a thread I started, something like "Just ported me head" or something of the sort.

I would do some measurements on the one you pulled from your car and see how much warping there is before making a decision.

 

[boost97gst]

Thicker gaskets do work but at the expense of excess knock. There's another jafro vid where he or one of his friend explains this. True though, it IS an option if the head's a bit on the thin side.

 

[bpk1337]

Well, since you're building either one it would be beneficial to get it mirror smoothed/decked for an MLS. Who are you sending it off to? Port/polish work? Look up jafromobiles videos on youtube for polishing the combustion chamber. A shop will charge a LOT of money to do this and you could pull everything before you send it off and polish the hell out of it. Save ya some money and perform quite a bit better. I guess if the 2nd one is flat it just depends on HOW flat. If they take too much more off then you might not be able to use it. I thought ~ 5.185 was the limit but i could be mistaken.

If you choose a composite then that could factor in a little and save ya some money. I would just want to be 100% sure the thickness is ok to run. GL bro!

5.185" is the service limit but you can use a thicker gasket to make up for any extra material that would need to be removed. I would suggest using Jafro's head porting video also. If you want some after results, search the newbie forums for a thread I started, something like "Just ported me head" or something of the sort.

I would do some measurements on the one you pulled from your car and see how much warping there is before making a decision.

Thicker gaskets do work but at the expense of excess knock. There's another jafro vid where he or one of his friend explains this. True though, it IS an option if the head's a bit on the thin side.

Thanks guys. I watch Jafro's videos religiously actually. I will probably try to do some light port/polishing myself. boost97gst is right about the thicker hg creating more knock. I believe the correct remedy is to enlarge the fly cuts on the pistons instead for valve clearance. I'm leaning towards taking the advice of going with my original my 1997 (G6S) head since it will give more room for the valves, and I'll be able to resurface it for an MLS gasket. A few last questions though..

1. I could try to take a better video if needed, but does it look like I will need new valve guides, and bigger valves or could I reuse the valve guides in my stock head? If not, would I perhaps be able to take the valves, and guides from the Craigslist (G6K) head, and get them pressed into my original 1997 (G6S) head? I'm thinking that this may end up costing more to overhaul in the long run if I need to get new guides, new valves, and machine new seats.

2. Let's say I did go with the Craigslist (G6K) head, and fly cut the pistons for valve clearance. What can be done about the scratched/dinged up cam caps, and cam journal mating areas on the head?[DOUBLEPOST=1409772935][/DOUBLEPOST]Anyone have any thoughts? Where are all my machinist at .